Library Malaria Bulletin No. 35: April 12-25, 2002
Sciences and Malaria
Cent Afr J Med 2001 Jan;47(1):14-7
The knowledge and
practice on malaria among community members in Zimbabwe.
Tsuyuoka R, Wagatsuma Y, Makunike B.
Japan International Co-operation Agency, P O Box 4060, Harare,
OBJECTIVES: To assess the knowledge of the cause, preventive
measures and symptoms of malaria, treatment seeking behaviour on
malaria and source of information about malaria among community
members for the planning of effective malaria intervention.
DESIGN: A cross sectional study was carried out using a
questionnaire, which was administered by health workers from
rural health centres. SETTING: Households in rural areas from
five districts namely Uzumba Maramba Pfungwe (UMP), Hurungwe,
Mount Darwin, Bulilimamangwe and Chipinge in Zimbabwe. SUBJECTS:
2,531 community members who were in charge of households sampled
systematically in the area. MAIN OUTCOME MEASURES: Percentage of
knowledge of transmission, signs and symptoms, prevention
methods such as residual house spraying and personal protection,
and treatment seeking practice on malaria. RESULTS: Knowledge of
malaria transmission was generally high ranging from 57.9% to
95.9%, although there were some misconceptions such as drinking
dirty water and poor hygiene. Knowledge of malaria preventive
methods was varied among districts ranging from 19.4% to 93.0%
about residual house spraying, and low (0.2% to 22.7%), (8.1% to
24.5%) about mosquito nets and repellents, respectively.
Knowledge of malaria signs was generally high although this also
varied among districts. Treatment seeking practice on malaria
shows that the majority of respondents (85.4%) visit the clinic
first when seeking treatment although there are other options
such as shops and traditional healers. Other sources of
information about malaria mentioned were, health workers
(72.9%), radio (44.0%), television (37.5%), teachers (25.0%) and
village community workers (10.0%). CONCLUSION: Despite
widespread knowledge about the cause of malaria and symptoms,
and the fairly extensive sources of health information,
understanding of the preventive measures was relatively low.
Appropriate health education is essential to stimulate changes
in both knowledge and behaviour in malaria control activities.
Schools can be effective health education tools as well as
BMC Int Health Hum Rights 2002 Apr 15;2(1):2
study of morbidity, morbidity-associated factors and cost of
treatment in Ngaoundere, Cameroon, with implications for health
policy in developing countries and development assistance
Holtedahl K, Hurum H.
Email: [email protected]
Abstract Background. In a
population-based epidemiological study in Ngaoundere, Cameroon,
we studied cross-sectional child morbidity and the cost of
necessary investigation and treatment. Methods. Three teams of
two to three health workers visited haphazardly selected
households in all major housing quarters. We asked permission to
enter for a health survey. Children with cough, fever or weight
loss as well as sick adults were offered free-of-charge local
hospital examination and treatment. Results. From 177 households
with 1777 persons 51 (2.9%) persons were referred. Thirty-five
of them had undiagnosed disease threatening individual health
and in many cases also public health. Seven were hospitalised,
including three adults with tuberculosis. Malnutrition was
diagnosed in nine small children. Four patients had AIDS, seven
had malaria. Average total cost for ambulant patients was 15 USD,
for hospitalised patients 110 USD. In the households, almost
half of the women 16-50 years of age had no schooling. Two per
cent of women and nine per cent of men were daily smokers.
Coughing children were more likely than non-coughing children to
live in a household with at least one smoker (OR= 3.58, 95% CI
1.72 to 7.46), and they generally lived in more poor households
(P=0.018). Twelve of 16 children with weight loss were referred
from households with a high poverty score. Conclusions. Adult
smoking and poverty affect children's health. The cost of
hospitalisation or long-lasting therapy is beyond the means of
most ordinary families. Diseases with severe consequences for
public health, like tuberculosis, AIDS and malaria should have
national programs with free, decentralised examination and
treatment. Access to generic drugs is important. A major
educational effort is needed to improve public health.
Trop Med Int Health 2002
treatment of malaria? Use of antimalarial drugs for children's
fevers in district medical units, drug shops and homes in
Nshakira N, Kristensen M, Ssali F, Reynolds Whyte S.
Child Health and Development Centre, Makerere University,
Kampala, Uganda, Hellerup, Denmark, Institute of Anthropology,
University of Copenhagen, Copenhagen, Denmark.
OBJECTIVE To evaluate the quality of pharmaceutical care of
malaria for children in eastern Uganda prescribed at government
health units and drug shops, and administered by caretakers at
home; and to assess its appropriateness in relation to national
treatment guidelines, which recommend chloroquine over 3 days.
METHODS We followed 463 children under 5 years whose caretakers
attended two drug shops and two government health units to seek
treatment for fever. The children were examined and the
caretakers interviewed on the day of enrolment in the study (day
0), and in their homes on days 3 and 7. Data was collected on
drug use prior to attending the shop or health unit, the
treatment provided at these study sites, and the administration
of drugs at home over the following 3 days. RESULTS Before
attending the study sites, 72% of children had already been
given some biomedical drugs, and 40% had received the
recommended drug, chloroquine. Health workers prescribed
chloroquine for 94% of the children, but only 34% of the
recommended doses followed guidelines. Two-thirds of the
children were prescribed an injection of chloroquine. By day 3,
according to caretaker reports, about 38% of the children had
received chloroquine in compliance with the instructions given
by the health workers and drug shop attendants. Only 28% of the
children had received chloroquine at the optimal dose of 20-30
mg/kg recommended by national policy. CONCLUSION The methods
were useful for examining adherence of both caretakers and
health care providers to national guidelines and the extent to
which caretakers were compliant with providers' prescriptions.
Chloroquine and antipyretics were the drugs of choice for fever
in these areas of rural eastern Uganda. But children did not
receive the recommended dosage of chloroquine because of lack of
compliance on the parts of providers as well as users of health
Southeast Asian J Trop Med Public Health
Poverty and malaria:
a study in a Thai-Myanmar border area.
Faculty of Social Sciences and Humanities, Mahidol University,
Salaya, Nakhon Pathom, Thailand.
An eight-month qualitative study was conducted in 1999 in four
villages of Bong Tee subdistrict, Kanchanaburi Province located
along the Thai-Myanmar border area using in-depth interviews of
key informants and malaria survey as research methodologies.
Malaria was a serious problem in 39.6% of the families surveyed
in June 1999. The four villages located in a valley covered with
forests and small streams which were ideal for malaria epidemic.
The structure of the villages has been changed from stable
communities to disrupted ones divided along ethnic and class
lines. There were 5 ethnic groups dominated by ethnic Karen.
Villagers were poor and thus deprived of anti-malaria resources
which allow them to remain exposed to malaria.
Southeast Asian J Trop Med Public Health
and malaria: implications for community development programs in
Tin-Oo, Pe-Thet-Htoon, Khin-Thet-Wai, Parks W, Bryan J.
