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PubMed2003

Impact of permethrin-treated bed nets on malaria, anemia, and growth in infants in an area of intense perennial malaria transmission in western Kenya.

As part of a community-based, group-randomized, controlled trial of insecticide-treated bed nets (ITNs) in an area with intense malaria transmission in western Kenya, a birth cohort (n = 833) was followed monthly until the age of 24 months to determine the potential beneficial and adverse effects of reduced malaria exposure during pregnancy and infancy. Malaria transmission and morbidity were comparable pre-intervention. The ITNs reduced malaria attack rates (force of infection) in infancy by 74%, and delayed the median time-to-first parasitemia (4.5 to 10.7 months; P < 0.0001). The incidence of both clinical malaria and moderate-severe anemia (hemoglobin level <7 g/dL) were reduced by 60% (P < 0.001 for both). Protective efficacy was greatest in infants less than three months old and similar in older infants and one-year-old children. Efficacy was lowest in the dry season. Infants from ITN villages experienced better height and weight gain. In areas of intense perennial malaria transmission, ITNs substantially reduce exposure to malaria and subsequent malaria-associated morbidity in children less than 24 months old. Reduced malaria exposure during infancy did not result, with continued ITN use, in increased malaria morbidity in one-year-old children.

Age Factors↗
PubMed1993

Malaria morbidity among children exposed to low seasonal transmission in Dakar, Senegal and its implications for malaria control in tropical Africa.

To measure morbidity due to malaria and to study its relationship with transmission and parasitemia in children living in an area of low malaria endemicity, a cohort study of 343 schoolchildren was undertaken during a one-year period in Dakar, Senegal. From parallel investigations on transmission and the frequency of malaria as a cause for outpatient visits, three different seasons were chosen for close monitoring of different clinical parasitologic, and sero-immunologic parameters. The daily incidence rates of malaria parasitemia and primary attacks were at a maximum level during the high transmission season (0.00198 and 0.00185 new cases/person/day, respectively) and decreased considerably during the season of low transmission. For each given period, the values of these two rates were close to each other, suggesting that each new infection was followed by a clinical attack. During the period of maximum transmission, clinical malaria prevalence was 1.36% and malaria was responsible for 36% of school absences due to medical reasons. At the end of the period of minimum transmission, clinical malaria prevalence was 0.15% and malaria was responsible for 3% of school absences due to medical reasons. In contrast, parasite prevalence hardly varied with the season (minimum 3.6%, maximum 7.5%). In a one-year period, the total number of new malarial infections was estimated between 173 and 230. Because of the existence of a vector density gradient in the area concerned, the annual malaria incidence varied considerably according to the children's place of residence.(ABSTRACT TRUNCATED AT 250 WORDS)

Absenteeism↗
PubMed2000

Monkeys of the rainforest in French Guiana are natural reservoirs for P. brasilianum/P. malariae malaria.

Monkey blood samples were collected from 214 monkeys relocated as part of the wildlife rescue organized in French Guiana during the filling of the Petit Saut Dam on the Sinnamary River. These samples were tested for malaria parasites by microscopy of thick blood filsm and by nested PCR for small subunit rRNA genes (SSUrRNA). Parasitic blood forms similar to Plasmodium brasilianum were detected in 4 monkey species: Alouatta seniculus macconnelli, Saguinus midas midas, Pithecia pithecia and Ateles paniscus paniscus, with the highest prevalence in Alouatta monkeys. PCR was more sensitive than the conventional method for detecting low-grade parasitaemia in positive monkeys. The examination of blood films indicated that 5.6% of the animals carried parasites whereas the nested PCR for ribosomal DNA indicated a prevalence of 11.3%. The P. brasilianum SSUrRNA gene sequence was analysed and aligned with those from P. malariae, P. falciparum and P. vivax. This suggested that P. brasilianum and P. malariae are very closely related. Similar results were obtained from analysis of the sequences in P. malariae and P. brasilianum isolates of a polymorphic gene fragment analogous to the merozoite surface protein-1 (MSP-1) gene of P. falciparum. The P. brasilianum/P. malariae sequences were more similar to those of P. vivax than to those of P. falciparum, at least in the gene region examined. The high degree of DNA homology in the sequences of the SSUrRNA and msp1-like genes is consistent with other characterizations demonstrating a taxonomic relationship between P. brasilianum and P. malariae species. Our results provide further evidence that P. brasilianum and P. malariae are virtually identical and should probably be considered to be a single malaria species. This raises the question as to whether monkeys living in the rainforest are natural reservoirs for both simian and human malaria. These results have implications for the interpretation of the current epidemiological situation in French Guiana.

