This study aimed to determine the prevalence of co-infection with malaria and intestinal parasites and assess its association with anemia in school-aged children from rural and urban settlements in Gabon. This cross-sectional study involved afebrile school children recruited at schools between May and June 2021. Blood and stool samples were collected from participants whose parents or legal guardians provided informed consent to participate in the study. Hemoglobin concentration (Hb) was measured using a HemoCue photometer (HemoCue 201, HemoCue, Angelholm, Sweden). Giemsa-stained blood films were examined to detect malaria parasites and any filarial infections, while the merthiolate-iodine concentration (MIC) method was used to identify intestinal parasitic infections (IPI). A total of four hundred and seventy (470) school-aged children were successfully enrolled in this study. The observed prevalence values were as follows: malaria infection at 69.6%, IPIs at 19.1%, filaria at 5.1%, Schistosoma infection at 15.0%, and anemia at 29.0%. Co-infections of malaria with IPIs, filaria, and Schistosoma were present in 12.3%, 4.7%, and 6.6% of the children, respectively. Malaria and filaria infections were associated with residing in Lastourville city (p < 0.05) and were also correlated with age (p < 0.05), whereas IPIs were associated with male gender and living in the city of Lastourville. Anemia was linked to malaria infection (p < 0.05) and was more prevalent among children living in rural areas. The findings of this study indicate that malaria, IPIs, and Schistosoma infections continue to pose a significant public health problem in the study area, even though only malaria infection appeared to be associated with anemia. Nevertheless, these results highlight the need for implementing control measures to reduce the prevalence of malaria, IPIs, filaria, and Schistosoma, particularly in Lastourville.
The protozoan Toxoplasma gondii is a ubiquitous and highly prevalent parasite that can theoretically infect all warm-blooded vertebrates. In humans, toxoplasmosis causes infections in both immunodeficient and immunocompetent patients, congenital toxoplasmosis, and ocular lesions. These manifestations have different degrees of severity. Clinical severity is determined by multiple factors, including the genotype of the T. gondii strain involved in the infection. T. gondii exhibits remarkable genetic diversity, which varies according to geography and ecotype (domestic or wild). Previous studies have demonstrated that wild strains of T. gondii are of particular epidemiological interest, as they have been associated with more severe forms of toxoplasmosis in different regions of the world. However, no data on wild strains of T. gondii are available from Africa. In this study, we describe for the first time a wild T. gondii strain from Africa. Wild animals from the forest environment of Gabon, Central Africa, were screened for chronic infection with T. gondii using quantitative PCR. The infecting T. gondii strains were genotyped whenever possible by the analysis of 15 microsatellite markers and by whole-genome sequencing. A new T. gondii genotype was identified in the DNA extract from a heart sample of a duiker (Cephalophus sp.) and was found to be highly divergent from previously described T. gondii populations worldwide, including those from domestic environments in Gabon. This discovery suggests the existence of a wild T. gondii population in Africa. The role of wild T. gondii strains in the incidence of severe toxoplasmosis in Africa remains unclear and requires further investigation.
The objective of this were conducted to elucidate spatiotemporal variations in malaria epidemiology in Gabon since 1980. For that, five databases, were used to collect and identify all studies published between 1980 and 2023 on malaria prevalence, antimalarial drug resistance, markers of antimalarial drug resistance and insecticide resistance marker. The findings suggest that Gabon continues to face malaria as an urgent public health problem, with persistently high prevalence rates. Markers of resistance to CQ persist despite its withdrawal, and markers of resistance to SP have emerged with a high frequency, reaching 100%, while ACTs remain effective. Also, recent studies have identified markers of resistance to the insecticides Kdr-w and Kdr-e at frequencies ranging from 25% to 100%. Ace1R mutation was reported with a frequency of 0.4%. In conclusion, the efficacy of ACTs remains above the threshold recommended by the WHO. Organo-phosphates and carbamates could provide an alternative for vector control.
