A public health development intervention between acceptability and feasibility: descriptive-interpretive discussion of an example.

Introduction: the National Tuberculosis Control Program (NTP) in Cameroon participated between 2016 and 2018 in a multi-country operational study of the Union against Tuberculosis and Lung Disease (The UNION) aiming at demonstrating the efficiency and feasibility of systematic tuberculosis preventive treatment (TPT) with 3 months of an isoniazid/rifampicin (3RH) combination in under-five child contacts of bacilliferous TB patients. Cameroon was one of the participating countries of the study. Despite the promising results communicated following this study, the coverage of TPT with 3RH in Cameroon remains low. We explored the intervention under aspects of acceptability and perceived feasibility. Methods: key participants and stakeholders in this descriptive interpretative study in Cameroon were interviewed in five focus groups or individually (31 individuals). The Focus Group Discussion (FGD) and interview transcripts were analysed for different components of acceptability using a theoretical framework and the results discussed confronting them with the main objective of the study, i.e. demonstrating feasibility. Results: the children's parents expressed overall positive feelings about and acceptance of the intervention, emphasizing the unexpected empathy shown by the health staff. The involved field staff, too, showed unreserved acceptance. On the other hand, managers at the intermediate and central levels showed scepticism as to the process of initiation of the study as well as to its feasibility in the given context, neglecting aspects of resources necessary for a scaling-up and of prioritisation. Conclusion: the adoption of a public health strategy, also internationally recognized as an effective and efficient intervention, requires more than the demonstration of its acceptability or feasibility during the term of a showcase project introduced by an external development partner. Adoption is conditioned by adoption and circumspect planning involving at each stage the stakeholders on all levels of the program.

Generating the evidence to support the establishment of a Respiratory Syncytial Virus surveillance system in Cameroon: A study protocol.

BACKGROUND: Respiratory syncytial virus (RSV) is one of the major pathogens frequently associated with severe respiratory tract infections in younger children and older adults globally. There is an unmet need with a lack of routine country-specific databases and/or RSV surveillance systems on RSV disease burden among adults in most low- and middle-income countries, including Cameroon. We aim to estimate the adult RSV burden needed to develop a framework for establishing an RSV surveillance database in Cameroon. METHODS AND ANALYSIS: A two-phase study approach will be implemented, including a literature review and a review of medical records. First, a systematic review of available literature will provide insights into the current burden of RSV in adults in Cameroon, searching the following databases: Global Health, PubMed, CINAHL, Embase, African Journal Online Library, Scopus, Global Index Medicus, Cochrane databases, and grey literature search. Identified studies will be included if they reported on the RSV burden of disease among Cameroonian adults aged ≥18 years from 1st January 1990 to 31st December 2023. A narrative synthesis of the evidence will be provided. A meta-analysis will be conducted using a random effect model, when feasible. Two co-authors will independently perform data screening, extraction, and synthesis and will be reported according to the PRISMA-P guidelines for writing systematic review protocols. Secondly, a retrospective cohort design will permit data analysis on RSV among adults in the laboratory registers at the National Influenza Center. Medical records will be reviewed to link patients' files from emanating hospitals to capture relevant demographic, laboratory, and clinical data. The International Classification of Diseases and Clinical Modifications 10th revision (ICD-10-CM) codes will be used to classify the different RSV outcomes retrospectively. RESULTS: The primary outcome is quantifying the RSV burden among the adult population, which can help inform policy on establishing an RSV surveillance database in Cameroon. The secondary outcomes include (i) estimates of RSV prevalence among Cameroonian adult age groups, (ii) RSV determinants, and (iii) clinical outcomes, including proportions of RSV-associated morbidity and/or death among age-stratified Cameroonian adults with medically attended acute respiratory tract infections. CONCLUSIONS: The evidence generated from the two projects will be used for further engagement with relevant stakeholders, including policymakers, clinicians, and researchers, to develop a framework for systematically establishing an RSV surveillance database in Cameroon. This study proposal has been registered (CRD42023460616) with the University of York Center for Reviews and Dissemination of the International Prospective Register of Systematic Reviews (PROSPERO).

Identifying opportunities for global surgery in Cameroon: an analysis of existing health policies and events.

