The monthly trends of malaria cases in children under 5 years of age in Guinea: comparative analysis between a seasonal malaria chemoprevention (SMC) and a non-SMC health district.

BACKGROUND: The Republic of Guinea, where malaria represents the leading cause of morbidity and mortality among children, the seasonal malaria chemoprevention (SMC) is deployed only in areas with very seasonal modes of transmission. It should target children at the highest risk of serious illness. The objective of the study was to prevent uncomplicated and serious cases of malaria in the target population. This study aimed to analyse the monthly trends in malaria-related morbidity among children under the age of 5 in Guinea. METHODS: This was a quasi-experimental study with routine data from the National Health Information System (SNIS). The two districts Mamou (the SMC intervention site) and Kindia (the control site) were selected to compare the monthly trends in malaria cases among children under the age of 5, from July to October, covering the years from 2015 to 2020. The statistical analysis used interrupted time series to estimate the effects of the SMC. RESULTS: The SMC programme contributed to a significant average reduction in the number of malaria cases of 225 cases per month in the intervention district (95% CI - 362 to - 88; p = 0.002), compared to the control district. However, the study also revealed that the effect of SMC varied between cycles, presenting different monthly malaria cases. CONCLUSION: The SMC contributed to a significant reduction in malaria cases among children under the age of 5 in the health district of Mamou from 2018 to 2020. However, this reduction varied by monthly SMC cycle. This study suggests extending the SMC in other areas with high perennial seasonal transmission respecting the World Health Organization SMC eligibility criteria, as a strategy in the dynamic of reducing malaria cases in children under the age of 5 in Guinea.

Health seeking behaviour associated with obstetric fistula care in Guinea: An analysis of the 2018 Demographic and Health survey.

This study aimed to analyze factors associated with obstetric fistula care-seeking behavior in Guinea, based on data from the 2018 Demographic and Health Survey. Women aged 15-49 years who reported having obstetric fistula constituted the study population, statistical analysis was using Stata 16.0 software. Multivariate logistic regression was used to identify the factors associated with fistula care-seeking behavior. Among women with obstetric fistula, 78.9% sought care; 21.1% of those who sought care underwent repair. Factors associated with care-seeking behavior were being divorced (AOR =8.08; 95% CI:1.56-41.84), having a job (AOR =3.23; 95% CI: 1.11-9.44), being a member of a poor household (AOR =6.49; 95% CI:1.21-34.82) and whose fistula had appeared 6 days or more after the occurrence of the causal circumstance (AOR =3.63 95% CI: 1.28-10.28). This study suggests that the foundations on which fistula prevention and treatment programs are built should be reviewed, taking into account the factors highlighted by this study.

Cette étude visait à analyser les facteurs associés aux comportements de recherche de soins pour la fistule obstétricale en Guinée, partant des données de l'enquête démographique et de santé de 2018. Les femmes âgées de 15 à 49 ans ayant déclaré avoir une fistule obstétricale ont constitué la population d'étude, l'analyse statistique a été réalisée à l'aide du logiciel Stata 16.0. La régression logistique multivariée a été utilisée pour identifier les facteurs associés aux comportements de recherche de soins pour la fistule. Parmi les femmes atteintes de fistule obstétricale, 78,9 % ont eu recours à des soins ; 21,1 % de celles qui ont recouru ont subi une réparation. Les facteurs associés aux comportements de recherche de soins étaient le fait d'être divorcée (ORA=8.08 ; 95% IC :1.56-41.84), d'avoir un travail (ORA =3.23 ; 95% IC : 1.11-9.44), d'être membre d'un ménage pauvre (ORA =6.49 ; 95% IC :1.21-34.82) et dont la fistule était apparue 6 jours ou plus après la survenue de la circonstance causale (ORA =3.63 95% IC : 1.28-10.28). Cette étude suggère de revoir les bases sur lesquelles les programmes de prévention et de traitement de la fistule sont construits, tout en prenant en compte les facteurs mis en évidence par cette étude.

Cluster randomised trial of a health system strengthening approach applying person-centred communication for the prevention of female genital mutilation in Guinea, Kenya and Somalia.