Background: Gastrointestinal parasites (GIPs) pose a significant global challenge to the poultry industry, affecting health, welfare, and production performance. Few studies have been conducted in Gabon on the prevalence of these infections in chickens. Aim: This cross-sectional survey aims to assess the presence and diversity of GIP among chickens in the M'passa department. Methods: Between April and October 2022, we randomly collected 402 fecal samples from local and exotic chicken breeds from four semi-intensive poultry farms and 11 free-range chicken sites in the M'passa department, southeast Gabon. These samples were analyzed for GIP using flotation and sedimentation methods. Results: This study found 14 GIP eggs and oocytes in 72.9% (293/402) of examined chickens. Capillaria spp. (39.5%) and Ascaridia (31.1%) species were the most frequently identified parasites. Other identified parasites included Eimeria spp. (20.1%), Strongyloides avium (16.9%), Choanotaenia infundibulum (13.4%), Hymenolepis spp. (10.4%), Chilomastix gallinarum (7.7%), and Entamoaba. (1.7%). Single infections occurred in 39.3% (115/293, 95% IC: 33.7-44.9) of cases, while mixed infections were recorded in 60.7% (178/293, 95% IC: 55.1-66.3). The study also identified significant differences in prevalence among local and exotic breeds, genders, and age groups. Conclusion: This study revealed a high prevalence of GIP in Gabon chickens, potentially harming their health and productivity. We recommend implementing effective control measures against these infections to enhance the health and productivity of chickens in the region.
The Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS) is still one of the main causes of death in sub-Saharan Africa. Antiretroviral therapies (ARTs) have significantly improved the health conditions of people living with HIV/AIDS (PLWHA). Consequently, a significant drop in morbidity and mortality, along with a reduced incidence of opportunistic infections (OIs), has been observed. However, certain atypical and biological profiles emerge in ART patients post-examination. The objective of this study was to identify the risk factors that contributed to the onset of OIs in HIV patients undergoing ART in Gabon. Epidemiological and biological data were obtained from medical records (2017 to 2019) found at the outpatient treatment centre (CTA) of Franceville in Gabon. Samples for blood count, CD4, and viral load analysis at CIRMF were collected from PLWHA suffering from other pathogen-induced conditions. A survey was carried out and data were analysed using Rstudio 4.0.2 and Excel 2007 software. Biological and socio-demographic characteristics were examined concerning OIs through both a univariate analysis via Fisher's exact tests or chi2 (χ2), and a multivariate analysis via logistic regression. Out of the 300 participants initially selected, 223 were included in the study, including 154 (69.05%) women and 69 (30.95%) men. The mean age was 40 (38.6; 41.85), with individuals ranging from 2 to 77 years old. The study cohort was classified into five age groups (2 to 12, 20 to 29, 30 to 39, 40 to 49, and 50 to 77 years old), among which the groups aged 30 to 39 and 40 to 49 emerged as the largest, comprising 68 (30.5%) and 75 (33.6%) participants, respectively. It was noted that 57.9% of PLWHA had developed OIs and three subgroups were distinguished, with parasitic, viral, and bacterial infections present in 18%, 39.7%, and 55.4% of cases, respectively. There was a correlation between being male and having a low CD4 T-cell count and the onset of OIs. The study revealed a high overall prevalence of OIs, and extending the study to other regions of Gabon would yield a better understanding of the risk factors associated with the onset of these infections.
