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.

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.

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).

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.

Geographic Disparities in Domestic Pig Population Exposure to Ebola Viruses, Guinea, 2017-2019.

Although pigs are naturally susceptible to Reston virus and experimentally to Ebola virus (EBOV), their role in Orthoebolavirus ecology remains unknown. We tested 888 serum samples collected from pigs in Guinea during 2017-2019 (between the 2013-16 epidemic and its resurgence in 2021) by indirect ELISA against the EBOV nucleoprotein. We identified 2 hotspots of possible pig exposure by IgG titer levels: the northern coast had 48.7% of positive serum samples (37/76), and Forest Guinea, bordering Sierra Leone and Liberia, where the virus emerged and reemerged, had 50% of positive serum samples (98/196). The multitarget Luminex approach confirms ELISA results against Ebola nucleoprotein and highlights cross-reactivities to glycoprotein of EBOV, Reston virus, and Bundibugyo virus. Those results are consistent with previous observations of the circulation of Orthoebolavirus species in pig farming regions in Sierra Leone and Ghana, suggesting potential risk for Ebola virus disease in humans, especially in Forest 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.

Synthesis, optimization, and characterization of precipitation derived starch nanoparticles from guinea seeds.

Guinea starch nanoparticles (GS-SNP) were developed using ultrasound and nanoprecipitation techniques. The physicochemical, thermal, structural, morphological, pasting, and rheological properties of GS-SNP were examined and compared with native starch. The particle size of GS-SNP was 391.50-206.00 nm, with a PDI of 0.35-0.23 and a zeta potential of -37.5 to -13 mV. The amylose content of GS-SNP increased with a decrease in relative crystallinity, and a VH-type crystalline structure was observed. The GS-SNP were in round shape with some self-aggregated granules. The water and oil absorption capacity, solubility, and gelatinization temperature of GS-SNP increased, but the swelling power was restricted. The viscosity of the GS-SNP dispersion remained almost constant throughout the heating but slightly increased after cooling. A higher degree of shear thinning was observed due to a fluid-like gel network and weak gel structure. The optimum conditions were: 50 % amplitude, 30 min time, and a starch to ethanol ratio (1:4) with 85 % maximum desirability. Overall, the findings suggest that GS-SNP have promising potential for application in a liquid system where viscosity of the system cannot be significantly influenced by temperature.

Evaluating the risk of conflict on recent Ebola outbreaks in Guinea and the Democratic Republic of the Congo.

BACKGROUND: Reducing Ebola virus transmission relies on the ability to identify cases and limit contact with infected bodily fluids through biosecurity, safe sex practices, safe burial and vaccination. Armed conflicts can complicate outbreak detection and interventions due to widespread disruption to governments and populations. Guinea and the Democratic Republic of the Congo (DRC) have historically reported the largest and the most recent Ebola virus outbreaks. Understanding if conflict played a role in these outbreaks may help in identifying key risks factors to improve disease control. METHODS: We used data from a range of publicly available data sources for both Ebola virus cases and conflict events from 2018 to 2021 in Guinea and the DRC. We fitted these data to conditional logistic regression models using the Self-Controlled Case Series methodology to evaluate the magnitude in which conflict increased the risk of reported Ebola virus cases in terms of incidence rate ratio. We re-ran the analysis sub-nationally, by conflict sub-event type and tested any lagged effects. RESULTS: Conflict was significantly associated with an increased risk of reported Ebola virus cases in both the DRC and Guinea in recent outbreaks. The effect was of a similar magnitude at 1.88- and 1.98-times increased risk for the DRC and Guinea, respectively. The greatest effects (often higher than the national values) were found in many conflict prone areas and during protest/riot-related conflict events. Conflict was influential in terms of Ebola virus risk from 1 week following the event and remained important by 10 weeks. CONCLUSION: Extra vigilance is needed following protests and riot-related conflict events in terms of Ebola virus transmission. These events are highly disruptive, in terms of access to transportation and healthcare and are often in urban areas with high population densities. Additional public health messaging around these types of conflict events, relating to the risks and clinical symptoms may be helpful in reducing transmission. Future work should aim to further understand and quantify conflict severity and intensity, to evaluate dose-response relationships in terms of disease risk.

Genomic characterization of SARS-CoV-2 in Guinea, West Africa.