Amino Acid Sequence↗
PubMed2002

Relationship between reactive nitrogen intermediates and total immunoglobulin E, soluble CD21 and soluble CD23: comparison between cerebral malaria and nonsevere malaria.

To search for evidence of a protective role of the CD23/NO pathway against cerebral malaria, concentrations of reactive nitrogen intermediates (RNI) and sCD21, total immunoglobulin (Ig)E and sCD23 were compared between 17 cases of cerebral malaria and 33 controls. The geometric mean of sCD23 concentration was higher among cerebral malaria cases than among controls (optical density 2643/1495, P = 0.01). The ratio between sCD21 and sCD23 was significantly lower in cerebral malaria cases than in controls (0.67 +/- 0.02 versus 0.77 +/- 0.02, respectively, P = 0.009). Multiple linear regression analysis showed that, among cerebral malaria cases, there was a clear correlation between RNI and both IgE (P = 0.007) and sCD21 (P < 0.0001). Among controls, there was a strong negative correlation between RNI and sCD23 concentrations (r = -0.61, P < 0.0001). However, multivariate analysis unmasked the fact that, in controls, there was also a positive correlation between RNI and IgE (P = 0.045). Logistic regression showed that increased RNI concentrations were associated with a cerebral malaria adjusted odds ratio of 1.05 per unit increase [95% confidence interval (CI) 1.006-1.1, P = 0.02] and that an increased ratio between sCD21 and sCD23 was associated with protection from cerebral malaria (adjusted OR = 0.00001 per unit increase (95% CI 0-0.03, P = 0.005). These different immunological profiles suggest that, among controls, the CD23/NO pathway was chronically stimulated whereas, in cerebral malaria, its stimulation was acute, which could explain why some patients developed cerebral malaria and others did not.

Animals↗
PubMed1998

High prevalence of Plasmodium malariae and Plasmodium ovale in malaria patients along the Thai-Myanmar border, as revealed by acridine orange staining and PCR-based diagnoses.

The prevalence of the four human malaria parasites was investigated among malaria patients at northern, central and southern towns in Thailand along the border with Myanmar between September 1995 and May 1996. Thin smears obtained from 548 Thai and Burmese patients were reviewed by an acridine orange staining method, and many mixed infections with two to four species, including P. malariae and P. ovale, were detected. These diagnostic results were compared with those by two PCR-based diagnoses, microtitre plate hybridization (MPH) and a nested PCR method, both of which targets the same, species-specific regions in the 18S rRNA genes. In both PCR diagnoses, many P. malariae and P. ovale infections were also detected. Detection sensitivity of P. malariae infection was higher in nested PCR than MPH, and a total prevalence of P. malariae infection estimated by nested PCR reached 24.3% (133/548). In 16 of them, the size of PCR products amplified by the P. malariae-specific primer was about 20-bp shorter than the expected size of 115-bp. Four of 16 possessed two different bands with normal and shorter sizes, suggesting that P. malariae isolates may be separated into two types, and that those with shorter products may be new variant form (s) with a nucleotide deletion in the target region. On the other hand, 21 P. ovale infections (3.8%) were detected by nested PCR, but four of them were MPH-negative because of the sequence variation at the probe region. These results indicated that the prevalence of P. malariae and P. ovale along the Thai-Myanmar border may be substantially higher than previously reported.