Tropical Health Program, Australian Center for International and
Tropical Health and Nutrition, University of Queensland,
Email: [email protected]
This paper examines the gender roles
linked to division of labor and potential exposure to mosquitos
and malaria prevention activities. A "Human Development
Initiative" (HDI) Project has been launched in Laputta, a
mangrove delta region of Myanmar assisted by United Nations
Development Program since 1994. The project aims to improve
rural community access to primary health care and provide
micro-credit programs, income generation schemes, and
educational opportunities as a basis for community empowerment.
Women and children of low-income households are the target
beneficiaries. Prior to self-care training program and
distribution of self-care manuals, altogether 20 focus group
discussions (separately assigned to men and women) were
conducted in eight study villages between January to February
2000. The primary vector for malaria in study area is Anopheles
sundaicus. Rural women were prone to malaria due to exposure to
mosquitos within the peak biting period at night because of
their gender assigned roles. Both men and women perceived that
mosquitos commonly bite before midnight, more at dusk. Lack of
awareness of correlation between mosquitos and malaria together
with lack of affordability enhance either non-use or shared use
of bed-nets at home. Rural women did not consider destruction of
breeding places of mosquitos as their major concern. Thus, it is
essential for program planners to motivate local women for more
active participation in vector control measures within and
beyond their households in the context of community development
J Immunol 2002 May 1;168(9):4674-81
The Role of IL-18 in
Blood-Stage Immunity Against Murine Malaria Plasmodium yoelii
265 and Plasmodium berghei ANKA.
Singh RP, Kashiwamura Si S, Rao P, Okamura H, Mukherjee A,
Malaria Research Group, International Center for Genetic
Engineering and Biotechnology, and Institute of Pathology,
Safdarjung Hospital, New Delhi, India. Department of
Bacteriology, Hyogo College of Medicine, Nishinomiya, Japan.
A possible protective role of IL-18 in host defense against
blood-stage murine malarial infection was studied in BALB/c mice
using a nonlethal strain, Plasmodium yoelii 265, and a lethal
strain, Plasmodium berghei ANKA. Infection induced an increase
in mRNA expression of IL-18, IL-12p40, IFN-gamma, and TNF-alpha
in the case of P. yoelii 265 and an increase of IL-18, IL-12p40,
and IFN-gamma in the case of P. berghei ANKA. The timing of mRNA
expression of IL-18 in both cases was consistent with a role in
the induction of IFN-gamma protein expression. Histological
examination of spleen and liver tissues from infected controls
treated with PBS showed poor cellular inflammatory reaction,
massive necrosis, a large number of infected parasitized RBCs,
and severe deposition of hemozoin pigment. In contrast,
IL-18-treated infected mice showed massive infiltration of
inflammatory cells consisting of mononuclear cells and Kupffer
cells, decreased necrosis, and decreased deposition of the
pigment hemozoin. Treatment with rIL-18 increased serum IFN-gamma
levels in mice infected with both parasites, delayed onset of
parasitemia, conferred a protective effect, and thus increased
survival rate of infected mice. Administration of neutralizing
anti-IL-18 Ab exacerbated infection, impaired host resistance
and shortened the mean survival of mice infected with P. berghei
ANKA. Furthermore, IL-18 knockout mice were more susceptible to
P. berghei ANKA than were wild-type C57BL/6 mice. These data
suggest that IL-18 plays a protective role in host defense by
enhancing IFN-gamma production during blood-stage infection by
Sci Prog 2002;85(Pt 1):89-111
antifolates in Plasmodium falciparum, the causative agent of
PHLS Malaria Laboratory, London School of Hygiene and Tropical
Medicine, London WC1F 7HT.
Email: [email protected]
Every year there are 270 million
clinical attacks of malaria and 2 million deaths, caused by the
protozoan Plasmodium falciparum. Most of these cases occur in
Africa. Chloroquine-resistance has led to reliance on
anti-malarial antifolates, in particular the synergistic
combination sulfadoxine/pyrimethamine (S/P) which targets
enzymatic synthesis of folate co-factors through dihydropteroate
synthase (DHPS) and dihydrofolate reductase (DHFR). Resistance
to S/P is now increasing and replacement antimalarials are
needed. Crystal structures are not yet available for these key
enzymes in the folate pathway. This review focuses on the
activity of drugs on DHFR in malaria parasites, attempts to
interpret differences in activity of pyrimethamine and its
related drugs, and to clarify how residue changes due to point
mutations determine the development of resistance. In homology-modelled
P. falciparum DHFR (PfDHFR), the typical structure of four
alpha-helices, 8-stranded beta-sheet, four Loops and eight Turns
is clearly seen. Long polar sequences specific for Plasmodium
are inserted in Turns 1 and 2. Structures immediately concerned
in drug binding are beta-A, L1, alpha-B, alpha-C, T-3, beta-E,
alpha-F, and beta-F. The roles of several mutations associated
with resistance are discussed. In view of sequence differences
in turn 3 in PfDHFR and in the human enzyme, and the marked
interaction with residues of T3 of the experimental flexible
antifolate WR99210 effective in pyrimethamine and cycloguanil
resistance, further drug development in this area is indicated.
Indian J Med Res 2001 May;113:186-91
malaria outbreak in Bahraich district, Uttar Pradesh.
Dhiman RC, Pillai CR, Subbarao SK.
Malaria Research Centre (ICMR), Delhi, India.
BACKGROUND & OBJECTIVES: Based on the reports of 139 fever
related deaths in Jarwal primary health centre (PHC) of Bahraich
district, Uttar Pradesh (UP) during April to September 1999, a
study was undertaken to explore the possibility of outbreak of
Plasmodium falciparum malaria in the area and reasons of
outbreak. METHODS: The study was undertaken during
September-October 1999 in Bahraich district, UP. The study
included a parasitological and an entomological survey. Blood
slides from fever cases were collected and examined following
standard procedures for detection of species and stage of
parasite. The resting adult mosquitoes were collected from human
dwellings and cattle sheds from selected villages.
Susceptibility status of Anopheles culicifacies to 4 per cent
DDT and 0.05 per cent deltamethrin was determined under
laboratory conditions following the WHO procedure. In vitro drug
sensitivity of P. falciparum to chloroquine was also estimated.
RESULTS: Overall slide positivity rate (SPR) was found to be
33.8 with a preponderance of P. falciparum (88.4%). There was an
outbreak of Pf malaria in Jarwal and surrounding areas as well.
Foci of P. falciparum malaria were found in Jarwal, Fakharpur
and Hazoorpur PHCs around Kaisarganj PHC. In addition, P.
falciparum cases, were also reported from Motipur and Tejwapur.
INTERPRETATION & CONCLUSION: Poor surveillance of affected
areas resulting in low annual parasite incidence (API), lack of
insecticidal spray in the currently affected PHCs as the API was
less than 2 and development of resistance in P. falciparum to
chloroquine were found as the possible reasons for the outbreak.