Introduction: the burden of diseases amenable to surgery, obstetrics, trauma, and anesthesia (SOTA) care is increasing globally but low- and middle-income countries are disproportionately affected. The Lancet Commission on Global Surgery proposed National Surgical, Obstetrics, and Anesthesia Plans as national policies to reduce the global SOTA burden. These plans are dependent on comprehensive stakeholder engagement and health policy analysis. Objective: in this study, we analyzed existing national health policies and events in Cameroon to identify opportunities for SOTA policies. Methods: we searched the Cameroonian Ministry of Health´s health policy database to identify past and current policies. Next, the policies were retrieved and screened for mentions of SOTA-related interventions using relevant keywords in French and English, and analyzed using the 'eight-fold path´ framework for public policy analysis. Results: we identified 136 policies and events and excluded 16 duplicates. The health policies and events included were implemented between 1967 and 2021. Fifty-nine policies and events (49.2%) mentioned SOTA care: governance (n=25), infrastructure (n=21), service delivery (n=11), workforce (n=11), information management (n=10), and funding (n=8). Most policies and events focused on maternal and neonatal health, followed by anesthesia, ophthalmologic surgery, and trauma. National, multinational civil society organizations and private stakeholders supported these policies and events, and the Cameroonian Ministry of Public Health was the largest funder. Conclusion: most Cameroonian SOTA-related policies and events focus on maternal and neonatal care, and health financing is the health system component with the least policies and events. Future SOTA policies should build on existing strengths while improving neglected areas, thus attaining shared global and national goals by 2030.

Dietary risk assessment of drinking water and fish from cultivated wetlands of Ndop.

This study evaluated pesticide exposure practices, and the potential health risks of drinking water and consuming fish from the cultivated wetlands of Ndop, Cameroon. Six hundred and twenty-six questionnaires were conveniently administered to farmers (≥ 26 years old) in a cross-sectional study to assess exposure practices and dietary risks. The Chi-square and Pearson correlation coefficients were used to establish relationships between variables. The PRIMET model was used to predict a worst-case dietary risk. The pesticide handling practices of 90% of farmers were inadequate. Chlorpyriphos, lambda-cyhalothrin, fipronil, and paraquat dichloride posed a possible dietary risk at recommended and applied doses, with chlorpyrifos having the highest exposure toxicity ratio (ETRdiet = 36.72). Paraquat dichloride, fipronil, and lambda-cyhalothrin posed a possible dietary risk at 26.3%, 58.3%, and 62.2% of their recommended concentrations, respectively. Remarkably, the dietary risk for cypermethrin was acceptable at 5.8 times its recommended dose (ETRdietR = 0.29). The significant positive correlation (p = 0.000) between PECfish and ETRdiet, suggests a possible health risk of consuming fish and drinking water harvested from the wetlands, thus the need for replacing pesticides posing possible risks at lower or recommended concentrations with less toxic alternatives and to train farmers on pesticide application practices.

Mother-Child Approach to Cervical Cancer Prevention in a Low Resource Setting: The Cameroon Baptist Convention Health Services Story.

INTRODUCTION: The rates of cervical cancer screening in Cameroon are unknown and HPV vaccination coverage for age-appropriate youths is reported at 5%. OBJECTIVES: To implement the mother-child approach to cervical cancer prevention (cervical screening by HPV testing for mothers and HPV vaccination for daughters) in Meskine, Far North, Cameroon. METHODS: After the sensitization of the Meskine-Maroua region using education and a press-release by the Minister of Public Health, a 5-day mother-child campaign took place at Meskine Baptist Hospital. The Ampfire HPV Testing was free for 500 women and vaccination was free for age-appropriate children through the EPI program. Nurses trained in cervical cancer education conducted group teaching sessions prior to having each woman retrieve a personal sample. Self-collected samples were analyzed for HPV the same day. All women with positive tests were assessed using VIA-VILI and treated as appropriate for precancers. RESULTS: 505 women were screened, and 92 children vaccinated (34 boys and 58 girls). Of those screened, 401 (79.4%) were aged 30-49 years old; 415 (82%) married; 348 (69%) no education. Of the HPV positive cases (101): 9 (5.9%) were HPV 16, 11 (10.1%) HPV 18, 74 (73%) HPV of 13 other types. Those who were both HPV and VIA-VILI positive were treated by thermal ablation (63%) or LEEP (25%). CONCLUSION: The mother-child approach is an excellent method to maximize primary and secondary prevention against cervical cancer.