INTRODUCTION: There is limited evidence on effective health systems interventions for preventing female genital mutilation (FGM). This study tested a two-level intervention package at primary care applying person-centred communication (PCC) for FGM prevention. METHODS: A cluster randomised trial was conducted in 2020-2021 in 180 antenatal care (ANC) clinics in Guinea, Kenya and Somalia. At baseline, all clinics received guidance and materials on FGM prevention and care; at month 3, ANC providers at intervention sites received PCC training. Data were collected from clinic managers, ANC providers and clients at baseline, month 3 and month 6 on primary outcomes, including delivery of PCC counselling, utilisation of level one materials, health facility preparedness for FGM prevention and care services and secondary outcomes related to clients' and providers' knowledge and attitudes. Data were analysed using multilevel and single-level logistic regression models. RESULTS: Providers in the intervention arm were more likely to deliver PCC for FGM prevention compared with those in the control arm, including inquiring about clients' FGM status (adjusted OR (AOR): 8.9, 95% CI: 6.9 to 11.5; p<0.001) and FGM-related beliefs (AOR: 9.7, 95% CI: 7.5 to 12.5; p<0.001) and discussing why (AOR: 9.2, 95% CI: 7.1 to 11.9; p<0.001) or how (AOR: 7.7, 95% CI: 6.0 to 9.9; p<0.001) FGM should be prevented. They were more confident in their FGM-related knowledge (AOR: 7.0, 95% CI: 1.5 to 32.3; p=0.012) and communication skills (AOR: 1.8; 95% CI: 1.0 to 3.2; p=0.035). Intervention clients were less supportive of FGM (AOR: 5.4, 95% CI: 2.4 to 12.4; p<0.001) and had lower intentions of having their daughters undergo FGM (AOR: 0.3, 95% CI: 0.1 to 0.7; p=0.004) or seeking medicalised FGM (AOR: 0.2, 95% CI: 0.1 to 0.5; p<0.001) compared with those in the control arm. CONCLUSION: This is the first study to provide evidence of an effective FGM prevention intervention that can be delivered in primary care settings in high-prevalence countries. TRIAL REGISTRATION AND DATE: PACTR201906696419769 (3 June 2019).

Prevalence and factors associated with unskilled childbirth attendance in Guinea: Analysis of the 2018 Demographic and Health Survey.

This study aimed to analyze the prevalence and factors associated with the unassisted delivery by qualified health personnel in the Republic of Guinea, based on data from the 2018 demographic and health survey. Multivariate logistic regression was used to identify the associated factors. The prevalence of unassisted delivery was 40.8%; it was 38.4% in rural areas and 2.3% in urban areas. Factors associated with this type of delivery included the performance of no ANC (ORa = 6.19 IC95%: [4.86 - 7.87], p<0.001) and those who had performed one to three ANC (ORa =1.75 IC95%: [1.49 - 2.05], p<0.001) the perception of the distance to the health institution as a problem (ORa =1.28 IC95%: [1.10 - 1.48], p<0.001), belonging to the poor wealth index (ORa = 2.77 IC 95%: [2.19 - 3.50], p<0.001) and average (ORa = 2.01 IC95%: [1.57 - 2.57], p<0.001), the fact of residing in the region of Faranah (ORa = 2.24 IC95%: [1.37 - 3.65], p<0.001) and rural areas (ORa = 4.15 IC95%: [3.10 - 5.56], p<0.001). Strengthening community awareness, making functional ambulances available to rural health centers and making prenatal care inputs available in health institutions would help to reduce the scale of unassisted deliveries in the Republic of Guinea.

Cette étude visait à analyser la prévalence et les facteurs associés à l'accouchement non assisté par un personnel de santé qualifié en Guinée, partant des données de l'enquête démographique et de santé de 2018. La régression logistique multivariée a servi à identifier les facteurs associés. La fréquence de l'accouchement non assisté était de 40.8% ; elle était de 38.4% en milieu rural et 2.3% en milieu urbain. Les facteurs associés à ce type d'accouchement comprenaient la réalisation d'aucune CPN (ORa =6.19 IC95% : [4.86 - 7.87], p<0.001) et celles qui avaient réalisées une à trois CPN (ORa =1.75 IC95% : [1.49 - 2.05], p<0.001) la perception de la distance pour la structure de santé comme un problème (ORa =1.28 IC95% : [1.10 - 1.48], p<0.001), l'appartenance à l'indice de richesse pauvre (ORa =2.77 IC95% : [2.19 - 3.50], p<0.001) et moyenne (ORa =2.01 IC 95% : [1.57 - 2.57], p<0.001), le fait de résider dans la région de Faranah (ORa =2.24 IC95% : [1.37 - 3.65], p<0.001) et rurale (ORa =4,15 IC 95% : [3,10 - 5,56], p<0,001). Le renforcement de la sensibilisation communautaire, la mise d'ambulances fonctionnelles à la disposition des centres de santé ruraux et rendre disponible les intrants de soins prénatals dans les structures sanitaires contribueraient serte à réduire l'ampleur des accouchements non assistés en Guinée.

