Improving quality of care and use of contraceptives in Senegal

In the 1990s, the government of Senegal implemented a series of policy changes for the provision of family planning services through the public sector. A strategy to provide high quality services through reference centres was adopted. This paper presents findings from a longitudinal survey of 1,320 Senegalese women who had sought family planning services at ten public sector facilities--five reference centres and five health centres. Information was collected on the quality of care they received at the time they adopted family planning. One thousand one hundred and ten of the respondents were followed up sixteen months later to ascertain their contraceptive status. The first principal finding was that attendees at reference centres reported receiving relative better care than those who attended health centres. On average, clients at reference centres received 4.3 out of five units of care, compared to 3.8 units as reported by health centre clients. Second, multivariate analyses indicated that quality of care received at the time of adopting a contraceptive has a significant influence on subsequent contraceptive use. Those who received good care were 1.3 times more likely to be using a method than others.     

Bionomics of Anopheles gambiae Giles,An. arabiensis Patton,An. funestus Giles and An. nili (Theobald) (Diptera: Culicidae) and transmission of Plasmodium falciparum in a Sudano-Guinean zone (Ngari,Senegal)

An entomological study was conducted in a village of Sudano-Guinean savanna in Senegal, during the rainy season from July to November 2001, to investigate the biology and the involvement of each anopheline species in malaria transmission. Mosquitoes were captured when landing on human volunteers and by pyrethrum spray catches. Twelve anopheline species were captured. Four species amounted to 97% of human-bait sampling: Anopheles gambiae molecular form S, An. arabiensis, An. funestus, and An. nili s.s. All An. gambiae and An. nili females were fed on human, whereas the anthropophilic rate was 94.5% for An. funestus and 88.9% for An. arabiensis. Plasmodium falciparum was the only malaria parasite found, and infecting only An. gambiae, An. arabiensis, An. funestus, and An. nili. The circumsporozoite rate was 4.5% for An. gambiae, 1.6% for An. arabiensis, 3.9% for An. funestus, and 2.1% for An. nili. During the period of study, the entomological inoculation rate was estimated to 264 infected bites. An. gambiae, An. arabiensis, An. funestus, and An. nili were responsible respectively of 56, 3, 20, and 21% of malaria transmission. This study shows for the first time the implication of An. nili in malaria transmission in this area and the complexity of the malaria vectorial system that should be taken into account for any malaria control strategy.     

Amplification of the sylvatic cycle of dengue virus type 2, Senegal, 1999-2000: entomologic findings and epidemiologic considerations

After 8 years of silence, dengue virus serotype 2 (DENV-2) reemerged in southeastern Senegal in 1999. Sixty-four DENV-2 strains were isolated in 1999 and 9 strains in 2000 from mosquitoes captured in the forest gallery and surrounding villages. Isolates were obtained from previously described vectors, Aedes furcifer, Ae. taylori, Ae. luteocephalus, and--for the first time in Senegal--from Ae. aegypti and Ae. vittatus. A retrospective analysis of sylvatic DENV-2 outbreaks in Senegal during the last 28 years of entomologic investigations shows that amplifications are periodic, with intervening, silent intervals of 5-8 years. No correlation was found between sylvatic DENV-2 emergence and rainfall amount. For sylvatic DENV-2 vectors, rainfall seems to particularly affect virus amplification that occurs at the end of the rainy season, from October to November. Data obtained from investigation of preimaginal (i.e., nonadult) mosquitoes suggest a secondary transmission cycle involving mosquitoes other than those identified previously as vectors.     

Delivery of the HIV-1 Tat protein to dendritic cells by the CyaA vector induces specific Th1 responses and high affinity neutralizing antibodies in non human primates

The human immunodeficiency virus type 1 (HIV-1) Tat is a key protein playing a major role in the infectivity of the virus. Thus, HIV-Tat based vaccines have been proposed as an attractive option to treat AIDS. Recently, we have shown that the recombinant detoxified adenylate cyclase (CyaA) from Bordetella pertussis carrying HIV-Tat (CyaA-E5-Tat), targets dendritic cells (DCs) and induces specific Th1 polarized and neutralizing antibody responses in mice. To further explore the potentialities of this prototype vaccine for human use, we analyzed the CyaA-E5-Tat induced antibody responses in non-human primates and established the biological characteristics of these antibodies. African Green Monkeys (AGM) were immunized with CyaA-E5-Tat in the presence or in the absence of alum adjuvant. First, we showed that the anti-CyaA antibodies induced by such immunization does not interfere with the binding of CyaA-E5-Tat to its receptor at the DC surface, the alphaMbeta2 integrin. Monkeys immunized with CyaA-E5-Tat, with or without alum, produced anti-Tat antibodies that mainly recognized the N-terminal domain of the Tat protein. Importantly, all sera obtained after three immunizations displayed the capacity to bind to Tat and neutralize its transactivating function in vitro. Finally, in the absence of alum, CyaA-E5-Tat, induced Th1 Tat specific T cell responses. These findings reveal that CyaA-E5-Tat is efficiently delivered in non-human primates and had a significant impact on the generation of neutralizing anti-Tat antibodies. These observations are, thus, encouraging for the use of the CyaA vector in human and also suggest that CyaA-E5-Tat might be a useful tool to decipher the biological characteristic of such antibodies.     

The presence of calbindin in rat cortical neurons protects in vitro from oxydative stress

Free radicals are highly reactive chemicals containing an unpaired electron and are normally produced by the cellular metabolism. The oxydative stress is defined as a lack of balance between the production of free radicals and the activity of antioxydant metabolites. It induces cellular damages to lipids, proteins and membranes. Abnormal calcium metabolism can be a consequence of oxydative stress leading to increased intracellular concentrations. Calbindin D₂₈K is a calcium binding protein which could have a neuroprotective action against various cellular insults. In this study rat cortical cell cultures were exposed during various times and at different concentrations to the couple Xanthine/Xanthine oxydase (XA/XO), which produces the superoxyde radical O₂⁻. Neuronal survival revealed that XA/XO is toxic for cortical cell cultures. The Calbindin D_28K immunocytochemical study shows that the percentages of Calbindin positive cells are greater in surviving neurons following the XA/XO exposure compared to controls. There is a time-dependent and a dose-dependent relation between the number of surviving neurons and the percentage of Calbindin positive neurons. These results suggest that the presence of cytosolic neuronal Calbindin D_28k is associated with a greater resistance to oxydative stress.