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1.
Am J Hum Genet ; 111(5): 927-938, 2024 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-38701745

RESUMO

Leukocyte telomere length (LTL) varies significantly across human populations, with individuals of African ancestry having longer LTL than non-Africans. However, the genetic and environmental drivers of LTL variation in Africans remain largely unknown. We report here on the relationship between LTL, genetics, and a variety of environmental and climatic factors in ethnically diverse African adults (n = 1,818) originating from Botswana, Tanzania, Ethiopia, and Cameroon. We observe significant variation in LTL among populations, finding that the San hunter-gatherers from Botswana have the longest leukocyte telomeres and that the Fulani pastoralists from Cameroon have the shortest telomeres. Genetic factors explain ∼50% of LTL variation among individuals. Moreover, we observe a significant negative association between Plasmodium falciparum malaria endemicity and LTL while adjusting for age, sex, and genetics. Within Africa, adults from populations indigenous to areas with high malaria exposure have shorter LTL than those in populations indigenous to areas with low malaria exposure. Finally, we explore to what degree the genetic architecture underlying LTL in Africa covaries with malaria exposure.


Assuntos
Malária Falciparum , Telômero , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , África Subsaariana/epidemiologia , População Negra/etnologia , População Negra/genética , Doenças Endêmicas , Leucócitos/metabolismo , Malária Falciparum/genética , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Plasmodium falciparum/genética , Plasmodium falciparum/patogenicidade , População da África Subsaariana , Telômero/genética , Homeostase do Telômero/genética , Botsuana , Tanzânia , Camarões , População da África Austral
2.
PLoS Genet ; 20(7): e1011344, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39074161

RESUMO

Deciphering the evolutionary forces controlling insecticide resistance in malaria vectors remains a prerequisite to designing molecular tools to detect and assess resistance impact on control tools. Here, we demonstrate that a 4.3kb transposon-containing structural variation is associated with pyrethroid resistance in central/eastern African populations of the malaria vector Anopheles funestus. In this study, we analysed Pooled template sequencing data and direct sequencing to identify an insertion of 4.3kb containing a putative retro-transposon in the intergenic region of two P450s CYP6P5-CYP6P9b in mosquitoes of the malaria vector Anopheles funestus from Uganda. We then designed a PCR assay to track its spread temporally and regionally and decipher its role in insecticide resistance. The insertion originates in or near Uganda in East Africa, where it is fixed and has spread to high frequencies in the Central African nation of Cameroon but is still at low frequency in West Africa and absent in Southern Africa. A marked and rapid selection was observed with the 4.3kb-SV frequency increasing from 3% in 2014 to 98% in 2021 in Cameroon. A strong association was established between this SV and pyrethroid resistance in field populations and is reducing pyrethroid-only nets' efficacy. Genetic crosses and qRT-PCR revealed that this SV enhances the expression of CYP6P9a/b but not CYP6P5. Within this structural variant (SV), we identified putative binding sites for transcription factors associated with the regulation of detoxification genes. An inverse correlation was observed between the 4.3kb SV and malaria parasite infection, indicating that mosquitoes lacking the 4.3kb SV were more frequently infected compared to those possessing it. Our findings highlight the underexplored role and rapid spread of SVs in the evolution of insecticide resistance and provide additional tools for molecular surveillance of insecticide resistance.


Assuntos
Anopheles , Sistema Enzimático do Citocromo P-450 , Elementos de DNA Transponíveis , Resistência a Inseticidas , Inseticidas , Malária , Mosquitos Vetores , Piretrinas , Animais , Anopheles/genética , Anopheles/parasitologia , Anopheles/efeitos dos fármacos , Piretrinas/farmacologia , Resistência a Inseticidas/genética , Mosquitos Vetores/genética , Mosquitos Vetores/parasitologia , Mosquitos Vetores/efeitos dos fármacos , Malária/transmissão , Malária/parasitologia , Malária/genética , Elementos de DNA Transponíveis/genética , Sistema Enzimático do Citocromo P-450/genética , Inseticidas/farmacologia , Uganda , Humanos , Camarões
3.
Nature ; 577(7792): 665-670, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31969706

RESUMO

Our knowledge of ancient human population structure in sub-Saharan Africa, particularly prior to the advent of food production, remains limited. Here we report genome-wide DNA data from four children-two of whom were buried approximately 8,000 years ago and two 3,000 years ago-from Shum Laka (Cameroon), one of the earliest known archaeological sites within the probable homeland of the Bantu language group1-11. One individual carried the deeply divergent Y chromosome haplogroup A00, which today is found almost exclusively in the same region12,13. However, the genome-wide ancestry profiles of all four individuals are most similar to those of present-day hunter-gatherers from western Central Africa, which implies that populations in western Cameroon today-as well as speakers of Bantu languages from across the continent-are not descended substantially from the population represented by these four people. We infer an Africa-wide phylogeny that features widespread admixture and three prominent radiations, including one that gave rise to at least four major lineages deep in the history of modern humans.