Epidemiology of Tinea Capitis Among School-Children in Dschang, Western Cameroon.

Data on the epidemiology of tinea capitis (TC), an infection of the scalp by dermatophytes, are scarce in Cameroon. This study aimed to determine the prevalence of TC among school-children in the Dschang Subdivision, Western Cameroon. A cross-sectional study was carried out in June 2021 in Dschang including pupils aged 5-13. First, a standardized questionnaire was administered to participant for the collection of sociodemographic data. Then, samples were collected and cultured onto Sabouraud-Chloramphenicol-Gentamicin Agar. The etiological agents were identified based on their morphological features and with MALDI-TOF mass spectrometry. A total of 1070 children were clinically examined and 108 (10.1%) children presented with TC lesions. The mean age of the 1070 participants was 8.3 ± 2.6 years (range: 5-13 years); 772 (72.2%) were males. The use of borehole water (OR = 0.01, 95%CI[0.001-0.03]), spring water (OR = 0.2, 95%CI[0.08-0.50]), rainwater (OR = 0.004, 95%CI[0.001-0.016]), and hairdressing salons visits (OR = 0.413, 95%CI[0.196-0.872]) were associated with a decreased TC risk in the multivariate logistic regression analysis. In contrast, sharing bed with siblings (OR = 4.48, 95%CI[2.095-9.60]) was associated with an increased TC risk in children. Among the 32 dermatophytes isolated in culture, Microsporum audouinii was the most frequent (43.8%), followed by Trichophyton rubrum (25.0%) and T. soudanense (25.0%). Microsporum canis and T. violaceum were both rarely isolated. Further studies are warranted to assess the association of TC with domestic water usage that has been highlighted in this study.

Genetic tracing of the illegal trade of the white-bellied pangolin (Phataginus tricuspis) in western Central Africa.

The white-bellied pangolin is subject to intense trafficking, feeding both local and international trade networks. In order to assess its population genetics and trace its domestic trade, we genotyped 562 pangolins from local to large bushmeat markets in western central Africa. We show that the two lineages described from the study region (WCA and Gab) were overlapping in ranges, with limited introgression in southern Cameroon. There was a lack of genetic differentiation across WCA and a significant signature of isolation-by-distance possibly due to unsuspected dispersal capacities involving a Wahlund effect. We detected a c. 74.1-82.5% decline in the effective population size of WCA during the Middle Holocene. Private allele frequency tracing approach indicated up to 600 km sourcing distance by large urban markets from Cameroon, including Equatorial Guinea. The 20 species-specific microsatellite loci provided individual-level genotyping resolution and should be considered as valuable resources for future forensic applications. Because admixture was detected between lineages, we recommend a multi-locus approach for tracing the pangolin trade. The Yaoundé market was the main hub of the trade in the region, and thus should receive specific monitoring to mitigate pangolins' domestic trafficking. Our study also highlighted the weak implementation of CITES regulations at European borders.

Prevalence and associated factors of coexisting forms of malnutrition in children under 5 years age in a rural area of Cameroon.

BACKGROUND: Malnutrition of children under 5 years of age is persistent in Cameroon principally in rural areas. Moreover, there is limited knowledge of coexisting forms of malnutrition (CFM) among children of this age. Therefore, the aim of this study was to assess the prevalence of CFM in a cohort of children under 5 years and to identify the associated factors. METHODS: A cross-sectional study was conducted in the Health Districts of the locality of Dschang in the West region of Cameroon between June 2021 to November 2021. Data were collected from 200 under-five children of both sexes and an interviewer-administered questionnaire was administered to consented children's mothers/guardians. Malnutrition in children was assessed by WHO growth standards (weight-for-height, weight-for-age, height-for-age and body mass index-for-age). The different CFM were defined by the presence of two autonomous forms of malnutrition in the same child. Logistic regression analyses were done to identify factors associated to different coexisting forms of malnutrition. RESULTS: The results obtained showed prevalences of 4.20% for the coexistence of underweight with wasting, 7.8% for the coexistence of underweight with stunting and 14.8% for the coexistence of stunting with overweight. Lower maternal age (15-24 years old; OR = 0.09; p = 0.05) and lower education level (primary education, OR = 23.33; p = 0.00) were associated with the coexistence of underweight with wasting. Marital status (single mother, OR = 0.28; p = 0.00) was associated to the coexistence of stunting with overweight/obesity. CONCLUSION: The findings of this study provide evidence on the coexistence of different forms of malnutrition among children below five years of age in rural area of Cameroon. These finding would guide future research, policies, and programs on the management of malnutrition in rural areas of Cameroon.

