Utility of plasma anti-gSG6-P1 IgG levels in determining changes in Anopheles gambiae bite rates in a rural area of Cameroon.

The applicability of the specific human IgG antibody response to Anopheles gambiae salivary Gland Protein-6 peptide 1 (gSG6-P1 salivary peptide) as a biomarker able to distinguish the level of exposure to mosquito bites according to seasonal variations has not yet been evaluated in Central African regions. The study aimed to provide the first reliable data on the IgG anti-gSG6-P1 response in rural area in Cameroon according to the dry- and rainy-season. Between May and December 2020, dry blood samples were collected from people living in the Bankeng village in the forest area of the Centre region of Cameroon. Malaria infection was determined by thick-blood smear microscopy and multiplex PCR. The level of IgG anti-gSG6-P1 response, was assessed by enzyme-linked immunosorbent assay. Anopheles density and aggressiveness were assessed using human landing catches. The prevalence of malaria infection remains significantly higher in the rainy season than in the dry season (77.57% vs 61.44%; p = 0.0001). The specific anti-gSG6-P1 IgG response could be detected in individuals exposed to few mosquito bites and showed inter-individual heterogeneity even when living in the same exposure area. In both seasons, the level of anti-gSG6-P1 IgG response was not significantly different between Plasmodium infected and non-infected individuals. Mosquito bites were more aggressive in the rainy season compared to the dry season (human biting rate-HBR of 15.05 b/p/n vs 1.5 b/p/n) where mosquito density was very low. Infected mosquitoes were found only during the rainy season (sporozoite rate = 10.63% and entomological inoculation rate-EIR = 1.42 ib/p/n). The level of IgG anti-gSG6-P1 response was significantly higher in the rainy season and correlated with HBR (p ˂ 0.0001). This study highlights the high heterogeneity of individual's exposure to the Anopheles gambiae s.l vector bites depending on the transmission season in the same area. These findings reinforce the usefulness of the anti-gSG6-P1 IgG response as an accurate immunological biomarker for detecting individual exposure to Anopheles gambiae s.l. bites during the low risk period of malaria transmission in rural areas and for the differentiating the level of exposure to mosquitoes.

Rationalizing artemisinin-based combination therapies use for treatment of uncomplicated malaria: A situation analysis in health facilities and private pharmacies of Douala 5e-Cameroon.

Artemisinin-based combination therapies (ACTs) represent one of the mainstays of malaria control. Despite evidence of the risk of ACTs resistant infections in resource-limited countries, studies on the rational use of ACTs to inform interventions and prevent their emergence and/or spread are limited. The aim of this study was designed to analyze practices toward ACTs use for treating the treatment of uncomplicated malaria (UM) in an urban community. Between November 2015 and April 2016, a cross-sectional and prospective study was conducted in the 6 health facilities and all pharmacies in the Douala 5e subdivision, Cameroon. Anonymous interviews including both open- and closed-ended questions were conducted with selected participants among drug prescribers, patients attending the health facilities, and customers visiting the pharmacies. Data analysis was performed using StataSE11 software (version 11 SE). A total of 41 prescribers were included in the study. All were aware of national treatment guidelines, but 37.7% reported not waiting for test results before prescribing an antimalarial drug, and the main reason being stock-outs at health facilities. Likewise, artemether+lumefantrine/AL (81%) and dihydroartemisinin+piperaquine (63.5%) were the most commonly used first- and second-line drugs respectively. Biological tests were requested in 99.2% (128/129) of patients in health facilities, 60.0% (74) were performed and 6.2% were rationally managed. Overall 266 (35%) of 760 customers purchased antimalarial drugs, of these, 261 (98.1%) agreed to participate and of these, 69.4% purchased antimalarial drugs without a prescription. ACTs accounted for 90.0% of antimalarials purchased from pharmacies, of which AL was the most commonly prescribed antimalarial drug (67.1%), and only 19.5% of patients were appropriately dispensed. The current data suggest a gap between the knowledge and practices of prescribers as well as patients and customers misconceptions regarding the use of ACTs in Douala 5e subdivision. Despite government efforts to increase public awareness regarding the use of ACTs as first-line treatment for UM, our findings point out a critical need for the development, implementation and scaling-up of control strategies and continuing health education for better use of ACTs (prescription and dispensing) in Cameroon.

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.

HIV, HBV, HCV and T. pallidum infections among blood donors and Transfusion-related complications among recipients at the Laquintinie hospital in Douala, Cameroon.

BACKGROUND: Transfusion-transmissible infections (TTIs) pose a major health risk in Cameroon given the high prevalence of such pathogens and increased demands for blood donations in the local communities. This study aims at establishing the prevalence of commonly encountered TTIs among blood donors and transfusion-related complications among recipients in an urban center of Cameroon. METHODS: A total of 477 blood donors and 83 blood recipients were recruited by consecutive sampling at the Laquintinie Hospital in Douala (LHD), Cameroon. Serum samples from blood donors were tested by quantitative enzyme-linked immunosorbent assays (ELISA) and/or using various Rapid diagnostic test (RDT) for presence of Hepatits B (HBV) viral antigens, and antibodies to human immunodeficiency (HIV-1/2), Hepatits B (HCV) and Treponema pallidum. Recipient's medical records were also analyzed for possible transfusion-associated complications. RESULTS: The male/female sex ratio of the blood donors was 4/1 with a mean age of 30.2 (Sd = 8.3) years. Of all blood donors, 64/467 (13.7%) were infected by at least one of the four TTIs. Infected volunteer donors represented 8.3% while infected family donors comprised 14.3% of the donor population. The prevalence of HCV, HIV, HBV and T. pallidum were 1.3%, 1.8%, 3.5%, and 8.1%, respectively. More than half of the blood recipients were female (78.3%) and the mean age was 20.6 (SD = 16.1) years. The causes of severe anemia indicative of transfusion in recipients varied with wards (postpartum hemorrhage, caesarean section, uterine or cervical lacerations, abortions, urinary tract infections, severe malaria, vaso-occlusive attacks, wounds and gastrointestinal bleeding). The most frequent complications were chills and hematuria, which represented 46.1% of all observed complications. Other complications such as nausea, vomiting, jaundice, sudden diarrhea, anxiety, tachycardia, or hyperthermia were also found in recipients. Three cases of deaths occurred during the study, including a girl of less than one year. CONCLUSION: This study confirms the presence of blood-borne infectious diseases in blood donors at the LHD, identifying T. pallidum as the greatest threat to blood safety in the region, and hematuria as the most common immunological complications in blood recipients.