Microbial biodiversity of natural toothbrushes in Mali

Different oral hygiene practices are used to overcome endemic diseases such as dental caries and oral infections. In Mali (Africa), natural plant-based toothbrushes are used for eliminating bacterial biofilm. The repertoire of microorganisms associated with natural toothbrushes is unknown. The aim of our study is to study microbial flora in particular the methanogenic archaea associated with natural toothbrushes recently recognized as responsible for periodontitis and peri-implantitis. We investigated the methanogens and bacteria associated with 15 different natural plant toothbrushes collected in Bamako local market (Mali). Microbiological investigations consisted in culturing the bacteria on agar plates and searching archaea using molecular techniques. No archaea were demonstrated by molecular biology but 50 bacterial species, including 33 aero-anaerobic and 17 aerobic species, were isolated from natural toothbrushes. We isolated Pseudomonas sp., Staphylococcus sp. and Klebsiella pneumoniae, which are acknowledged as opportunistic human pathogens. This study has highlighted the likely impact of the use of natural toothbrushes in the spread of potentially pathogenic bacteria in the human oral cavity.

[Frequency of glucose-6-phosphate dehydrogenase deficiency (A-376/202) in three Malian ethnic groups]

Erythrocyte G6PD deficiency is the most common worldwide enzymopathy. The aim of this study was to determine erythrocyte G6PD deficiency in 3 ethnic groups of Mali and to investigate whether erythrocyte G6PD deficiency was associated to the observed protection against malaria seen in Fulani ethnic group. The study was conducted in two different areas of Mali: in the Sahel region of Mopti where Fulani and Dogon live as sympatric ethnic groups and in the Sudanese savannah area where lives mostly the Malinke ethnic group. The study was conducted in 2007 in Koro and in 2008 in Naguilabougou. It included a total 90 Dogon, 42 Fulani and 80 Malinke ethnic groups. Malaria was diagnosed using microscopic examination after Giemsa-staining of thick and thin blood smear. G6PD deficiency (A-(376/202)) samples were identified using RFLP (Restriction Fragment Length Polymorphism) assay and analysis of PCR-amplified DNA amplicon. G6PD deficiency (A-(376/202)) rate was 11.1%, 2.4%, and 13.3% in Dogon, Fulani, and Malinke ethnic group respectively. Heterozygous state for G6PD (A-(376/202)) was found in 7.8% in Dogon; 2.4% in Fulani and 9.3% in Malinke ethnic groups while hemizygous state was found at the frequency of 2.2% in Dogon and 4% in Malinke. No homozygous state was found in our study population.We conclude that G6PD deficiency is not differing significantly between the three ethnic groups, Fulani, Dogon and Malinke.

[Place of malaria among febrile illnesses in two ethnic tribes living in sympatry in Mali from 1998 to 2008]

In Africa, malaria is responsible for 25-40% of all outpatient visits and 20-50% of all hospitalizations. In malaria-endemic areas, individuals do not behave the same toward the outcome of clinical malaria. The aim of this study is to determine the prevalence of malaria in the locality among the different ethnic groups, evaluate the place of malaria among febrile illnesses, and assess the relationship between fever and parasite density of Plasmodium falciparum. Studies on susceptibility to malaria between the Fulani and Dogon groups in Mali were conducted in Mantéourou and the surrounding villages from 1998 to 2008. We carried out six cross-sectional studies during the malaria transmission and longitudinal surveys (July to December depending on the year) during the 10-year duration. In longitudinal studies, clinical data on malaria and other diseases frequently observed in the population were recorded. It appears from this work that malaria is the leading cause of febrile syndromes. We observed a significant reduction in malaria morbidity in the study population from 1998 to 2008. The pyrogenic threshold of parasitaemia was 1,000 parasites/mm(3) of blood in the Dogon and 5,000 parasites/mm(3) of blood in the Fulani.We have also found that high parasitical densities were not always associated with fever. Malaria morbidity was higher among the Dogon than in Fulani. The immunogenetic factors might account for this difference in susceptibility to malaria between Fulani and Dogon in the area under study. With regard to this study, it is important to take into account the ethnic origin of subjects when interpreting data of clinical and malarial vaccine trials.

Maternal country of origin, breast milk characteristics and potential influences on immunity in offspring

Breast milk contains pro- and anti-inflammatory cytokines and chemokines with potential to influence immunological maturation in the child. We have shown previously that country of birth is associated with the cytokine/chemokine profile of breast milk. In this study we have investigated how these differences in breast milk affect the cellular response of cord blood mononuclear cells (CBMCs) and intestinal epithelial cells (IECs, cell line HT-29) to microbial challenge. Ninety-five women were included: 30 from Mali in West Africa, 32 Swedish immigrants and 33 native Swedish women. CBMCs or IECs were stimulated in vitro with breast milk, alone or in combination with lipopolysaccharide (LPS) or peptidoglycan (PGN). Breast milk in general abrogated the LPS-induced down-regulation of surface CD14 and Toll-like receptor (TLR)-4 expression on CB monocytes, while inhibiting the PGN-induced TLR-2 up-regulation. However, breast milk from immigrant women together with LPS induced a lower CBMC release of interleukin (IL)-6 (P = 0·034) and CXCL-8/IL-8 (P = 0·037) compared with breast milk from Swedish women, while breast milk from Swedish women and Mali women tended to increase the response. The same pattern of CXCL-8/IL-8 release could be seen after stimulation of IECs (HT-29). The lower CBMC and IEC (HT-29) responses to microbial compounds by breast milk from immigrant women could be explained by the fact that breast milk from the immigrant group showed a divergent pro- and anti-inflammatory content for CXCL-8/IL-8, transforming growth factor-β1 and soluble CD14, compared to the other two groups of women. This may have implications for maturation of their children's immune responses.

Association of rs7719175, located in the IL13 gene promoter, with Schistosoma haematobium infection levels and identification of a susceptibility haplotype

Urinary schistosomiasis is a parasitic disease caused by Schistosoma haematobium helminths. S. haematobium eggs may remain trapped within the bladder or the ureter walls, causing major pathological disorders in the urogenital system. The polymorphism rs1800925(C/T) of the IL13 gene promoter, which is functional, has previously been associated with susceptibility to S. haematobium infection. The aim of this study was to further our understanding and to determine whether, in the 5q31-q33 region, rs1800925 affects infection levels alone or in synergy with other polymorphisms. After sequencing the IL13 promoter and increasing the single-nucleotide polymorphism density, we performed a linkage disequilibrium analysis between rs1800925 and the other markers in a Malian population. Multivariate linear regression analysis and electrophoretic mobility shift assay (EMSA) were performed to characterized markers in linkage disequilibrium with rs1800925. An additional polymorphism, rs7719175, in the IL13 promoter was associated with controlling infection levels in multivariate analysis. The haplotype rs7719175T-rs1800925C was associated with high infection levels. EMSA indicated that rs7719175 affects the binding of transcriptional factors to the promoter region. Polymorphisms rs7719175 and rs1800925 have a synergistic role in the control of infection levels caused by S. haematobium and using them as a haplotype allows a better discrimination between infected subjects.