Acridine Orange↗
PubMed2006

Mefloquine is highly efficacious against chloroquine-resistant Plasmodium vivax malaria and Plasmodium falciparum malaria in Papua, Indonesia.

BACKGROUND: During the period of 1996-1999, we prospectively monitored 243 Javanese adults and children after arriving in Papua, Indonesia, and microscopically documented each new case of malaria by active surveillance. METHODS: In a randomized, open-label, comparative malaria treatment trial, 72 adults and 50 children received chloroquine for each incident case of malaria, and 74 adults and 47 children received mefloquine. RESULTS: Among 975 primary treatment courses, the cumulative 28-day curative efficacies were 26% and 82% for chloroquine against Plasmodium falciparum malaria and Plasmodium vivax malaria, respectively. Mefloquine cure rates were far superior (96% against P. falciparum malaria and 99.6% against P. vivax malaria). CONCLUSIONS: Mefloquine is a useful alternative treatment for P. vivax malaria and P. falciparum malaria in areas such as Papua, where chloroquine is still recommended as the first-line therapeutic agent.

Adult↗
PubMed1999

Field evaluation of the ICT malaria P.f/P.v immunochromatographic test for detection of Plasmodium falciparum and Plasmodium vivax in patients with a presumptive clinical diagnosis of malaria in eastern Indonesia.

In areas such as eastern Indonesia where both Plasmodium falciparum and Plasmodium vivax occur, rapid antigen detection tests for malaria need to be able to detect both species. We evaluated the new combined P. falciparum-P. vivax immunochromatographic test (ICT Malaria P.f/P.v.) in Radamata Primary Health Centre, Sumba, Indonesia, from February to May 1998 with 560 symptomatic adults and children with a presumptive clinical diagnosis of malaria. Blinded microscopy was used as the "gold standard," with all discordant and 20% of concordant results cross-checked blindly. Only 50% of those with a presumptive clinical diagnosis of malaria were parasitemic. The ICT Malaria P.f/P.v immunochromatographic test was sensitive (95. 5%) and specific (89.8%) for the diagnosis of falciparum malaria, with a positive predictive value (PPV) and a negative predictive value (NPV) of 88.1 and 96.2%, respectively. HRP2 and panmalarial antigen line intensities were associated with parasitemia density for both species. Although the specificity and NPV for the diagnosis of vivax malaria were 94.8 and 98.2%, respectively, the overall sensitivity (75%) and PPV (50%) for the diagnosis of vivax malaria were less than the desirable levels. The sensitivity for the diagnosis of P. vivax malaria was 96% with parasitemias of >500/microl but only 29% with parasitemias of <500/microl. Nevertheless, compared with the test with HRP2 alone, use of the combined antigen detection test would reduce the rate of undertreatment from 14.7 to 3.6% for microscopy-positive patients, and this would be at the expense of only a modest increase in the rate of overtreatment of microscopy-negative patients from 7.1 to 15. 4%. Cost remains a major obstacle to widespread use in areas of endemicity.

Adolescent↗
PubMed2002

Field evaluation of the ICT Malaria Pf/Pv immunochromatographic test for the detection of asymptomatic malaria in a Plasmodium falciparum/vivax endemic area in Thailand.