Background and Aim: Rodents are carriers or reservoirs of various bacteria, protozoa, viruses, and ectoparasites. Given the proximity of various rodent species and humans, there is a potential for the transmission of pathogens. Data on ecto- and endo-parasite prevalence in rodent populations in Gabon are limited. To fill this gap, we conducted a study in Libreville to investigate the occurrence of ecto- and endo-parasites in rodents. Materials and Methods: We captured and euthanized 68 rodents belonging to the genus Praomys and examined their ecto- and endo-parasite fauna, dissected their gastrointestinal tract for helminths, and prepared blood smears to examine blood-borne pathogens. Results: Our analyses identified three pathogen taxa: helminths (Protospirura spp., Trichuris spp., and Taenia spp.), protozoa (Babesia spp.), bacteria (Anaplasma spp.), and arthropods (Laelaps and Haemaphysalis). Overall, 91.2% of the rodents were infected with at least one pathogen and ectoparasite, with helminth occurrence rate of 63.2% and ectoparasite occurrence at 44.1%. Protozoan infections (Babesia spp.) were found in 10.3% of the rodents, whereas bacteria (Anaplasma Conclusion: Native rodents in Libreville harbor various infectious agents, ecto- and endo-parasites. These findings highlight the potential health risks associated with Praomys rodents for the transmission of various diseases to human population in Gabon and emphasize the need for investigation of rodents for their role as disease carriers.
Parasites and infectious diseases pose significant threats to primate populations, especially in captive non-human primates (NHPs). This study aimed to assess the diversity and prevalence of intestinal parasites in NHPs at the CIRMF Primatology Center. A total of 97 fecal samples were analyzed using parasitological techniques, including sodium chloride flotation and modified Baermann sedimentation methods. An overall parasite prevalence of 93.81% (91/97) was observed. Sixteen groups of parasites with zoonotic potential were identified, comprising ten genera of nematodes (Trichuris, Enterobius, Hookworm, Trichostrongylus, Mammomonogamus, Spirure, Oesophagostomum, Schistosoma, Ascaris, and Strongyloides), three genera of protists (Eimeria, Balantioides coli/Buxtonella, and Entamoeba), one genus of cestodes (Hymenolepis), and two genera of trematodes (Dicrocoelium and Paramphistomum). High prevalences were noted for Oesophagostomum spp. (83.5%), Strongyloides spp. (52.58%), and Trichostrongylus spp. (50.52%). These findings underscore the potential role of the CIRMF Primatology Center in maintaining and facilitating the transmission of intestinal parasites with high zoonotic potential. The co-existence of human and NHP parasites in shared environments, such as zoos and research facilities, emphasizes the need for a holistic, One Health approach that addresses the interconnected health of humans, animals, and the environment. This study highlights the urgent need for collaborative strategies to mitigate the risks of zoonotic parasite transmission between NHPs and humans in captive settings.
BackgroundNon-human primate (NHPs) conservation sites could be sites of exchange of pathogens involved in infectious diseases. It is important to assess the potential risks associated with this type of structure. The objective of this study was to carry out a risk assessment of the Primatology Centre housed in the Interdisciplinary Centre for Medical Research of Franceville (CIRMF).MethodsA questionnaire was administered to the centre's staff to assess the risk associated with each workstation, followed by a review of the various pathogens identified in NHPs. The data were analysed using two diagrams: the Kiviat diagram and the Pareto diagram.ResultsBased on our results, a variety of pathogens such as viruses, bacteria and parasites, potentially transmissible to humans, were described in the NHPs at the Primatology Centre of CIRMF. The position most exposed to zoonotic risks was that of animal handlers.ConclusionThe Primatology Centre of CIRMF is a potential transfer site for the transfer of zoonotic agents. To avoid the risk of parasite exchange between staff and animals, the implementation of biosecurity measures is essential.
Malaria is a significant public health challenge in Gabon, with high prevalence rates in rural and semi-urban areas. This study investigated Plasmodium infection prevalence among outpatients at a medical laboratory in Franceville, Gabon, in 2020. Data from 500 patients were analyzed, revealing an overall infection rate of 33.2% and the presence of four Plasmodium species: P. falciparum, P. malariae, P. ovale, and possibly P. vivax for the first time in Gabon. Co-infections were common, with P. falciparum and P. ovale spp. being the most prevalent at 23.5%. Asymptomatic infections accounted for 81.3% of cases, while symptomatic infections were 18.7%. P. falciparum was associated with symptomatic cases, while non-falciparum species were linked to asymptomatic infections. The findings suggest Franceville has perennial malaria transmission, highlighting the role of Plasmodium species diversity in disease severity and clinical presentation, including the first report of P. vivax infection in the Gabonese population.