[Immunity in human schistosomiasis: hope for a vaccine]

Schistosomiasis remains a major worldwide public health problem in several endemic areas despite implementation of control measures. Vaccination would be an effective, long-term treatment option for future control of schistosomiasis. Although several parasite antigens have been identified as schistosomiasis vaccine candidates, major hurdles must still be overcome to develop a vaccine suitable for clinical trials in the field. Better understanding of immune responses to Schistosoma infection in both animal models and humans suggests that development of a vaccine is possible. The purpose of this review is to summarize the mechanisms of protective immunity against Schistosoma infection and to provide perspective on the development of a vaccine.

[Snakebites in the Sudanian and Sahelian zones of Mali: epidemiology, symptoms and treatment]

The purpose of this study was to document the epidemiology, symptoms and treatment of snake envenomation in Mali between 2005 and 2006. Data was collected using two methods, i.e., household surveys and retrospective surveys. Household surveys carried out in a village of 597 people showed that the annual average incidence was 164 snakebites per 100,000 inhabitants. Retrospective surveys were conducted in 35 healthcare facilities (5 regional hospitals and 30 district health centers) located in 5 parts of the country. Study periods ranged from 2 to 11 years depending on the location. The mean annual incidence of snakebite including dry-bites without envenomation was 27 per 100,000 inhabitants (range, 15-59). Hospital mortality was 4.7% (67/1433) (range, 2.2-6.7%). The population at risk consisted mainly of working men who accounted for 68.4% (980/1433). Patients between 15 and 30 years accounting for 41.2% (590/1433) of the sample were at highest risk for snakebite (chi2=9.96; p=6.10-3). The frequency of snakebite increased from 9.9% (142/1433) in Mopti in the North to 39.9% (572/1433) in Sikasso in the South (chi2=11.93; p=0,017). Snakebites most frequently occurred during the rainy season (56.6%) but only 0.68% of victims were referred to the health center. Hemorrhagic and inflammatory syndromes were the main complications of envenomation. Treatment was always symptomatic. Antivenom serum requirements ranged from 63 to 200 ampoules per year. Our results show that the frequency of snakebites remains grossly underestimated based on hospital data.

Pharmacokinetics of sulfadoxine and pyrimethamine in intermittent preventive treatment of malaria in pregnancy

Malaria during pregnancy is associated with maternal and fetal morbidity and mortality. In order to minimize the burden, sulfadoxine-pyrimethamine (SP) is widely used in Africa as an intermittent preventive treatment of malaria in pregnancy (IPTp). However, only limited data are available on the pharmacokinetics of sulfadoxine and pyrimethamine during pregnancy. We conducted a prospective, self-matched, multicenter study of 98 pregnant women in four African countries in order to determine the effects of pregnancy on SP pharmacokinetics. After adjusting for the effects of potential confounders, blood concentrations (associated with therapeutic efficacy) of pyrimethamine were higher (geometric mean ratio (GMR) 1.33; 95% confidence interval (CI) 1.18-1.51; P < 0.001) and those of sulfadoxine were lower (GMR 0.91; 95% CI 0.84-0.98; P = 0.013) on day 7 after SP administration during pregnancy than after the postpartum period. SP pharmacokinetic parameters differed significantly among the study sites. Given the inconsistency of changes in pharmacokinetic parameters between sulfadoxine and pyrimethamine as well as among the study sites, it is not possible to recommend any dose adjustment to prolong the therapeutic life span of the fixed dose combination of SP for IPTp on the basis of our study findings.

[Haemophilus influenzae b among bacterial meningitis in Bamako (2002-2004)]

In Mali little study exist on the meningitis with Haemophilus influenzae b (Hib). This weak data availability on Hib meningitis, didn't permit to introduce the immunization against this pathology in the Expanded Program Immunization (EPI) of Mali. The present survey aims to improve the availability of the data on Hib meningitis and to advocate for the introduction of immunization against Hib in EPI in Mali. The survey consisted to the exploitation of spinal fluid examination data for the suspected cases of meningitis, sent by the different health centers to National Institute for Public Health Research (INRSP) on the period going from October 1st, 2002 to September 30, 2004. According to the survey, on 230 cases of meningitis whose germs have been identified to the latex and the culture, Hib occupies the 3rd place with 21.3% among the bacterial meningitises. In Bamako Hib occupies the 2nd place (27.4%) according to the source. The persons less than 1 year (59.6%) were the more affected (p < 0.001) and the diseases distribution has been observed during the dry seasons (51.0%) and rainy (49.0%) without meaningful impact of temperature and rainfall (p > 0.05) (p = 0.8249). The cases of Hib identified were more sensitive to ciprofloxacine (100%) and to ceftriaxone (100%). Taken into consideration the cost raised of quinolones and cephalosporines, and in reference to the high mortality and frequent complications known of Hib meningitis, the introduction of immunization against Haemophilus influenzae in the Expanded Program Immunization should contribute to a better control of this disease.

[Randomized clinical trial of two malaria prophylaxis regimens for pregnant women in Faladie, Mali]

From June 2003 to May 2004 we carried out a comparative study of two malaria prophylaxis regimens for pregnant women. The purpose was to compare the efficacy of two regimens using chloroquine (CQ) or sulfadoxine-pyrimethamine (SP) during pregnancy and delivery in a village located in an endemic area of Mali. The study was carried out in Faladié (District of Kati) located 80 km from Bamako. Prophylaxis was administered during the second and third trimesters of pregnancy (except the 9th month for SP). A total of 301 pregnant women were enrolled including 150 in the CQ group and 151 in the SP group. At the onset of the study, the two groups were comparable with regard to socio-demographic and malaria factors. At the time of delivery, malaria infection was reduced by 43.3% in the CQ group (P < 10-6), and by 79.1% in the SP group (p < 10-6). The anemia rate was reduced by 57.5% in the CQ group (Ch2 of McNemar = 0.017), and by 74.8% in the SP group (Ch2 of McNeamar = 0.025). The incidence of placental infection was 20.6 % in the CQ group versus 8.3 % in the SP group (p = 4.10-3). Overall 16.7% of newborns presented low birth weight at delivery including 70.4% in the CQ group. The findings of this study suggest that intermittent presumptive treatment using SP is more effective than intermittent presumptive treatment using CQ in protecting both the mother and newborn against intra-uterine malaria transmission and its consequences.