Rapid antigen assays provide an effective tool for the detection of malaria in symptomatic patients. However, the efficacy of these devices for detecting asymptomatic malaria, where parasite levels are normally significantly lower than in symptomatic patients, is less well established. We evaluated the efficacy of a new combined Plasmodium falciparum-Plasmodim vivax immunochromatographic test (ICT Malaria Pf/Pv) in a cross-sectional malaria survey of the village of Ban Kong Mong Tha, Kanchanaburi Provice, Thailand, from August to December 2000. A total of 1,976 bleeds were made from 559 individuals over the course of the study. Blinded microscopy of thick and thin blood films was used as the gold standard; all discordant and 10% of concordant results were cross-checked. Of 1,976 ICT Malaria Pf/Pv dipsticks tested, 98.3% (n = 1,943) performed as expected, as evidenced by the appearance of the control line. The ICT Malaria Pf/Pv test was both sensitive (100.0%) and specific (99.7 %) for the diagnosis of falciparum malaria with parasitemias of > or = 500 trophozoites/microL; however, only 15.9% (13/82) of infected individuals had parasitemia rates this high. When P. falciparum parasitemia rates were < 500/microL, the sensitivity of the diagnosis was only 23.3%, with a positive predictive value (PPV) and a negative predictive value (NPV) of 76.2 and 97.2%, respectively. The ICT Malaria Pf/Pv test was specific, but not sensitive, for the diagnosis of vivax malaria with parasite rates of > or = 500 trophozoites/microl, with sensitivity, specificity, PPV, and NPV of 66.7%, 99.9%, 66.7%, and 99.9%, respectively. At parasite rates of < 500/microL, corresponding values were 0.0%, 99.9%, 0%, and 95.1%. Because of the relatively high cost of these assays, low parasite rates found in the majority of asymptomatic individuals, and low sensitivity of this assay with rates of < 500/microl, use of this assay as a tool for active case detection is of limited value in western Thailand.

Adolescent↗
PubMed1964

PARTIAL SUPPRESSION OF MALARIA PARASITES, AND OF THE TRANSMISSION OF MALARIA, IN AEDES AEGYPTI (L.) DOUBLY-INFECTED WITH SEMLIKI FOREST VIRUS AND PLASMODIUM GALLINACEUM BRUMPT.

Laboratory experiments were undertaken with Aedes aegypti infected with both Semliki Forest virus (SFV) from infant mice and Plasmodium gallinaceum from fowls to determine if such double infection of mosquitos suppressed their ability to transmit the malaria parasite, a possibility suggested to explain reduction in malaria transmission in Uganda in 1960 when Anopheles funestus and Anopheles gambiae were transmitting both malaria and o'nyongnyong virus to the African population. In general, transmission of fowl malaria was not prevented by SFV infection in Aedes, although some malariometric indices, and consistently the mean oocyst count, were slightly lower in doubly-infected mosquitos than in controls. In one experiment, however, 60% of the Aedes infected 8 days previously with SFV died within 48 hours of ingesting a malarious meal. Mortality was selectively in favour of the survival of SFV-infected mosquitos negative for, or least heavily infected with, malaria; depression in the presence of the virus of the intensity of malaria infection in the individual Aedes also occurred. Some physiological factor-a stress in adult life or, possibly more important, suboptimal larval nutrition-appears to have been crucial to eliciting the adverse effect on the mosquitos themselves and on their malaria infections. Suppression of the development of a malaria parasite in a mosquito, and of malaria transmission, by concurrent infection of the vector with an arbovirus can happen, but is by no means inevitable.It is shown that a doubly-infected Aedes can transmit both Semliki Forest virus and P. gallinaceum simultaneously.

Aedes↗
PubMed1996

Lack of association between levels of transplacentally acquired Plasmodium falciparum-specific antibodies and age of onset of clinical malaria in infants in a malaria endemic area of Nigeria.