Parallel multi-criteria decision analysis for sub-national prioritization of zoonoses and animal diseases in Africa: The case of Cameroon.

The use of multi-criteria decision analysis (MCDA) for disease prioritization at the sub-national level in sub-Sahara Africa (SSA) is rare. In this research, we contextualized MCDA for parallel prioritization of endemic zoonoses and animal diseases in The Adamawa and North regions of Cameroon. MCDA was associated to categorical principal component analysis (CATPCA), and two-step cluster analysis. Six and seven domains made of 17 and 19 criteria (out of 70) respectively were selected by CATPCA for the prioritization of zoonoses and animal diseases, respectively. The most influencing domains were "public health" for zoonoses and "control and prevention" for animal diseases. Twenty-seven zoonoses and 40 animal diseases were ranked and grouped in three clusters. Sensitivity analysis resulted in high correlation between complete models and reduced models showing the robustness of the simplification processes. The tool used in this study can be applied to prioritize endemic zoonoses and transboundary animal diseases in SSA at the sub-national level and upscaled at the national and regional levels. The relevance of MCDA is high because of its contextualization process and participatory nature enabling better operationalization of disease prioritization outcomes in the context of African countries or other low and middle-income countries.

Predictive values of an immunological fecal occult blood test for the diagnosis of colorectal cancer compared using colonoscopy in symptomatic patients in Yaounde (Cameroon).

INTRODUCTION: The predictive value of immunological fecal occult blood (iFOB) testing for the screening of colorectal cancer has been well described in the Western world. However, its relevance in Sub-Saharan Africa (SSA) is not well evaluated. It could be altered by the other causes of lower gastrointestinal bleeding such as parasitic infections. The aim of this study was to highlight the performance of an iFOB test for the prediction of colorectal cancer (CRC) during colonoscopy in SSA. METHODOLOGY: We conducted an analytical cross-sectional study in two digestive endoscopic centers of Yaoundé (Cameroon) from the 1st July to the 31 November 2022. Patients presenting with an indication for colonoscopy without any overt gastrointestinal bleeding were included. Sociodemographic and clinical data were collected. All consenting patients underwent a qualitative immunologic occult test through the iFOB test before colonoscopy. Data were analyzed using SPSS version 23.0 software. The performance of the iFOB test for the diagnosis of CRC during colonoscopy was evaluated in terms of sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV). RESULTS: We included 103 patients during the study period with a male predominance and a sex ratio of 1.7. The median age [IQR] was 52 [38-65] years (range 1 - 84 years). The most common colonoscopic lesions were polyps in 23 patients (22.3%), CRC in 17 patients (16.5%) and hemorrhoids in 15 patients (14.6%). Patients testing positive for iFOB test accounted for 43.7% (45 patients). Among these patients, 31.1% (14 patients) had a CRC. The Se of the occult blood test for CRC detection was calculated to be 82.3% (95%CI: 56.7-96.2); the Sp was 63.9% (95% CI: 53-74); the PPV was 31.1% (95% CI: 24-39) and the NPV was 94.8% (95% CI: 86.6-98.1). CONCLUSION: The iFOB test has a good NPV, but a poor PPV for the diagnosis of CRC in our study.

[Thyroid surgery in a context of scarce resources at Saint Martin de Porres Dominican Hospital (Yaounde, Cameroon)]. / Chirurgie thyroïdienne dans le contexte de populations avec de faibles ressources à l'hôpital dominicain Saint Martin de Porres (Yaoundé, Cameroun).