[Spatial cluster detection without point source specification: the use of five methods and comparison of their results]

BACKGROUND

Various statistical methods have been developed to describe spatial heterogeneity, in terms of high risk zones. If no source can be determined, this heterogeneity can be globally or locally described. Global methods test a statistic estimated over the whole studied geographical area, whereas local methods estimate a statistic on each spatial unit (or regrouping unit). This paper aimed to present, and to compare results of an epidemiological application, of five methods of spatial cluster detection.

METHODS

The two global detection methods were: 1) Moran's coefficient, a classically used autocorrelation coefficient; 2) Tango's statistic, a spatial generalization of the Chi(2) statistic. The three local methods were: 1) the local application of Moran's coefficient, proposed by Anselin; 2) the scan statistic, which searches for grouping of spatial units; 3) the oblique regression tree, which splits the studied zone into sub-zones of different risks. These five methods were applied to the description of the spatial heterogeneity of the malaria risk over a hyperendemic village, in Mali.

RESULTS

All the methods highlighted a significant spatial heterogeneity. Both global methods (Moran's coefficient and Tango's statistic) showed weak spatial correlations. Local Moran's coefficient (with Bonferronis' adjustment) highlighted five spatial units. The scan statistic identified a single high risk cluster. The regression oblique tree split the study area into six sub-zones; the sub-zone with the higher risk was consistent with the cluster identified by the scan statistic.

CONCLUSION

These presented methods do not require any previous knowledge of a source. They allow evaluating spatial risk heterogeneity over the entire geographical area under study. It is noteworthy that shape, size, and spatial heterogeneity characteristics (either global or local) of the study area, as well as the definition of the proximity, significantly influence the spatial risk analysis' outcome. Although their results should be cautiously interpreted, these methods are useful for preliminary field studies or epidemiological surveys.

[Digestive parasitic diseases to HIV/AIDS infected patients of internal medicine and infectious diseases wards of the hôpital du Point "G" Bamako - Mali]

We conducted a prospective study in internal medicine and infectious diseases wards of the hospital of Point " G " in Bamako, Mali from January to December 2002. Overall 112 patients HIV positive, thirty-five patients (31,25%) had at least a digestive parasitic disease. We found that the most frequent parasite in stools sample were protozoa (82,85%). The second most frequent parasites were helminthes (20,33%). HIV/AIDS opportunistic parasites represented 40% of all parasites found. These included 25,71% cases of Cryptosporidium sp, 8,57% cases of Isospora belli and 5,71 % for microsporidia. The functional signs of our patients were mostly asthenia and weight loss. The physical signs were conjunctive pallor (71, 42%) and diarrhea (85, 71%). Generalized itching was present in 54, 28% of cases and abdominal pains in 25, 71% of cases. The global lethality was 37, 14% (13/35). The deaths were due to the HIV infection. The parasites appear even frequent at patients infected by HIV/AIDS, in spite of the advent of antiretroviral therapy. The efficient molecule research against the opportunist parasite must constitute one of our priorities in tropical area.

[Morbidity and mortality of infectious diseases determined mass vaccination in children under 5 ans in Bamako District]

Available facts on morbidity and mortality due to PEV diseases for children under 5 years come from routine facts in Bamako District. The Present study through population investigation proposed to evaluate indicators. It was about a transversal investigation realised about 1014 children less than 5 year living in Bamako (on October 2000). The selection of children has been made by boring after stratification of the district based on socio-economic level and stabilization of population of different sectors. According to study, the global incidence rate of target patients of PEV is about 4.93% +- 1.33%. These rate were about 4.14% +- 1.22% for measles which is the 1st cause of morbidity among target patients of PEV, 0.69% +- 0.50% for whooping cough, 0.903% +- 0.19 for poliomyelitis and 0% for neo natal tetanus. For tuberculosis of which evolution have been appreciated trough counting of antituberculosis clinic register (DAT) during 10 years (1990-1999), its tendency was increasing. The death rate registered during investigation was related to measles with an estimated rate of 4.93% +- 4.31%. Results analysis, global incidence of PEV target patients was in decrease at Bamako district. At vaccinated patients against measles (64.3%) and whooping cough (57.14%) is in favour for an investigation about effective vaccinal.

Malaria prevention practices in Mopti region, Mali

OBJECTIVES

To assess insecticide-treated nets (ITNs) use, other malaria prevention measures, knowledge of malaria and diffusion of information about ITNs by the National Malaria Control Programme (NMCP) in Mali.

DESIGN

A descriptive cross-sectional study.

SETTING

Four villages in Mopti region, Mali that had participated in the Mopti Regional Malaria Control Program (MRMCP) ITN Education Programme five years prior.

PARTICIPANTS

Three hundred thirty nine randomly-selected households. Within each household, mothers of children one to nine years of age were interviewed regarding knowledge of malaria and prevention practices.

RESULTS

Overall, 11% of households used ITNs, with 97% of these in two villages. Ninety eight percent of households used bednets, 22% used insecticide sprays and 39% used mosquito coils. Significant predictors of ITNs use were: head of household literacy, larger family size, Bambara ethnicity, hearing about the NMCP and hearing about ITNs from health agents. Reasons why ITNs were not used included not knowing anything about ITNs, cost and not having net impregnation services readily available in the village. Levels of knowledge concerning malaria disease, transmission and prevention varied amongst the four villages. ITN households had significantly higher levels of knowledge about malaria and its prevention.

CONCLUSION

Five years after the implementation of the MRMCP, ITNs use was low and diffusion of malaria prevention information was unequal among villages. Future efforts in improving the programme must recognise these differences in knowledge and ITNs utilisation and make village-specific changes that are acceptable for each village.

[Intestinal parasitosis during AIDS diarrhoea]

The main goal of this work was to study the parasitic infections during AIDS diarrhoea. A longitudinal study was carried out from October 2000 to November 2001 in the Hepato-Gastro-Enterology department of Gabriel Toure Hospital and in the Department of Epidemiology and Parasitic infections of Faculty of Medicine, Pharmacy and Odonto-stomatology of Bamako (Mali), concerning HIV positive patients suffering from diarrhoea. Detecting microbes in stools has been done through direct microscopic examination and according to procedures of Henricksen Poblenz Baerman, Kato Katz and the PCR. Among the 70 patients involved, the sex-ratio was 53%, the average age was 35 +/- 8.4 years. Fever weight loss, skin affections and digestive mycosis were often associated. Opportunistic infections have been relatively frequent with Cryptosporidium parvum with 20%, Isospora belli with 8.5% and Microsporidium with 11.5% of cases. Other non-opportunistic microbes were found. Death within the first two weeks seems more important in case of infection by Cryptosporidium parvum. The frequency and the danger of those opportunistic infections require their efficient diagnosis and care management.