A cohort of 117 newborns was followed longitudinally for 12 months to determine the age of onset of clinical malaria and the subsequent episodes of malaria, and to investigate the possible existence of a correlation between level of transplacentally acquired Plasmodium falciparum-specific antibodies and age of onset of malaria in the infant. The mean age of onset of malaria in 49 infants was 4.48 +/- 1.54 months. Mean (+/- S.D.) age of onset of clinical malaria in haemoglobin AA infants (4.38 +/- 1.14) was significantly (P < 0.05) lower compared with haemoglobin AS (5.58 +/- 2.43) infants. No correlation was obtained between the age of onset of malaria and the level of cord serum total IgG, IgM and antibodies to P. falciparum antigens. Cord blood seropositivity for antibodies to the blood stage antigen Pf155/RESA and its C-terminal repeat sequence (EENV)6 or to the (NANP)6 peptide representing repeats of the circumsporozoite protein (CSP) did not influence the age of onset of clinical malaria. However, infants with haemoglobin AS whose cord blood was seropositive for antibodies to the (EENV)6 or (NANP)6 peptide showed delayed onset (P < 0.001) of malaria compared with AA seropositive infants. Although our results indicate that transplacentally acquired antibodies to the studied antigens alone offer no significant protection against malaria during the first few months of life, antibodies in concert with other factors such as haemoglobin genotype may contribute to the protection of the newborn.

Age Factors↗
PubMedDate not supplied

Comparison of the ParaSight-F test and the ICT Malaria Pf test with the polymerase chain reaction for the diagnosis of Plasmodium falciparum malaria in travellers.

Rapid and accurate methods are needed for the diagnosis of imported malaria. The ParaSight-F test and the ICT Malaria Pf test are commercially available kits marketed for the diagnosis of Plasmodium falciparum malaria. Both tests are antigen-capture assays based on the detection of P. falciparum histidine-rich protein 2 in peripheral blood. Using microscopy and a polymerase chain reaction (PCR)-based method as reference standards, we performed a 'blinded' comparison of these assays for the detection of P. falciparum infection in 200 febrile travellers returning from malaria-endemic areas. As determined by PCR and microscopy, 148 travellers had malaria and, of these patients, 54.7% (81/148) were infected with P. vivax only, 31.1% (46/148) with P. falciparum only, 9.5% (14/148) with P. ovale, 0.7% (1/148) with P. malariae, and 4.1% (6/148) had mixed infections. Compared to PCR, the ParaSight-F and ICT Malaria Pf tests had initial sensitivities of 94% and 90% and specificities of 95% and 97%, respectively, for the detection of P. falciparum malaria. When discrepant samples were retested with day 0 and day 1 bloods, the sensitivities improved to 96% and 94%, respectively. The 2 remaining false negative results with the Para-Sight-F test and 2 of the 3 false negative results with the ICT Malaria Pf test occurred in samples with < 100 parasites/microL. The performance of these kits was not significantly different (P = 0.75) and both are simple, rapid, and accurate tests for the detection of P. falciparum infection in the returned traveller.

Adolescent↗
PubMed2004

Impact of El Niño and malaria on birthweight in two areas of Tanzania with different malaria transmission patterns.

BACKGROUND: Malaria infection increases low birthweight especially in primigravidae. Malaria epidemics occur when weather conditions favour this vector borne disease. Forecasting using the El Niño Southern Oscillation (ENSO) may assist in anticipating epidemics and reducing the impact of a disease which is an important cause of low birthweight. The aim of the present study was to determine the impact of the malaria epidemic in East Africa during 1997-1998 on birthweights in two different areas of Tanzania and to explore ESNO's potential for forecasting low birthweight risk in pregnant women. METHOD: A retrospective analysis of birthweight differences between primigravidae and multigravidae in relation to malaria cases and rainfall for two different areas of Tanzania: Kagera, which experiences severe outbreaks of malaria, and Morogoro which is holoendemic. Birthweight and parity data and malaria admissions were collected over a 10-year period from two district hospitals in these locations. RESULTS: The risk of delivering a low birthweight baby in the first pregnancy increases approximately 5 months following a malaria epidemic. An epidemic of marked reduced birthweight in primigravidae compared with multigravidae occurred, related to the ENSO of 1997-1998. In Kagera this birthweight difference and the risk of low birthweight were significantly lower compared with Morogoro, except after the ENSO when the two areas had similar differences. No significant interaction was noted between secundigravidae and any of the risk periods. The results indicate that the pressure of malaria is much greater on pregnant women, especially primigravidae, living in the Morogoro location. CONCLUSIONS: Surveillance of birthweight differences between primigravidae and multigravidae is a useful indicator of malaria exposure.