Assuntos
População Negra/genética , População Negra/história , Comportamento Alimentar/etnologia , Migração Humana/história , Filogenia , Alelos , Animais , Arqueologia , Sepultamento , Camarões , Criança , Pré-Escolar , Cromossomos Humanos Y/genética , DNA Antigo/análise , Feminino , Marcadores Genéticos/genética , Genética Populacional , Genoma Humano/genética , Haplótipos/genética , História Antiga , Humanos , Idioma/história , Masculino , Pan troglodytes/genética , Análise de Componente Principal
4.
Hum Mol Genet ; 32(12): 1946-1958, 2023 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-36752565

RESUMO

Recent data suggest that only a small fraction of severe malaria heritability is explained by the totality of genetic markers discovered so far. The extensive genetic diversity within African populations means that significant associations are likely to be found in Africa. In their series of multi-site genome-wide association studies (GWAS) across sub-Saharan Africa, the Malaria Genomic Epidemiology Network (MalariaGEN) observed specific limitations and encouraged country-specific analyses. Here, we present findings of a GWAS of Cameroonian participants that contributed to MalariaGEN projects (n = 1103). We identified protective associations at polymorphisms within the enhancer region of CHST15 [Benjamin-Hochberg false discovery rate (FDR) < 0.02] that are specific to populations of African ancestry, and that tag strong eQTLs of CHST15 in hepatic cells. In-silico functional analysis revealed a signature of epigenetic regulation of CHST15 that is preserved in populations in historically malaria endemic regions, with haplotype analysis revealing a haplotype that is specific to these populations. Association analysis by ethnolinguistic group identified protective associations within SOD2 (FDR < 0.04), a gene previously shown to be significantly induced in pre-asymptomatic malaria patients from Cameroon. Haplotype analysis revealed substantial heterogeneity within the beta-like globin (HBB) gene cluster amongst the major ethnic groups in Cameroon confirming differential malaria pressure and underscoring age-old fine-scale genetic structure within the country. Our findings revealed novel insights in the evolutionary genetics of populations living in Cameroon under malaria pressure with new significant protective loci (CHST15 and SOD2) and emphasized the significant attenuation of genetic association signals by fine-scale genetic structure.


Assuntos
Estudo de Associação Genômica Ampla , Malária , Humanos , Camarões/epidemiologia , Epigênese Genética , Polimorfismo de Nucleotídeo Único/genética , Malária/epidemiologia , Malária/genética
5.
J Infect Dis ; 229(Supplement_2): S275-S284, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38164967

RESUMO

Monkeypox virus (MPXV) is a reemerging virus of global concern. An outbreak of clade I MPXV affected 20 captive chimpanzees in Cameroon in 2016. We describe the epidemiology, virology, phylogenetics, and clinical progression of this outbreak. Clinical signs included exanthema, facial swelling, perilaryngeal swelling, and eschar. Mpox can be lethal in captive chimpanzees, with death likely resulting from respiratory complications. We advise avoiding anesthesia in animals with respiratory signs to reduce the likelihood of death. This outbreak presented a risk to animal care staff. There is a need for increased awareness and a One Health approach to preparation for outbreaks in wildlife rescue centers in primate range states where MPXV occurs. Control measures should include quarantining affected animals, limiting human contacts, surveillance of humans and animals, use of personal protective equipment, and regular decontamination of enclosures.


Assuntos
Monkeypox virus , Pan troglodytes , Animais , Humanos , Camarões , Surtos de Doenças , Animais Selvagens
6.
Emerg Infect Dis ; 30(3): 577-580, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38407249

RESUMO

Despite zoonotic potential, data are lacking on enteric infection diversity in wild apes. We employed a novel molecular diagnostic platform to detect enteric infections in wild chimpanzees and gorillas. Prevalent Cryptosporidium parvum, adenovirus, and diarrheagenic Escherichia coli across divergent sites and species demonstrates potential widespread circulation among apes in Africa.


Assuntos
Criptosporidiose , Cryptosporidium , Animais , Gorilla gorilla , Pan troglodytes , Camarões/epidemiologia , Tanzânia/epidemiologia , Escherichia coli
7.
Emerg Infect Dis ; 30(3): 432-443, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38325363

RESUMO

During 1979-2022, Cameroon recorded 32 laboratory-confirmed mpox cases among 137 suspected mpox cases identified by the national surveillance network. The highest positivity rate occurred in 2022, indicating potential mpox re-emergence in Cameroon. Both clade I (n = 12) and clade II (n = 18) monkeypox virus (MPXV) were reported, a unique feature of mpox in Cameroon. The overall case-fatality ratio of 2.2% was associated with clade II. We found mpox occurred only in the forested southern part of the country, and MPXV phylogeographic structure revealed a clear geographic separation among concurrent circulating clades. Clade I originated from eastern regions close to neighboring mpox-endemic countries in Central Africa; clade II was prevalent in western regions close to West Africa. Our findings suggest that MPXV re-emerged after a 30-year lapse and might arise from different viral reservoirs unique to ecosystems in eastern and western rainforests of Cameroon.