Specificity of serological screening tests and reference laboratory tests to diagnose gambiense human African trypanosomiasis: a prospective clinical performance study.

BACKGROUND: Serological screening tests play a crucial role to diagnose gambiense human African trypanosomiasis (gHAT). Presently, they preselect individuals for microscopic confirmation, but in future "screen and treat" strategies they will identify individuals for treatment. Variability in reported specificities, the development of new rapid diagnostic tests (RDT) and the hypothesis that malaria infection may decrease RDT specificity led us to evaluate the specificity of 5 gHAT screening tests. METHODS: During active screening, venous blood samples from 1095 individuals from Côte d'Ivoire and Guinea were tested consecutively with commercial (CATT, HAT Sero-K-SeT, Abbott Bioline HAT 2.0) and prototype (DCN HAT RDT, HAT Sero-K-SeT 2.0) gHAT screening tests and with a malaria RDT. Individuals with ≥ 1 positive gHAT screening test underwent microscopy and further immunological (trypanolysis with T.b. gambiense LiTat 1.3, 1.5 and 1.6; indirect ELISA/T.b. gambiense; T.b. gambiense inhibition ELISA with T.b. gambiense LiTat 1.3 and 1.5 VSG) and molecular reference laboratory tests (PCR TBRN3, 18S and TgsGP; SHERLOCK 18S Tids, 7SL Zoon, and TgsGP; Trypanozoon S2-RT-qPCR 18S2, 177T, GPI-PLC and TgsGP in multiplex; RT-qPCR DT8, DT9 and TgsGP in multiplex). Microscopic trypanosome detection confirmed gHAT, while other individuals were considered gHAT free. Differences in fractions between groups were assessed by Chi square and differences in specificity between 2 tests on the same individuals by McNemar. RESULTS: One gHAT case was diagnosed. Overall test specificities (n = 1094) were: CATT 98.9% (95% CI: 98.1-99.4%); HAT Sero-K-SeT 86.7% (95% CI: 84.5-88.5%); Bioline HAT 2.0 82.1% (95% CI: 79.7-84.2%); DCN HAT RDT 78.2% (95% CI: 75.7-80.6%); and HAT Sero-K-SeT 2.0 78.4% (95% CI: 75.9-80.8%). In malaria positives, gHAT screening tests appeared less specific, but the difference was significant only in Guinea for Abbott Bioline HAT 2.0 (P = 0.03) and HAT Sero-K-Set 2.0 (P = 0.0006). The specificities of immunological and molecular laboratory tests in gHAT seropositives were 98.7-100% (n = 399) and 93.0-100% (n = 302), respectively. Among 44 reference laboratory test positives, only the confirmed gHAT patient and one screening test seropositive combined immunological and molecular reference laboratory test positivity. CONCLUSIONS: Although a minor effect of malaria cannot be excluded, gHAT RDT specificities are far below the 95% minimal specificity stipulated by the WHO target product profile for a simple diagnostic tool to identify individuals eligible for treatment. Unless specificity is improved, an RDT-based "screen and treat" strategy would result in massive overtreatment. In view of their inconsistent results, additional comparative evaluations of the diagnostic performance of reference laboratory tests are indicated for better identifying, among screening test positives, those at increased suspicion for gHAT. TRIAL REGISTRATION: The trial was retrospectively registered under NCT05466630 in clinicaltrials.gov on July 15 2022.

Healthcare workers' knowledge, attitude and practices on infection prevention and control in the context of the COVID-19 pandemic at the Faranah regional hospital and associated healthcare centers, Guinea.