SARS-CoV-2 has claimed several million lives since its emergence in late 2019. The ongoing evolution of the virus has resulted in the periodic emergence of new viral variants with distinct fitness advantages, including enhanced transmission and immune escape. While several SARS-CoV-2 variants of concern trace their origins back to the African continent-including Beta, Eta, and Omicron-most countries in Africa remain under-sampled in global genomic surveillance efforts. In an effort to begin filling these knowledge gaps, we conducted retrospective viral genomic surveillance in Guinea from October 2020 to August 2021. We found that SARS-CoV-2 clades 20A, 20B, and 20C dominated throughout 2020 until the coincident emergence of the Alpha and Eta variants of concern in January 2021. The Alpha variant remained dominant throughout early 2021 until the arrival of the Delta variant in July. Surprisingly, despite the small sample size of our study, we also found the persistence of the early SARS-CoV-2 clade 19B as late as April 2021. Together, these data help fill in our understanding of the SARS-CoV-2 population dynamics in West Africa early in the COVID-19 pandemic.

Valorization of guinea grass seed (Megathyrsus maximus): Synthesis and utilization of cellulose microfiber to reinforce esterified and cross-linked guinea starch films.

The present study extracts starch from guinea grass seed and fiber from the starch extraction residue. The fibrous residue was chemically converted into cellulose microfiber (CMF) and used to reinforce the native, esterified and crosslinked guinea starch films. The films were developed with 5 % starch, 40 % glycerol and 0, 2.5, 5, and 10 % CMF based on the dry matter of starch. SEM images of all film samples showed good compatibility of CMF with starch molecules, and no fractures or pores were observed. Adding filler materials to modified starch films slightly increased the film thickness (0.24 to 0.30 mm) due to the high dimensions of CMF, which comprise a significant amount of the composite's volume. A synergetic effect of starch modification and CMF in films decreased the moisture content (21.98 to 9.21 %), water solubility (25.65 to 15.47 %), water vapor permeability (6.96×10-7 to 1.65×10-7g∙mm2∙day∙Pa), and elongation at the break (33.51 to 16.79 %) while increasing the tensile strength (1.84 to 3.85 MPa) and Young's modulus (5.49 to 22.93 MPa). The L* and a* values of the films decreased, and the b* and opacity values of the films increased with the addition of CMF. The XRD graph showed that all films have semicrystalline structures with peaks at 18°, 20°, and 22°, and the degree of crystallinity increases (32.3 to 55.1 %) with CMF. All film samples showed good thermal stability up to 315 °C. In conclusion, esterified starch-based films exhibited superior barrier properties and flexibility. On the contrary, cross-linked starch films demonstrated higher tensile strength and lower water solubility.

Perspectives and experiences of healthcare providers on the response to the COVID-19 pandemic in three maternal and neonatal referral hospitals in Guinea in 2020: a qualitative study.

BACKGROUND: The COVID-19 pandemic has adversely affected access to essential healthcare services. This study aimed to explore healthcare providers' perceptions and experiences of the response to the COVID-19 pandemic in three referral maternal and neonatal hospitals in Guinea. METHODS: We conducted a longitudinal qualitative study between June and December 2020 in two maternities and one neonatology referral ward in Conakry and Mamou. Participants were purposively recruited to capture diversity of professional cadres, seniority, and gender. Four rounds of in-depth interviews (46 in-depth interviews with 18 respondents) were conducted in each study site, using a semi-structured interview guide that was iteratively adapted. We used both deductive and inductive approaches and an iterative process for content analysis. RESULTS: We identified four themes and related sub-themes presented according to whether they were common or specific to the study sites, namely: 1) coping strategies & care reorganization, which include reducing staffing levels, maintaining essential healthcare services, suspension of staff daily meetings, insertion of a new information system for providers, and co-management with COVID-19 treatment center for caesarean section cases among women who tested positive for COVID-19; 2) healthcare providers' behavior adaptations during the response, including infection prevention and control measures on the wards and how COVID-19-related information influenced providers' daily work; 3) difficulties encountered by providers, in particular unavailability of personal protective equipment (PPE), lack of financial motivation, and difficulties reducing crowding in the wards; 4) providers perceptions of healthcare service use, for instance their fear during COVID-19 response and perceived increase in severity of complications received and COVID-19 cases among providers and parents of newborns. CONCLUSION: This study provides insights needed to be considered to improve the preparedness and response of healthcare facilities and care providers to future health emergencies in similar contexts.