Assuntos
Monkeypox virus , Mpox , Humanos , Camarões/epidemiologia , Monkeypox virus/genética , Ecossistema , Mpox/epidemiologia , África Ocidental/epidemiologia
8.
BMC Immunol ; 25(1): 54, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39090586

RESUMO

BACKGROUND: HIV-exposed uninfected infants (HEU) appear more vulnerable to infections compared to their HIV-unexposed uninfected (HUU) peers, generally attributed to poor passive immunity acquired from the mother. This may be due to some genetic factors that could alter the immune system. We thus sought to determine the distribution of Killer Cell Immunoglobulin-Like Receptors (KIRs) genes in HEU versus HUU and study their associations with the occurrence of infection-related hospitalization. METHODS: A cohort study was conducted from May 2019 to April 2020 among HEU and HUU infants, including their follow-up at weeks 6, 12, 24, and 48, in reference pediatric centers in Yaoundé-Cameroon. The infant HIV status and infections were determined. A total of 15 KIR genes were investigated using the sequence-specific primer polymerase chain reaction (PCR-SSP) method. The KIR genes that were significantly associated with HIV-1 status (HEU and HUU) were analyzed for an association with infection-related hospitalizations. This was only possible if, and to the extent that, infection-related hospitalizations varied significantly according to status. Multivariate logistic regression analyses were conducted to determine the association between KIR gene content variants and HIV status, while considering a number of potential confounding factors. Furthermore, the risk was quantified using relative risk, odds ratio, and a 95% confidence interval. The Fisher exact test was employed to compare the frequency of occurrences. A p-value of less than 0.05 was considered statistically significant. RESULTS: In this cohort, a total of 66 infants participated, but only 19 acquired infections requiring hospitalizations (14.81%, 04/27 HUU and 38.46%, 15/39 HEU, p = 0.037). At week 48 (39 HEU and 27 HUU), the relative risk (RR) for infection-related hospitalizations was 2.42 (95% CI: 1.028-5.823) for HEU versus HUU with OR 3.59 (1.037-12.448). KIR2DL1 gene was significantly underrepresented in HEU versus HUU (OR = 0.183, 95%CI: 0.053-0.629; p = 0.003), and the absence of KIR2DL1 was significantly associated with infection-related hospitalization (p < 0.001; aOR = 0.063; 95%CI: 0.017-0.229). CONCLUSION: Compared to HUU, the vulnerability of HEU is driven by KIR2DL1, indicating the protective role of this KIR against infection and hospitalizations.


Assuntos
Infecções por HIV , HIV-1 , Hospitalização , Receptores KIR2DL1 , Humanos , Infecções por HIV/genética , Infecções por HIV/imunologia , Infecções por HIV/epidemiologia , Camarões/epidemiologia , Lactente , Hospitalização/estatística & dados numéricos , HIV-1/fisiologia , Masculino , Feminino , Receptores KIR2DL1/genética , Estudos de Coortes , Recém-Nascido , Predisposição Genética para Doença , Biomarcadores , Genótipo
9.
Cancer Causes Control ; 35(5): 787-798, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38177455

RESUMO

PURPOSE: To examine the association between benign breast disease (BBD) and breast cancer (BC) in a heterogeneous population of African women. METHODS: BC cases and controls were enrolled in three sub-Saharan African countries, Nigeria, Cameroon, and Uganda, between 1998 and 2018. Multivariable logistic regression was used to test the association between BBD and BC. Risk factors dually associated with BBD and BC were selected. Using a parametric mediation analysis model, we assessed if selected BC risk factors were mediated by BBD. RESULTS: Of 6,274 participants, 55.6% (3,478) were breast cancer cases. 360 (5.7%) self-reported BBD. Fibroadenoma (46.8%) was the most commonly reported BBD. Women with a self-reported history of BBD had greater odds of developing BC than those without (adjusted odds ratio [aOR] 1.47, 95% CI 1.13-1.91). Biopsy-confirmed BBD was associated with BC (aOR 2.25, 95% CI 1.26-4.02). BBD did not significantly mediate the effects of any of the selected BC risk factors. CONCLUSIONS: In this study, BBD was associated with BC and did not significantly mediate the effects of selected BC risk factors.