It is recommended that surveillance be strengthened in all PHCs
of Bahraich district to contain further extension of malaria in
Insect Mol Biol 2002 Apr;11(2):123-32
Isolation of cDNA
clones encoding putative odourant binding proteins from the
antennae of the malaria-transmitting mosquito, Anopheles gambiae.
Biessmann H, Walter MF, Dimitratos S, Woods D.
Developmental Biology Center, University of California, Irvine,
CA, USA; Inscent Inc., Irvine, CA, USA.
One way of controlling disease transmission by blood-feeding
mosquitoes is to reduce the frequency of insect-host
interaction, thus reducing the probability of parasite
transmission and re-infection. A better understanding of the
olfactory processes responsible for allowing mosquitoes to
identify human hosts is required in order to develop methods
that will interfere with host seeking. We have therefore
initiated a molecular approach to isolate and characterize the
genes and their products that are involved in the olfactory
recognition pathway of the mosquito Anopheles gambiae, which is
the main malaria vector in sub-Saharan Africa. We report here
the isolation and preliminary characterization of several cDNAs
from male and female A. gambiae antennal libraries that encode
putative odourant binding proteins. Their conceptual translation
products show extensive sequence similarity to known insect
odourant binding proteins (OBPs)/pheromone binding proteins (PBPs),
especially to those of D. melanogaster. The A. gambiae OBPs
described here are expressed in the antennae of both genders,
and some of the A. gambiae OBP genes are well conserved in other
disease-transmitting mosquito species, such as Aedes aegypti and
Curr Top Med Chem 2002 May;2(5):483-505
Perspectives in drug
design against malaria.
Pattanaik P, Raman J, Balaram H.
Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for
Advanced Scientific Research, Jakkur, Bangalore, 560064,
Email: [email protected]
Development of drug resistance by
Plasmodium falciparum and insecticide resistance by the mosquito
has lead to the resurgence of the most virulent forms of
malaria. This review aims to provide a general perspective on
drug design for P. falciparum malaria. Though numerous targets
have been identified, new clinically useful target-specific
inhibitors remain a distant prospect. This review focuses on
pathways and enzymes for which some structural information and
detailed biochemistry along with specificity of inhibitor action
is available. Aspects of the parasite glycolytic pathway,
nucleotide metabolism, proteases, redox metabolism and organelle
function have been used to highlight possible targets and
molecules that could inhibit their function.
Lancet 2002 Apr 13;359(9314):1311-2
of the sickle cell gene against malaria morbidity and mortality.
Aidoo M, Terlouw DJ, Kolczak MS, McElroy PD, ter Kuile FO,
Kariuki S, Nahlen BL, Lal AA, Udhayakumar V.
Division of Parasitic Diseases, National Center for Infectious
Disease, Centers for Disease Control and Prevention, 30333,
Atlanta, GA, USA
The high frequency of the sickle-cell haemoglobin (HbS) gene in
malaria endemic regions is believed to be due to a heterozygote
(HbAS) advantage against fatal malaria. Data to prospectively
confirm the protection associated with HbAS against mortality
are lacking. We show that HbAS provides significant protection
against all-cause mortality, severe malarial anaemia, and
high-density parasitaemia. This significant reduction in
mortality was detected between the ages of 2 and 16 months, the
highest risk period for severe malarial anaemia in this area.
These data are important in understanding the role of malaria in
the selection and maintenance of the sickle cell gene.
Curr Opin Infect Dis 2000 Oct;13(5):431-443
host-parasite interactions and new developments in chemotherapy,
immunology and vaccinology.
Perlmann P, Bjorkman A.
Department of Immunology, Stockholm University, and Karolinska
Institute, Infectious Diseases Unit, Karolinska Hospital,
Malaria remains the major parasitic disease, with 300-500
million new infections each year. This survey covers recent
advances in the field of parasite-host interactions, focusing on
Plasmodium falciparum, the most virulent of the human parasites.
Rapid progress in genomic research is creating a basis for the
development of new drugs and vaccines. Identification of
drug-resistance mutations facilitates evaluation of improved
drug policies, and attempts are being made to develop new
compounds that inhibit metabolic pathways that are specific to
the parasite. Cytoadherence of parasitized erythrocytes to
microvascular endothelium is responsible for the sequestration
of parasites, causing pathology and severe disease. Newly
identified molecular fine structures that mediate cytoadherence
may provide new targets for specific therapies. Humoral and
cell-mediated immunity induced by the parasite may be
protective, but may also be harmful by generating imbalance in
cytokine responses. Efforts are made to determine the pathways
that give rise to protection, with vaccination being the
principal goal for achieving malaria control. Different vaccine
constructs are being evaluated in preclinical and clinical
trials, including modified viral vectors, synthetic peptides,
DNA and new adjuvants.
Science 2002 Apr 19;296(5567):545-7
of dihydrofolate reductase between malaria parasite and human
Zhang K, Rathod PK.
Department of Chemistry, University of Washington, Seattle, WA
98195, USA, and Seattle Biomedical Research Institute, Seattle,
WA 98109, USA.
For half a century, successful antifolate therapy against
Plasmodium falciparum malaria has been attributed to
host-parasite differences in drug binding to dihydrofolate
reductase-thymidylate synthase (DHFR-TS). Selectivity may also
arise through previously unappreciated differences in regulation
of this drug target. The DHFR-TS of Plasmodium binds its cognate
messenger RNA (mRNA) and inhibits its own translation. However,
unlike translational regulation of DHFR or TS in humans, DHFR-TS
mRNA binding is not coupled to enzyme active sites. Thus,
antifolate treatment does not relieve translational inhibition
and parasites cannot replenish dead enzyme.
Science 2002 Apr 19;296(5567):482-3
the Host Is Smarter Than the Parasite.
The wily malaria parasite has become resistant to many
affordable frontline antimalarial drugs, and new drug targets
are desperately needed. Reporting in a Perspective on new work
(Zhang et al.), Goldberg suggests that we look for drug targets
among proteins that are shared by the host and parasite but
whose synthesis is regulated in a different way.
Biochem J 2002 May 1;363(Pt 3):833-838
synthetase from Plasmodium falciparum.
Meierjohann S, Walter RD, Muller S.
Division of Biological Chemistry and Molecular Microbiology,
School of Life Sciences, MSI/WTB complex, University of Dundee,
Dundee DD1 5EH, Scotland, U.K., and Bernhard Nocht Institute for
Tropical Medicine, Hamburg, Germany.
GSH is the major low-molecular-mass thiol in most organisms. The
tripeptide maintains a reduced intracellular environment and
protects cellular components from damaging oxidation. GSH is
synthesized by the action of two ATP-dependent enzymic steps, in
which gamma-glutamylcysteine synthetase (gamma-GCS) catalyses
the ligation of glutamate and cysteine and subsequently
glutathione synthetase (GS) adds glycine to the dipeptide.