Introduction: Surgical campaigns for thyroid surgery in low-income environments are very efficient, but there is little literature reporting results. These campaigns are complex due to multiple particularities: highly evolved cases, the need for professionals to travel or an obvious socio-cultural barrier influence towards the surgical act. We describe a surgical campaign in Cameroon to treat patients with goiter and issue some medical and sociocultural recommendations in view of our experience for its implementation with guarantees. Material and methods: An experienced group carried out an 11-day campaign at the Saint Martin de Porres Dominican Hospital, Yaounde, Cameroon. Demographic data, TSH values, surgery and complications after a 12-month follow-up were analyzed. Results: Thirty-eight patients with goiter were selected for the campaign and 32 patients (mean age, 40-years-old; 30 females) were operated. Bilateral goiter, as assessed with echography, was diagnosed in 13 patients (41%). Ten patients (31%) had a WHO grade II goiter (visible with the neck in a normal position). The surgical procedures were 18 unilateral thyroidectomy with isthmectomie, 13 total thyroidectomy, and 1 totalizing thyroidectomy, due to previous unilateral thyroidectomy (cancer recurrence). A pathological study in 13 patients (40%, extra cost 60 €) showed benign multinodular goiter/thyroid nodule (12 patients) and an extensive papillary carcinoma (one patient). Six months postoperatively, 3 patients had a slight dysphonia and one patient had persistent hypocalcemia. Follow-up was completed in all patients, either face to face (75%, 24 patients) or by phone (25%, 8 patients who failed to have a TSH test because of its cost, 23 €). Conclusions: Surgical campaigns to treat thyroid pathology can be carried out with guarantees if a series of important steps are followed: active participation of the patient's environment, thyroid ultrasound by the surgical team to decide which technique, intense awareness about monitoring and hormone replacement therapy, and the participation of local personnel for long-term follow-up.

Partial spike gene sequencing for the identification of SARS-CoV-2 variants circulating in Cameroon in 2021.

INTRODUCTION: Global monitoring of severe acute respiratory syndrome related coronavirus 2 (SARS-CoV-2) genetic sequences and associated metadata is essential for coronavirus disease 2019 (COVID-19) response. Therefore, Sanger's partial genome sequencing technique was used to monitor the circulating variants of SARS-CoV-2 in Cameroon. METHODOLOGY: Nasopharyngeal specimen was collected from persons suspected of SARS-CoV-2 following the national guidelines between January and December 2021. All specimens with cycle threshold (Ct) below 30 after amplification were eligible for sequencing of the partial spike (S) gene of SARS-CoV-2 using the Sanger sequencing method. RESULTS: During the year 2021, 1481 real time reverse transcriptase polymerase chain reaction (RT-PCR) SARS-CoV-2 positive samples were selected for partial sequencing of the S gene of SARS-CoV-2. Amongst these, 878 yielded good sequencing products. A total of 231 probable variants (26.3%) were identified. The variants were mainly represented by Delta (70.6%), Alpha (15.6%), Omicron (7.4%), Beta (3.5%), Mu (1.7%) and Gamma (0.4%). Phylogenetic analysis of the probable variants from Cameroon with reference strains confirmed that all prior and current variants of concern (VOC) clustered with their respective reference sequences. CONCLUSIONS: The surveillance strategy implemented in Cameroon, based on partial sequencing of the S gene enabled identification of the major circulating variants and provided information on the distribution of these variants, which contributed to implementing public health measures to control disease spread in the country.

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.

Acceptability of artificial intelligence for cervical cancer screening in Dschang, Cameroon: a qualitative study on patient perspectives.