BACKGROUND: In response to the COVID-19 pandemic, WHO launched a strategic preparedness and response plan, outlining public health measures to support countries worldwide. Healthcare workers have an increased risk of becoming infected and their behaviour regarding infection prevention and control (IPC) influences infection dynamics. IPC strategies are important across the globe, but even more in low-resource settings where capacities for testing and treatment are limited. Our study aimed to assess and implement COVID-19 pandemic preparedness and response measures in Faranah, Guinea, primarily focusing on healthcare workers' IPC knowledge, attitude and practice (KAP). METHODS: The study was conducted between April 2020 and April 2021 assessing IPC pandemic preparedness and response measures such as healthcare workers' KAP, alcohol-based handrub (ABHR) consumption and COVID-19 triaging in the Faranah Regional Hospital and two associated healthcare centres. The assessment was accompanied by IPC training and visual workplace reminders and done in pre- and post- phases to evaluate possible impact of these IPC activities. RESULTS: The overall knowledge score in the Faranah Regional Hospital was 32.0 out of 44 at baseline, and did not change in the first, but increased significantly by 3.0 points in the second follow-up. The healthcare workers felt closer proximity to SARS-CoV-2 overtime in addition to higher stress levels in all study sites. There was significant improvement across the observed triaging practices. Hand hygiene compliance showed a significant increase across study sites leading to 80% in Faranah Regional Hospital and 63% in healthcare centers. The average consumption of ABHR per consultation was 3.29 mL with a peak in February 2020 of 23 mL. CONCLUSION: Despite increased stress levels among HCWs, the ongoing IPC partnership well prepared the FRH in terms of triaging processes with a stronger impact on IPC practice than on theoretical knowledge. Throughout the pandemic, global shortages and surges in consumption did not affect the continuous ABHR provision of the FRH. This highlights local ABHR production as a key pandemic preparedness strategy.

The feasibility, acceptability, appropriateness and impact of implementing person-centered communication for prevention of female genital mutilation in antenatal care settings in Guinea, Kenya and Somalia.

BACKGROUND: There is limited evidence on how to engage health workers as advocates in preventing female genital mutilation (FGM). This study assesses the feasibility, acceptability, appropriateness and impact of a person-centered communication (PCC) approach for FGM prevention among antenatal care (ANC) providers in Guinea, Kenya and Somalia. METHODS: Between August 2020 and September 2021, a cluster randomised trial was conducted in 180 ANC clinics in three countries testing an intervention on PCC for FGM prevention. A process evaluation was embedded, comprising in-depth interviews (IDIs) with 18 ANC providers and 18 ANC clients. A qualitative thematic analysis was conducted, guided by themes identified a priori and/or that emerged from the data. RESULTS: ANC providers and clients agreed that the ANC context was a feasible, acceptable and appropriate entry point for FGM prevention counselling. ANC clients were satisfied with how FGM-related information was communicated by providers and viewed them as trusted and effective communicators. Respondents suggested training reinforcement, targeting other cadres of health workers and applying this approach at different service delivery points in health facilities and in the community to increase sustainability and impact. CONCLUSION: These findings can inform the scale up this FGM prevention approach in high prevalence countries.

Prevalence, risks factors, and control of hypertension in Guinean older adults in 2021: a cross-sectional survey.