Recently it was shown that the synthesis of gamma-glutamylcysteine
is crucial for the survival of the erythrocytic stages of the
malaria parasite Plasmodium falciparum by using the specific
gamma-GCS inhibitor buthionine sulphoximine. In order to
investigate further the synthetic pathway of the tripeptide in
the parasite, GS was cloned and expressed recombinantly. The
deduced amino acid sequence of P. falciparum GS shares only a
moderate degree of identity with other known GSs, but the
residues responsible for substrate and co-factor binding are
almost all conserved, with the exception of the ones involved in
gamma-glutamylcysteine binding. The protein is active as a dimer,
with a subunit molecular mass of 77 kDa, and the addition of
reducing reagents such as dithiothreitol is essential in
maintaining enzymic activity, indicating that thiol groups are
important for stability and enzymic activity. The K(app)(m)
values for gamma-glutamyl-alpha-aminobutyrate, ATP and glycine
were determined to be 107.1 &mgr;M, 59.1 &mgr;M and 5.04
mM, respectively, and the V(max) of 5.24+/-0.7 &mgr;mol
small middle dotmin(-1) small middle dotmg(-1) was in the same
range as that of the mammalian enzymes. However, the negative
co-operativity observed for gamma-glutamylcysteine binding to
the rat enzyme was not found for the parasite protein. This may
be due to the alteration of several amino acids in the gamma-glutamylcysteine-binding
Med Vet Entomol 2002 Mar;16(1):67-7
Development of an
exposure-free bednet trap for sampling Afrotropical malaria
Mathenge EM, Killeen GF, Oulo DO, Irungu LW, Ndegwa PN, Knols
International Centre of Insect Physiology and Ecology (ICIPE),
Mbita Point Research & Training Centre, Nyanza Province,
An exposure-free bednet trap (the 'Mbita trap') for sampling of
Afrotropical malaria vectors was developed during preliminary
studies of mosquito behaviour around human-occupied bednets. Its
mosquito sampling efficiency was compared to the CDC miniature
light-trap and human landing catches under semi-field conditions
in a screen-walled greenhouse using laboratory-reared Anopheles
gambiae Giles sensu stricto (Diptera: Culicidae). When compared
in a competitive manner (side by side), the Mbita trap caught
4.1+/-0.5 times as many mosquitoes as the CDC light-trap, hung
beside an occupied bednet (P < 0.000 1) and 43.2+/-10% the
number caught by human landing catches (P < 0.0001). The
ratio of Mbita trap catches to those of the CDC light trap
increased with decreasing mosquito density. Mosquito density did
not affect the ratio of Mbita trap to human-landing catches. In
a non-competitive comparison (each method independent of the
other), the Mbita trap caught 89.7+/-10% the number of
mosquitoes caught by human landing catches (P < 0.0001) and
1.2+/-0.1 times more mosquitoes than the CDC light trap (P =
0.0008). Differences in Mbita trap performance relative to the
human landing catch under noncompetitive vs. competitive
conditions were explained by the rate at which each method
captured mosquitoes. Such bednet traps do not expose people to
potentially infectious mosquito bites and operate passively all
night without the need for skilled personnel. This trap is
specifically designed to catch host-seeking mosquitoes only and
may be an effective, sensitive, user-friendly and economic
alternative to existing methods for mosquito surveillance in
Med Vet Entomol 2002 Mar;16(1):46-54
SCAR markers and
multiplex PCR-based identification of isomorphic species in the
Anopheles dirus complex in Southeast Asia.
Manguin S, Kengne P, Sonnier L, Harbach RE, Baimai V, Trung
HD, Coosemans M.
Institut de Recherche pour le Developpement (IRD), Centre de
Biologie et Gestion des Populations, Montpellier, France.
Email: [email protected]
The Anopheles dirus Peyton &
Harrison complex of mosquitoes (Diptera: Culicidae) comprises
seven known species, including important malaria vectors in
Southeast Asia. Specific identification of each species of the
complex, which cannot be distinguished using morphological
characters, is crucial for understanding vector ecology and
implementing effective control measures. Derived from individual
random amplified polymorphic DNA (RAPD) markers, sequence
characterized amplified regions (SCAR) were analysed for the
design of specific paired-primers. Combination of six SCAR
primers resulted in the development of a simple, robust, single
multiplex PCR able to identify three important malaria vectors
among the four most common species (A, B, C, D) of the complex:
species A from several Southeast Asian countries, species B from
Perlis, Malaysia, and species C and D from Thailand.
Med Vet Entomol 2002 Mar;16(1):28-38
risk variations derived from different agricultural practices in
an irrigated area of northern Tanzania.
Ijumba JN, Mosha FW, Lindsay SW.
Tropical Pesticides Research Institute, Arusha, Tanzania.
Email: [email protected]
Malaria vector Anopheles and other
mosquitoes (Diptera: Culicidae) were monitored for 12 months
during 1994-95 in villages of Lower Moshi irrigation area (37
degrees 20' E, 3 degrees 21' S; approximately700 m a.s.l.) south
of Mount Kilimanjaro in northern Tanzania. Adult mosquito
populations were sampled fortnightly by five methods: human bait
collection indoors (18.00-06.00hours) and outdoors
(18.00-24.00hours); from daytime resting-sites indoors and
outdoors; by CDC light-traps over sleepers. Anopheles densities
and rates of survival, anthropophily and malaria infection were
compared between three villages representing different
agro-ecosystems: irrigated sugarcane plantation; smallholder
rice irrigation scheme, and savannah with subsistence crops.
Respective study villages were Mvuleni (population 2200),
Chekereni (population 3200) and Kisangasangeni (population
approximately/= 1000), at least 7 km apart. Anopheles arabiensis
Patton was found to be the principal malaria vector throughout
the study area, with An. funestus Giles sensu lato of secondary
importance in the sugarcane and savannah villages. Irrigated
sugarcane cultivation resulted in water pooling, but this did
not produce more vectors. Anopheles arabiensis densities
averaged four-fold higher in the ricefield village, although
their human blood-index was significantly less (48%) than in the
sugarcane (68%) or savannah (66%) villages, despite similar
proportions of humans and cows (ratio 1:1.1-1.4) as the main
hosts at all sites. Parous rates, duration of the gonotrophic
cycle and survival rates of An. arabiensis were similar in
villages of all three agro-ecosystems. The potential risk of
malaria, based on measurements of vectorial capacity of An.
arabiensis and An.funestus combined, was four-fold higher in the
ricefield village than in the sugarcane or savannah villages
nearby. However, the more realistic estimate of malaria risk,
based on entomological inoculation rates, indicated that
exposure to infective vectors was 61-68% less for people in the
ricefield village, due to the much lower sporozoite rate in An.
arabiensis (ricefield 0.01%, sugarcane 0.1%, savannah 0.12%).