Disease Outbreaks↗
PubMed1989

Mechanisms of splenic control of murine malaria: cellular reactions of the spleen in lethal (strain 17XL) Plasmodium yoelii malaria in BALB/c mice, and the consequences of pre-infective splenectomy.

The splenic response in lethal 17XL Plasmodium yoelii murine malaria is vigorous, displaying marked phagocytosis, erythropoiesis, lymphopoiesis, plasmacytopoiesis, and, from day 3 of infection, increasing levels of parasitized erythrocytes. There is also a pronounced response of newly characterized fibroblastic stromal cells which branch and fuse with one another, forming extensive, complex, irregular, syncytial membranous sheets which provide a variety of barriers. Hence, I term these barrier cells (BC), and their fusion results in barrier-forming complexes (BFC). BC form adherent surfaces, trapping parasitized erythrocytes and monocytes-macrophages, facilitating phagocytosis. They envelop single plasma cells, erythrocytes, erythroblasts, lymphocytes, reticulocytes, monocytes-macrophages, or clusters of them. They surround blood vessels, forming blood-spleen barriers. They are insinuated into the circumferential reticulum at the periphery of white pulp, isolating white pulp. They form channels in red pulp, directing blood flow. They are associated with collagen. There appear to be several sources of BC. They may originate by activation of established reticular cells which form the filtration beds, by activation of reticular cells covering the pulp surface of capsule and trabeculae, and as a major source in this malaria, from circulating progenitors entering the splenic pulp from the vasculature. In non-lethal malaria, these barrier systems protect splenic reticulocytes from parasitization. In the lethal 17XL malaria they do not, and there follows a considerable increase in parasitization in the spleen with a corresponding increase in active macrophages. Large-scale parasitization and parasite recycling through the great stores of splenic reticulocytes in the lethal malaria, and the failure of parasitization of these splenic reticulocytes reserves on the non-lethal malaria, suggests that the actions of the spleen aggravate the lethal malaria and ameliorate the non-lethal. This is supported by the finding that non-lethal malaria is aggravated and lethal malaria ameliorated by splenectomy.

Animals↗
PubMed2002

Knowledge and behavior relating to malaria in malaria endemic villages of Khammouane Province, Lao PDR.

In order to provide basic data for evaluation of malaria control measures, a study on the knowledge and behavior of people regarding prevention of malaria was carried out in 8 malaria endemic villages in Khammouane Province of Lao PDR from 1999 to 2000. The total valid questionnaire respondents were 932, with a mean age of 32.3 +/- 14.9. 43.7% of the respondents were illiterate. About 44% of the respondents suffered from malaria in the past. About 55% of the illiterate group slept in mosquito nets, compared to 75.4% for the educated group. About 29% of the illiterate respondents had knowledge of malaria transmission by mosquito bites, compared to 48.8% for the educated groups. Out of 167 non-impregnated mosquito nets examined in two villages, 13 were in bad condition having holes or leaks and 39 female mosquitos including Anopheles spp were collected in these nets by early morning catches. Knowledge of malaria and behavior in relation to the prevention of malaria were significantly related to educational level. Health education as well as general education must be taken into account for communities in malaria endemic areas to become more involved in malaria control strategies.

Adult↗
PubMed2003

Performance of rapid malaria Pf antigen test for the diagnosis of malaria and false-reactivity with autoantibodies.