Efficacy and safety of artemether in the treatment of severe end complicated malaria in mali

We compared the efficacy and safety of artemether versus Quinine in 67 children from 3 months to 15 years old hospitalised for severe and complicated in the pediatric service of Gabriel Touré's Hospital Children were randomised to receive artemether or quinine. Artemether was given at 3,2mg/kg in day 1 (two times) and 1; 6mg single dose from day 2 to day5) and quinine was administrated at 20mg/kg (attack dose) followed by 10mg/kg every 8 hours until oral drug administration (10 mg/kg every 8 hours). The treatment for artemether lasted 5 days while quinine treatment lasted 7 day. Thirty tree and 34 children received respectively artemether and quinine. Two groups were comparable with baseline characteristics. Cerebral malaria was most frequent in the two with no statistical difference. Seventy height percent in artemether group compared to 82,4% in quinine group. No statistical difference was found between groups regarding parameters such as : Parasitic clearance, thermal clearances, delay of exit of the coma, upsurge, tolerance, and mortality. Artemether is as efficacious and well safe as quinine for the treatment of sevese and complicated malaria.

Impact of mass chemotherapy with praziquantel on Schistosoma haematobium and Schistosoma mansoni infections in Office du Niger, Mali

Aims This study was carried up to assess the impact of mass chemotherapy with praziquantel on the prevalence and intensity of Schistosoma haematobium and Schistosoma mansoni in Office du Niger. Materials and Methods It was a cross sectional study with two passages about which we compared a test group of 7 villages (n=2342) treated in 1989 to a control group of 7 villages (n=2263). Results One year after mass chemotherapy, baseline prevalence rates of Schistoosma haematobium, Schistoaoma mansoni and those of the double infection decreased by 50%, 54% and 62,9% respectively. The geometric mean egg counts of Schistosma haematobium (GMECSh) was reduced by 66.6% and that of Schistosoma mansoni (GMECSm) by 43.4%. However, in spite of mass treatment, the overall prevalence rates of Schistosoma haematobium and mansoni were always higher than 20% in young people aged of 6-19 years. Conclusion These data show that in irrigated area, efficacy of praziquantel is strongly affected by age. This persistance of infection in population raises up several questions according to host immunity, parasite biology and praziquantel efficacy.

Schistomiasis morbidity to hospital ward of hospital of point g in Bamako - Mali

Summary Aims The coinfection of the VIH and the schistosomiasis is affections brought back in schistosomiasis endemic area. We valued the level of morbidity partner to the schistosomiasis in hospital yard to patients hospitalized without distinction of immunological statute of patients. Patients and Methods Our study was retrospective and prospective. We included all patients hospitalized to internal Medicine and infectious diseases carriers of schistosomiasis to the mucous rectal biopsy and parasitologic exam of stools and urines between January 1998 and July 2005. Results Twenty-four patients were included in the survey of which 15 of masculine sex (62,50%) and 9 of feminine sex (37,50%). The sex ratio (H/F) = 1,66. The most tainted professions were pupils, peasants and housewives. Ten patients had benefited from the VIH tracking (41,66%) and 6 patients were seropositive for the VIH (25%). Sixty fifteen percent of patients accommodated Schistosoma haematobium (18 cases), 20,83% Schistosoma mansoni (5 cases) and 1 patient had a mixed infection. It doesn't exist a statistically difference between the frequency of species met (p = 0,061) . The main motives of hospitalization were the fever (12,50%), the hepatomegaly and splenomegaly, the ascite, the abdominal pain associated to the diarrhea and the diarrhea associated to an anemic syndrome with 8,20% for each of these motives. The most frequent clinical symptomatology was diarrhea (12,50%). The underlying pathologies more associated were the opportunist infections of the VIH (8,30%) the cirrhosis (12,50%), a syndrome amoebic dysentery syndrome (8,30%), a hepatic granuloma (8,30%). In the group of patients HIV positive the symptomatology was made of chronic and /or of glair - bloody diarrhea. One alone patient with a rate of CD4 = 279/mm3 presented prurigos in bouquet on the right flank. All patients without immunological statute distinction answered favorably to the treatment by the praziquantel. Conclusion The schistosomiasis stays even frequent in hospital yard of Bamako. The best understanding of the interaction between HIV and schistosomiasis is a pledge of the success of struggle programs in endemic area of schistosomiasis and of VIH.

Prevalence and perception of schistosomiasis in irrigated rice field area in Mali

Summary The aim of this work was to assess prevalence and clinic of schistosomiasis as well as the knowledge, attitude and practice (KAP) of populations living in the village of Molodo, a rice irrigated area of Mali. By cross sectional survey with a single passage, we enrolled 346 children aged of 7 to 14 years and 308 parents. The prevalence of Schistosoma haematobium and S. mansoni were respectively 72% and 68%. Micro-hematuria (Sy=86%; Sp=45%), urinary difficulty (Se=828% ; Sp=33%), high frequency of urine (Se=76% ; Sp=31%) and suspubians pain (Se=78% ; Sp=31%) associated with urinary schistosomiasis indicated that these symptoms could be relevant diagnosis signs. Similar observations could be considered as a good sign of diagnosis of intestinal schistosomiasis due to S. mansoni with abdominal pains (Se=75% ; Sp=36%), to have a fancy of stool (Se=75% ; Sp=32%), diarrhea (Se=71% ; Sp=32%), des conjunctival paleness (Se=85,% ; Sp=33%) et de spleen enlargement (Se=71% ; Sp=33%). The transmission patterns of schistosomiasis were not well known by populations, because only 15% of pupils and 38% of parents incriminated the canal and/or the 'fala" (the lake) as genitourinary bilharzias contamination source especially after bathing. The intestinal form was known by 11% of pupils and by 24% of parents. These results show that in spite of schistosomiasis endemic pattern, in this area, populations didn't know well this pathology.

Attitude and practice of health staff in the management of simple malaria in the health district of niono in mali

Summary The aim of this work was to assess the attitude and practice of health staff about malaria. We undertook a cross sectional survey in the district hospital, two community health centers (CSCOM), one private doctor's cabinet and one private nurse's cabinet. We observed the doctors and the nurses during the visit of 261 patients. The most frequent presumption diagnosis was simple malaria without vomiting (53%). Among presumption diagnosis the high frequency of confirmed cases was malaria with vomiting (42%). In the health center, injectable quinine was the most prescribed drug (82%), followed by chloroquine (23%). The injectable quinine was more prescribed by nurses (85%) than doctors (15%) (p=10-6). At the time of follow-up, 98% of patients was cured clinically. Even though malaria was the first reason of visit (99,2%), only one out of ten practitioners checked up temperature of patients. Treatment administered dit not follow guidelines suggested by the national program for malaria control. We thus suggested the training of health staff as well as regular supervision of health centers.

