High risk of virologic failure among HIV-infected children and adolescents routinely followed-up in Littoral region of Cameroon.

Virological response to antiretroviral therapy (ART) remains a challenge for HIV-infected children and adolescents due to non-optimization of pediatric ART for resource-limited settings. In this study, we aimed to investigate factors associated with virologic failure (VF) in HIV-infected-children and adolescents on ART in Cameroon. A prospective patient-based cohort study was conducted among HIV-infected children (0-9 years) and adolescents (10-19 years) followed-up between November 2018 and October 2019 in 38 healthcare centers located in the Littoral region of Cameroon. The 1st viral load (VL) was assessed after 6 months of ART initiation and the 2nd VL between 3 and 6 six months later in patients with VL ≥1000 copies/ml in accordance with the national algorithm using Abbott Real-Time HIV-1 Viral Load Assay. Multivariate analyses were performed to identify the determinants of higher risk of VF. Of 1,029 HIV-infected children and adolescents (393 children and 636 adolescents), 801 (77.8%) cumulatively presented with VL <1000 copies/mL within 12 months on ART. Adolescents were more likely to have VF than children (24.5% vs 18.3%, OR: 1.39; 95%CI: 1.00-1.93; p = 0.047). Patients followed-up in decentralized care units were significantly more likely to have VF compared to those attending the accredited treatment centers (26.1% vs 16.6%, OR: 1.88, 95%CI: 1.37-2.58; p<0.001). Our findings show a high rate of VL suppression (VLS, 77.8%) among HIV-infected children and adolescents, albeit lower than the established target of 90%. Being adolescent and patients followed in the decentralized care units are high risk factors for VF, thereby necessitating routine therapeutic education of patients and guardians in resource limited countries to improve VLS.

Effectiveness of Intermittent Preventive Treatment with Sulfadoxine-Pyrimethamine in Pregnancy: Low Coverage and High Prevalence of Plasmodium falciparum dhfr-dhps Quintuple Mutants as Major Challenges in Douala, an Urban Setting in Cameroon.

Intermittent preventive treatment in pregnancy with sulfadoxine and pyrimethamine (IPTp-SP) is a key component in the malaria control strategy implemented in Africa. The aim of this study was to determine IPTp-SP adherence and coverage, and the impact on maternal infection and birth outcomes in the context of widespread SP resistance in the city of Douala, Cameroon. Clinical and demographic information were documented among 888 pregnant women attending 3 health facilities, from the antenatal care visit to delivery. Positive samples were genotyped for P. falciparum gene (dhfr, dhps, and k13) mutations. The overall IPTp-SP coverage (≥three doses) was 17.5%, and 5.1% received no dose. P. falciparum prevalence was 16%, with a predominance of submicroscopic infections (89.3%). Malaria infection was significantly associated with locality and history of malaria, and it was reduced among women using indoor residual spraying. Optimal doses of IPTp-SP were significantly associated with reduced infection among newborns and women (secundiparous and multiparous), but there was no impact of IPTp-SP on the newborn bodyweight. Pfdhfr-Pfdhps quintuple mutants were over-represented (IRNI-FGKAA, IRNI-AGKAA), and sextuple mutants (IRNI-AGKAS, IRNI-FGEAA, IRNI-AGKGS) were also reported. The Pfk13 gene mutations associated with artemisinin resistance were not detected. This study highlights the role of ANC in achieving optimal SP coverage in pregnant women, the mitigated impact of IPTp-SP on malaria outcomes, and the high prevalence of multiple SP-resistant P. falciparum parasites in the city of Douala that could compromise the efficacy of IPTp-SP.

K-13 propeller gene polymorphisms isolated between 2014 and 2017 from Cameroonian Plasmodium falciparum malaria patients.

The emergence of artemisinin-resistant parasites since the late 2000s at the border of Cambodia and Thailand poses serious threats to malaria control globally, particularly in Africa which bears the highest malaria transmission burden. This study aimed to obtain reliable data on the current state of the kelch13 molecular marker for artemisinin resistance in Plasmodium falciparum in Cameroon. DNA was extracted from the dried blood spots collected from epidemiologically distinct endemic areas in the Center, Littoral and North regions of Cameroon. Nested PCR products from the Kelch13-propeller gene were sequenced and analyzed on an ABI 3730XL automatic sequencer. Of 219 dried blood spots, 175 were sequenced successfully. We identified six K13 mutations in 2.9% (5/175) of samples, including 2 non-synonymous, the V589I allele had been reported in Africa already and one new allele E612K had not been reported yet. These two non-synonymous mutations were uniquely found in parasites from the Littoral region. One sample showed two synonymous mutations within the kelch13 gene. We also observed two infected samples with mixed K13 mutant and K13 wild-type infection. Taken together, our data suggested the circulation of the non-synonymous K13 mutations in Cameroon. Albeit no mutations known to be associated with parasite clearance delays in the study population, there is need for continuous surveillance for earlier detection of resistance as long as ACTs are used and scaled up in the community.