Determinants of retention in care in an antiretroviral therapy (ART) program in urban Cameroon, 2003-2005

Background: Retention in long-term antiretroviral therapy (ART) program remains a major challenge for effective management of HIV infected people in sub-Saharan Africa. Highly Active Antiretroviral Therapy (ART) discontinuation raises concerns about drug resistance and could negate much of the benefit sought by ART programs. Methods: Based on existing patient records, we assessed determinants of retention in HIV care among HIV patients enrolled in an urban ART at two urban hospitals in Cameroon. Extended Cox regression  procedures were used to identify significant predictors of retention in HIV care. Results: Of 455 patients, 314 (69%) were women, median (IQR) age and baseline CD4 cell count were respectively 36 years (30 – 43) and 110 cells/μL (39 – 177). Forty patients (9%) had active tuberculosis (TB) at enrollment. After a median (IQR) follow-up of 18 months (10–18), 346 (75%) were still in care, 8 (2%) were known dead, and 101 (22%) were lost to follow-up (LFU). Severe immunosuppression (CD4 cell count ≤ 50 cells/μL) at baseline (aHR 2.3; 95% CI 1.4 - 3.7) and active tuberculosis upon enrollment (aHR 1.8; 95% CI 1.0 - 3.6) were independent predictors of cohort losses to follow-up within the first 6 months after HAART initiation. Conclusion: These data suggest that three-quarter of HIV patients initiated on HAART remained in care and on HAART by 18 months; however, those with compromised immunologic status at treatment initiation, and those co-infected with TB were at increased risk for being lost to follow-up within thefirst 6 months on treatment. Keywords: HIV, HAART, low income country, retention in care, loss to follow-up, cohort studies, Cameroon, sub-Sahara Afric

Chikungunya Virus, Cameroon, 2006

We report the isolation of chikungunya virus from a patient during an outbreak of a denguelike syndrome in Cameroon in 2006. The virus was phylogenetically grouped in the Democratic Republic of the Congo cluster, indicating a continuous circulation of a genetically similar chikungunya virus population during 6 years in Central Africa

ReBaStaBa: handling Bayesian networks with R

National audienc

Use of Bayesian modelling in risk assessment: Application to growth of Listeria monocytogenes and food flora in cold-smoked salmon

International audienceAn attempt to use a Bayesian approach to model variability and uncertainty separately in microbial growth in a risk assessment is presented. It was conducted within the framework of a French project aiming at assessing the exposure to Listeria monocytogenes in cold-smoked salmon. The chosen model describes the effect of time and temperature on bacterial growth. A Bayesian approach close to the one proposed by Pouillot et al. [Int. J. Food Microbiol. 81 (2003) 87] is used to estimate the variability and uncertainty of growth parameters from both literature data and data experimentally acquired during the project. Variability between strains and between products is taken into account. The growth of the food flora of cold-smoked salmon is also modelled by the same method. The results obtained for both models are used to predict the simultaneous growth of L. monocytogenes and food flora in cold-smoked salmon with a competitive model, expressing variability and uncertainty through a second-order Monte Carlo simulatio

Quantitative Risk Assessment of Listeria monocytogenes in French cold-smoked Salmon: II. Risk Characterization

International audienceA model for the assessment of exposure to Listeria monocytogenes from cold?smoked salmon consumption in France was presented in the first of this pair of articles (Pouillot et al., 2007, Risk Analysis, 27:683?700). In the present study, the exposure model output was combined with an internationally accepted hazard characterization model, adapted to the French situation, to assess the risk of invasive listeriosis from cold?smoked salmon consumption in France in a second?order Monte?Carlo simulation framework. The annual number of cases of invasive listeriosis due to cold?smoked salmon consumption in France is estimated to be 307, with a very large credible interval ([10; 12 453]), reflecting data uncertainty. This uncertainty is mainly associated with the dose-response model. Risk would be efficiently reduced through a decrease in the prevalence of L. monocytogenes or better control of the last steps of the cold?chain (shorter and/or colder storage during the consumer step). Reduction of the initial contamination levels of the contaminated products and improvement in the first steps of the cold?chain do not seem to be promising strategies for reducing the estimated risk. Despite the significant uncertainty associated with the predictions, this model provides a scientific base for risk managers and food business operators to manage the risk linked to cold-smoked salmon contaminated with Listeria moncytogenes and to apply the recent risk-based concept of risk management metrics illustrated here by the FSO (food safety objective)