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Background and Aim: Cryptosporidium spp. members of the phylum Apicomplexa are obligate protozoan parasites capable of infecting various vertebrate hosts, including rodents and chickens. Infection caused by these parasites may lead to zoonotic diseases in humans. The aim of this study was to estimate the prevalence of Cryptosporidium spp. in rodents and domestic chickens sampled in Franceville, Gabon. Materials and Methods: Two hundred and eighty-five samples were collected, of which 185 samples were from rodents and 100 from domestic chickens. Microscopy after modified Ziehl-Neelsen staining and nested polymerase chain reaction targeting the small subunit (SSU) rRNA gene were used to examine Cryptosporidium spp. Results: The overall prevalence of Cryptosporidium oocysts was 55.8%, with a prevalence of 72.4% in rodents and 25.0% in domestic chickens. Molecular analysis showed that Cryptosporidium spp. were present in 4.0% of the samples. No significant correlation was observed between Cryptosporidium spp. carriage and sex or location in this study. These results indicate that Cryptosporidium spp. persist and circulate in the studied animal species in Franceville, Gabon. Conclusion: Infection with Cryptosporidium is very common in rodents and chickens in Franceville. The potential risk of human contamination cannot be ruled out. More research should be conducted to characterize Cryptosporidium species circulating in rodents and chickens in Gabon. Such studies are essential to better understand the epidemiology of this protozoan and its potential impact on public health.
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Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral disease with a mortality rate reaching up to 40% in humans. Currently, CCHF affects three continents: Asia, Europe, and Africa. An increase in confirmed cases in Africa has been observed since 2000. In Central Africa, several countries have reported the circulation of CCHV virus (CCHFV). However, in Gabon, there is a lack of recent data on the circulation of the virus in the Gabonese population. To provide an overview of the epidemiological situation in Gabon, we tested 3,081 human serum samples collected between 2005 and 2008 in villages throughout the country for anti-CCHFV antibodies. Using a double-antigen ELISA kit, our study found 15/3,081 samples positive for CCHFV. These positive samples were also tested using the Blackbox CCHFV IgG kit and the Luminex technique. These analyses confirmed seven and four positives for the Blackbox CCHFV IgG kit and the Luminex technique, respectively. This study suggests low circulation of CCHFV in the rural human population of Gabon. Competent authorities must survey CCHFV to identify and prevent clinical cases in the human population.
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Rift Valley fever (RVF) is a mosquito-borne viral zoonosis caused by the Rift Valley fever virus (RVFV) that can infect domestic and wild animals. Although the RVFV transmission cycle has been well documented across Africa in savanna ecosystems, little is known about its transmission in tropical rainforest settings, particularly in Central Africa. We therefore conducted a survey in northeastern Gabon to assess RVFV circulation among wild and domestic animals. Among 163 wildlife samples tested using RVFV-specific RT-qPCR, four ruminants belonging to subfamily Cephalophinae were detected positive. The phylogenetic analysis revealed that the four RVFV sequences clustered together with a virus isolated in Namibia within the well-structured Egyptian clade. A cross-sectional survey conducted on sheep, goats and dogs living in villages within the same area determined the IgG RVFV-specific antibody prevalence using cELISA. Out of the 306 small ruminants tested (214 goats, 92 sheep), an overall antibody prevalence of 15.4% (95% CI [11.5-19.9]) was observed with a higher rate in goats than in sheep (20.1% versus 3.3%). RVFV-specific antibodies were detected in a single dog out of the 26 tested. Neither age, sex of domestic animals nor season was found to be significant risk factors of RVFV occurrence. Our findings highlight sylvatic circulation of RVFV for the first time in Gabon. These results stress the need to develop adequate surveillance plan measures to better control the public health threat of RVFV.