Assuntos
Doenças Mamárias , Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/etiologia , Estudos de Casos e Controles , Doenças Mamárias/epidemiologia , Adulto , Pessoa de Meia-Idade , Fatores de Risco , Camarões/epidemiologia , Uganda/epidemiologia , Nigéria/epidemiologia , Idoso , Adulto Jovem
10.
BMC Microbiol ; 24(1): 100, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38532357

RESUMO

BACKGROUND: Cameroon is a tuberculosis (TB) burden country with a 12% positivity among TB presumptive cases. Of the presumptive cases with a negative TB test, some are infected with Non-tuberculous Mycobacteria (NTM). However, the diagnosis of NTM infections remains difficult due to the lack of tools in many laboratories, particularly in resource limited laboratories and remote setting. The present study was undertaken to determine NTM profile and associated comorbidities among TB presumptive people. METHODS: A retrospective study was conducted from December 2018 to December 2019 in the Tuberculosis-National Reference Laboratory (TB-NRL) for Bacteriological analysis of samples and Jamot Hospital of Yaounde (JHY) for clinical evaluation of confirmed NTM patients. We included in this study data of 5267 TB presumptive people previously diagnosed using three consecutive samples and having culture and SD Bioline results with or without Microscopy and reverse hybridization-based Line Probe Assay(LPA) results. The data on co-morbidities or history of people infected with NTM were then collected from the three participants with available clinical data. RESULTS: We collected data of 5267 presumptive TB people. Among them, 3436 (65.24%), have a positive culture with 3200 (60.75%) isolates belong to Mycobacterium tuberculosis Complex (MBTC) and 236 (4.48%) to NTM. Our results showed that, 123 (52.11%) NTM were isolated from people with negative microscopy and 113 (47.88%) from people with positive microscopy. Among the 236 NTM, 108 (45.8%) isolates were identified using LPA. M. fortuitum was the most represented species (32.41%) followed by M. intracellulare (19.44%). Sputum had the highest proportion of NTM (56%), followed by bronchial aspirations (31%). The extra-pulmonary samples presented lower proportions of isolates compared to pulmonary samples. Some patients affected with NTM presented comorbidities as HIV infection, Pulmonary tuberculosis, Type 2 diabetes, Chronic bronchitis and Alveolar pneumonia. CONCLUSIONS: Our study showed the presence of NTM strains among presumptive TB people with a predominance of M. fortuitum and M. intracellulare. It is important to implement a surveillance system of NTM in TB burden country and also to develop a point-of-care test for NTM identification in limited-resource settings.


Assuntos
Diabetes Mellitus Tipo 2 , Infecções por HIV , Infecções por Mycobacterium não Tuberculosas , Tuberculose , Humanos , Micobactérias não Tuberculosas , Infecções por HIV/microbiologia , Infecções por Mycobacterium não Tuberculosas/microbiologia , Estudos Retrospectivos , Camarões , Tuberculose/microbiologia
11.
Ann Bot ; 134(1): 151-162, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38525918

RESUMO

BACKGROUND AND AIMS: Understanding anatomical variations across plant phylogenies and environmental gradients is vital for comprehending plant evolution and adaptation. Previous studies on tropical woody plants have paid limited attention to quantitative differences in major xylem tissues, which serve specific roles in mechanical support (fibres), carbohydrate storage and radial conduction (radial parenchyma, rays), wood capacitance (axial parenchyma) and water transport (vessels). To address this gap, we investigate xylem fractions in 173 tropical tree species spanning 134 genera and 53 families along a 2200-m elevational gradient on Mount Cameroon, West Africa. METHODS: We determined how elevation, stem height and wood density affect interspecific differences in vessel, fibre, and specific axial (AP) and radial (RP) parenchyma fractions. We focus on quantifying distinct subcategories of homogeneous or heterogeneous rays and apotracheal, paratracheal and banded axial parenchyma. KEY RESULTS: Elevation-related cooling correlated with reduced AP fractions and vessel diameters, while fibre fractions increased. Lower elevations exhibited elevated AP fractions due to abundant paratracheal and wide-banded parenchyma in tall trees from coastal and lowland forests. Vasicentric and aliform AP were predominantly associated with greater tree height and wider vessels, which might help cope with high evaporative demands via elastic wood capacitance. In contrast, montane trees featured a higher fibre proportion, scarce axial parenchyma, smaller vessel diameters and higher vessel densities. The lack of AP in montane trees was often compensated for by extended uniseriate ray sections with upright or squared ray cells or the presence of living fibres. CONCLUSIONS: Elevation gradient influenced specific xylem fractions, with lower elevations showing elevated AP due to abundant paratracheal and wide-banded parenchyma, securing greater vessel-to-parenchyma connectivity and lower embolism risk. Montane trees featured a higher fibre proportion and smaller vessel diameters, which may aid survival under greater environmental seasonality and fire risk.


Assuntos
Árvores , Clima Tropical , Madeira , Xilema , Madeira/anatomia & histologia , Madeira/fisiologia , Árvores/anatomia & histologia , Árvores/fisiologia , Xilema/anatomia & histologia , Xilema/fisiologia , Camarões , Altitude
12.
Malar J ; 23(1): 65, 2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38431623

