Testing the susceptibility of larval stages of Simulium to temephos and Bacillus thuringiensis var israelensis in Germany and Northern Cameroon.

Assays to evaluate the susceptibility of Simulium larvae to temephos and Bacillus thuringiensis var israelensis (Bti) were carried out by setting-up an in vitro laboratory test ('bio assay') and a semi-natural test ('système de goutières') to assess the LC50/LC90 values. Larvae of Simulium species in Cameroon (S. damnosum s.l., S. hargreavesi, S. vorax and S. cervicornutum) and (S. (Odagmia) ornatum and S. latipes) in Germany were identified and tested. In the bio-assay, 50 larvae were exposed for 10 min to concentrations from 0.01 to 10 ppm. For the Simulium from Germany, the LC50 (LC90) values after 3 and 6 h were 3.1 (27.9) and 0.14 (1.26) ppm for temephos and for Bti 7.8 (70.2) and 1.7 (15.3) ppm, respectively. For Cameroonian species, the values of LC50 (LC90) were lower, that is, 0.42 (8.04), 0.14 (2.70) and 0.073 (1.38) ppm, respectively, after 3, 6 and 12 h for temephos. In a semi natural condition, the LC50 of 10 min of application of temephos was 0.84 ppm after 3 h and a working solution (2.6 L) of Bti killed 50% after 6 h. To detect an upcoming of any resistance as it happened in Ivory Coast, a study of the occurrence resistance genes should be implemented.

The Spectrum of Childhood Tuberculosis in an African Setting: A Hospital-Based Experience in Bamenda, Cameroon.

OBJECTIVE: Difficulty in confirming childhood tuberculosis leads to late diagnosis and subsequently poor outcomes. This study aimsto determinethe epidemiology, clinical features, diagnostic modalities, and outcomes of childhood tuberculosis at the Bamenda Regional Hospital. MATERIALS AND METHODS: This was a retrospective study involving childrenaged between0-15 years with confirmed tuberculosis fromJanuary 1, 2012, to December 31, 2021. We excluded children without proven tuberculosis diagnosis. Data were obtained from files using predesigned data collection forms. RESULTS: In total, 108 proven cases of childhood tuberculosis were managed in our study period out of which 86 fulfilled our inclusion criteria and were recruited. This gave a prevalence of 4.5% at the Bamenda Regional Hospital. The mean age of the children was 9.6±4.5years. We had a sex ratio of 0.8. The most frequent presenting symptoms were cough (98.8%) and fever (87.2%). Gene Xpert confirmed the diagnosis in 96.2% of the children, smear microscopy in 88.5%, and histopathological analysis in 100% of biopsied specimens. Non-cavitating lesions (43.6%) were the most frequent chest x-ray finding. The majority of the childhood tuberculosis cases were pulmonary (96.5%). Most children (76.7%) were cured and the mortality was 11.3%. The risk of death of children younger than 5 years (P= .015)wasincreased 9 times. CONCLUSIONS: We found the prevalence of childhood tuberculosis to be 4.5% at the Bamenda Regional Hospital. Most children presented with cough, fever, and weight loss. There was a high cure rate and low mortality, and age less than 5 years significantly increased the risk of mortality.