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Fiebre del Valle del Rift , Virus de la Fiebre del Valle del Rift , Animales , Ovinos , Perros , Animales Domésticos , Animales Salvajes , Gabón/epidemiología , Estudios Transversales , Ecosistema , Filogenia , Rumiantes , Cabras , Anticuerpos Antivirales , Bosques , Estudios SeroepidemiológicosRESUMEN
BACKGROUND: Strengthening the surveillance of zoonotic diseases emergence in the wild meat value chains is a critical component of the prevention of future health crises. Community hunters could act as first-line observers in zoonotic pathogens surveillance systems in wildlife, by reporting early signs of the possible presence of a disease in the game animals they observe and manipulate on a regular basis. METHODS: An experimental game was developed and implemented in a forested area of Gabon, in central Africa. Our objective was to improve our understanding of community hunters' decision-making when finding signs of zoonotic diseases in game animals: would they report or dissimulate these findings to a health agency? 88 hunters, divided into 9 groups of 5 to 13 participants, participated in the game, which was run over 21 rounds. In each round the players participated in a simulated hunting trip during which they had a chance of capturing a wild animal displaying clinical signs of a zoonotic disease. When signs were visible, players had to decide whether to sell/consume the animal or to report it. The last option implied a lowered revenue from the hunt but an increased probability of early detection of zoonotic diseases with benefits for the entire group of hunters. RESULTS: The results showed that false alerts-i.e. a suspect case not caused by a zoonotic disease-led to a decrease in the number of reports in the next round (Odds Ratio [OR]: 0.46, 95% Confidence Interval [CI]: 0.36-0.8, p < 0.01). Hunters who had an agricultural activity in addition to hunting reported suspect cases more often than others (OR: 2.05, 95% CI: 1.09-3.88, p < 0.03). The number of suspect case reports increased with the rank of the game round (Incremental OR: 1.11, CI: 1.06-1.17, p < 0.01) suggesting an increase in participants' inclination to report throughout the game. CONCLUSION: Using experimental games presents an added value for improving the understanding of people's decisions to participate in health surveillance systems.
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Animales Salvajes , Zoonosis , Animales , Humanos , Zoonosis/epidemiología , Zoonosis/prevención & control , Carne , Probabilidad , Juegos ExperimentalesRESUMEN
Coronaviruses (CoVs, Coronaviridae) are a diverse group of viruses that infect mammals, birds, and fish. Seven CoVs infect humans, among which Severe Acute Respiratory Syndrome CoVs-1 and -2 and Middle East respiratory syndrome CoVs have shown how they can impact global health and the economy. Their spillover from bats-the natural reservoir-to humans has required intermediary hosts. Prevention requires that active surveillance be conducted on animals. Today, there is no data concerning the genetic diversity of CoVs naturally circulating in wild primates. This study aimed to screen wild great apes and mandrills in Gabon for CoVs. A total of 229 faecal samples of great apes and mandrills collected from 2009 to 2012 in forests and national parks were used for the detection of CoVs by nested PCR using primers targeting a conserved region of the RNA-dependent RNA polymerase. While all samples were negative, this lack of detection could be related to sample size, the transient nature of the infection, or because faecal samples are not suitable for detecting CoVs in primates. A longitudinal study should be performed and other non-invasive methods used to collect respiratory samples to better evaluate the circulation of CoVs in these primates.
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Astroviruses (AstVs), enteroviruses (EVs), and caliciviruses (CaVs) infect several vertebrate taxa. Transmitted through the fecal-oral route, these enteric viruses are highly resistant and can survive in the environment, thereby increasing their zoonotic potential. Here, we screened for AstVs, EVs, and CaVs to investigate the role of domestic animals in the emergence of zoonoses, because they are situated at the human/wildlife interface, particularly in rural forested areas in Central Africa. Rectal swabs were obtained from 123 goats, 41 sheep, and 76 dogs in 10 villages located in northeastern Gabon. Extracted RNA reverse-transcribed into cDNA was used to detect AstVs, EVs, and CaVs by amplification of the RNA-dependent RNA polymerase (RdRp), or capsid protein (VP1) gene using PCR. A total of 23 samples tested positive, including 17 goats for AstVs, 2 goats, 2 sheep, 1 dog for EVs, and 1 dog for CaVs. Phylogenetic analyses revealed that AstV RdRp sequences clustered with sheep-, goat-, or bovine-related AstVs. In addition, one goat and two sheep VP1 sequences clustered with caprine/ovine-related Evs within the Enterovirus G species, and the CaV was a canine vesivirus. However, human-pathogenic Evs, EV-B80 and EV-C99, were detected in goats and dogs, raising questions on the maintenance of viruses able to infect humans.