RESUMO

BACKGROUND: Neonicotinoids are potential alternatives for controlling pyrethroid-resistant mosquitoes, but their efficacy against malaria vector populations of sub-Saharan Africa has yet to be investigated. The aim of the present study was to test the efficacy of four neonicotinoids against adult populations of the sibling species Anopheles gambiae and Anopheles coluzzii sampled along an urban-to-rural gradient. METHODS: The lethal toxicity of three active ingredients for adults of two susceptible Anopheles strains was assessed using concentration-response assays, and their discriminating concentrations were calculated. The discriminating concentrations were then used to test the susceptibility of An. gambiae and An. coluzzii mosquitoes collected from urban, suburban and rural areas of Yaoundé, Cameroon, to acetamiprid, imidacloprid, clothianidin and thiamethoxam. RESULTS: Lethal concentrations of neonicotinoids were relatively high suggesting that this class of insecticides has low toxicity against Anopheles mosquitoes. Reduced susceptibility to the four neonicotinoids tested was detected in An. gambiae populations collected from rural and suburban areas. By contrast, adults of An. coluzzii that occurred in urbanized settings were susceptible to neonicotinoids except acetamiprid for which 80% mortality was obtained within 72 h of insecticide exposure. The cytochrome inhibitor, piperonyl butoxide (PBO), significantly enhanced the activity of clothianidin and acetamiprid against An. gambiae mosquitoes. CONCLUSIONS: These findings corroborate susceptibility profiles observed in larvae and highlight a significant variation in tolerance to neonicotinoids between An. gambiae and An. coluzzii populations from Yaoundé. Further studies are needed to disentangle the role of exposure to agricultural pesticides and of cross-resistance mechanisms in the development of neonicotinoid resistance in some Anopheles species.


Assuntos
Anopheles , Guanidinas , Inseticidas , Malária , Piretrinas , Tiazóis , Animais , Inseticidas/farmacologia , Camarões , Resistência a Inseticidas , Mosquitos Vetores , Neonicotinoides/farmacologia , Piretrinas/farmacologia
13.
Malar J ; 23(1): 155, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38769514

RESUMO

BACKGROUND: Cameroon is one of the countries with the highest burden of malaria. Since 2018, there has been an ongoing conflict in the country, which has reduced access to healthcare for populations in affected regions, and little is known about the impact on access to malaria services. The objective of this study was to understand the current situation regarding access to malaria services in Cameroon to inform the design of interventions to remove barriers and encourage the use of available services. METHODS: A qualitative research study was carried out to understand the barriers preventing communities accessing care, the uptake of community health worker (CHW) services, and to gather perceptions on community engagement approaches, to assess whether these could be an appropriate mechanism to encourage uptake of community health worker (CHW) services. Twenty-nine focus group discussions and 11 in-depth interviews were carried out between May and July 2021 in two regions of Cameroon, Southwest and Littoral. Focus group discussions were held with CHWs and community members and semi-structured, in-depth interviews were conducted with key stakeholders including regional government staff, council staff, community leaders and community-based organisations. The data were analysed thematically; open, descriptive coding was combined with exploration of pre-determined investigative areas. RESULTS: The study confirmed that access to healthcare has become increasingly challenging in conflict-affected areas. Although the Ministry of Health are providing CHWs to improve access, several barriers remain that limit uptake of these services including awareness, availability, cost, trust in competency, and supply of testing and treatment. This study found that communities were supportive of community engagement approaches, particularly the community dialogue approach. CONCLUSION: Communities in conflict-affected regions of Cameroon continue to have limited access to healthcare services, in part due to poor use of CHW services provided. Community engagement approaches can be an effective way to improve the awareness and use of CHWs. However, these approaches alone will not be sufficient to resolve all the challenges faced by conflict-affected communities when accessing health and malaria services. Additional interventions are needed to increase the availability of CHWs, improve the supply of diagnostic tests and treatments and to reduce the cost of treatment for all.


Assuntos
Acessibilidade aos Serviços de Saúde , Malária , Pesquisa Qualitativa , Camarões , Malária/prevenção & controle , Humanos , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Agentes Comunitários de Saúde/estatística & dados numéricos , Grupos Focais , Participação da Comunidade/estatística & dados numéricos , Masculino , Feminino , Adulto
14.
Malar J ; 23(1): 99, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589868

