The aim of this study was to investigate the status of trace metals (As, Cr, Cu, Ni, Pb, Fe, and Zn) and health and carcinogenic risk associated then in the Ebolowa Municipal Lake (EML) basin. To this end, 21 water samples were collected from the EML and its two tributaries, Mfoumou and Bengo\'o, and analyzed by Quantofix method (nanocolors and visiocolor ECO) by using the MACHEREY-NAGEL photometer. The data were processed using multivariate statistics. The results showed that all the physicochemical parameters (pH, EC, and TDS), with the exception of TDS, comply with were within WHO limits. The distribution of trace metals at the three sites investigated was as follows: Zn (80-400 ± 1.58 µg/L) > Cu (50-150 ± 9.38 µg/L) > Fe (10-40 ± 0.71 µg/L) > Pb (1-20 ± 3.02 µg/L) > As (1-9 ± 0.44 µg/L) > Ni (1-9 ± 1.48 µg/L). However, the highest values were observed in the EML and the Mfoumou River, where Pb pollution was noted. Statistical analysis showed that anthropogenic inputs increase the presence of Cr, Cu, Pb, and Zn. Trace Metal Pollution Index values were below 15 at all sites, illustrating low levels of pollution. The trace metal evaluation index values for the Bengo\'o stream are pure (mean = 0.6), slightly affected in the Mfoumou stream (mean = 2.0), and moderately affected in the EML (mean = 2.2). The toxicity load index values illustrate that the waters studied are toxic. The non-carcinogenic (HI) and carcinogenic (CR) health risk index values suggest a risk linked to oral ingestion in the LME and Mfoumou watercourses. The latter appears to be the main source of allochthonous pollutant input to the EML.

The Ebolowa Municipal Lake (EML) (South Cameroon) in order to identify the early diagenesis processes taking place in the lake and the factors influencing them. To this end, 21 samples were collected. In situ, hydrogen potential, redox potential, conductivity, dissolved oxygen content, and turbidity were measured. In the laboratory, the samples were subjected to mineralogical analysis by X-ray diffraction, geochemical analysis by X-ray fluorescence and ICP-MS, and statistical analysis. The coefficient of variation (Qi) was calculated from the geochemical data. In the water column, OD > 2 mg/L, pH > 7 and Eh < 0 mV. In sediments: pH < 7, Eh values are lower. The contents of 2.08 ≤ TOC ≤ 12.65%. The mineralogical procession consists of quartz, kaolinite, gibbsite, goethite, and siderite. The latter is only present in the EML. The sediments are dominated by SiO2 (60.44-89.47%), Al2O3 (6.55-18.17%), and Fe2O3 (1.15-6.21%). The Qi values range from 0.73 to 2.31. The Mn/Fe ratio values are below 0.40. Qi > 1 for Al, Fe, Mn, Mg, K, Na, P, Ni, Co, Zn, Pb, Cd, Cu, Ba, and V, and Qi < 1 for Si; Qi = 1 for Ca. The hierarchical cluster analysis shows two groups: the first one includes the samples from the central and western parts, while the second one includes those from the eastern and southern parts of the lake. The water column is subject to oxic conditions, while the sediments are anoxic. The rapid consumption of oxygen is due to organic mineralization, which is the main diagenesis observed in the lake. This phenomenon is more accentuated in the western part of the lake.

Monitoring the trend of insecticide resistance and understanding associated genetic mechanisms is important for designing efficient malaria vector control strategies. This study was conducted to provide temporal data on insecticide resistance status and mechanisms in the major malaria vector Anopheles gambiae s.l. from Ebolowa, Southern Cameroon. Methods: Larvae of An. gambiae s.l. were collected from typical breeding sites throughout the city and reared to adulthood. Emerging adults were morphologically identified and WHO tube assays were performed to determine their susceptibility to carbamate, organophosphate and pyrethroid insecticides at diagnostic doses. When resistance was observed, its intensity was determined by performing WHO tube tests using 5 and 10 times the concentration of the diagnostic dose. Metabolic resistance mechanisms were investigated using insecticide-synergist assays. Sibling species of the An. gambiae complex were identified using SINE-PCR protocol. TaqMan assay was used to genotype the L1014F and L1014S kdr mutations, and the N1575Y mutation, an amplifier of the resistance conferred by the L1014F mutation. Results: Anopheles coluzzii was by far the dominant (99%) member of the An. gambiae s.l. complex in Ebolowa. The species was fully susceptible to carbamates and organophosphates, but resistant to all pyrethroid insecticides tested. Resistance was of moderate intensity for deltamethrin (mortality: 37%, 70% and 99% for 1×, 5× and 10× insecticide concentration, respectively) but rather of high intensity for permethrin (5% for 1×; 62% for 5× and 75% for 10×) and for alphacypermethrin (4.4% for 1×; 57% for 5× and 80% for 10×). Pre-exposure to the synergist PBO resulted in a full recovery of the susceptibility to delthametrin, but this was not observed for the other two pyrethroids tested. L1014S (kdr-East) and the N1575Y mutations were absent, whereas the L1014F (kdr-West) mutation was present at a high frequency (75%), showing a significant association with resistance to permethrin (OR = 3.8; 95%; CI [1.9−7.4]; p < 0.0001) and alphacypermethrin (OR = 3; 95%; CI [1.6−5.4]; p = 0.0002). Conclusion: The increased resistance of An. gambiae s.l. to pyrethroid insecticides as observed in Ebolowa poses a threat to the efficacy of LLINs used to protect populations from the bites of Anopheles mosquitoes that transmit malaria parasites. The present study further highlights the urgent need to implement resistance management strategies in order to maintain the effectiveness of insecticide-based vector control interventions and prevent a rebound in malaria-related mortality.

UNASSIGNED: survival of HIV-infected children is a challenge in developing countries. In Cameroon, HIV-related mortality among children under the age of 15 in 2018 was 20%. Paradoxically, the Southern Cameroon region, despite high seroprevalence among children (4.1%) and low antiretroviral therapy coverage (around 64%), is not among the regions of Cameroon most affected by HIV/AIDS-related pediatric mortality. The purpose of this study was to calculate survival rate and to identify its determinants in HIV-infected children aged 6 months-15 years.
UNASSIGNED: we conducted a retrospective, prospective cohort study data-collection in three health care facilities specialized in treating HIV-positive children in Ebolowa, South Cameroon from January 2008 to December 2018. The study was conducted in two phases, a retrospective collection phase for the selection of medical records of HIV-positive children that met inclusion criteria in consultation registries and a prospective collection phase in which we collected information from parents about the future of children. Informed parental consent was obtained during this second phase. Socio-demographic, clinical, paramedical, therapeutic data as well as data about the future of children were collected. Mean survival time and factors associated with survival were determined using the Kaplan Meier model. Cox proportional hazards regression allowed for the identification of survival determinants. Evaluation criterion was the death. Significance level was set at 5%.
UNASSIGNED: a total of 186 patients were enrolled in the study: the average follow-up period was 18.5 months. Survival rate was 66.7%. The majority of deaths (67%) occurred before the sixth month of follow-up. After multivariate analysis, an age less than 2 years [aHR: 18.6 (6.48-53.59); p=0.001), severe anemia [aHR: 7.69 (1.02-57.9); p=0.04) and the presence of opportunistic infections [aHR: 4.52 (2.51-8.14); p=0.05] were independently and significantly associated with survival.
UNASSIGNED: in addition to early antiretroviral therapy, good clinical and paraclinical monitoring is needed to improve the survival of HIV-infected children.