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The first detection of canine parvovirus type-2 (CPV-2) was in the early 1970s, when it was known to cause severe gastroenteritis in dogs. However, it has evolved over the years into CPV-2a within 2 years, into CPV-2b after 14 years, into CPV-2c after 16 years and more recently CPV-2a-, 2b- and 2c-like variants reported in 2019, with a global distribution. Reports on the molecular epidemiology of this virus are missing in most African countries. The report of clinical cases among vaccinated dogs in Libreville in Gabon triggered the execution of this study. The objective of this study was to characterize circulating variants from dogs showing clinical signs suggestive of CPV that were examined by a veterinarian. A total of eight (8) fecal swab samples were collected, and all had positive PCR results. Sequencing, Blast analysis and assembly of two whole genomes and eight partial VP2 sequences were performed, and the sequences submitted to GenBank. Genetic characterization revealed the presence of CPV-2a and CPV-2c variants with predominance of the former. Phylogenetically, the Gabonese CPVs formed distinct groups similar to Zambian CPV-2c and Australian CPV-2a sequences. The antigenic variants CPV-2a and CPV-2c have not yet been reported in Central Africa. However, these CPV-2 variants circulate in young, vaccinated dogs in Gabon. These results suggest additional epidemiological and genomic studies are required in order to evaluate the occurrence of different CPV variants in Gabon and effectiveness of the commercial vaccines used against protoparvovirus in the country.
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Enfermedades de los Perros , Infecciones por Parvoviridae , Parvovirus Canino , Perros , Animales , Parvovirus Canino/genética , Gabón/epidemiología , Infecciones por Parvoviridae/epidemiología , Infecciones por Parvoviridae/veterinaria , Enfermedades de los Perros/epidemiología , Enfermedades de los Perros/prevención & control , Australia , FilogeniaRESUMEN
Wild animals harbor pathogens that can be infectious agents for humans, including parasites. This study aimed to identify gastrointestinal parasites and assess their prevalence and the potential risk for humans associated with consuming these animals. The research was conducted from August to December 2019. Parasitological analyses were carried out on the feces and intestines of 113 wild animals, including antelopes (24), duikers (58), porcupines (18), small monkeys (Cercopithecus) (8), nandinia (2), pangolin (1), genet (1), and a crocodile (1), from the Zadié Department in the province of Ogooué-Ivindo in the northeast of Gabon. The results revealed 15 taxa of gastrointestinal parasites, including nine nematodes: Strongylids (61/113), Strongyloides spp. (21/113), Ascaris spp. (21/113), Trichuris spp. (39/113), Capillaria spp. (9/113), Protostrongylus spp. (5/113), Enterobius spp. (8/113), Toxocara spp. (7/113) and Mammomonogamus spp. (5/113); three species of protozoa, namely Balantidium spp. (12/113), Eimeria spp. (17/113), and Entamoeba spp. (9/113); two species of trematodes, namely Fasciola spp. (18/113) and Paramphistomum spp. (21/113); and cestode species, Taenia spp. (1/113). The prevalence of gastrointestinal parasitism in these animals was 85.84% (97/113). In addition, among these parasitic taxa, some are potential pathogens for humans, such as Ascaris spp., Balantidium spp., Entamoeba spp., and Taenia spp. The consumption of games, particularly offal, infested by these parasites, could threaten human health.