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.
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.
Caliciviruses (Caliciviridae) and astroviruses (Astroviridae) are among the leading cause of non-bacterial foodborne disease and gastroenteritis in human. These non-enveloped RNA viruses infect a wide range of vertebrate species including rodents. Rodents are among the most important hosts of infectious diseases globally and are responsible for over 80 zoonotic pathogens that affect humans. Therefore, screening pathogens in rodents will be is necessary to prevent cross-species transmission to prevent zoonotic outbreaks. In the present study, we screened caliciviruses and astroviruses in order to describe their diversity and whether they harbor strains that can infect humans. RNA was then extracted from intestine samples of 245 rodents and retrotranscribed in cDNA to screen caliciviruses and astroviruses by PCRs. All the samples tested negative for caliciviruses and while astroviruses were detected in 18 (7.3%) samples of Rattus rattus species. Phylogenetic analyses based on the RdRp gene showed that all the sequences belonged to Mamastrovirus genus in which they were genetically related to R. rattus related AstVs previously detected in Gabon or in Rattus spp. AstV from Kenya and Asia. These findings suggested that transportation such as land and railway, as well national and international trade, are likely to facilitate spread of AstVs by the dissemination of rodents.
Background: In Central Africa, it is difficult to fight against antibiotic resistance, because of a lack of data and information on bacterial resistance, due to the low number of studies carried out in the field. To fill this gap, we carried out a systematic review of the various studies, and devise a molecular epidemiology of antimicrobial resistance from humans, animals and the environmental samples.Method: A systematic search of all publications from 2005 to 2020 on bacterial resistance in Central Africa was performed on Pubmed, Google scholar and African journals online. All circulating resistance genes, prevalence and genetic carriers of these resistances were collected. The study area was limited to the 9 countries of Central Africa. Results: Five hundred seventeen studies were identified through a literature search, and sixty studies carried out in 8 countries were included. Among all articles included, 43 articles were from human. Our study revealed not only the circulation of beta-lactamase and carbapenemase genes, but also several other types of resistance genes. To finish, we noticed that some studies reported mobile genetic elements such as integrons, transposons, plasmids, or chromosomes.Conclusion: The scarcity of data poses difficulties in the implementation of effective strategies in the fight against antibiotic resistance, which requires a health policy in a "One Health" approach.
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.
Background. Intestinal parasites are among the most important infectious agents with an impact on human health. Indeed, in the lack of an available treatment option, these parasites could constitute a real health problem in the population. In the present study, we investigated for the first time the effect of a novel synthetic heterocyclic ((C15H12N5OCL)2-(benzo(d)(1,2,3)triazol-1-yl)-N-benzylideneacetohydrazine) compound on two intestinal parasites (Entamoeba histolytica and Giardia lamblia). Methods. The parasite isolates tested were collected from outpatients at the General Pediatric Hospital in Kirkuk, Iraq, between September 2019 and January 2020. Thus, we studied the in vivo and in vitro pharmaceutical activity of the ingredient on both parasites. The toxicological effects of the substance on some blood parameters and liver and kidney function tests were also studied. Results. After five days of treatment, the drugs in vivo action on G. lamblia resulted in an inhibition rate of 88.2% at a dose of 1 mg/kg. On the other hand, we observed that the influence of this synthetic substance on cultured E. histolytica was very close to the metronidazole effect. The maximum result was at a concentration of 1 g/ml and was obtained after 72 hours of incubation with an inhibition rate of 89.4%. The substance did not affect the blood parameters or the studied liver and kidney functions. Conclusion. It can be concluded that this substance is highly effective against both E. histolytica and G. lamblia, and that it has no toxic effects on the studied parameters. Therefore, it could be a promising pharmacophore for intestinal protozoan parasites including E. histolytica and G. lamblia and an alternative or competitor to the current medications available.