The factors associated with contraceptive use among young female students in rural Guinea / Facteurs associés à l'utilisation des méthodes contraceptives chez les jeunes filles élèves en milieu rural guinéen

Introduction: The low use of modern contraceptive methods by young girls is a real public health problem in sub-Saharan Africa, especially among young female students living in rural areas. The purpose of this study was to analyze the factors associated with contraceptive use among young female students in rural Guinea. Method: This was an analytical cross-sectional study including 607 students from 10 secondary schools in the rural district of Kankan, Guinea. Results: A total of 607 female students were interviewed and included in this study. They had an average age of 17.3 ± 1.7 years, 50.9% were in junior high school, and 49.1% were in high school. During our survey period, 67.7% of the girls reported being sexually active, while only 24.4% were on modern contraception. In the bivariate analysis, factors such as age, religion, school level, having heard of contraception, and having had sexual intercourse were statistically associated with contraceptive use. In the multivariate analysis, factors such as age (OR = 2.1; CI = 1.1­3.8), religion (OR = 5.1; CI = 2.8­9.5), and having had sexual intercourse (OR = 2.2; CI = 1.4­3.5) remained statistically associated with the use of contraceptive methods among young female students. Conclusion: Our study highlights the need to increase awareness of, and access to, contraceptive methods in schools in order to improve contraceptive practice and, in turn, to reduce the frequency of unwanted and early pregnancies among young female students in rural areas of Guinea.

Introduction: La faible utilisation des méthodes contraceptives modernes par les jeunes filles constitue un véritable problème de santé publique en Afrique subsaharienne, en particulier chez les jeunes filles élèves et résidant en milieu rural. Cette étude visait à analyser les facteurs associés à l'utilisation des méthodes contraceptives chez les jeunes filles élèves en milieu rural guinéen. Méthodes: Il s'agissait d'une étude transversale analytique incluant 607 élèves de 10 écoles secondaires du district rural de Kankan en Guinée. Résultats: Au total, 607 jeunes filles élèves ont été interrogées et incluses dans cette étude. Leur moyenne d'âge était de 17,3 ± 1,7 ans, 50,9 % d'entre elles fréquentaient le collège et 49,1 % le lycée. Pendant notre période d'enquête, 67,7 % des jeunes filles ont déclaré être sexuellement actives alors que seules 24,4 % étaient sous contraception moderne. En analyse bivariée, les facteurs comme l'âge, la religion, le niveau scolaire, avoir déjà entendu parler de contraception et avoir déjà eu un rapport sexuel étaient statistiquement associés à l'utilisation de méthodes contraceptives. En analyse multivariée, les facteurs comme l'âge (RCa = 2,1 ; IC = 1,1-3,8), la religion (RCa = 5,1 ; IC = 2,8-9,5) et avoir déjà eu un rapport sexuel (RCa = 2,2 ; IC = 1,4-3,5) restaient statistiquement associés à l'utilisation de méthodes contraceptives chez les jeunes filles en milieu scolaire. Conclusion: Notre étude souligne le besoin de renforcer la sensibilisation et l'accès aux méthodes contraceptives en milieu scolaire en vue d'améliorer la pratique contraceptive, et par ricochet réduire la fréquence des grossesses non désirées et précoces chez les jeunes filles élèves en milieu rural guinéen.

SARS-CoV-2 seroprevalence in vaccine-naïve participants from the Democratic Republic of Congo, Guinea, Liberia, and Mali.

OBJECTIVES: The InVITE study, starting in August 2021, was designed to examine the immunogenicity of different vaccine regimens in several countries including the Democratic Republic of Congo, Guinea, Liberia, and Mali. Prevaccination baseline samples were used to obtain estimates of previous SARS-CoV-2 infection in the study population. METHODS: Adult participants were enrolled upon receipt of their initial COVID-19 vaccine from August 2021 to June 2022. Demographic and comorbidity data were collected at the time of baseline sample collection. SARS-CoV-2 serum anti-Spike and anti-Nucleocapsid antibody levels were measured. RESULTS: Samples tested included 1016, 375, 663, and 776, from DRC, Guinea, Liberia, and Mali, respectively. Only 0.8% of participants reported a prior positive SARS-CoV-2 test, while 83% and 68% had anti-Spike and anti-Nucleocapsid antibodies, respectively. CONCLUSIONS: Overall SARS-CoV-2 seroprevalence was 86% over the accrual period, suggesting a high prevalence of SARS-CoV-2 infection. Low rates of prior positive test results may be explained by asymptomatic infections, limited access to SARS-CoV-2 test kits and health care, and inadequate surveillance. These seroprevalence rates are from a convenience sample and may not be representative of the population in general, underscoring the need for timely, well-conducted surveillance as part of global pandemic preparedness.

PASQUALE - A long-term partnership to improve hand hygiene and capacity building in infection prevention and control in the Faranah region of Guinea.

Across the globe, hand hygiene (HH) is promoted to fight the spread of healthcare associated infections. Despite multiple ongoing HH campaigns and projects, the healthcare associated infection rates remain high especially in low- and middle-income countries. In the narrative overview presented here, we aim to share objectives, framework, successes and challenges of our long-term partnership in Guinea to offer guidance for other projects aiming to sustainably improve HH.