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Arboviruses represent a real public health problem globally and in the Central African subregion in particular, which represents a high-risk zone for the emergence and re-emergence of arbovirus outbreaks. Furthermore, an updated review on the current arbovirus burden and associated mosquito vectors is lacking for this region. To contribute to filling this knowledge gap, the current study was designed with the following objectives: (i) to systematically review data on the occurrence and distribution of arboviruses and mosquito fauna; and (ii) to identify potential spillover mosquito species in the Central African region in the last 30 years. A web search enabled the documentation of 2454 articles from different online databases. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) and the quality of reporting of meta-analyses (QUORUM) steps for a systematic review enabled the selection of 164 articles that fulfilled our selection criteria. Of the six arboviruses (dengue virus (DENV), chikungunya virus (CHIKV), yellow fever virus (YFV), Zika virus (ZIKV), Rift Valley fever virus (RVFV), and West Nile virus (WNV)) of public health concern studied, the most frequently reported were chikungunya and dengue. The entomological records showed >248 species of mosquitoes regrouped under 15 genera, with Anopheles (n = 100 species), Culex (n = 56 species), and Aedes (n = 52 species) having high species diversity. Three genera were rarely represented, with only one species included, namely, Orthopodomyia, Lutzia, and Verrallina, but individuals of the genera Toxorhinchites and Finlayas were not identified at the species level. We found that two Aedes species (Ae. aegypti and Ae. albopictus) colonised the same microhabitat and were involved in major epidemics of the six medically important arboviruses, and other less-frequently identified mosquito genera consisted of competent species and were associated with outbreaks of medical and zoonotic arboviruses. The present study reveals a high species richness of competent mosquito vectors that could lead to the spillover of medically important arboviruses in the region. Although epidemiological studies were found, they were not regularly documented, and this also applies to vector competence and transmission studies. Future studies will consider unpublished information in dissertations and technical reports from different countries to allow their information to be more consistent. A regional project, entitled "Ecology of Arboviruses" (EcoVir), is underway in three countries (Gabon, Benin, and Cote d'Ivoire) to generate a more comprehensive epidemiological and entomological data on this topic.
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Toxoplasma gondii is an obligatory intracellular parasite that causes a zoonotic disease capable of infecting nearly all warm-blooded hosts, including humans. However, reports on the molecular prevalence of T. gondii in humans are rare in Gabon. The present study aimed to evaluate the serological and molecular prevalence of T. gondii among apparently healthy rural populations in four regions of Gabon. This study included six hundred blood samples from the Interdisciplinary Center for Medical Research (CIRMF) bank, including 300 women and 300 men living in 111 villages. Blood samples were screened using enzyme-linked fluorescent assay (ELFA), while buffy coat samples were analyzed using PCR analyses. Of the 600 samples screened, 548 (91.3%) showed IgG antibodies against T. gondii; 11 (2%) had both IgG and IgM. Among the 548 positive samples, 155 (28%) had higher IgG titers (>300 UI/ml), and 49 of them (31.6%) were detected with T. gondii DNA. The present findings on human toxoplasmosis in Gabon suggest that at an older age, reactivation of old infections seems more frequent than new infections, as indicated by the presence of T. gondii using PCR among elevated IgG subjects without IgM. Further studies should be performed to identify the genotypes of T. gondii that infect humans in Gabon.
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Humanos , Toxoplasma , Toxoplasmosis Congénita , Población Rural , Humanos , PrevalenciaRESUMEN
Background After the first cases of coronaviruses disease 2019 (COVID-19) in China in January 2020, we conducted an epidemiological surveillance of COVID-19 in Gabon. Methods We led molecular investigations on nasopharyngeal and oropharyngeal samples from the 1161 first suspected cases of COVID-19. We diagnosed the first case of COVID-19 on March, 12 2020. Results Among those suspected cases, 83 were confirmed cases. There was no significant difference in prevalence of SARS-CoV-2 between age groups (p=0.14). 73% were asymptomatic. The viral loads were significantly higher in the nasopharyngeal samples than in the oropharyngeal samples (p=0.03). There was no significant difference in viral loads between age groups (p=0.9895) and no correlation between clinical symptoms and viral loads (p=0.06042). A phylogenetic analysis performed with five sequences of the spike S gene showed that two sequences had the D614G mutation. Conclusion In conclusion, this study provides the first molecular data from Gabon concerning the COVID-19 pandemic. The data showed that most of the infected people were asymptomatic. The viral load was higher in the nasopharyngeal samples. The S gene analyzed suggested both introduction of the D614 and G614 variant in Gabon.
