Acute febrile illness is a common problem managed by clinicians and health systems globally, particularly in the Tropics. In many regions, malaria is a leading and potentially deadly cause of fever; however, myriad alternative etiologies exist. Identifying the cause of fever allows optimal management, but this depends on many factors including thorough knowledge of circulating infections. Arboviruses such as dengue (DENV) cause fever and may be underdiagnosed in sub-Saharan Africa where malaria is a major focus. We examined cases of fever in western Cameroon that tested negative for malaria and found 13.5% (13/96) were due to DENV, with 75% (9/12) of these being DENV serotype 2 infections. Two complete DENV2 genomes were obtained and clustered closely to recent isolates from Senegal and Burkina Faso. The seroprevalence of DENV in this region was 24.8% (96/387). Neutralizing antibodies to DENV2 were detected in all (15/15) seropositive samples tested. Chikungunya (CHIKV) is an arthritogenic alphavirus that is transmitted by Aedes mosquitoes, the same principal vector as DENV. The seroprevalence for CHIKV was 15.7% (67/427); however, CHIKV did not cause a single case of fever in the 96 subjects tested. Of note, being seropositive for one arbovirus was associated with being seropositive for the other (Χ2 = 16.8, p<0.001). Taken together, these data indicate that Aedes-transmitted arboviruses are endemic in western Cameroon and are likely a common but underappreciated cause of febrile illness. This work supports the need for additional study of arboviruses in sub-Saharan Africa and efforts to improve diagnostic capacity, surveillance systems, and arbovirus prevention strategies.

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

Background Many studies have reported high efficacy and safety of artesunate-amodiaquine (AS-AQ) and artemether-lumefantrine (AL) when administered under direct observation in Cameroon. There is paucity of data to support their continuous use in home-based treatment of uncomplicated Plasmodium falciparum malaria in Cameroon. Hence, this study aimed to assess the effectiveness and safety of AS-AQ versus AL for home-based treatment of uncomplicated P. falciparum malaria among children 6–120 months in Yaoundé, Cameroon. Methods A two-arm, open-label, randomized, controlled trial comparing the equivalence of AS-AQ (experimental group) and AL (control group) was carried out from May 2019 to April 2020 at two secondary hospitals in Yaoundé. Participants were randomized to receive either AS-AQ or AL. After the first dose, antimalarial drugs were given at home, rather than under direct observation by a study staff. The conventional on-treatment and post-treatment laboratory and clinical evaluations were not done until day 3 of the full antimalarial treatment course. The evaluation of effectiveness was mainly based on per protocol polymerase chain reaction adjusted adequate clinical and parasitological response (PP PCR adjusted ACPR) on day 28 post-treatment. Safety was based on assessment of adverse events (AEs) and severe adverse events (SAEs) from day 1 to day 28. Results A total of 242 children were randomized to receive AS-AQ (n = 114) and AL (n = 128). The PP PCR adjusted day 28 cure rates were [AS-AQ = 96.9% (95% CI, 91.2–99.4) versus AL = 95.5% (95% CI, 89.9–98.5), P = 0.797]. Expected mild to moderate adverse events were reported in both arms [AS-AQ = 83 (84.7%) versus AL = 99 (86.1%), P = 0.774]. The most common adverse events included: transient changes of hematologic indices and fever. Conclusions This study demonstrated that AS-AQ and AL are effective and safe for home management of malaria in Yaoundé. The evidence from this study supports the parallel use of the two drugs in routine practice. However, the findings from this study do not describe the likely duration of antimalarial effectiveness in holoendemic areas where multiple courses of treatment might be required. Trial registration: This study is a randomized controlled trial and it was retrospectively registered on 23/09/2020 at ClinicalTrials.gov with registration number NCT04565184.