This contrast was attributed to better socio-economic conditions
of rice farmers, facilitating relatively more use of
antimalarials and bednets for their families. Our findings show
that, for a combination of reasons, the malaria challenge is
lower for villagers associated with an irrigated rice-growing
scheme (despite greater malaria vector potential), than for
adjacent communities with other agro-ecosystems bringing less
socio-economic benefits to health. This encourages the
development of agro-irrigation schemes in African savannahs,
provided that residents have ready access to antimalaria
materials (i.e. effective antimalaria drugs and insecticidal
bednets) that they may better afford for protection against the
greater vectorial capacity of An. arabiensis from the ricefield
Med Vet Entomol 2002 Mar;16(1):116-9
Impact of untreated
bednets on prevalence of Wuchereria bancrofti transmitted by
Anopheles farauti in Papua New Guinea.
Bockarie MJ, Tavul L, Kastens W, Michael E, Kazura JW.
Papua New Guinea Institute of Medical Research, Madang.
Email: [email protected]
Despite the growing evidence that
insecticide-treated mosquito nets reduce malaria morbidity and
mortality in a variety of epidemiological conditions, their
value against lymphatic filariasis infection and disease is yet
to be established. The impact of untreated bednets on the
prevalence of Wuchereria bancrofti (Cobbold) (Nematoda:
Filarioidea) infection and disease was investigated on Bagabag
island in Papua New Guinea, where both malaria and filariasis
are transmitted by the same vector mosquitoes of the Anopheles
punctulatus Donitz group (Diptera: Culicidae). Community-wide
surveys were conducted recording demographic characteristics
including bednet usage. Physical examinations for hydrocoele and
lymphoedema were performed and blood samples assessed for
filarial and malaria parasites. Mosquitoes were sampled using
the all-night landing catch method and individually dissected to
determine W. bancrofti infection and infective rates. Bednet
usage among residents was 61% and the mean age of users (25.6
years) was similar to non-users (22.5 years). Anopheles farauti
Laveran was the only species were found to contain filarial
larvae: 2.7% infected (all stages), 0.5% infective (L3). The
overall W. bancrofti microfilaraemia and antigenaemia rates were
28.5% and 53.1%, respectively. Bednet users had lower prevalence
of W. bancrofti microfilaraemia, antigenaemia and hydrocoele
rates than non-users. In comparison, untreated bednets had no
effect on the prevalence and intensity of Plasmodium falciparum
and P. vivax infections. The impact of bednet usage on rates of
microfilaraemia and antigenaemia remained significant even when
confounding factors such as age, location and sex were taken
into account, suggesting that untreated bednets protect against
W. bancrofti infection.
Med Vet Entomol 2002 Mar;16(1):112-5
control in an African village by community application of 'deet'
mosquito repellent to ankles and feet.
Durrheim DN, Govere JM.
Communicable Disease Control, Department of Health, Nelspruit,
Mpumalanga Province, South Africa.
Email: [email protected]
The malaria vector Anopheles arabiensis
Patton (Diptera: Culicidae) shows a marked predilection (>
80%) for biting the ankles and feet of human subjects, as
revealed by our previous observations at Malahlapanga in the
Kruger National Park, South Africa. Topical application of
insect repellent, 15% deet (N,N-diethyl-3-methylbenzamide), to
feet and ankles reduced the overall biting rate of An.
arabiensis by 69%. A focal malaria epidemic in Albertsnek
village (25 degrees 33'S, 31 degrees 59' E) near the Mozambique
border, following flooding during February 2000, provided an
opportunity to apply these findings of operational research for
outbreak containment. Twice-nightly topical application of deet
to ankles and feet of Albertsnek inhabitants was followed by
rapid restoration of preepidemic malaria incidence levels after
one incubation period. This encouraging outcome should be
attempted in other outbreak-prone settings where infective
mosquito bites are sporadic and malaria has unstable endemicity.
Med Vet Entomol 2002 Mar;16(1):109-11
Male size does not
affect mating success (of Anopheles gambiae in Sao Tome).
Charlwood JD, Pinto J, Sousa CA, Ferreira C, Do RV.
Centro de Malaria e outras Doencas Tropicais, Instituto de
Higiene e Medicina Tropical, Lisbon, Portugal.
Email: [email protected]
For malaria control, the utility of
transgenic vector Anopheles mosquitoes (Diptera: Culicidae)
refractory to Plasmodium transmission, will depend on their
interbreeding with the wild vector population. In many species,
larger males are more successful in obtaining mates. In Sao Tome
island, we determined that size did not affect mating success of
male Anopheles gambiae Giles sensu stricto, the main malaria
vector in tropical Africa. Also we showed that larval
intraspecific competition is probably insignificant in this
population of An. gambiae. Thus, the potential success of
transgenic An. gambiae is unlikely to be affected by size
selection under field conditions.
Indian J Malariol 2001 Mar-Jun;38(1-2):9-18
controlled trial comparing artemether and quinine in the
treatment of cerebral malaria in Bangladesh.
Faiz MA, Rahman E, Hossain MA, Rahman MR, Yunus EB, Samad R,
Department of Medicine, Chittagong Medical College,
A randomized controlled trial on 51 patients receiving
artemether and 54 patients receiving quinine was undertaken to
compare the effectiveness of intramuscular artemether and
parenteral quinine in the treatment of cerebral malaria in
adults in Bangladesh. Case fatality, fever and parasite
clearance times were not significantly different in the two
treatment groups. Coma resolution time was significantly delayed
in artemether recipients. Results of the study suggest that
treatment with artemether is as effective as parenteral quinine
in the treatment of cerebral malaria in adults.
Indian J Malariol 2001
An outbreak of
Plasmodium falciparum malaria due to Anopheles minimus in
central Assam, India.
Dev V, Ansari MA, Hira CR, Barman K.
Malaria Research Centre (Field Station), Sonapur-782 402, India.
Epidemiological investigations were conducted in Nellie
subcentre, PHC Jhargaon, under Morigaon district (Assam). The
results of fever cases revealed 68 per cent slide positivity
rate (SPR) and 40 per cent slide falciparum rate (SfR). The Pf
proportion was > 87 per cent and remaining cases were P.
vivax infections. An. minimus was incriminated as a malaria
vector during the study period. The sporozoite rate was 3.08 per
cent. The indoor man mosquito contact was 35 per bait/night as
against 23 in outdoors. Results of susceptibility test revealed
that the vector was still susceptible to both DDT and malathion
at discriminating dosages. The study revealed that inadequate
surveillance and vector control measures were contributing
factors for malaria outbreak. In view of this, insecticide
treated nets may be introduced to provide cost-effective control
Indian J Malariol 2001 Mar-Jun;38(1-2):25-31
observations on malaria in some parts of Darrang District,
Kamal S, Das SC.