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COVID-19 , Humanos , COVID-19/epidemiología , Gabón/epidemiología , Pandemias , SARS-CoV-2 , Carga ViralRESUMEN
Rabies is a zoonotic neurological life-threatening neglected tropical disease present worldwide, and Gabon is listed as an endemic country. However, despite strong clinical suspicion in humans and molecular confirmation of rabies virus (RABV) infections in dogs for several decades, no molecularly confirmed human case in Gabon has ever been reported. In this study, we describe two cases of human rabies and provide the first molecular diagnostic report on suspected human rabies cases in Gabon. Our results showed that the RABVs isolated from the patients are closely related to other RABV strains belonging to the African 1A subclade in the Cosmopolitan lineage isolated more than 20 years ago from Gabonese dog brains, suggesting that only this species circulates in the country. Because both patients had a history of dog bites a few weeks before symptom onset and the main causative agent of human rabies worldwide is dog-associated RABV, we conclude that dogs are likely to be the source of human infection in this study.
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Bats host many viruses pathogenic to humans, and increasing evidence suggests that rotavirus A (RVA) also belongs to this list. Rotaviruses cause diarrheal disease in many mammals and birds, and their segmented genomes allow them to reassort and increase their genetic diversity. Eighteen out of 2,142 bat fecal samples (0.8%) collected from Europe, Central America, and Africa were PCR-positive for RVA, and 11 of those were fully characterized using viral metagenomics. Upon contrasting their genomes with publicly available data, at least 7 distinct bat RVA genotype constellations (GCs) were identified, which included evidence of reassortments and 6 novel genotypes. Some of these constellations are spread across the world, whereas others appear to be geographically restricted. Our analyses also suggest that several unusual human and equine RVA strains might be of bat RVA origin, based on their phylogenetic clustering, despite various levels of nucleotide sequence identities between them. Although SA11 is one of the most widely used reference strains for RVA research and forms the backbone of a reverse genetics system, its origin remained enigmatic. Remarkably, the majority of the genotypes of SA11-like strains were shared with Gabonese bat RVAs, suggesting a potential common origin. Overall, our findings suggest an underexplored genetic diversity of RVAs in bats, which is likely only the tip of the iceberg. Increasing contact between humans and bat wildlife will further increase the zoonosis risk, which warrants closer attention to these viruses.IMPORTANCE The increased research on bat coronaviruses after severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) allowed the very rapid identification of SARS-CoV-2. This is an excellent example of the importance of knowing viruses harbored by wildlife in general, and bats in particular, for global preparedness against emerging viral pathogens. The current effort to characterize bat rotavirus strains from 3 continents sheds light on the vast genetic diversity of rotaviruses and also hints at a bat origin for several atypical rotaviruses in humans and animals, implying that zoonoses of bat rotaviruses might occur more frequently than currently realized.
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Quirópteros/virología , Infecciones por Rotavirus/transmisión , Infecciones por Rotavirus/virología , Rotavirus/genética , Zoonosis/transmisión , Zoonosis/virología , Animales , COVID-19/transmisión , COVID-19/virología , Diarrea/virología , Variación Genética , Genoma Viral , Genotipo , Caballos , Humanos , Metagenómica , Coronavirus del Síndrome Respiratorio de Oriente Medio/aislamiento & purificación , Filogenia , SARS-CoV-2/aislamiento & purificaciónRESUMEN
BACKGROUND AND AIM: Trypanosomosis is a major impediment to livestock farming in sub-Saharan Africa. It is a vector-borne disease caused by several species of protozoan parasites, namely, trypanosomes. The present study aimed to identify the diversity of trypanosome species infecting sheep and goats from Mongo County and to determine the frequency of these parasites. MATERIALS AND METHODS: This study was conducted on 286 trypanotolerant goats and sheep from Mongo regions located in South Gabon, using polymerase chain reaction. RESULTS: Analyses showed that the overall occurrence of trypanosomosis in small ruminants was 13.6% (39/286). Our results also showed that two factors, species and season, could affect the occurrence rate of Trypanosoma. A total of six Trypanosoma species were identified, two in sheep (Trypanosoma simiae and Trypanosoma theileri) and five in goats (Trypanosoma vivax, T. simiae, T. simiae Tsavo, Trypanosoma congolense, and Trypanosoma brucei), though Trypanosoma simiae was the most important species. Mixed infections were also found in goats (54.5%) and sheep (3.57%). CONCLUSION: Our study demonstrated that small ruminants could represent a reservoir of biodiversity for Trypanosoma parasites.