BACKGROUND: The incidence of arterial hypertension increases with the aging of the population, but its magnitude remains insufficiently assessed. The aim of this study was to investigate the prevalence of hypertension and associated factors in elderly people in Guinea. METHODS: Data were obtained from a cross-sectional general population survey, conducted among people aged ≥ 60 years. A stratified enumeration area random sample survey was conducted in the four natural regions of Guinea from February to April 2021. This study included an interview on sociodemographic data, and a clinical examination. Hypertension was defined as systolic blood pressure ≥ 140mmHg and/or diastolic blood pressure ≥ 90mmHg or previous diagnosis of hypertension (with or without antihypertensive medication). Hypertension control was defined as blood pressure below 140/90 mmHg during treatment. Age-standardized prevalence was calculated, and logistic regression was used to examine factors associated with hypertension. RESULTS: A total of 1698 adults (1079 men, mean age: 71.6 ± 9.4 years) had at least two blood pressure measurements. The standardized prevalence of hypertension was 61.4% [95% CI: 61.3-61.6], ranging from 52% in Middle Guinea to 67% in Upper Guinea, and was higher in women (65.2%: 65.0-65.4) than in men (59.1%:58.9-59.3). Among those with hypertension, 46.7% were unaware of their condition before the survey and 49.6% were on treatment and only 18.5% had controlled hypertension. Whatever the residence (rural or urban), increasing age, being unmarried, working as a trader or functionary, jobless, living in upper Guinea, low monthly income, intake of extra salt, known diabetic, overweight, and obesity increased the risk of hypertension. In urban area, female sex (AOR: 1.14: 1.12-1.17), living in lower Guinea (AOR: 3.08: 2.97-3.20), being Maninka (AOR: 1.26: 1.21-1.31), being Nguerze (AOR: 1.71: 1.63-1.81) increased the risk of hypertension, but living in forest Guinea (AOR: 0.88: 0.83-0.93), being Soussou (AOR: 0.88: 0.85-0.92) decreased the risk. In rural area, living in forest Guinea (AOR: 2.14: 2.03-2.26), being Soussou (AOR: 1.14: 1.12-1.17) increased the risk of hypertension, but female sex (AOR: 0.96: 0.94-0.98), living in lower Guinea (AOR: 0.87: 0.85-0.89), being Maninka (AOR: 0.94: 0.92-0.97), being Nguerze (AOR: 0.50: 0.47-0.52) decreased the risk. CONCLUSION: Hypertension is a major problem in the elderly population in Guinea, and the level of treatment and control in elderly with known hypertension is inadequate. The place of hypertension among cardiovascular diseases and the identification of associated factors underlines the need to develop innovative approaches to control this major risk factor.

Ebola virus circulation in a non-epidemic Guinean rural area: A mixed-method approach to assessing endemicity.

OBJECTIVES: This study aimed to investigate the prevalence of orthoebolavirus antibodies in Madina Oula, a non-epidemic rural area in Guinea, in 2022. METHODS: A cross-sectional study was conducted from March 14 to April 3, 2022 involving recording household and socio-demographic characteristics, lifestyle data, and collecting dried blood spots from 878 individuals in 235 households. Dried blood spots were tested using multiplex serology to detect antibodies to different orthoebolaviruses: Ebola virus, Bundibugyo virus, Sudan virus, Reston virus, and Bombali virus. Seroprevalence was estimated with a 95% confidence interval and a Z-test was performed to compare the seropositivity between children aged under 15 years and those over 15 years. Household and participant characteristics were analyzed using descriptive statistic, and socio-historical conditions were discussed. RESULTS: The serological analysis conducted in 2022 on 878 participants revealed varying reactivity to orthoebolavirus antigens, notably, with glycoprotein antigens, particularly, glycoprotein Sudan virus (16%). A total of 21 samples exhibited reactivity with at least two antigens, with a median age of 27 years (interquartile range 10.00-35.00), ranging from 2 to 80 years. There is no significant difference between seropositivity in children aged under 15 (2.86%) years and those over 15 (2.14%) years. The antibody presence varied per village, with the highest prevalence observed in Ouassou and Dar-es-Salam. CONCLUSIONS: Serological data in a region unaffected by recent Ebola outbreaks indicate possible orthoebolavirus endemicity, emphasizing the need for preparedness against known or novel orthoebolaviruses with potential cross-reactivity.

Statistical modeling of maximum temperature in Guinea.

A statistical analysis of maximum temperature from twelve weather stations in parts of Guinea is provided. Using maximum likelihood estimation, maximum temperature data was fitted by the Generalized Extreme Value distribution. Data from all of the twelve stations were adequately fit by the Generalized Extreme Value distribution. Return level estimates are provided. Significant trends in maximum temperature were found for four of the stations. The four stations exhibited significant positive trends at the 5% significance level.

A novel indicator in epidemic monitoring through a case study of Ebola in West Africa (2014-2016).

The E/S (exposed/susceptible) ratio is analyzed in the SEIR model. The ratio plays a key role in understanding epidemic dynamics during the 2014-2016 Ebola outbreak in Sierra Leone and Guinea. The maximum value of the ratio occurs immediately before or after the time-dependent reproduction number (Rt) equals 1, depending on the initial susceptible population (S(0)). It is demonstrated that transmission rate curves corresponding to various incubation periods intersect at a single point referred to as the Cross Point (CP). At this point, the E/S ratio reaches an extremum, signifying a critical shift in transmission dynamics and aligning with the time when Rt approaches 1. By plotting transmission rate curves, ß(t), for any two arbitrary incubation periods and tracking their intersections, we can trace CP over time. CP serves as an indicator of epidemic status, especially when Rt is close to 1. It provides a practical means of monitoring epidemics without prior knowledge of the incubation period. Through a case study, we estimate the transmission rate and reproduction number, identifying CP and Rt = 1 while examining the E/S ratio across various values of S(0).