National Institute of Communicable Diseases, Rajahmundry-533
A study on malaria conducted in tribal villages of Darrang
district, Assam during April 1994 to March 1995 revealed that
the malaria incidence due to Plasmodium falciparum was
considerably high. Slide positivity rate (SPR) ranged between
2.3 to 45.67 per cent with transmission from May to October. P.
falciparum was the dominant species (91.7 per cent) followed by
P. vivax (7.25 per cent) and mixed infection (Pv + Pf = 1.05 per
cent). Malaria cases were recorded throughout the year in all
the age groups including infants, however, age groups between
0-1 and 21-30 years were more affected. Among 17 anophelines
collected, Anopheles vagus, An. jamesii, An. crawfordi and An.
minimus were the most abundant species. Known vectors of malaria
like An. annularis, An. culicifacies, An. minimus, An.
philippinensis and An. varuna were detected. Perennial
transmission of malaria was attributed to low socio-economic
conditions, poor surveillance and inadequate intervention
Indian J Malariol 2001 Mar-Jun;38(1-2):19-24
A study on clinical
profile of falciparum malaria in a tertiary care hospital in
Harris VK, Richard VS, Mathai E, Sitaram U, Kumar KV, Cherian
AM, Amelia SM, Anand G.
Department of Clinical Pathology, Christian Medical College and
Hospital, Vellore-632 004, India.
Malaria continues to be a major problem in tropical countries.
To study the clinical features and complications of malaria in a
tertiary care hospital in south India, records of 183 patients
were analysed. Among 86 patients with P. falciparum and mixed
infection, 24 (28 per cent) had cerebral malaria and 32 (37 per
cent) had hyperbilirubinemia. Twenty-three out of 32 (72 per
cent) patients with jaundice had direct hyperbilirubinemia and
elevated liver enzymes suggesting hepatocellular damage.
Mortality of the order of 10 per cent was seen only in P.
falciparum malaria. High incidence of hepatic involvement and
hepatorenal failure were the unusual features observed in the
Transfusion 2002 Mar;42(3):357-62
Potential value of
Plasmodium falciparum-associated antigen and antibody detection
for screening of blood donors to prevent transfusion-transmitted
Silvie O, Thellier M, Rosenheim M, Datry A, Lavigne P, Danis
M, Mazier D.
INSERM (National Institute for Health and Medical Research) Unit
511 (Cellular and Molecular Immunobiology of Parasitic
Infections), Hospital University Center, Pitie-Salpetriere.
BACKGROUND: Malaria antibody detection is a valuable tool in the
prevention of transfusion-transmitted malaria in countries with
a high proportion of donors with travel exposure to malaria. The
immunofluorescent antibody test (IFAT) is still the reference
method, but it is not suitable for screening of blood donors.
ELISA would be an interesting alternative to the IFAT, but it
lacks sensitivity. STUDY DESIGN AND METHODS: To evaluate the
potential value of a combined screening strategy based on
malaria antigen and antibody detection, plasma samples from 203
patients infected with Plasmodium falciparum were tested with an
ELISA for the detection of malaria antibodies (Malaria IgG
CELISA, Cellabs) and a P. falciparum histidine-rich protein-2
kit (Malaria P.f., ICT Diagnostics) for the detection of malaria
antigens. RESULTS: Among patients with positive IFAT results,
CELISA had a sensitivity of 71 percent, whereas the combined
screening tests (CELISA and Malaria P.f.) had a sensitivity of
88 percent (p < 0.001). Sequential samples from 50 patients
were tested. The combined screening tests shortened the
detection of seroconversion from 11.4 +/- 1.6 to 5.3 +/- 1.1
days (p < 0.001). CONCLUSION: Combined malaria antigen and
antibody detection, with methods compatible with mass screening,
may constitute an attractive alternative to the IFAT for blood
Eur J Clin Nutr 2002 Mar;56(3):192-9
Anemia in pregnancy
in rural Tanzania: associations with micronutrients status and
Hinderaker SG, Olsen BE, Lie RT, Bergsjo PB, Gasheka P,
Bondevik GT, Ulvik R, Kvale G.
Centre for International Health, University of Bergen, Norway,
and Haydom Lutheran Hospital, Tanzania.
OBJECTIVE:: We studied the association between anemia in
pregnancy and characteristics related to nutrition and
infections. DESIGN:: Cross-sectional study. SETTING:: Four
antenatal clinics in rural northern Tanzania. SUBJECTS/METHODS::
A total of 2547 women were screened for hemoglobin (Hb) and
malaria plasmodia in capillary blood and for infections in
urine. According to their Hb, they were assigned to one of five
groups and selected accordingly, Hb<70 g/l (n=10), Hb=70-89
g/l (n=61), Hb=90-109 g/l (n=86), Hb=110-149 g/l (n=105) and Hb>/=150
g/l (n=50). The 312 selected subjects had venous blood drawn,
were interviewed, and their arm circumference was measured. The
sera were analyzed for ferritin, iron, total iron binding
capacity (TIBC), cobalamin, folate, vitamin A, C-reactive
protein (CRP), and lactate dehydrogenase (LD). Transferrin
saturation (TFsat) was calculated. Urine was examined by
dipsticks for nitrite. MAIN OUTCOME MEASURES:: Unadjusted and
adjusted odds ratio (OR and AOR) of anemia with Hb<90 g/l.
RESULTS:: Anemia (Hb<90 g/l) was associated with iron
deficiency (low s-ferritin; AOR 3.4). The association with
vitamin deficiencies were significant in unadjusted analysis
(low s-folate; OR 3.1, low s-vitamin A; OR 2.6). Anemia was also
associated with markers of infections (elevated s-CRP; AOR 3.5,
urine nitrite positive; AOR 2.4) and hemolysis (elevated s-LD;
AOR 10.1). A malaria positive blood slide was associated with
anemia in unadjusted analysis (OR 2.7). An arm circumference
less than 25 cm was associated with anemia (AOR 4.0). The
associations with less severe anemia (Hb 90-109 g/l) were
similar, but weaker. CONCLUSIONS:: Anemia in pregnancy was
associated with markers of infections and nutritional
deficiencies. This should be taken into account in the
management of anemia at antenatal clinics. SPONSORSHIP:: The
study was supported by the Norwegian Research Council (NFR) and
the Centre for International Health, University of Bergen. DOI:
Ethiop Med J 1999 Jul;37(3):173-9
Rapid diagnosis of
severe malaria based on the detection of Pf-Hrp-2 antigen.
Birku Y, Welday D, Ayele D, Shepherd A.
Department of Pharmacology, Faculty of Medicine, Addis Ababa
University, Addis Ababa.