BACKGROUND: Cervical cancer is the fourth most frequent cancer among women, with 90% of cervical cancer-related deaths occurring in low- and middle-income countries like Cameroon. Visual inspection with acetic acid is often used in low-resource settings to screen for cervical cancer; however, its accuracy can be limited. To address this issue, the Swiss Federal Institute of Technology Lausanne and the University Hospitals of Geneva are collaborating to develop an automated smartphone-based image classifier that serves as a computer aided diagnosis tool for cancerous lesions. The primary objective of this study is to explore the acceptability and perspectives of women in Dschang regarding the usage of a screening tool for cervical cancer relying on artificial intelligence. A secondary objective is to understand the preferred form and type of information women would like to receive regarding this artificial intelligence-based screening tool. METHODS: A qualitative methodology was employed to gain better insight into the women's perspectives. Participants, aged between 30 and 49 were invited from both rural and urban regions and semi-structured interviews using a pre-tested interview guide were conducted. The focus groups were divided on the basis of level of education, as well as HPV status. The interviews were audio-recorded, transcribed, and coded using the ATLAS.ti software. RESULTS: A total of 32 participants took part in the six focus groups, and 38% of participants had a primary level of education. The perspectives identified were classified using an adapted version of the Technology Acceptance Model. Key factors influencing the acceptability of artificial intelligence include privacy concerns, perceived usefulness, and trust in the competence of providers, accuracy of the tool as well as the potential negative impact of smartphones. CONCLUSION: The results suggest that an artificial intelligence-based screening tool for cervical cancer is mostly acceptable to the women in Dschang. By ensuring patient confidentiality and by providing clear explanations, acceptance can be fostered in the community and uptake of cervical cancer screening can be improved. TRIAL REGISTRATION: Ethical Cantonal Board of Geneva, Switzerland (CCER, N°2017-0110 and CER-amendment n°4) and Cameroonian National Ethics Committee for Human Health Research (N°2022/12/1518/CE/CNERSH/SP). NCT: 03757299.

Globally, cervical cancer is the fourth most frequent cancer among women. However, 90% of all deaths caused by cervical cancer occur in low-and middle-income countries. Methods traditionally used in settings like Cameroon to detect cervical cancer unfortunately lack accuracy. Therefore, researchers at the Swiss Federal Institute of Technology Lausanne and the University Hospitals of Geneva are developing an artificial intelligence-based computer aided diagnosis tool to detect pre-cancerous lesions using a smartphone application. The aim of this study was to explore the acceptability and perspectives regarding an AI-based tool for cervical cancer screening for women in Dschang, a city in the west of Cameroon. A qualitative methodology was conducted with six focus groups and a total of 32 participants. The main concerns highlighted by the study are related to privacy, trust in the ability of the healthcare providers, accuracy of the tool as well as the potential negative impact of smartphones. In conclusion, our results show that a computer aided diagnosis tool using artificial intelligence is mostly acceptable to women in Dschang, as long as their confidentiality is preserved, and they are provided with clear explanations beforehand.

Identifying critical growth stage and resilient genotypes in cowpea under drought stress contributes to enhancing crop tolerance for improvement and adaptation in Cameroon.

Drought stress following climate change is likely a scenario that will have to face crop growers in tropical regions. In mitigating this constraint, the best option should be the selection and use of resilient varieties that can withstand drought threats. Therefore, a pot experiment was conducted under greenhouse conditions at the Research and Teaching Farm of the Faculty of Agronomy and Agricultural Sciences of the University of Dschang. The objectives are to identify sensitive growth stage, to identify drought-tolerant genotypes with the help of yield-based selection indices and to identify suitable selection indices that are associated with yield under non-stress and stress circumstances. Eighty-eight cowpea genotypes from the sahelian and western regions of Cameroon were subjected to drought stress at vegetative (VDS) and flowering (FDS) stages by withholding water for 28 days, using a split plot design with two factors and three replications. Seed yields under stress (Ys) and non-stress (Yp) conditions were recorded. Fifteen drought indices were calculated for the two drought stress levels against the yield from non-stress plants. Drought Intensity Index (DII) under VDS and FDS were 0.71 and 0.84 respectively, indicating severe drought stress for both stages. However, flowering stage was significantly more sensitive to drought stress compared to vegetative stage. Based on PCA and correlation analysis, Stress Tolerance Index (STI), Relative Efficiency Index (REI), Geometric Mean Productivity (GMP), Mean Productivity (MP), Yield Index (YI) and Harmonic Mean (HM) correlated strongly with yield under stress and non-stress conditions and are therefore suitable to discriminate high-yielding and tolerant genotypes under both stress and non-stress conditions. Either under VDS and FDS, CP-016 exhibited an outstanding performance under drought stress and was revealed as the most drought tolerant genotype as shown by ranking, PCA and cluster analysis. Taking into account all indices, the top five genotypes namely CP-016, CP-021, MTA-22, CP-056 and CP-060 were identified as the most drought-tolerant genotypes under VDS. For stress activated at flowering stage (FDS), CP-016, CP-056, CP-021, CP-028 and MTA-22 were the top five most drought-tolerant genotypes. Several genotypes with insignificant Ys and irrelevant rank among which CP-037, NDT-001, CP-036, CP-034, NDT-002, CP-031, NDT-011 were identified as highly drought sensitive with low yield stability. This study identified the most sensitive stage and drought tolerant genotypes that are proposed for genetic improvement of cowpea.