Serological evidence of zoonotic filovirus exposure among bushmeat hunters in Guinea.

Human Ebola virus (EBOV) outbreaks caused by persistent EBOV infection raises questions on the role of zoonotic spillover in filovirus epidemiology. To characterise filovirus zoonotic exposure, we collected cross-sectional serum samples from bushmeat hunters (n = 498) in Macenta Prefecture Guinea, adjacent to the index site of the 2013 EBOV-Makona spillover event. We identified distinct immune signatures (20/498, 4.0%) to multiple EBOV antigens (GP, NP, VP40) using stepwise ELISA and Western blot analysis and, live EBOV neutralisation (5/20; 25%). Using comparative serological data from PCR-confirmed survivors of the 2013-2016 EBOV outbreak, we demonstrated that most signatures (15/20) were not plausibly explained by prior EBOV-Makona exposure. Subsequent data-driven modelling of EBOV immunological outcomes to remote-sensing environmental data also revealed consistent associations with intact closed canopy forest. Together our findings suggest exposure to other closely related filoviruses prior to the 2013-2016 West Africa epidemic and highlight future surveillance priorities.

Community-based assessment of the dynamics of urban landscape characteristics and ecosystem services in the rainforest and guinea savanna ecoregions of Nigeria.

Understanding the dynamics of urban landscapes and their impacts on ecological well-being is crucial for developing sustainable urban management strategies in times of rapid urbanisation. This study assesses the nature and drivers of the changing urban landscape and ecosystem services in cities located in the rainforest (Akure and Owerri) and guinea savannah (Makurdi and Minna) of Nigeria using a combination of remote sensing and socioeconomic techniques. Landsat 8 datasets provided spatial patterns of the normalised difference vegetation index (NDVI) and normalised difference built-up index (NDBI). A household survey involving the administration of a semi-structured questionnaire to 1552 participants was conducted. Diminishing NDVI and increasing NDBI were observed due to the rising trend of urban expansion, corroborating the perception of over 54% of the respondents who noted a decline in landscape ecological health. Residential expansion, agricultural practices, transport and infrastructural development, and fuelwood production were recognised as the principal drivers of landscape changes. Climate variability/change reportedly makes a 28.5%-34.4% (Negelkerke R2) contribution to the changing status of natural landscapes in Akure and Makurdi as modelled by multinomial logistic regression, while population growth/in-migration and economic activities reportedly account for 19.9%-36.3% in Owerri and Minna. Consequently, ecosystem services were perceived to have declined in their potential to regulate air and water pollution, reduce soil erosion and flooding, and mitigate urban heat stress, with a corresponding reduction in access to social services. We recommend that urban residents be integrated into management policies geared towards effectively developing and enforcing urban planning regulations, promoting urban afforestation, and establishing sustainable waste management systems.

Rodent control strategies and Lassa virus: some unexpected effects in Guinea, West Africa.

The Natal multimammate mouse (Mastomys natalensis) is the host of Lassa mammarenavirus, causing Lassa haemorrhagic fever in West Africa. As there is currently no operational vaccine and therapeutic drugs are limited, we explored rodent control as an alternative to prevent Lassa virus spillover in Upper Guinea, where the disease is highly endemic in rural areas. In a seven-year experiment, we distributed rodenticides for 10-30 days once a year and, in the last year, added intensive snap trapping for three months in all the houses of one village. We also captured rodents both before and after the intervention period to assess their effectiveness by examining alterations in trapping success and infection rates (Lassa virus RNA and IgG antibodies). We found that both interventions reduced the rodent population by 74-92% but swiftly rebounded to pre-treatment levels, even already six months after the last snap-trapping control. Furthermore, while we observed that chemical control modestly decreased Lassa virus infection rates annually (a reduction of 5% in seroprevalence per year), the intensive trapping unexpectedly led to a significantly higher infection rate (from a seroprevalence of 28% before to 67% after snap trapping control). After seven years, we conclude that annual chemical control, alone or with intensive trapping, is ineffective and sometimes counterproductive in preventing Lassa virus spillover in rural villages. These unexpected findings may result from density-dependent breeding compensation following culling and the survival of a small percentage of chronically infected rodents that may spread the virus to a new susceptible generation of mice.