Blood samples collected from 34 patients with severe malaria who
were involved in antimalarial treatment studies were tested with
rapid dipstick assay (Rapid Test Malaria, RTM from Quorum
Diagnostics Inc., Vancouver, BC, Canada), based on the detection
of Histidine Rich Protein (HRP-2) of Plasmodium falciparum. This
was compared with the conventional Giemsa stained thin and thick
blood smears. The study was done from March 1998 to May 1998, at
the Basic Research Laboratory of the Faculty of Medicine, Addis
Ababa University. Comparable number of patients (n = 32) with
various diagnosis other than falciparum malaria were used as
controls. The rapid dip-stick assay was positive in 31 among 34
of the severe malaria cases with sensitivity of 91.2%,
specificity of 93.7%, positive predictive value (PPV) of 93.9%
and negative predictive value (NPV) of 90.9%. The three cases
missed by the RTM, had parasitemia of 66,000, 44,000, and
40,000/microL of blood which might be due to genetic
heterogeneity of the HPR-2 expression. Among the controls, there
were 2 false positive cases which may be as a result of
persistent HPR-2 antigen after the clearance of peripheral
parasitemia. The dip-stick method is a very quick, sensitive and
specific diagnostic tool with limits of detection comparable or
better than those provided by the light microscopy. The
simplicity of the technique makes this method more applicable in
the resource deprived laboratories of developing countries
provided the kit is affordable for large scale use.
Ethiop Med J 1999 Apr;37(2):97-109
An in-vivo study of
falciparum malaria sensitivity to Chloroquine in unstable
malaria endemic area of central Ethiopia.
Kebede F, Taffa N, Tedla T.
PLAN International Ethiopia, P.O. Box 3062, Addis Ababa.
The role of Chloroquine as a first line drug to treat P.
falciparum is almost universally becoming questionable. This
study was conducted in one of the country's unstable malaria
endemic area, North Shoa with the objective of assessing the
in-vivo treatment efficacy of Chloroquine to falciparum malaria
using the standard WHO 14 days treatment response monitoring
guideline. A total of 427 patients were followed among which
87.8% showed treatment failure. This was more pronounced in
children than in adults (Chi-square for trend = 8.16; P <
0.01). Clinical presentation with high grade fever on day 0 was
found to be more predictive of treatment failure in children (OR
= 2.06; 95% CI = 1.26, 3.36; P < 0.005). Tendency to remain
febrile on subsequent follow up days was also more observed in
children compared to adults. Treatment failure was further
associated with high Parasite Density Index (PDI) on day 0 in
all age groups (OR = 1.99; 95% CI = 1.04, 3.83; P < 0.05).
Supplemented with large scale sensitivity studies, it is high
time that switch to alternate drugs needs due consideration by
J Biol Chem 2002 Apr 15; [epub ahead of
The structural motif
in chondroitin sulfate for adhesion of plasmodium falciparum-infected
erythrocytes comprises disaccharide units of 4-O-sulfated and
non-sulfated N-acetylgalactosamine linked to glucuronic acid.
Chai W, Beeson JG, Lawson AM.
Glycosciences Laboratory, Imperial College School of Medicine,
Harrow, Middx HA1 3UJ.
An important characteristic of malaria parasite Plasmodium
falciparum-infected red blood cells (IRBCs) is their ability to
adhere to host endothelial cells and accumulate in various
organs. Sequestration of IRBCs in the placenta, associated with
excess perinatal and maternal mortality, is mediated in part by
adhesion of parasites to the glycosaminoglycan chondroitin
sulfate A (CSA) present on syncytiotrophoblasts lining the
placental blood spaces. To define key structural features for
parasite interactions we isolated from CSA oligosaccharide
fractions and established by electrospray mass spectrometry and
HPLC disaccharide-composition analysis their differing chain
length, sulfate content, and sulfation pattern determined.
Testing these defined oligosaccharide fragments for their
ability to inhibit IRBC adhesion to immobilized CSA revealed the
importance of non-sulfated disaccharide units in combination
with 4-O-sulfated disaccharides for interaction with IRBCs.
Selective removal of 6-O-sulfates from oligo- and
polysaccharides to increase the proportion of non-sulfated
disaccharides enhanced activity indicating that 6-O-sulfation
interferes with the interaction of CSA with IRBCs.
Dodecasaccharides with four or five 4-O-sulfated and two or one
non-sulfated disaccharide units, respectively, comprise the
minimum chain length for effective interaction with IRBCs.
Comparison of the activities of CSA and CSB oligo- and
polysaccharides, with a similar sulfation pattern and content
achieved from partial desulfation, demonstrated that glucuronic
acid rather than iduronic acid residues are important for IRBC
Trop Med Int Health 2002 Apr;7(4):304-8
Comparison of three
antigen detection methods for diagnosis and therapeutic
monitoring of malaria: a field study from southern Vietnam.
Huong NM, Davis TM, Hewitt S, Huong NV, Uyen TT, Nhan DH,
Cong le D.
National Institute of Malariology, Parasitology and Entomology,
OBJECTIVES: To compare the sensitivity, specificity and
post-treatment persistence of three commonly used rapid antigen
detection methods. METHOD: We studied 252 Vietnamese patients
aged from 4 to 60 years, 157 with falciparum and 95 with vivax
malaria and 160 healthy volunteers. An initial blood sample was
taken for microscopy, and OptiMAL, immunochromatographic test (ICT)
malaria P.f./P.v. and Paracheck-Pf tests. Patients with
falciparum malaria were treated with an artesunate-based
combination regimen and those with vivax malaria received
chloroquine. Eighty-seven patients with falciparum malaria who
were initially positive for one of the antigen tests and who
remained blood smear-negative underwent follow-up testing over
28 days. RESULTS: Paracheck-Pf was the most sensitive test for
Plasmodium falciparum (95.8% vs. 82.6% for ICT malaria P.f./P.v.
and 49.7% for OptiMAL). Specificities were all 100%. For vivax
malaria, OptiMAL performed better than ICT malaria P.f./P.v.
(sensitivities 73.7% and 20.0%, respectively), with 100%
specificity in both cases. All tests had low sensitivities (<
or = 75.0%) at parasitaemias < 1000/microl regardless of
malaria species. During follow-up, Paracheck-Pf remained
positive in the greatest proportion of patients, especially at
higher parasitaemias (> 10,000/microl). Residual OptiMAL
positivity occurred only in a relatively small proportion of
patients (< 10%) with parasitaemias > 10,000/microl during
the first 2 weeks after treatment. CONCLUSIONS: Although
microscopy remains the gold standard for malaria diagnosis,
Paracheck-Pf may prove a useful adjunctive test in uncomplicated
falciparum malaria in southern Vietnam. OptiMAL had the lowest
sensitivity for P. falciparum but it might have a use in the
diagnosis of vivax malaria and perhaps to monitor efficacy of
treatment for falciparum malaria where microscopy is
Trop Med Int Health 2002 Apr;7(4):298-303
in highland Kenya: indoor residual house-spraying vs.
Guyatt HL, Corlett SK, Robinson TP, Ochola SA, Snow RW.
