Analysis of a tuberculosis model with undetected and lost-sight cases

International audienceA deterministic model of tuberculosis (TB) in sub-Saharan Africa including undetected and lost-sight cases is presented and analyzed. The model is shown to exhibit the phenomenon of backward bifurca-tion, when a stable disease-free equilibrium co-exists with one or more stable endemic equilibrium points when the associated basic reproduction number (R 0) is less than unity. Analyzing the model obviously reveals that exogenous reinfection plays a key role on the existence of backward bifurcation. However, an analysis of the ranges of exogenous reinfection suggested that backward bifurcation occurs only for very high and unrealistic ranges of the exogeneous reinfection rate. Random perturbation of reinfection rates was performed to gain insight into the role of this latter on the stability of the disease free equilibrium

Rifampicin resistance in new bacteriologically confirmed pulmonary tuberculosis patients in Cameroon: a cross-sectional survey

Abstract Objective In Cameroon, tuberculosis (TB) cases are diagnosed and treated within a nationwide network of 248 diagnostic and treatment centres. In 2016, the centers notified a total of 175 multidrug-resistant (MDR-)TB cases, most of them retreatment cases. According to the WHO, the expected number of MDR-TB cases was estimated to be 1200 (1000–2200) corresponding to a rate of 6.8 (4.3–9.4) per 100,000 population. This indicates a notification gap of more than 80%. The objective of this study was to estimate the prevalence of MDR-TB in new bacteriologically confirmed pulmonary TB cases. We undertook a nationwide cross sectional survey during 6 weeks. Results During the study period, the NTP notified 1478 new bacteriologically confirmed pulmonary TB cases. Among them, 1029 (70%) had a valid Xpert result and 16 were identified with rifampicin resistant (RR-TB), a tracer of MDR-TB. This gives a prevalence of 1.6% (95% CI 0.8–2.3) among incident cases. The rate of RR-TB in the regions varied between 0 and 3.3%. If the results of this study are confirmed, the incidence rate given by WHO (2.8%, 95% CI 2.1–3.4) might be an over-estimation