RESUMO

BACKGROUND: Malaria remains a major global health problem often worsened by political instability and armed conflict. The purpose of the study was to explore community knowledge, attitudes and practices on malaria prevention, and to understand the burden of malaria and health-seeking behaviours of caregivers of children under-five in conflict-affected communities of the South West and Littoral Regions of Cameroon. METHODS: A cross-sectional survey involving internally displaced persons (IDPS), host population, and their children under-five was conducted across 80 communities. The survey was conducted from May to June 2021. Participants were interviewed using a structured questionnaire. Malaria prevalence for children under-five was determined using rapid diagnostic tests (RDT) on blood samples. Association between variables and displacement status was measured using chi square test and multivariate logistic regression model was fitted to identify factors associated with adequate knowledge on malaria prevention. RESULTS: A total of 2386 adults participated in the study and 1543 RDTs were conducted for children under-five. Adequate levels of knowledge and attitudes on malaria prevention was recorded among 1258 (52.9%) of the participants, with very strong evidence to suggest the level to be higher among the host (59.5%) compared to the IDPs (49.5%) and returnees (39.7%) (p < 0.001). Good practices towards malaria prevention was 43.3%, with very strong evidence indicating lower levels among IDPs (42.8%) and returnees (28.5%) compared to the host (49.4%) (p < 0.001). Malaria prevalence for children under-five was 54.0% and adequate health-seeking for suspected episodes of malaria was 53.0%, without any difference among IDPs (51.78%) and returnees (48.7%) compared to host populations (55.4%) (p = 0.154). Multivariate logistic regression model showed that there was quite strong evidence to suggest primary and secondary levels of education have higher odds of having correct knowledge of malaria prevention (adjusted odds ratio (AOR) 1.71, 95% confidence interval (CI): 1.11-2.64, p = 0.015 and AOR 1.80, 95% CI 1.15-2.82, p = 0.010 respectively). There was very strong evidence to suggest that owning a radio or a television was associated with greater odds of having a higher knowledge on malaria prevention (AOR 1.49, 95% CI 1.233-1.81, p = 0.000 and AOR 1.47, 95% CI 1.18-1.84, p = 0.001). CONCLUSION: Over half of the population have correct knowledge and attitudes towards malaria prevention but gaps in complete knowledge remained. Some of the caregivers know the correct malaria preventive practices coupled with largely unsatisfactory treatment approaches and reflected by the high prevalence of malaria among their children. In order to effectively treat malaria, innovative strategies should target community participation.


Assuntos
Cuidadores , Malária , Adulto , Criança , Humanos , Estudos Transversais , Camarões/epidemiologia , Malária/epidemiologia , Malária/prevenção & controle , Malária/diagnóstico , Conhecimentos, Atitudes e Prática em Saúde , Aceitação pelo Paciente de Cuidados de Saúde
15.
Malar J ; 23(1): 243, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39138579

RESUMO

BACKGROUND: In endemic locations, asymptomatic malaria is a major contribution to the rise in clinical malaria. In order to achieve the goal of interrupting malaria transmission, control programmes should take into consideration carriers of asymptomatic malaria parasite. Hence, the purpose of this study was to look at the prevalence and risk factors of asymptomatic malaria in children in Nkwen village. METHODS: Using a cross-sectional and community-based design, conducted between June and December 2022, a total of 246 children were enrolled after obtaining informed and signed consent from parents and/ or guardians. To collect data, pre-tested, closed-ended, structured questionnaires were used, ensuring the accuracy and reliability of the information gathered. A digital thermometer with infrared forehead capability was used to take participants' body temperature, providing precise measurements and respondents with temperature < 37.5 °C, and not presenting any symptoms or indicators of malaria were included in the study, ensuring the focus on asymptomatic cases. Blood samples were collected by venipuncture and screened for the presence of asymptomatic parasitaemia using blood smear microscopy and nested polymerase chain reaction (PCR). Data was entered into Microsoft Excel worksheet and analysed using SPSS version 23 software. Logistic regression models were carried out to explore the risk factors associated with asymptomatic malaria at household and individual levels and statistically significant association was considered at a p-value < 0.05. RESULTS: A total of 246 healthy children were examined for asymptomatic malaria infection using microscopy and PCR. Of the examined children, 65.9% (162/246) were malaria positive by PCR while 59.3% (146/246) were malaria positive by microscopy. Considering both diagnostic methods, females had a greater prevalence of asymptomatic malaria than males. In logistic analysis, the risk of developing asymptomatic malaria was associated several factors: previous malaria episode (OR = 5.14; CI 2.94-9.01), family history of malaria (OR = 3.86; CI 2.21-6.74), homestead near swampy areas (OR = 3.56; CI 2.10-10.61), non-utilization of insecticide treated nets (OR = 4.36; CI 2.53-7.5), non-usage of indoor residual spray (IRS) (OR = 6.67; CI 3.75-11.86) and opened eaves (OR = 3.86; CI 2.21-6.74). No associations were established between asymptomatic malaria and the following factors: age group (p > 0.05), gender (p > 0.05) and type of wall construction (p > 0.05). CONCLUSION: The high rate of asymptomatic malaria in this study is a significant problem and may jeopardize the current malaria control effort. Personal and house-level risk factors were linked with asymptomatic malaria. Therefore, it should be considered when evaluating and restructuring more successful malaria elimination tactics to accomplish the intended goals of malaria control.


Assuntos
Infecções Assintomáticas , Malária , Humanos , Fatores de Risco , Prevalência , Feminino , Estudos Transversais , Masculino , Pré-Escolar , Infecções Assintomáticas/epidemiologia , Criança , Camarões/epidemiologia , Lactente , Malária/epidemiologia , Adolescente
16.
Malar J ; 23(1): 6, 2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38178125