Wellcome Trust Research Laboratories/KEMRI, Nairobi,
Email: [email protected]
This study compares the effectiveness
and cost-effectiveness of indoor residual house-spraying (IRS)
and insecticide-treated bednets (ITNs) against infection with
Plasmodium falciparum as part of malaria control in the
highlands of western Kenya. Homesteads operationally targeted
for IRS and ITNs during a district-based emergency response
undertaken by an international relief agency were selected at
random for evaluation. Five hundred and ninety homesteads were
selected (200 with no vector control, 200 with IRS and 190 with
ITNs). In July 2000, residents in these homesteads were randomly
sampled according to three age-groups: 6 months-4 years, 5-15
years, and > 15 years for the presence of P. falciparum
antigen (Pf HRP-2) using the rapid whole blood
immunochromatographic test (ICT). The prevalence of P.
falciparum infection amongst household members not protected by
either IRS or ITN was 13%. Sleeping under a treated bednet
reduced the risk of infection by 63% (58-68%) and sleeping in a
room sprayed with insecticide reduced the risk by 75% (73-76%).
The economic cost per infection case prevented by IRS was US$ 9
compared to US$ 29 for ITNs. This study suggests that IRS may be
both more effective and cheaper than ITNs in communities
subjected to low, seasonal risks of infection and as such should
be considered as part of the control armamentarium for malaria
Korean J Parasitol 2002 Mar;40(1):1-7
malaria in Thailand.
Silachamroon U, Krudsood S, Phophak N, Looareesuwan S.
Hospital for Tropical Diseases, Faculty of Tropical Medicine,
Mahidol University, Bangkok 10400, Thailand.
The purpose of treatment for uncomplicated malaria is to produce
a radical cure using the combination of: artesunate (4
mg/kg/day) plus mefloquine (8 mg/kg day) for 3 days: a fixed
dose of artemether and lumefantrine (20/120 mg tablet) named
Coartem (4 tablets twice a day for three days for adults
weighing more than 35 kg): quinine 10 mg/kg 8-hourly plus
tetracycline 250 mg 6-hourly for 7 days (or doxycycline 200 mg
as an alternative to tetracycline once a day for 7 days) in
patients aged 8 years and over: Malarone (in adult 4 tablets
daily for 3 days). In treating severe malaria, early diagnosis
and treatment with a potent antimalarial drug is recommended to
save the patient's life. The antimalarial drugs of choice are:
intravenous quinine or a parenteral form of an artemisinin
derivative (artesunate i.v./i.m. for 2.4 mg/kg followed by 1.2
mg/kg injection at 12 and 24 hr and then daily for 5 dayss;
artemether i.m. 3.2 mg/kg injection followed by 1.6 mg/kg at 12
and 24 hrs and then daily for 5 days; artemether i.m. (Artemotil)
with the same dose of artemether or artesunate suppository (5
mg/kg) given rectally 12 hourly for 3 days. Oral artemisinin
derivatives (artesunate, artemether, and dihydroartemisinin with
4 mg/kg/day) could replace parenteral forms when patients can
tolerate oral medication. Oral mefloquine (25 mg/kg divided into
two doses 8 hrs apart) should be given at the end of the
artemisinin treatment course to reduce recrudescence.
Chembiochem 2001 Nov 5;2(11):838-43
conformationally constrained peptidomimetics and an efficient
human-compatible delivery system in synthetic vaccine design.
Moreno R, Jiang L, Moehle K, Zurbriggen R, Gluck R, Robinson
JA, Pluschke G.
Swiss Tropical Institute Socinstrasse 57 4002 Basel Switzerland.
Peptide and protein mimetics are potentially of great value in
synthetic vaccine design. The mimetics should function by
stimulating the immune system to produce antibodies that
recognize the intact parasite. Also the mimetics should be
presented to the immune system in a way that leads to efficient
antibody production. Here we investigate the application of
cyclic peptidomimetics presented on immunopotentiating
reconstituted influenza virosomes (IRIVs), a form of antigen
delivery that is licensed already for human clinical use, in
synthetic vaccine design. We focus on the central (NPNA)(n)
repeat region of the circumsporozoite (CS) protein of the
malaria parasite Plasmodium falciparum as a model system. Cyclic
peptidomimetics of the NPNA repeats were incorporated into both
an IRIV and (for comparison) a multiple-antigen peptide (MAP).
Both IRIV and MAP delivery forms induced mimetic-specific
humoral immune responses in mice, but only with the mimetic-IRIV
preparations did a significant fraction of the elicited
antibodies cross-react with sporozoites. The results demonstrate
that IRIVs are a delivery system suitable for the efficient
induction of antibody responses against conformational epitopes
by use of cyclic template-bound peptidomimetics. Combined with
combinatorial chemistry, this approach may have great potential
for the rapid optimization of molecularly defined synthetic
vaccine candidates against a wide variety of infectious agents.
Southeast Asian J Trop Med Public Health 2001 Sep;32(3):615-20
A rapid polymerase
chain reaction based method for identification of the Anopheles
dirus sibling species.
Huong N T, Sonthayanon P, Ketterman A J, Panyim S.
Institute of Malariology, Parasitology and Entomology, Quinhon,
A simple polymerase chain reaction (PCR) based method was
developed to differentiate the Anopheles dirus, species A, B, C
and D in Thailand using specific primers designed from species
specific sequences. The PCR protocol was optimized to obtain
products of 120 bp, 75 bp, 60 bp and 172 bp for species A, B, C
and D, respectively. This method used a cocktail of four primer
sets to identify these An. dirus sibling species. The method is
very sensitive as only a small portion of mosquito was required
allowing the rest of the mosquito to be used for other analyses.
Specimens also kept for up to 14 years could be analyzed
unambiguously from either larvae or adult. This method is
advantageous over other PCR-based methods for identification of
malaria vectors because it does not require any specific DNA
extraction. A mosquito specimen was homogenized in 1x PCR
buffer, then the supernatant directly used for PCR
identification, allowing a large number of samples to be
processed at the same time. It provides a simple and rapid
practical method for screening An. dirus species, which is
essential in malaria vector epidemiological studies in Southeast
Southeast Asian J Trop Med Public Health
Malaria past and
present: the case of North Sulawesi, Indonesia.
Royal Institute for Linguistics and Anthropology (KITLV), Leiden,
The Netherlands. Email: [email protected]
The incidence and impact of malaria in
North Sulawesi have declined both in the short term during the
1990s, and over a much longer timespan (though perhaps less
continuously) since the end of the colonial period. The
improvement already seems to have been well underway before
deliberate vector control activities became extensive in the
second half of the 1970s, and environmental changes affecting
the Anopheles mosquito fauna, in particular the replacement of
primary and secondary forest by permanent farmland, are probably
the principal reasons for the long-term trend; other possible
factors include the increasing use of antimalarial drugs. The
well-documented decline in malaria incidence over the years
1991-1997, nevertheless, probably reflects the unprecedented
scale of residual insecticide spraying in the province during
that period, while the slight resurgence of the disease in the
last three years corresponds to the subsequent cessation of
house spraying as a result of the current economic crisis.
Despite the evident importance of environmental change as a
factor ameliorating the malaria situation in the long term,
experience from the colonial era suggests that the prospects for
deliberate environmental management (species sanitation) as an
alternative malaria control strategy are poor.