Identification of the Kna/Knb polymorphism and a method for Knops genotyping

BACKGROUND

DNA mutations resulting in the McCoy and Swain-Langley polymorphisms have been identified on complement receptor 1 (CR1)-a ligand for rosetting of Plasmodium falciparum-infected RBCs. The molecular identification of the Kna/Knb polymorphism was sought to develop a genotyping method for use in the study of the Knops blood group and malaria.

STUDY DESIGN AND METHODS

CR1 deletion constructs were used in inhibition studies of anti-Kna. PCR amplification of Exon 29 was followed by DNA sequencing. A PCR-RFLP was developed with NdeI, BsmI, and MfeI for the detection of Kna/Knb, McCa/McCb, and Sl1/Sl2, respectively. Knops phenotypes were determined with standard serologic techniques.

RESULTS

A total of 310 Malian persons were phenotyped for Kna with 200 (64%) Kn(a+) and 110 (36%) Kn(a-). Many of the Kn(a-) exhibited the Knops-null phenotype, that is, Helgeson. The Kna/b DNA polymorphism was identified as a V1561M mutation with allele frequencies of Kna (V1561) 0.9 and Knb (M1561) 0.1.

CONCLUSION

The high frequency (18%) of Knb in West African persons suggests that it is not solely a Caucasian trait. Furthermore, because of the high incidence of heterozygosity as well as amorphs, accurate Knops typing of donors of African descent is best accomplished by a combination of molecular and serologic techniques.

[Assessment of chloroquine resistance two years after stopping chemoprophylaxis in 0 to 9-year-old children living in a malaria-endemic village of Mali]

This study was carried out in the village of Faladié, Mali located in the malaria-endemic Kati region, two years after routine use of chloroquine prophylaxis was discontinued in children 0 to 9 years old. The main purpose of this study was to assess changes in chloroquine resistance. Two cross-sectional surveys in association with WHO in vivo chloroquine sensitivity testing were conducted, i.e., one in September 2000 and one in December 2002. Findings in 2000 showed that 77.5% of mothers administered chloroquine prophylaxis to their children in compliance with physician orders. The plasmodic index was 62%. The overall level of parasitologic resistance (based on the 1996 WHO in vivo tests) was 80%. The overall therapeutic failure rate was 17.5%. Findings in 2002 demonstrated a plasmodic index of 28%, an overall parasitologic resistance rate of 45% (based on WHO in vivo tests), and an overall therapeutic failure rate of 15%. The diminution of resistance in 2002 may be due to the decrease of drugs pressure and to low exposure of individuals to mosquitoes at the end of transmission season. Althougt these data indicate a 44% drop in chloroquine resistance (P=0.0001), no increase in the clinical efficacy of chloroquine was observed (P=0.05). In view of these results we propose more emphasis on information campaigns to increase public awareness of the need for chemoprophylaxis only for pregnant women, on the promotion of the use of bednets and insecticide-impregnated materials, and on environmental management.

[Epidemiology of malaria in a village of Sudanese savannah area in Mali (Bancoumana). 2. Entomo-parasitological and clinical study ]

We carried out five cross sectional surveys between 1993 and 1994 to assess the epidemiology of malaria in the village of Bancoumana, located in the Sudanese savannah areas of Mali. Each survey included a collection of entomological, clinical, parasitological and immunological data. The study population involved 1600 children from six months to 9 years of age. The main vector was Anopheles gambiae s.l., man bite rate and entomological inoculation rate were maximum respectively in August (peak of the transmission season) and October (end of transmission season). Plasmodium. falciparum was the main parasite species observed. Spleen enlargement rate, parasite rate, gametocyte rate and parasite density varied significantly with age and season. The parasite rate, gametocyte rate and parasite density were significantly low in October 1994 compared with October 1993 while the entomologic parameter did not show any variation over the two years. This reduction of parasitologic index between 1993 and 1994 may be related to an increase of anti-malarial drug use in the population. Our results show that malaria is hyperendemic in the village of Bancoumana.

[Epidemiology of malaria in a village of Sudanese savannah in Mali (Bancoumana). Anti-TRAP and anti-CS humoral immunity response]

Vaccine development research is an important component of malaria control strategies. Thrombospondin related anonymous protein (TRAP) and the circumsporozoite (CS) protein are two antigens of sporozoite surface. Immune response to these two antigens may contribute to the development of anti-sporozoite vaccine. Recent studies suggest that antibodies anti-TRAP may partially block sporozoites penetration in hepatocyte, and thereby reducing malaria morbidity. We carried out a study to assess the seroprevalence of anti-TRAP and anti-CS antibodies and to identify a possible role of these antibodies on malaria morbidity in children 1-9 years old living in a rural hyperendemic village. We performed 5 cross sectional surveys and a longitudinal follow up in 1993 and 1994. During each cross sectional study, children were examined for fever and splenomegaly; all febrile children received thick film examination, and serologic analysis was performed in one third of these, randomly selected. The results show that the seroprevalence of anti-TRAP and anti-CS varied with age and season (p < 0.05). Association between the prevalence of anti-TRAP and splenomegaly was observed during two cross sectional surveys (June and October 1993). The presence of anti-TRAP antibody was associated with Plasmodium falciparum infection at the beginning of the transmission season (June 1993 and July 1994). A negative association between the level of anti-TRAP title and parasitemia was observed (March and October 1994). These findings suggest no clear evidence of the protective role of anti-TRAP antibodies in uncomplicated malaria, possibly due to the limited persistence of these antibodies under natural situations.

[Transmission of schistosomiasis in an urban population and prevalence of intestinal helminthiasis in Bamako, Mali ]

Parasitological, malacological and anthropological studies were performed to assess the prevalence of Schistosoma haematobium and S. mansoni in schoolchildren living in the suburban area of Bamako. A total of 1017 schoolchildren aged 6-14 years were selected in two different areas between September 1997 and December 1999. In Djikoroni, the prevalence of S. haematobium and S. mansoni was 80.7% (339/420) and 22.8% (85/372) respectively. There was no significant difference of prevalence and intensity of infection with S. haematobium between schools, gender and age (p > 0.05), whereas, those of S. mansoni were higher in the vicinity of (+/- 100 m from) major sites where infected Biomphalaria pfeifferi were found (p < 0.001). In Niomirambougou, S. haematobium was prevalent in 46.7% (279/597) and S. mansoni in 28.2% (134/475). Boys and children aged 11-14 years were more infected (p < 0.001). Associated intestinal helminths (Hymenolepis nana, Necator americanus and Ascaris lumbricoides) were relatively scarce (prevalence < 1%). The prevalences of schistosome infected snails intermediate host were relatively high, 49.3% (100/203) in B. pfeifferi, 20.6% (88/138) in B. truncatus and 24.1% (7/29) in B. globosus. We recorded a total of 2514 water contacts about which 1130 in December and 1384 in January. Most of the children, 42.9% (1077/2511) were attracted to water bodies for bathing, swimming and playing, suggesting the lack of recreational facilities in these areas. Developing local control programmes in schools located in the vicinity of water bodies would contribute to break the parasite transmission cycle in Bamako.