Phenotypic changes of γδ T cells in Plasmodium falciparum placental malaria and pregnancy outcomes in women at delivery in Cameroon.

Introduction: Depending on the microenvironment, γδ T cells may assume characteristics similar to those of Th1, Th2, Th17, regulatory T cells or antigen presenting cells. Despite the wide documentation of the effect of Th1/Th2 balance on pregnancy associated malaria and outcomes, there are no reports on the relationship between γδ T cell phenotype change and Placental Malaria (PM) with pregnancy outcomes. This study sought to investigate the involvement of γδ T cells and its subsets in placental Plasmodium falciparum malaria. Methods: In a case-control study conducted in Yaoundé, Cameroon from March 2022 to May 2023, peripheral, placental and cord blood samples were collected from 50 women at delivery (29 PM negative: PM- and 21 PM positive: PM+; as diagnosed by light microscopy). Hemoglobin levels were measured using hemoglobinometer. PBMCs, IVBMCs and CBMCs were isolated using histopaque-1077 and used to characterize total γδ T cell populations and subsets (Vδ1+, Vδ2+, Vδ1-Vδ2-) by flow cytometry. Results: Placental Plasmodium falciparum infection was associated with significant increase in the frequency of total γδ T cells in IVBMC and of the Vδ1+ subset in PBMC and IVBMC, but decreased frequency of the Vδ2+ subset in PBMC and IVBMC. The expression of the activation marker: HLA-DR, and the exhaustion markers (PD1 and TIM3) within total γδ T cells and subsets were significantly up-regulated in PM+ compared to PM- group. The frequency of total γδ T cells in IVBMC, TIM-3 expression within total γδ T cells and subsets in IVBMC, as well as HLA-DR expression within total γδ T cells and Vδ2+ subset in IVBMC were negatively associated with maternal hemoglobin levels. Furthermore, the frequency of total γδ T cells in PBMC and PD1 expression within the Vδ2+ subset in CBMC were negatively associated with birth weight contrary to the frequency of Vδ1-Vδ2- subset in PBMC and HLA-DR expression within the Vδ2+ subset in IVBMC which positively associated with maternal hemoglobin level and birth weight, respectively. Conclusion: The data indicate up-regulation of activated and exhausted γδ T cells in Plasmodium falciparum placental malaria, with effects on pregnancy outcomes including maternal hemoglobin level and birth weight.

IoT-based monitoring system and air quality prediction using machine learning for a healthy environment in Cameroon.

This paper is aimed at developing an air quality monitoring system using machine learning (ML), Internet of Things (IoT), and other elements to predict the level of particulate matter and gases in the air based on the air quality index (AQI). It is an air quality assessor and therefore a means of achieving the Sustainable Development Goals (SDGs), in particular, SDG 3.9 (substantial reduction of the health impacts of hazardous substances) and SDG 11.6 (reduction of negative impacts on cities and populations). AQI quantifies and informs the public about air pollutants and their adverse effects on public health. The proposed air quality monitoring device is low-cost and operates in real-time. It consists of a hardware unit that detects various pollutants to assess air quality as well as other airborne particles such as carbon dioxide (CO2), methane (CH4), volatile organic compounds (VOCs), nitrogen dioxide (NO2), carbon monoxide (CO), and particulate matter with an aerodynamic diameter of 2.5 microns or less (PM2.5). To predict air quality, the device was deployed from November 1, 2022, to February 4, 2023, in certain bauxite-rich areas of Adamawa and certain volcanic sites in western Cameroon. Therefore, machine learning algorithm models, namely, multiple linear regression (MLR), support vector regression (SVR), random forest regression (RFR), XGBoost (XGB), and K-nearest neighbors (KNN) were applied to analyze the collected concentrations and predict the future state of air quality. The performance of these models was evaluated using mean absolute error (MAE), coefficient of determination (R-square), and root mean square error (RMSE). The obtained data in this study show that these pollutants are present in selected localities albeit to different extents. Moreover, the AQI values obtained range from 10 to 530, with a mean of 132.380 ± 63.705, corresponding to moderate air quality state but may induce an adverse effect on sensitive members of the population. This study revealed that XGB regression performed better in air quality forecasting with the highest R-squared (test score of 0.9991 and train score of 0.9999) and lowest RMSE (test score of 1.5748 and train score of 0. 0073) and MAE (test score of 0.0872 and train score of 0.0020), while the KNN model had the worst prediction (lowest R-squared and highest RMSE and MAE). This embryonic work is a prototype for projects in Cameroon as measurements are underway for a national spread over a longer period of time.

