Short-term spontaneous fluctuations of HBV DNA levels in a Senegalese population with chronic hepatitis B.

BACKGROUND: We evaluated the short-term spontaneous fluctuations of HBV DNA and HBsAg levels in Senegalese patients with chronic infection with hepatitis B virus and normal ALT and determined factors related to these fluctuations. METHOD: A total of 87 patients with persistent normal ALT values were enrolled in the study. Serum samples were obtained at three different visits, with an interval of 2 months (M0, M2, and M4), and without initiating anti HBV treatment. Levels of HBV DNA, quantitative HBsAg, ALT and AST, genotyping and viral DNA mutations were analyzed. RESULTS: Among the 87 patients, genotype E was predominant (75%). The median HBV DNA level was 2.9 log10 IU/mL [2.2-3.4], 2.7 log10 IU/mL [2.1-3.6] and 2.7 log10 IU/mL [2.1-3.4] at M0, M2 and M4, respectively. The values ranged from <1.1 to 7 log10 IU/mL and 55 (63%) had HBV DNA fluctuations≥0.5 log10 IU/mL between two visits. Patients in whom HBV DNA fluctuated ≥0.5 log10 IU/mL between M0 and M2 also had significant fluctuations between M2 and M4, while patients with stable HBV DNA between M0 and M2 showed a stable viral load between M2 and M4. The only factor found to be associated with HBV DNA fluctuations≥0.5 log10 IU/mL was a low BMI (<21 kg/ m2). HBsAg levels were not correlated with HBV DNA levels. CONCLUSION: Sixty-three percent of the enrolled Senegalese population showed a large, short-term fluctuation of HBV DNA levels. Such fluctuations may have an impact on therapeutic management, requiring closer monitoring.

Operational impact of health problems observed during a four-month military deployment in Ivory Coast.

Diseases always have a significant impact during military deployments. We evaluated the operational impact of health problems observed in a French infantry battalion (n = 690) during a 4-month assignment in Ivory Coast. In all, 55.7% of soldiers consulted at least once and sought care for 608 health problems. A total operational incapacity was observed in 22.2% of cases (7.6/1,000 person-days). The 5 diseases causing the greatest operational incapacity were diarrhea (2.1 days lost/1,000 person-days), musculoskeletal diseases and injuries (53.7 days), malaria (29 days), dental diseases (30.9 days), and fevers of undetermined origin (7 days). The incidence of diarrhea and skin infections was higher in rank-and-file troops than among noncommissioned officers. It was also higher during the mission's first month, when individual susceptibility to infections is suspected to be highest. Some diseases that are not serious nonetheless have a significant operational impact and should be better studied to determine preventive measures.

[Current situation and future perspectives for malaria prophylaxis among travellers and military personnel]. / Situation actuelle et perspectives de la prophylaxie du paludisme chez le voyageur et dans les forces armées.

Malaria remains a major public health problem, both for travellers and for the 40,000 French soldiers deployed each year to endemic areas. Epidemiological data show that imported malaria (IM) is on the increase, and that migrants account for more than 60% of malaria cases notified each year in France. The increase in IM among French military personnel is explained by prematurely terminated chemoprophylaxis on return, repeated short missions, and more cases of P. vivax and P. ovale infection. The choice of chemoprophylaxis depends mainly on the level of chloroquine resistance in the country visited. The atovaquone-proguanil combination is well tolerated and only requires 7 days of intake on return from the endemic area. Doxycycline monohydrate is cheaper and better-tolerated than mefloquine, and is thus preferred for French military personnel. However, its short half-life necessitates very good compliance. Chemoprophylaxis should be combined with vector control measures and with personal protection (impregnated bednets, protective clothing, repellents, and indoor insecticide spraying). The need for these measures should be clearly explained before departure, during the stay, and after return.

Urban malaria in Dakar, Senegal: chemosusceptibility and genetic diversity of Plasmodium falciparum isolates.