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Human African Trypanosomiasis (HAT) is an infectious disease due to a protozoa parasite of the Trypanosoma genus. In West and Central Africa, this disease is caused by the subspecies Trypanosoma brucei gambiense. Several foci of this disease are currently active and causing the death of hundreds of people in endemic areas. In this article, we report two cases of gambiense HAT in one Indonesian and one Gabonese men in two historical foci of Gabon in 2019. Both patients had fever with temperatures above 38°C, an altered state of consciousness, cachexia, and multiple dermabrasions on the abdomen related to scratching lesions. The diagnostic revealed second-stage infection of both patients with T. b. gambiense; this result was confirmed by a polymerase chain reaction assay. Despite treatment with a combination of eflornithine and nifurtimox, as recommended by the World Health Organization for late-stage T. b. gambiense HAT, one of the two patients died. Thus, these cases highlight the importance of early HAT diagnosis and prompt patient care to fight effectively against this disease.
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We report the nearly complete genome sequence of an enterovirus 99 strain (Cpz-IJC08) detected in a healthy chimpanzee from the Tchimpounga Sanctuary in the Republic of Congo. According to the phylogeny, Cpz-IJC08 clustered with Cpz-IJC04, a previously identified chimpanzee enterovirus from the same sanctuary, isolated from an animal with signs of acute flaccid paralysis.
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Little research on coronaviruses has been conducted on wild animals in Africa. Here, we screened a wide range of wild animals collected in six provinces and five caves of Gabon between 2009 and 2015. We collected a total of 1867 animal samples (cave-dwelling bats, rodents, non-human primates and other wild animals). We explored the diversity of CoVs and determined the factors driving the infection of CoVs in wild animals. Based on a nested reverse transcription-polymerase chain reaction, only bats, belonging to the Hipposideros gigas (4/156), Hipposideros cf. ruber (13/262) and Miniopterus inflatus (1/249) species, were found infected with CoVs. We identified alphacoronaviruses in H. gigas and H. cf. ruber and betacoronaviruses in H. gigas. All Alphacoronavirus sequences grouped with Human coronavirus 229E (HCoV-229E). Ecological analyses revealed that CoV infection was significantly found in July and October in H. gigas and in October and November in H. cf ruber. The prevalence in the Faucon cave was significantly higher. Our findings suggest that insectivorous bats harbor potentially zoonotic CoVs; highlight a probable seasonality of the infection in cave-dwelling bats from the North-East of Gabon and pointed to an association between the disturbance of the bats' habitat by human activities and CoV infection.