[Systematic search for parasites among leprosy patients in Mali]

Practice of multidrug therapy in leprosy (combination Dapsone + Rifampicine + Clofazimine) established since 1981, has significantly reduced the incidence of the disease. However, immunosuppression due to treatment of multi-drugs therapy induced adverse reactions with glucocorticoid and the change in host immune response due to the leprosy itself, might increase the risk of parasitic infections. To test this hypothesis, we carried out a case-control study at the "Institut Marchoux" in Bamako. Stool and urine samples from all patients included in the study were examined for parasites identification. In addition, we performed thick and thin blood film to identify malaria infection and skin biopsy (snip) to detect onchocerciasis. A total of 121 cases of leprosy and 219 controls aged 10-84 years old were included in the study from March 1999 to February 2000. Sixty two percent (n = 121) of cases were treated with glucocorticoid. The prevalence of infection due to Entamoeba coli and Entamoeba histolytica were higher in cases than in controls (p = 0.02). The prevalence of infection due to hookworms was higher in cases than in controls. There was no difference of the infections to the other intestinal parasites. Three cases of cryptosporidiosis and one case of isosporosis were observed in leprosy group vs none in the control group. There was no significant difference between cases and controls with regard to prevalence of Schistosoma haematobium, Trichomonas vaginalis and Onchocera volvulus. The prevalence of Plasmodium falciparum was 4.9% (6/121) in the leprosy case and 7.8% (17/219) in the control group. In conclusion, despite the corticotherapy and immunosuppression due to leprosy, there was no difference in prevalence of pathogenic parasites. Entomoeba coli, Entamoeba histolytica which have significantly higher prevalence among the cases were not pathogen therefore there was no higher risk of severe intestinal parasitosis among the cases of leprosy. Treatment with glycocorticoid in patients with leprosy did not suggest any impact on the prevalence of this parasitic infections. In addition, multidrug therapy did not show any effect on the carriage of Plasmodium falciparum.

[Gastrointestinal manifestations of AIDS in adults in Mali]

Our main objective consists in evaluating the frequency of digestive signs and digestive opportunistic infections in AIDS patients with diarrhea. The prospective study occurred from January 1997 to July 1998 in Bamako hospitals. The patients underwent a clinical examination, blood and stools tests, and sometimes upper digestive endoscopy. Among 434 cases of AIDS, 426 patients (98%) had at least one digestive sign. The main digestive signs were diarrhea (80.1%), abdominal pains (62.2%), vomiting (47.2%) and dysphagea (36.6%). Isospora belli and Cryptosporidium parvum have been pointed up in respectively 9% and 16.3% of examined specimen. Echerichia coli was found in 8.6% of stool cultures and in 2.9% in the case of Salmonella Arizonae. Twenty cases of Kaposi's sarcoma were diagnosed and mycosis was found in 71.9% of patients. In conclusion, digestive change is a constant phenomenon in AIDS patients. Patients survival could be improved by early management, improvement of diagnosis and provisioning of medicines.

[Prevalence and perception of schistosomiasis in a periurban school of Bamako in Mali]

The prevalence of urinary and intestinal schistosomiasis, the knowledge, attitude and practice (KAP) regarding the disease among both the children and their parents were investigated in Djikoroni para, a Suburban area of Bamako. The prevalence of Schistosoma haematobium and S. mansoni were respectively 69.8% and 8.7%. Compared with the girls, the boys were significantly more infected by S. haematobium (p = 5.10(-3)), but no difference between the sexes was observed for S. mansoni (p = 0.36). Interviews indicated that 88% of children and 91% of adults considered micro-haematuria as a pathology, but did not know anything about intestinal schistosomiasis. The low sensitivity of micro-haematuria (56.8%) and of the criterion "abdominal pains" (66.7%) indicated that they couldn't be relevant diagnosis signs. The symptoms and mode of transmission were generally well understood for S. haematobium but not for S. mansoni. The later parasite, its intermediate host and their interactions were unknown. The main man water contacts are bathing and playing in the Woyowayanko and in the Niger river. Inadequate perception of schistosomiasis contributes to maintain schistosomiasis at a high level of prevalence in Djikoroni.

[Treatment of epilepsy in rural areas in Mali]

Epilepsy is a public health problem in Africa due to prevalence and social exclusion. We report a follow-up protocol for epileptic patients treated at home in rural areas of Mali. The objectives were: education for the patient, family, and village leaders in orders to achieve good compliance, uninterrupted supply of generic phenobarbitol, follow-up visits once a month for one year then every two months if good compliance with a country physician with delivery of phenobarbitol in sufficient quantity to reach the next visit, verification of correct drug dosage and use, supervision of treatment effect. After two years, the follow-up visits showed that 57.4% of the patients had been seizure free for at least 24 months (more than 4 monthly seizures before treatment). Rate of seizures decreased in 15.7% of the patients. Results were excellent with no seizures, clear physical, psychic and social improvement (work, married life, school attendance). Very few side effects were observed. There were no cases of poisoning. The management scheme is very cost effective: 1.5 USD per month per patient, including phenobarbitol and implementation. There is a need for anti-epilepsy programs in Africa which should be implemented on the local (rural medicalisation), national and international level ("Epilepsy out of the shadows" campaign).

[Evaluation and treatment of snake bites in Bancoumana village in Mali]

A retrospective study was conducted on the epidemiological patterns and treatment of snakebites in the village of Bancoumana, 60 km south-west from Bamako. We analysed a total of 17 cases (8 males and 9 females). The distribution of snakebite cases by gender and by age showed that among subjects aged 5 to 20 years, boys were more exposed than girls (6 vs. 2), whereas, in those of 21 years and above, females were more frequently bitten than males (7 vs. 2) (p = 0.04). The treatment was mainly based on the use of anti-inflammatories and antibiotics, and sometimes of saline, glucose or anti-tetanic serum. Vitamin K was used in 7 cases and no patient was treated specifically. The success of therapy mostly depended on the shortness of delay between the snakebite occurring and patient referral to the health centre, and the low rate of envenomation. All the patients referred the same day they were bitten were cured, whereas three persons referred to the health centre at D3, D7 and D43 after bite died. The surveillance parameters were oedema, bleeding and vomiting.