The chemosusceptibility and genetic polymorphism of Plasmodium falciparum populations from 48 patients hospitalized for malaria at the Hospital Principal in Dakar, Senegal were investigated during the 2002 malaria transmission season. Sixty-two percent of the isolates collected were from patients with severe malaria and 38% were from patients with mild malaria. In vitro activities of chloroquine, quinine, cycloguanil, atovaquone, mefloquine, halofantrine, and artesunate were evaluated. The prevalence of mutations in the Plasmodium falciparum dihydrofolate reductase (dhfr) and dihyropteroate synthetase (dhps) genes and the P. falciparum chloroquine resistance transporter (Pfcrt) gene associated with cycloguanil, pyrimethamine, sulfadoxine, and chloroquine resistance were estimated. The genetic polymorphism of the parasite populations was evaluated by analysis of the highly polymorphic regions of merozoite surface protein 1 (msp1) block 2 and msp2. Seventy percent of the isolates were assessed by an in vitro assay. Fifty-two percent of the isolates were chloroquine resistant, 45% were cycloguanil resistant, and 24% were atovaquone resistant. Four percent had low susceptibility to quinine. The Pfcrt and dhfr mutations were associated with in vitro chloroquine- and antimetabolic drug-resistant isolates, respectively. Approximately 70% of the isolates contained two or more clones. Genetic diversity of P. falciparum was high. The prevalence of allelic family K1 of msp1 was 68%. Isolates of P. falciparum were highly resistant to chloroquine, cycloguanil and atovaquone. The transmission rate of malaria in Dakar is low but a high degree of genetic polymorphism can increase severe malaria, as shown by persons coming to Dakar from areas highly endemic for malaria. Areas with urban malaria should use vector control measures and efficient chemoprophylaxis for non-immune populations.

Molecular epidemiology of hepatitis B virus in Dakar, Sénégal.

Using DNA chip technology and real-time quantitative PCR, molecular profile of HBV strains infecting blood donors and patients in Dakar, Sénégal was studied. All HBsAg-positive blood donors (n = 175) and all patients who presented with chronic hepatitis B (n = 29) between 1st June 2003 and 31st July 2003 were studied. One patient, a blood donor, was coinfected by HCV, and nine patients had anti-HDV antibodies. Few persons in either group were HBeAg-positive. Viral load values were relatively low but correlated with biochemical abnormalities. Patients were infected mainly by genotype E (72%). Patients infected by genotype A (28%) tended to be younger than other patients. There was no significant difference between the blood donors and the patients with hepatitis B as regards virological markers, including viral load, when the HBV genotype was taken into account. The BCP A1762T and G1764A mutations were found in four patients and one patient, respectively; the two mutations were never found in the same patient. The W28* mutation at position 1896 of the core was detected in 19 of the 32 genotyped patients, 18 (83%) of whom had genotype E infection. ALT levels were not influenced by HBV mutations. This study shows a low frequency of clinical signs in HBsAg-positive blood donors, a relatively low level of viral replication, and a high frequency of pre-core mutants in this West African population. These results underline the importance of molecular characterization of HBV infection as specific treatments become available in this region.

Ischemic and hemorrhagic strokes in Dakar, Senegal: a hospital-based study.

BACKGROUND AND PURPOSE: Basic stroke features are hardly known in sub-Saharan countries, and no data are available in Senegal. METHODS: We performed a retrospective hospital-based study in Dakar, Senegal, to assess risk factors and etiology of stroke. Patients were recruited from January 1, 2003, to July 31, 2004, at the Hôpital Principal, Dakar. Strokes had to be ascertained by computed tomography. RESULTS: A total of 107 patients were studied. Seventy percent of strokes were of ischemic nature. For ischemic strokes, mean age was 64.2 years. Hypertension was the main risk factor, occurring in 68%, and diabetes was encountered in 37.3%. Lacunar strokes and cardioembolism accounted for 20% and 13.3%, respectively. Because of the lack of systematic investigations, two thirds of strokes were of undetermined origin. Mortality within 1 month was 38%. For hemorrhagic strokes, mean age was 51 years and 1 month mortality was 56%. CONCLUSIONS: Hypertension is the main risk factor for both ischemic and hemorrhagic strokes in this hospital-based study.