RESUMO

BACKGROUND: Approximately 32 million pregnant women are at risk of malaria with up to 10,000 maternal deaths and 200,000 neonates at risk annually. Intermittent Preventive Treatment (IPT) with sulfadoxine-pyrimethamine (SP) is recommended by the World Health Organization (WHO) to reduce disease in pregnancy and adverse maternal and newborn outcomes. At least three doses of SP should be taken by pregnant women during antenatal consultation (ANC) beginning from the thirteenth week of pregnancy till parturition. The aim of this study was to assess uptake of IPT during pregnancy and risk factors for maternal anaemia and infant birth weight in Dschang, West region of Cameroon. METHODS: A total of 380 consenting pregnant women at delivery were recruited in a cross- sectional prospective survey between January to December 2021. Data on ANC attendance, total dose of IPT and history of malaria were abstracted from hospital ANC records while socio-demographic characteristics, bed net use and obstetrics history of each participant were also recorded through an interview. Further, blood samples were collected from the intervillous space for assessment of maternal anaemia and microscopic parasitology. Nested PCR based on amplification of the Plasmodium 18S sRNA was carried out to detect submicroscopic infection. IPTp coverage was calculated per WHO recommendation and the prevalence of anaemia and low birth weight were estimated as proportions in the total sample of pregnant women and live births, respectively. Crude and adjusted odds ratios and their 95% confidence intervals were used to estimate associations between pregnancy outcomes considered and risk factors in specific and general models. A p < 0.05 was considered significant. The R software (V4.1.4) was used for all analyses. RESULTS: A majority of pregnant women was aged between 24 and 34 years old (59.2%) and had secondary education (58.8%). Uptake of ≥ 3 IPTp was 64.99% with 77.20% of all who received at least one IPTp doses taking a mix of SP and DP or DP alone in successive ANC contacts. Those with four or more ANC contacts (73.42%) were more likely to have received at least one IPTp. Furthermore, 13.9% of live births had low birthweights (BW < 2500 g) and one in four parturient women with moderate anaemia by WHO criteria. Microscopy (blood smear examination) and PCR-based diagnosis revealed between 0% and 1.57% of parasite-infected placental samples, respectively. Reported malaria in pregnancy predicted maternal anaemia at birth but not birth weight. Only gestational age (< 37 weeks) and bed net use (< 5 months) significantly predicted infant birth weight at delivery. CONCLUSION: The uptake of WHO recommended IPT doses during pregnancy was moderately high. Reported malaria in pregnancy, poor bed net coverage, gestational age less than 37 weeks adversely affect maternal haemoglobin levels at birth and infant birth weight. Asymptomatic and submicroscopic placental parasite infections was found at low prevalence. Together these results highlight the importance of maintaining aggressive measures to prevent malaria in pregnancy and protect the health of mother and baby.


Assuntos
Anemia , Antimaláricos , Infecções por HIV , Malária , Complicações Parasitárias na Gravidez , Recém-Nascido , Feminino , Humanos , Gravidez , Adulto Jovem , Adulto , Lactente , Antimaláricos/uso terapêutico , Peso ao Nascer , Estudos Transversais , Mães , Camarões/epidemiologia , Estudos Prospectivos , Placenta , Malária/epidemiologia , Malária/prevenção & controle , Malária/tratamento farmacológico , Pirimetamina/uso terapêutico , Sulfadoxina/uso terapêutico , Recém-Nascido de Baixo Peso , Fatores de Risco , Combinação de Medicamentos , Resultado da Gravidez , Complicações Parasitárias na Gravidez/epidemiologia , Complicações Parasitárias na Gravidez/prevenção & controle , Complicações Parasitárias na Gravidez/tratamento farmacológico , Anemia/parasitologia , Infecções por HIV/tratamento farmacológico
17.
J Surg Res ; 293: 158-167, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37774593

RESUMO

INTRODUCTION: Surgical care is a significant component of the overall health expenditure in low- and middle-income countries. In Cameroon, out-of-pocket payments for surgical service are very high with many patients declining potentially curative surgical procedures. Less than 2% of the population is enrolled in a health insurance scheme leading to a propensity for catastrophic health expenses when accessing care. To assess the perceived barriers and motivations for health insurance subscription among health-care users in Cameroon. METHODS: This was a cross-sectional community-based qualitative study conducted in the Center Region of Cameroon. A total of 37 health-care users (health insurance subscribers and nonsubscribers) were purposively identified. Four focused group discussions and thirteen in-depth interviews were conducted. All anonymized transcripts were analyzed using a thematic analysis approach. RESULTS: The six major themes identified as barriers to health insurance subscription were lack of trust in the existing health insurance schemes, inadequate knowledge on how health insurance works, premiums believed to be too expensive, the complexity of the claims processing system, minimal usage of health-care services and practice of self-medication. Motivational factors included the knowledge of having access to quality health services even without money in the event of an unforeseen illness and having a large family/household size. The importance of mass sensitization on the benefits of health insurance was noted. CONCLUSION: Health insurance is still very underutilized in Cameroon. This results in significant out-of-pocket payment for health services by Cameroonians with catastrophic consequences to households. With most Cameroonians in the informal sector and underemployed, it is imperative to put in place a national strategic plan to overcome existing barriers and increase health insurance coverage especially among the poor. This has the potential to significantly increase access to safe, quality, timely and affordable surgical care.