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Alphacoronavirus/genética , Betacoronavirus/genética , Cuevas , Quirópteros/virología , Infecciones por Coronavirus/epidemiología , Variación Genética , Animales , Secuencia de Bases/genética , Coronavirus Humano 229E/genética , Infecciones por Coronavirus/virología , Eulipotyphla/virología , Gabón/epidemiología , Humanos , Filogenia , Prevalencia , Primates/genética , ARN Viral/genética , ARN Viral/aislamiento & purificación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Roedores/genética , Estaciones del AñoRESUMEN
BACKGROUND AND AIM: Gastrointestinal infestations caused by intestinal parasites are the most important diseases and the most common in pigs in the tropics. These parasites are often associated with a huge economic loss. This study aimed to assess the diversity and prevalence of gastrointestinal parasites in farmed pigs from Haut-Ogooue Province, in South East Gabon. MATERIALS AND METHODS: From March 2018 to July 2018, 156 samples of pig feces collected from nine different farms were analyzed under light microscopy. The identification of eggs, cysts, and oocysts in fecal samples was done using two qualitative techniques: Flotation and sedimentation. RESULTS: After examination, the results obtained revealed an overall infestation level of 98.7% (154/156). We found ten parasite types with infestation levels that varied from species: Balantidium coli (120/156), Oesophagostomum spp. (100/156), Isospora suis (102/156), Ancylostoma spp. (17/156), Trichostrongylus spp. (28/156), Hyostrongylus spp. (13/156), Strongyloides spp. (7/156), Ascaris suum (8/156), Globocephalus spp. (1/156), and spirurida (1/156). The study of risk factors revealed that factors such as sex, age, and physiological condition may influence the diversity and level of infestation of animals by gastrointestinal parasites. CONCLUSION: For better prevention of parasitism in these farms, it would be interesting to implement health monitoring and to ensure good hygiene. Finally, further studies would be needed to better evaluate the distribution of these parasites in Gabon and the involvement of these animals in the transmission cycle of parasitic zoonoses.
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Rift Valley fever (RVF) is a zoonotic disease, which caused several epidemics in humans in many countries of Africa. Using an inhibition enzyme-linked immunosorbent assay (ELISA), real-time reverse transcription PCR, and nested one-step reverse transcription PCR, we conducted a cross-sectional study in populations of sheep and goats from the Mongo County in 2014 to determine the circulation of the Rift Valley fever virus (RVFV) in small ruminants from this area. From a total of 201 small ruminants (95 sheep and 106 goats), the overall IgG seroprevalence against the RVFV was 6.47% (13/201). No RVFV RNA was detected in the animal plasmas. Logistic regression analysis showed that age, species, sex, and locality were not the significant risk factors. The findings of this study highlight the risk of RVF for domestic ruminants bred in this region and for the human rural population living in contact with these animals and they emphasize the need to develop adequate control measures to limit this threat.
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Enfermedades de las Cabras/sangre , Fiebre del Valle del Rift/sangre , Virus de la Fiebre del Valle del Rift/aislamiento & purificación , Enfermedades de las Ovejas/sangre , Animales , Anticuerpos Antivirales/sangre , Femenino , Gabón/epidemiología , Enfermedades de las Cabras/epidemiología , Cabras , Inmunoglobulina G/sangre , Masculino , ARN Viral/sangre , Fiebre del Valle del Rift/epidemiología , Factores de Riesgo , Estudios Seroepidemiológicos , Ovinos , Enfermedades de las Ovejas/epidemiología , Especificidad de la EspecieRESUMEN
Caves house pathogenic microorganisms, some of which are transmitted by blood-sucking arthropods. In Africa, previous studies identified mosquitoes, sand flies and biting midges as the main potential vectors of cave-dwelling pathogens. However, to understand their involvement in pathogen spillover, it is crucial to characterize their diversity, community composition and dynamics. Using CDC light traps, we collected hematophagous Diptera in six caves of Gabon during one-shot or longitudinal sampling, and investigated their species diversity and dynamics in relation with external rainfall. Overall, we identified 68 species of mosquitoes, sand flies and biting midges, including 45 new records for Gabon. The dominant species were: Uranotaenia nigromaculata, Anopheles smithii s.l., Culex. rima group and Culex quasiguiarti for mosquitoes, Spelaeophlebotomus gigas and Spelaeomyia emilii for sand flies and the Culicoides trifasciellus group and Culicoides fulvithorax for biting midges. The survey revealed that species assemblages were cave-specific and included mainly troglophilous and trogloxenous species. Both diversity and abundance varied according to the cave and sampling time, and were significantly associated with rainfall. These associations were modulated by the cave specific environmental conditions. Moreover, the presence of trogloxenous and troglophilous species could be of high significance for pathogen transfers between cave and epigeous hosts, including humans.