Evaluation of an immunofluorescent-antibody test using monoclonal antibodies directed against Enterocytozoon bieneusi and Encephalitozoon intestinalis for diagnosis of intestinal microsporidiosis in Bamako (Mali)

A 2-month study was carried out in Mali to evaluate an immunofluorescent-antibody test (IFAT) using monoclonal probes specific for Enterocytozoon bieneusi or Encephalitozoon intestinalis. Sixty-one human immunodeficiency virus (HIV)-seropositive adult patients and 71 immunocompetent children were enrolled. Microsporidia were detected in stools from 8 of 61 patients (13.1%) seropositive for HIV. A single species, E. bieneusi, was identified. All the children were negative for microsporidia. The sensitivity and specificity of IFAT were 100% compared with those of PCR, which was used as the "gold standard." Moreover, species identification by IFAT was more rapid and less expensive than that by PCR. These results show the suitability of IFAT for detection of microsporidia in developing countries.

Treatment with phenobarbital and monitoring of epileptic patients in rural Mali

OBJECTIVE

To assess the efficacy of phenobarbital treatment for epileptic patients in rural Mali.

METHODS

Epileptic patients were treated at home with phenobarbital at daily dosages ranging from 50 mg for children to 200 mg for adults and their condition was monitored. Advice was given to patients, their families, and the village authorities in order to achieve compliance. An uninterrupted supply of generic phenobarbital was provided and a rural physician made two follow-up visits to each village to ensure that the drug was taken in the correct doses. The physician gave information to the population, distributed the phenobarbital in sufficient quantities to cover the periods between visits, and monitored the patients' responses to treatment. During the first year the physician visited the patients every two months. The frequency of visits was subsequently reduced to once every four months.

FINDINGS

In the six months preceding treatment the average rate of seizures among patients exceeded four per month. After a year of treatment, 80.2% of the patients experienced no seizures for at least five months. A total of 15.7% of patients experienced a reduction in seizures. In many cases no further seizures occurred and there were improvements in physical health, mental health and social status. There were very few side-effects and no cases of poisoning were reported. The cost of treatment per patient per year was 7 US dollars for generic phenobarbital and 8.4 US dollars for logistics.

CONCLUSION

Low doses of phenobarbital were very effective against epilepsy. However, there is an urgent need for programmes involving increased numbers of physicians in rural areas and, at the national level, for the inclusion of epilepsy treatment in the activities of health care facilities. Internationally, an epilepsy control programme providing free treatment should be developed.

[Ultrasonographic aspects of urinary schistosomiasis in children of the Dogon plateau and the Niger office; impact of praziquantel treatment]

Urinary bilharziasis is a parasitic infection responsible for vesical, urethral and renal lesions. The authors demonstrate the importance of ambulatory echography on a large scale and describe various echographic lesions. Vesical attacks occurred in 27% of the wall irregularity, 44% of the masses and polyps. Pyelic and urethral abnormalities occurred in 16.6% and 29.9% of cases respectively at the baseline in 1991. These prevalence rates decreased after seven years, in 1998. The authors discuss the utility of chemotherapy with praziquantel and the necessity of a periodical mass treatment in the areas with high bilharziasis endemicity in Mali.

[Reinfection with Schistosoma haematobium and mansoni despite repeated praziquantel office treatment in Niger, Mali]

The dynamics of reinfection by Schistosoma haematobium and Schistosoma mansoni after repeated treatment with praziquantel (40 mg/kg body weight, single dose) was studied in a cohort of schoolchildren living in an endemic area. A total of 214 urine and 220 stool samples were collected and examined at three different times, i.e., February 1989, July 1989 and February 1990. Mass chemotherapy was administered at the beginning of study (February 89). Treatment was repeated in children with positive tests at each subsequent sampling. Prevalence rates were 55.1 p. 100, 3.7 p. 100, and 35.0 p. 100 for Schistosoma haematobium and 62.7 p. 100, 46.3 p. 100 and 73.1 p. 100 for Schistosoma mansoni in February 1989, July 1989 and February 1990 respectively (p < 0.001). From July 1989 to February 1990, reinfection was observed in 84.5 p. 100 of children by Schistosoma haematobium versus 57.8 p. 100 by Schistosoma mansoni. The risk of reinfection by Schistosoma haematobium was higher in children between the ages of 7 and 10 years than in children between the ages of 11 and 15 years (p < 0.001), The incidence of intense Schistosoma haematobium egg excretion rose from 0 p. 100 in July 1989 to 6.0 p. 100 in February 1990. The incidence of intense Schistosoma mansoni excretion in February 1990 was 4.5 p. 100. The reinfection rate at 7 months was over 50 p. 100 for both parasite species despite repeated treatment. This finding demonstrates that additional measures such as proper sanitation and vector control are needed to control human schistosomiasis in irrigated rice paddies.

[Onchocerciasis and epilepsy. Epidemiological survey in Mali]

A door-to-door survey was conducted in 18 villages in Mali with a total of 5,243 inhabitants classified according to the endemicity of onchocerciasis. Each epileptic was matched with two controls. The survey protocol included the following steps in cases and controls: census taking, socioeconomic data, screening for epilepsy, clinical examination, laboratory testing to detect parasites in stools and urine, and snip-test. The crude prevalence of epilepsy was 13.35 per 1,000 (n = 70). Epidemiological study provided a number of valuable demographic insights concerning age at onset, type of seizure activity during seizure and personal and family medical history. A transverse study showed that the prevalence of epilepsy was not significantly higher (p = 9.09) in zones of high endemicity of onchocerciasis (16.1 per 1000) than in zones of low endemicity (10.8 per 1000). Case-control findings showed evidence of onchocerciasis in 22.4 p. 100 of epileptics and 21.7 p. 100 of controls (odds ratio = 1.02 IC 95 p. 100: 0.4-2.19, not significant). Various risk factors including genetic factors and low socio-economic status could explain the trend toward a higher incidence of epilepsy as well as higher morbidity rates in zones of high endemicity of onchocerciasis.

