Lassa Virus Seroprevalence in Sibirilia Commune, Bougouni District, Southern Mali.

Lassa virus (LASV) is endemic to several nations in West Africa. In Mali, LASV was unknown until an exported case of Lassa fever was reported in 2009. Since that time, rodent surveys have found evidence of LASV-infected Mastomys natalensis rats in several communities in southern Mali, near the border with Côte d'Ivoire. Despite increased awareness, to date only a single case of Lassa fever has been confirmed in Mali. We conducted a survey to determine the prevalence of LASV exposure among persons in 3 villages in southern Mali where the presence of infected rodents has been documented. LASV IgG seroprevalence ranged from 14.5% to 44% per village. No sex bias was noted; however, seropositivity rates increased with participant age. These findings confirm human LASV exposure in Mali and suggest that LASV infection/Lassa fever is a potential public health concern in southern Mali.

[Prevalence of maternal and placental malaria and of neonatal low birth weight in a semi-urban area of Bamako (Mali)]. / Prévalence du paludisme maternel, placentaire et du petit poids de naissance au cours du travail d'accouchement et en post-partum en milieu périurbain à Bamako (Mali).

In 2006, the Malian government established a program for free insecticide-treated net (ITNs) distribution during antenatal care visit (ANC) and intermittent preventive treatment during pregnancy with sulfadoxine-pyrimethamine (IPTp-SP) for pregnant women. In March to November of 2009, we conducted a cross-sectional study in peri-urban areas of Bamako, Mali to determine the malaria prevalence among pregnant women and their newborn children in the context of this policy. We included 379 pregnant women aged 15 to 45 years. At delivery, malaria was diagnosed using peripheral thick smears in mothers and newborns, as well as umbilical cord blood and placental blood. The prevalence of Plasmodium falciparum malaria was 2.4, 1.6 and 0.5% respectively in mother, placenta and cord samples; we observed a low birth weight rate of 12.1%. Approximately 77% of our parturient were housewives. The illiteracy rate among this group was 72.3%. Of the 379 women, 73% had at least three prenatal visits, 83% had received at least one free ITNs and 72% had received IPTp-SP during antenatal visit. Among them, 81% claimed to have complied with IPTp-SP. No congenital malaria was found. The prevalence of malaria in both mother and newborn has show a significant decrease in Bamako, compared with previous studies before the implementation of IPTp-SP policy in Mali. A high rate of coverage and use of IPTp-SP and ITNs correlate with lower malaria prevalence in pregnant women.

Assessing malaria burden during pregnancy in Mali.

Malaria infection during pregnancy is associated with adverse consequences including low birth weight (LBW) and maternal anemia, particularly in primigravidae and secundigravidae. In preparation for a clinical trial of the efficacy of chloroquine (CQ) and sulfadoxine-pyrimethamine (SP) containing prevention regimens during pregnancy, we conducted a one-year cross sectional study in Koro and Bandiagara, Mali using an assessment methodology developed by the Centers for Disease Control and Prevention (CDC) to generate basic data on malarial burden during pregnancy. Two hundred and sixty-one and 192 women were enrolled in Koro and Bandiagara, respectively. Rates of placental parasitemia were 17.1 and 42.3% in Koro and Bandiagara, respectively, despite high (70-80%) use of preventive medication (mainly CQ). Low gravidity (1st and 2nd pregnancies) was associated with peripheral (p<0.001) and placental (p<0.001) malaria only in Bandiagara, whereas it was associated with low birth weight in both sites (p<0.001 in Koro and p=0.002 in Bandiagara). First and second pregnancies were the most important characteristics associated with placental malaria (RR=2.78, 95%CI 1.81-4.29) and (ARR=2.06, 95%CI 1.03-4.15) and low birth weight (RR=4.26, 95%CI 2.50-7.27) and (ARR=4.51, 95%CI 2.55-8.00). Birth during the rainy season was associated with placental infection in univariate analysis. Characteristics such as younger age, having fever during pregnancy, and unmarried status were associated with low birth weight only in univariate analysis and singleton premature delivery and low gravidity were associated with low birth weight in both univariate and multivariate analysis. Data from this assessment demonstrated the high burden of malaria during pregnancy in Mali. Results had been used by researchers as local reference data and by ministry of health for to stop recommending CQ prophylaxis. The methodology could be used by other malaria-endemic countries to direct their national malaria program efforts.

Urinary disease in 2 Dogon populations with different exposure to Schistosoma haematobium infection: progression of bladder and kidney diseases in children and adults.

BACKGROUND: Schistosoma haematobium infection causes severe urinary disease and considerable mortality. The factors that determine disease progression from mild to severe stages are not fully understood. METHODS: Here we describe a cross-sectional epidemiological study of kidney and bladder diseases in 2 Dogon populations with different exposure to S. haematobium infection. RESULTS: Early and high exposure resulted in more-severe disease, especially among young subjects, without clear evidence of a more-rapid development of immunity. Nevertheless, 50%-60% of subjects of all age classes in both villages showed no evidence of disease. Kidney and bladder disease peaked biphasically among young subjects and adults >25 years old. The first peak corresponded with infections of maximum intensity, whereas the second peak occurred among adults with infections of very low intensity. Kidney disease was correlated with circulating anodic antigen concentration in serum, whereas bladder disease was correlated with egg count and eosinophil cationic protein concentration in urine. Kidney and bladder disease did not correlate. Severe kidney disease was more frequent in certain families. CONCLUSIONS: The frequency of urinary disease is increased by infections acquired early during life, is regulated by strong clinical immunity in certain subjects, and may be dependent on hereditary factors. Kidney and bladder disease may involve different mechanisms of pathogenesis, which may differ between children and adults.

Comparison of intermittent preventive treatment with chemoprophylaxis for the prevention of malaria during pregnancy in Mali.

BACKGROUND: Malaria during pregnancy contributes to maternal anemia and low birth weight. In East Africa, several studies have demonstrated that intermittent preventive treatment (IPT) with sulfadoxine-pyrimethamine (SP) is more efficacious than weekly chloroquine (CQ) chemoprophylaxis in preventing these adverse consequences. To our knowledge, there are no published trials evaluating IPT in West Africa. METHODS: We undertook a randomized controlled trial of weekly CQ chemoprophylaxis, 2-dose IPT with CQ, and 2-dose IPT with SP; 1163 women were enrolled. RESULTS: In multivariate analyses, when compared with weekly CQ, IPT/SP was associated with a reduction in third-trimester anemia (adjusted odds ratio [AOR], 0.49; P<.001), placental parasitemia (AOR, 0.69; P=.04), and low birth weight (<2500 g) (AOR, 0.69; P=.04). The prevalence of placental infection remained unexpectedly high, even in the IPT/SP group (24.5%), possibly because of the intensity of seasonal transmission. There were no significant differences in stillbirths, spontaneous abortions, or neonatal deaths among the 3 groups. CONCLUSIONS: In Mali, IPT with SP appears more efficacious than weekly chloroquine chemoprophylaxis in preventing malaria during pregnancy. These data support World Health Organization recommendations to administer at least 2 doses of IPT during pregnancy. In intensely seasonal transmission settings in Mali, >2 doses may be required to prevent placental reinfection prior to delivery.