Drug resistance markers within an evolving efficacy of anti-malarial drugs in Cameroon: a systematic review and meta-analysis (1998-2020).

BACKGROUND: Malaria remains highly endemic in Cameroon. The rapid emergence and spread of drug resistance was responsible for the change from monotherapies to artemisinin-based combinations. This systematic review and meta-analysis aimed to determine the prevalence and distribution of Plasmodium falciparum drug resistance markers within an evolving efficacy of anti-malarial drugs in Cameroon from January 1998 to August 2020. METHODS: The PRISMA-P and PRISMA statements were adopted in the inclusion of studies on single nucleotide polymorphisms (SNPs) of P. falciparum anti-malarial drug resistance genes (Pfcrt, Pfmdr1, Pfdhfr, Pfdhps, Pfatp6, Pfcytb and Pfk13). The heterogeneity of the included studies was evaluated using the Cochran's Q and I2 statistics. The random effects model was used as standard in the determination of heterogeneity between studies. RESULTS: Out of the 902 records screened, 48 studies were included in this aggregated meta-analysis of molecular data. A total of 18,706 SNPs of the anti-malarial drug resistance genes were genotyped from 47,382 samples which yielded a pooled prevalence of 35.4% (95% CI 29.1-42.3%). Between 1998 and 2020, there was significant decline (P < 0.0001 for all) in key mutants including Pfcrt 76 T (79.9%-43.0%), Pfmdr1 86Y (82.7%-30.5%), Pfdhfr 51I (72.2%-66.9%), Pfdhfr 59R (76.5%-67.8%), Pfdhfr 108 N (80.8%-67.6%). The only exception was Pfdhps 437G which increased over time (30.4%-46.9%, P < 0.0001) and Pfdhps 540E that remained largely unchanged (0.0%-0.4%, P = 0.201). Exploring mutant haplotypes, the study observed a significant increase in the prevalence of Pfcrt CVIET mixed quintuple haplotype from 57.1% in 1998 to 57.9% in 2020 (P < 0.0001). In addition, within the same study period, there was no significant change in the triple Pfdhfr IRN mutant haplotype (66.2% to 67.3%, P = 0.427). The Pfk13 amino acid polymorphisms associated with artemisinin resistance were not detected. CONCLUSIONS: This review reported an overall decline in the prevalence of P. falciparum gene mutations conferring resistance to 4-aminoquinolines and amino alcohols for a period over two decades. Resistance to artemisinins measured by the presence of SNPs in the Pfk13 gene does not seem to be a problem in Cameroon. Systematic review registration PROSPERO CRD42020162620.

Vaccinators' Perception of HPV Vaccination in the Saa Health District of Cameroon.

Introduction: Cervical cancer is the second most prevalent cancer among women in Cameroon. In November 2020, the HPV vaccine was introduced into the expanded programme on immunisation. However, uptake of the vaccine has been slow in the Centre region as opposed to other regions in the country. We therefore sought to describe vaccinators' perception of HPV vaccination in Saa health district. Methods: A self-administered questionnaire with both open-ended and closed questions was used to assess the perception of HPV vaccination among 24 vaccinators from the Saa health district. Quantitative data were summarised as proportions while qualitative data were deductively and inductively coded and thematically analysed. Results: Most vaccinators (75%, n = 18) had a good knowledge about cervical cancer and HPV vaccination. Fourteen (58.3%, n = 14) vaccinators correctly reported the target group, number and spacing of doses for the HPV vaccine. Fourteen (58.3%) vaccinators favoured HPV vaccination while the others (n = 10) were sceptical. Sceptics felt manufacturers hadn't given enough proof of the safety of the vaccine and lacked confidence in government's assessment of the epidemiological situation. The COVID 19 pandemic, fear of infertility and the negative influence of social media were perceived as the main reasons for community hesitancy. Vaccinators criticised health authorities for failing to sensitise the population about the HPV vaccine before its introduction. Conclusion: Vaccinators' perceptions of HPV vaccination may influence the offer of HPV vaccination services. Measures to increase acceptance of HPV vaccination and ownership of the activity among vaccinators have to be put in place.

Toxicovigilance Systems and Practices in Africa.

African consumers and citizens are growingly aware of the wide range of toxic poisoning scenarios from different products and hazards. Recurrent episodes on poisoning that have been reported in Africa include toxic hazards in consumers' products ranging from food to herbal medicine, drugs, and cosmetics. Chemical poisoning remains an issue that is overlooked by public health stakeholders in Africa. Available information on toxicovigilance systems and practices in African countries is reviewed in terms of increasing development, organization and articulation levels. Less than nine out of 54 African countries have a legally recognized toxicovigilance system. Of these, the majority have created toxicovigilance systems recently, and are facing many challenges in developing them, at regional and country levels. Basic structures for a good toxicovigilance system include a phone line service (available 24/7), and hospital facilities. Pesticides emerge as the hazard recognized by all of the toxicovigilance systems, and may represent a prototypic toxicant towards a toxicovigilance system that is inclusive of a wider spectrum of toxicological hazards for the protection of community health. Toxicovigilance today is more reactive than preventive in Africa, but some milestones are present that constitute some promising seminal efforts.