Prevalence and risk factors of transmission of hepatitis delta virus in pregnant women in the Center Region of Cameroon.

BACKGROUND: Hepatitis B virus (HBV) and hepatitis delta virus (HDV) co-infection has been described as the most severe form of viral hepatitis, and can be co-transmitted from mother-to-child. A seroprevalence of 4.0% of HDV infection was reported in pregnant women in Yaoundé, and 11.9% in the general population in Cameroon. Our objective was to describe the rate of HDV infection in HBsAg-positive pregnant women and to determine risk factors associated with mother-to-child transmission of HDV. MATERIALS AND METHODS: A cross-sectional, descriptive study was conducted from January 2019 to July 2022 among pregnant women attending antenatal contacts in seven health structures in the Centre Region of Cameroon. A consecutive sampling (non-probability sampling) was used to select only pregnant women of age over 21 years, who gave a written informed consent. Following an informed consent, an open-ended questionnaire was used for a Knowledge, Attitude and Practice (KAP) survey of these women, and their blood specimens collected and screened for HBsAg, anti-HIV and anti-HCV antibodies by rapid tests and ELISA. HBsAg-positive samples were further screened for HBeAg, anti-HDV, anti-HBs, and anti HBc antibodies by ELISA, and plasma HDV RNA load measured by RT-qPCR. RESULTS: Of 1992 pregnant women, a rate of 6.7% of HBsAg (133/1992) with highest rate in the rural areas, and 3.9% of hepatitis vaccination rate were recorded. Of 130, 42 (32.3%) were anti-HDV antibody-positive, and 47.6% had detectable HDV RNA viraemia. Of 44 anti-HDV-positive cases, 2 (4.5%) were co-infected with HBV and HCV, while 5 (11.4%) with HIV and HBV. Multiple pregnancies, the presence of tattoos and/or scarifications were significantly associated with the presence of anti-HDV antibodies. Of note, 80% of women with negative HBeAg and positive anti-HBe serological profile, had plasma HDV RNA load of more than log 3.25 (>10.000 copies/ml). CONCLUSION: These results show an intermediate rate of HDV infection among pregnant women with high level of HDV RNA viremia, which suggest an increased risk of vertical and horizontal co-transmission of HDV.

Community Perceptions of Blackfly Nuisance and Acceptability of the "Slash and Clear" Vector Control Approach in the Ntui Health District of Cameroon: A Qualitative Study.

Besides being vectors of the onchocerciasis parasite, blackflies are a source of nuisance in onchocerciasis-endemic communities. We investigated the experience of residents in the Ntui Health District (Cameroon) regarding blackfly nuisance and assessed their perceptions of a novel "Slash and Clear" (S&C) intervention for blackfly control. Focus group discussions were conducted before and after S&C implementation (respectively, in February 2022 and December 2023). Blackflies were known to emerge from the river areas and cause disease. To prevent blackfly bites, the population often covered their body with protective clothing and applied various substances (kerosene, oil, or lemon) to their skin. Post-intervention data showed reduced blackfly nuisance, and the willingness to sustain blackfly control in the long-term was unanimous among community leaders and members, including the village volunteers who implemented the S&C intervention. In conclusion, blackfly nuisance is evident in the Ntui onchocerciasis focus of Cameroon and led to a panoply of coping practices, some of which could be detrimental to their health. Implementing S&C for blackfly control is well accepted and could sustainably alleviate the nuisance caused by blackflies while simultaneously breaking the onchocerciasis transmission cycle.