Introduction Despite all the efforts made to control or even eliminate malaria, the disease continues to claim the highest number of victims of vector-borne pathogens in the world and Sub-Saharan countries bear the heaviest burden. The lack of knowledge of the role of various protagonists involved in the transmission of this parasitic disease, such as mosquito vectors and the plasmodial species they transmit as well as the host species they infect in a locality, constitutes one of the main causes of the persistence of malaria. In Gabon, in several areas, entomological data on malaria transmission remain poorly known. Thus, this study aimed to determine the diversity of Anopheles involved in malaria transmission in different environments of the province of Nyanga in southwest Gabon. Methods For this, an entomological study was carried out in the four main localities of the province of Nyanga to provide answers to these shortcomings. Mosquitoes were collected over several nights using the human landing catch method. The identification of Anopheles and malaria parasites circulating in the different sites was achieved by combining morphological and molecular analysis tools. Results A total of five hundred and ninety-one (591) mosquitoes belonging to the Culicidae family were collected. From this collection of adult mosquitoes, nine species of Anopheles mosquitoes notably species of the Anopheles nili complex (53.46%) followed by those of Anopheles gambiae complex (22.01%), Anopheles funestus group (18.24%), Anopheles moucheti complex (5.66%) and Anopheles hancocki (0.63%). Approximately 18 percent of these Anopheles species were infected with Plasmodium spp. Anopheles funestus , known to be involved in malaria transmission to humans, and An. moucheti -like, recently discovered in Gabon, and whose status in Plasmodium transmission is not yet elucidated, were found to be infected with great ape Plasmodium . Discussion Our results raise the question of the potential switch of simian malaria parasites to humans. If these observations are confirmed in the future, and the infective capacity of the bridge vectors is demonstrated, this new situation could ultimately constitute an obstacle to progress in the fight against malaria.
Background In Gabon, malaria remains a major public health problem. All malaria cases with axillary temperature ≥ 37.5°C with a parasites density ≥ 1200/μL are serious cases and must be treated as a medical emergency. Thus, early diagnosis is essential for successful treatment. Because of the impact of malaria on the population, the surveillance of malaria infections in hospitals is urgently needed. The aim of this study was to to assess of clinical cases of malaria in a private health structure in Franceville between 2017 and 2019. Methods For that, we conducted a retrospective study using data on malaria cases recorded in a private medical analysis laboratory in Franceville, southeast Gabon. Malaria was diagnosed in this laboratory using a Rapid Diagnostic Test and confirmed by microscopic analysis. Results Analysis of 2518 patient forms revealed an increase in malaria prevalence in Franceville between 2017-2019. The global clinical cases was 26.1% (658/2015). Children under 5 years (44.0%) and patients aged 5-14 years (40.1%) were more affected than patients aged ≥15 years (18.8%, P=0.0001). Malaria infection was also significantly dependent on season and gender. We observed at least three Plasmodium species and the predominant Plasmodium species was P. falciparum 80.0%, followed by P. ovale (19.5%) and P. malariae (17.8%). Conclusion Our study showed that malaria remains a public health priority for the population of Franceville and that the prevalence of clinical cases of malaria at the laboratory decrease between 2017 and 2019. Our results highlight the need for strategies to control malaria in Franceville, adapted to epidemiological contexts and environmental constraint.
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.
In this study, we used a predator-enabled metagenomics strategy to sample the virome of a remote and difficult-to-access densely forested African tropical region. Specifically, we focused our study on the use of army ants of the genus Dorylus that are obligate collective foragers and group predators that attack and overwhelm a broad array of animal prey. Using 209 army ant samples collected from 29 colonies and the virion-associated nucleic acid-based metagenomics approach, we showed that a broad diversity of bacterial, plant, invertebrate and vertebrate viral sequences were accumulated by army ants: including sequences from 157 different viral genera in 56 viral families. This suggests that using predators and scavengers such as army ants to sample broad swathes of tropical forest viromes can shed light on the composition and the structure of viral populations of these complex and inaccessible ecosystems.