Reservoir displacement by an invasive rodent reduces Lassa virus zoonotic spillover risk.

The black rat (Rattus rattus) is a globally invasive species that has been widely introduced across Africa. Within its invasive range in West Africa, R. rattus may compete with the native rodent Mastomys natalensis, the primary reservoir host of Lassa virus, a zoonotic pathogen that kills thousands annually. Here, we use rodent trapping data from Sierra Leone and Guinea to show that R. rattus presence reduces M. natalensis density within the human dwellings where Lassa virus exposure is most likely to occur. Further, we integrate infection data from M. natalensis to demonstrate that Lassa virus zoonotic spillover risk is lower at sites with R. rattus. While non-native species can have numerous negative effects on ecosystems, our results suggest that R. rattus invasion has the indirect benefit of decreasing zoonotic spillover of an endemic pathogen, with important implications for invasive species control across West Africa.

Seroprevalence and Phylogenetic Characterization of Hepatitis E Virus (Paslahepevirus balayani) in Guinean Pig Population.

Background: Hepatitis E virus (HEV) is transmitted by the fecal route, usually through contaminated water in humans and/or infected animals, especially pigs. The objective of this study was to evaluate the level of anti-HEV antibodies in a panel of pig sera and to identify HEV in pig feces in farms. Methodology: The presence of HEV antibodies was tested by an in-house ELISA and a commercial ELISA IDvet. HEV genome was assessed by nested RT-PCR, and then, genotype was identified by sequencing (MinION Nanopore technology). Results: In 2017-2019, the 43% seroprevalence found in Forest Guinea was significantly higher than the 7% found in the Lower region (p < 0.01). Presence of HEV genotype 3c was demonstrated during a secondary study in the Lower region (Conakry) in 2022. Conclusion: The presence of HEV-3c in pigs calls for an evaluation of seroprevalence in human populations and for a HEV genotype human circulation check. Contribution Heading: This study is the first report, to our knowledge, of seroprevalence and characterization of HEV infection in pigs in Guinea.

Freshwater macroinvertebrates along the Nigeria-Cameroon border enhance the conservation value of the lower Guinea forest biodiversity hotspot.

In Nigeria and tropical Africa, the bias towards the protection of natural sites on account of terrestrial biodiversity or their resultant ecosystem services has led to a considerably low number of freshwater conservation studies in the region. To close this gap, six lotic freshwater systems in three different natural sites (Obudu Mountains, Agbokim Waterfalls, and Cross River National Park) along the Cameroon border of Nigeria were evaluated for the biodiversity of macroinvertebrates and some aspects of water quality in December 2021 and March 2022. Among other macroinvertebrate-related indices, the community conservation index (CCI), which considers the presence of threatened, rare, and notable species, was used for the conservation evaluation of the freshwater systems. The Ephemeroptera-Plecoptera-Trichoptera (EPT) species were notably rich at the sites, with over 12 species each at the Afundu Stream, Kwa River, Cataract Stream, and Agbokim River. All of the sites had a very high conservation value, according to the CCI, which was greater than 20. Some Obudu sites (Grotto and Becheve streams), despite having fewer EPT taxa, had higher CCI than the Kwa or Agbokim River. This was due to the presence of the endangered damselflies (Africocypha centripunctata and Allocnemis vicki) at the Obudu sites and a rare mayfly species in Nigeria (Tricorythus tinctus), which was reported at Agbokim and Kwa Rivers. The presence of a notable damselfly genus (Pentaphlebia) at the Afundu stream of the Obudu Mountains also raises some hope that the critically endangered damselfly (Pentaphlebia gamblesi), whose adult was last seen in 1973, could still be alive at the site. Canonical Correspondence Analysis revealed that the proportion of scrapers had a strong association with high BOD and EC in Agbokim River, while the Becheve and Grotto streams which had high vegetal cover was positively associated with shredders. Also, increasing DO in Afundu Stream, Kwa River and Cataract Stream was positively associated with EPT richness. This study revealed that more freshwater ecological studies need to be conducted at isolated natural sites and protected areas in Africa. Findings from such studies have implications for preserving freshwater ecosystems of high conservation value from the various threats that characterize the Anthropocene.