Assuntos
Atenção à Saúde , Motivação , Humanos , Camarões , Estudos Transversais , Seguro Saúde , Gastos em Saúde
18.
J Med Primatol ; 53(1): e12687, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38083993

RESUMO

We tested for Rift Valley fever virus (RVFV) from at least 15 species of non-human primates. RVFV IgG/IgM antibodies were detected in 3.7% (2 out of 53) of chimpanzees (Pan troglodytes) and in 1.4% (1 out of 72) of unidentified non-human primate species. This study was the first investigation of RVFV in monkeys in Cameroon.


Assuntos
Febre do Vale de Rift , Vírus da Febre do Vale do Rift , Animais , Febre do Vale de Rift/diagnóstico , Camarões , Anticorpos Antivirais , Primatas , Estudos Soroepidemiológicos
19.
AIDS Behav ; 28(9): 2950-2960, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38767726

RESUMO

Mental health-related stigma is a prominent barrier to improved mental health outcomes globally and may be particularly harmful to populations with other stigmatized identities. We aimed to understand intersectional depression- and HIV-related stigma among people with HIV (PWH) entering HIV care in Cameroon. Using baseline data from a cohort of PWH entering HIV care in Cameroon between 2019 and 2020, we characterized depression- and HIV-related stigma in the population overall and by sociodemographic sub-group. We also explored substantively meaningful variation in stigma endorsement by depressive symptom severity (Patient Health Questionnaire-9 [PHQ-9]) and causal attribution of depression. Among those with elevated depressive symptoms (PHQ-9 scores > 4), we estimated the association between stigma type and depressive symptom severity using binomial regression. Among 398 participants, 49% endorsed low HIV- and depression-related stigma (N = 195), 10% endorsed high HIV- and depression-related stigma (N = 38), 29% endorsed high depression-related stigma only (N = 116), and 12% endorsed high HIV-related stigma only (N = 49). Respondents with and without heightened depressive symptoms commonly believed depressive symptoms were caused by HIV (N = 140; 32.9%). Among those with elevated depressive symptoms, the prevalence of moderate to severe symptoms was higher among those endorsing high HIV-related stigma only (prevalence ratio 1.55; 95% confidence interval: 1.01, 2.37) compared to those reporting low HIV- and depression-related stigma. HIV- and depression-related stigma are both common among PWH entering HIV care in Cameroon. The consistent association between HIV-related stigma and poor psychosocial well-being among people with HIV necessitates the urgent scale-up of evidence-based HIV-related stigma interventions specifically.


Assuntos
Depressão , Infecções por HIV , Estigma Social , Humanos , Camarões/epidemiologia , Infecções por HIV/psicologia , Infecções por HIV/epidemiologia , Infecções por HIV/complicações , Masculino , Feminino , Adulto , Depressão/epidemiologia , Depressão/psicologia , Pessoa de Meia-Idade , Inquéritos e Questionários , Adulto Jovem
20.
AIDS Behav ; 28(3): 898-906, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37843686

RESUMO

Many adolescents under 18 years old who sell sex are at elevated risk for sexually transmitted infection (STI) acquisition, which may persist into adulthood. There has been limited study of the burden of the risks and vulnerabilities among women who started selling sex as adolescents across Sub-Saharan Africa. In this study, a Adult female sex workers (FSW) recruited through respondent-driven sampling in five cities in Cameroon from December 2015 to October 2016 completed a questionnaire and human immunodeficiency virus (HIV) and syphilis testing. Multivariable logistic regression analysis controlling for age was used to identify factors associated with reporting selling sex before age 18. Selling sex before age 18 was reported by 11.5% (256/2,220) of FSW. Initiation of selling sex as an adolescent was positively associated with experiencing dysuria (adjusted odds ratio [aOR]:1.50, 95% confidence interval [CI]:1.08-2.10) or genital warts (aOR:1.78, 95% CI:1.08-2.94) and negatively associated with prior recent testing for HIV (aOR:0.71, 95% CI:0.53-0.96) or STIs (aOR:0.65, 95% CI:0.44-0.96). Consistent condom use with clients was negatively associated with early initiation of selling sex (aOR:0.58, 95% CI:0.42-0.80), while experience of recent sexual violence was positively associated with early initiation (aOR:1.74, 95% CI:1.15-2.63). There were no independent significant differences in HIV (24.5%) or syphilis (8.3%) prevalence. Given the limited use of HIV and STI testing services by women who sold sex as adolescents, the prevalence of forced sex, condomless sex, and STI symptoms were high. Programs serving FSW should more vigorously aim to serve adolescents and adults who began selling sex early.


Assuntos
Infecções por HIV , Profissionais do Sexo , Infecções Sexualmente Transmissíveis , Sífilis , Adulto , Adolescente , Feminino , Humanos , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Sífilis/epidemiologia , Camarões/epidemiologia , Cidades , Infecções Sexualmente Transmissíveis/epidemiologia , Infecções Sexualmente Transmissíveis/diagnóstico , HIV , Inquéritos e Questionários , Prevalência
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