Child malaria treatment practices among mothers in the district of Yanfolila, Sikasso region, Mali

We studied child malaria treatment practices among mothers living in the District of Yanfolila in southern Mali. For sampling, we first chose five of 13 health areas with probability proportional to size. Then villages, compounds and mothers with at least one child aged 1-5 years were randomly chosen. We assessed the spleen size of one 1-5 year-old child of each mother, collected a thick blood film and recorded the body temperature of every child whose mother thought he/she was sick. 399 mothers in 28 villages were interviewed with a structured questionnaire divided into two parts. If the child had had soumaya (a term previously associated with uncomplicated malaria) during the past rainy season, we asked about signs and symptoms, health-seeking behaviour (who the mother consulted first) and treatment. If not, information about knowledge of the disease and treatment to be given was collected. 86% of the mothers interviewed stated that their child had been sick and almost half of them had had soumaya. All mothers named at least one sign by which they recognized the disease. Vomiting, fever and dark urine/yellow eyes/jaundice were the three most common signs mentioned. 75.8% managed their child's disease at home and used both traditional and modern treatment. The most common anti-malarial drug was chloroquine, often given at inappropriate dosage. The sensitivity and specificity of the mothers' diagnosis was poor, although this might be explained by the large percentage of children who had already been treated at the time of the interview. The results of our survey call for prompt educational action for the correct treatment of uncomplicated malaria/soumaya, particularly for mothers and possibly for shopkeepers. The high spleen rate (58.1%) among randomly selected children confirms that malaria is a common disease in this area. Improved case-management at home could only be beneficial.

Toxicity and genotoxicity of antimalarial alkaloid rich extracts derived from Mitragyna inermis O. Kuntze and Nauclea latifolia

The toxicity and the genotoxicity of antimalarial alkaloid rich extracts derived from two plants used in traditional medicine in Mali (Mitragyna inermis (Willd.) O. Kuntze Rubiaceae and Nauclea latifolia (Sm.) Rubiaceae) were evaluated on in vitro and in vivo systems. The results demonstrated that an alkaloid rich extract derived from M. inermis induced a strong inhibition of protein synthesis in mammalian cells but did not exhibit mutagenic or genotoxic activity. An alkaloid rich extract derived from N. latifolia could interact in vitro with DNA of bacteria and mammalian cells, leading to G2-M cell cycle arrest and heritable DNA-damage, as well as inducing in vivo single-strand breaks in liver, kidney and blood cells.

Hemoglobin C associated with protection from severe malaria in the Dogon of Mali, a West African population with a low prevalence of hemoglobin S

The malaria hypothesis proposes a survival advantage for individuals with hemoglobin variants in areas of endemic Plasmodium falciparum malaria. Hemoglobin C (HbC) is a possible example in West Africa, where this hemoglobin has a centric distribution with high frequencies among certain populations including the Dogon ethnic group. To test whether HbC is associated with protection from malaria, we performed a case-control study in the Dogon of Bandiagara, Mali. HbC was present in 68 of 391 (17.4%) of uncomplicated malaria control cases, whereas it was detected in only 3 of 67 cases (4.5%) of severe malaria (odds ratio [OR], 0.22; P =. 01). Further, HbC was present in only 1 of 34 cases (2.9%) with cerebral manifestations, the most common presentation of severe malaria in this population (OR, 0.14; P =.03). Episodes of uncomplicated malaria and parasitemias (4800-205 050/microL) were identified in cases of homozygous HbC (HbCC), which indicates that P falciparum parasites are able to efficiently replicate within HbCC erythrocytes in vivo. These findings suggest that HbC does not protect against infection or uncomplicated malaria but can protect against severe malaria in the Dogon population of Bandiagara, Mali. The data also suggest that the protective effect associated with HbC may be greater than that of HbS in this population.

What does a single determination of malaria parasite density mean? A longitudinal survey in Mali

Temporal variations of blood parasite density were evaluated in a longitudinal study of young, asymptomatic men in a village with endemic malaria in Mali (West Africa). Our main intention was to challenge the value of a single measure of parasite density for the diagnosis of malaria, and to define the level of endemicity in any given area. Parasitaemia and body temperature were recorded three times a day in the wet season (in 39 subjects on 12 days) and in the dry season (in 41 subjects on 13 days). Two thousand nine hundred and fifty seven blood smears (98.5% of the expected number) were examined for malaria parasites. We often found 100-fold or greater variations in parasite density within a 6-hour period during individual follow-up. All infected subjects had frequent negative smears. Although fever was most likely to occur in subjects with a maximum parasite density exceeding 10000 parasites/mm3 (P = 0.009), there was no clear relationship between the timing of these two events. Examples of individual profiles for parasite density and fever are presented. These variations (probably due to a 'sequestration-release' mechanism, which remains to be elucidated) lead us to expect a substantial impact on measurements of endemicity when only a single sample is taken. In this study, the percentage of infected individuals varied between 28.9% and 57.9% during the dry season and between 27.5% and 70.7% during the wet season. The highest rates were observed at midday, and there were significant differences between days. Thus, high parasite density sometimes associated with fever can no longer be considered as the gold standard in the diagnosis of malaria. Other approaches, such as decision-making processes involving clinical, biological and ecological variables must be developed, especially in highly endemic areas where Plasmodium infection is the rule rather than the exception and the possible causes of fever are numerous.

Identification of complement receptor one (CR1) polymorphisms in west Africa

Complement receptor one (CR1) is a ligand for the rosetting of Plasmodium falciparum infected red cells with uninfected cells. Since CR1 exhibits three known polymorphisms, we studied European-Americans (n = 112) and African-Americans (n = 330) and Malians (n = 158) to determine if genetic differences existed in an area endemic for malaria that could offer a survival advantage. The frequencies of Knops blood group phenotypes McC(b+) and Sl(a-) were greatly increased in Africans vs Europeans. Although the frequency of McC(b+) was similar between Africans from the USA or Mali, the Sl(a-) phenotype was significantly higher in Mali (39% vs 65%, respectively). There was an increased frequency of the largest size (250 kD) of CR1 in Mali, but this did not differ significantly from the USA (P = 0.09). Both cohorts of Africans had higher expression of red cell CR1 than European-Americans but this showed little difference between the USA and Mali groups. Thus, the most important CR1 polymorphism relevant to rosetting of malaria infected cells appears to be the Knops blood group.

Antimalarial activity of four plants used in traditional medicine in Mali

Mitragyna inermis (De Willd.) O. Kuntze Rubiaceae, Nauclea latifolia (Sm.) Rubiaceae, Glinus oppositofolius (Linn) Molluginaceae and Trichilia roka (Forsk.) Chiv. Meliaceae were investigated for their in vitro antimalarial activity. Leaves, roots and stem barks were submitted to aqueous, hydromethano and chloroform extractions and antimalarial activity was evaluated by microscopic and flow cytometric analysis. The results present evidence that the alkaloids contained in chloroform extracts and ursolic acid, purified from the hydromethanol extract of M. inermis induced a significant decrease of parasite proliferation. However, aqueous extracts, traditionally used for medication did not show high antimalarial activity. Statistical comparison between microscopic and cytometric analysis demonstrated the validity of this new technique for the screening of active antimalarial compounds isolated from plants.