Recently introduced rapid nonmicroscopic immunocapture assays for the diagnosis of malaria infection are being evaluated for their sensitivity and specificity in various epidemiological settings. A Plasmodium falciparum histidine-rich protein-2 (PfHRP-2)-based assay (ICT malaria Pf assay) was evaluated for its performance and compared to that of Giemsa-stained thick blood film microscopy. Of the 515 patients tested, 163 were positive for malaria parasites on thick blood film microscopy: 87 were infected with P. vivax; 63 with P. falciparum; 1 with P. malariae; and 12 with both P. falciparum and P. vivax. The ICT assay detected 53 P. falciparum infections and, as expected, failed to detect all but one case of P. vivax. Three cases of mixed infections were also not detected by this assay. The performance of the ICT assay in diagnosing P. falciparum infection was comparable to that of microscopy. The sensitivity of the ICT assay was 82% and the specificity 99.0%. The ICT assay also detected 4 false-positive cases. These patients reported treatment with chloroquine in the previous 2-5 weeks. The specificity of the assay was evaluated in different groups of patients, who had tested negative for malaria infection by microscopy. These patients were selected from different disease groups: rheumatoid arthritis; hepatitis C; toxoplasmosis; schistosomiasis; and hydatid disease. Of the 225 patients studied, 133 were positive for rheumatoid factor. Thirty-five (26%) of the 133 patients had false positive-reactions with the ICT assay, while only four had false positive-reactions with the OptiMAL test. After the rheumatoid factor was absorbed 33 of the 35 false-positive specimens were negative when retested with the ICT assay. Our study shows that the PfHRP-2-based ICT assay gave a false positive-reaction in 26% of the patients who had rheumatoid factors, but were negative for malaria by microscopy. We conclude that new rapid nonmicroscopic methods for the diagnosis of malaria that complement or support blood film microscopy would be of great use in the diagnosis and treatment of patients with malaria and also in epidemiological studies.

Animals↗
PubMed1989

The microepidemiology of malaria and its importance to malaria control.

Recent studies in West Africa and in Papua New Guinea have shown that the prevalence of malaria can vary widely between neighbouring villages and within different parts of the same village. Both genetic and environmental factors are likely to contribute to these variations. Clustering in households of genetically determined red cell abnormalities, and possibly of immune response genes, may contribute to differences in the prevalence of malaria within a village. Environmental factors probably play the major part in explaining differences between villages. The position of a village in relation to mosquito breeding sites, the design of houses and the level at which anti-mosquito measures are used will all influence the degree to which its inhabitants are exposed to infection. Attitudes to the treatment of a case of malaria may also contribute to local variations in the prevalence of malaria. Malaria parasitaemia and splenomegaly will be less frequent in a community where effective treatment is given immediately at home, or sought promptly from a primary health care worker, than in a neighbouring community where there is a much greater reliance on traditional medicines. Recognition of local variations in the prevalence of malaria is important because identification of the factors responsible for a low prevalence in one village but a high one in a neighbouring community may indicate a possible control measure. Local variations in the epidemiology of malaria must also be taken into account when any kind of malaria intervention trial is planned.

Animals↗
PubMedDate not supplied

Short-term impact of an acute attack of malaria on the cognitive performance of schoolchildren living in a malaria-endemic area of Sri Lanka.

A prospective study was conducted from January 1998 to November 1999 in a malaria-endemic area of Sri Lanka to determine the short-term impact of an acute attack of malaria on the cognitive performance of 648 schoolchildren attending grades 1 to 5 (mostly aged 6-11 years) in 4 schools. Three groups were studied comprising children with malaria, children with non-malarial fever, and healthy controls. Cognitive performance in language and mathematics at the time of presentation and 2 weeks later was assessed. At the time of presentation, children with malaria scored significantly less in both mathematics and language than children with non-malarial fever and healthy controls. Two weeks later, the mathematics and language scores of children with malaria improved but the scores were significantly lower than the scores of children with non-malarial fever (P < 0.001) and controls (P < 0.001). Having malaria was a significant predictor of cognitive performance after controlling for other confounding factors. These findings suggest that an acute attack of uncomplicated malaria causes significant short-term impairment of cognitive performance. The impairment persists for more than 2 weeks and appears to be cumulative with repeated attacks of malaria.

Acute Disease↗