Hugues Clotaire Nana Djeunga

Higher Institute for Scientific and Medical Research (ISM) · Molecular Parasitology and Genetic Epidemiology (MPGE)

Background and methods Circulating Loa loa antigens are often detected in individuals with heavy L. loa infections by diagnostic tests for lymphatic filariasis (LF) caused by Wuchereria bancrofti . This is a major challenge to LF mapping and elimination efforts in loiasis co-endemic areas. However, it also provides an opportunity to identify antige...

Background Reducing contact between humans and black flies can lead to interruption of onchocerciasis transmission. The Esperanza Window Trap (EWT) has been shown to be an effective tool for reducing black fly densities. Several shape-based improvements to this trapping system have been made to optimise its effectiveness, but optimisation of this t...

Background Black flies are present worldwide and are represented by 2,348 species (2,331 living species and 17 fossils) classified under 31 genera. In Africa, 124 species of black flies have been described, of which 55 are known to occur in Cameroon. However, these identifications are all based on morphology and, for S. damnosum only, on cytotaxono...

BACKGROUND Among the millions of mobile applications (“apps”) in existence, thousands fall under the category of mobile health (mHealth). While the utility of mHealth apps has been demonstrated for disease diagnosis, treatment data management, and health promotion strategies, to be effective they must reach and be used by their target audience. An...

Background Ivermectin (Mectizan) is an anthelmintic drug that plays a major role in the fight against two major filarial diseases, onchocerciasis and lymphatic filariasis. Unlike previous drugs that had serious and sometimes fatal side effects, ivermectin has been considered to be safe and, therefore, is widely used. Data reporting the clinical pre...

Background: The control of onchocerciasis currently relies on annual distribution of single dose ivermectin. Because ivermectin has minimal effects on the adult parasite, mass drug administration (MDA) campaigns against onchocerciasis require at least 15 years of annual uninterrupted ivermectin distribution. Mathematical models have predicted that...

Background Soil-transmitted helminths (STH) remain the most common parasites of the gastrointestinal tract in Cameroon. However, despite all efforts put in place for their control, their prevalence remains unexpectedly high in some parts of the country. This systematic review aims to identify and delineate areas of high transmission (hotspots) of S...

Background Although Slash and Clear has proven effective in reducing blackfly densities in low transmission foci, the impact of this strategy in high transmission settings with large rivers and important vector densities remains to be demonstrated. Methods/Principal findings A controlled before-and-after community-based intervention comprising two...

Background Alternative strategies are recommended to accelerate onchocerciasis elimination in problematic areas including areas where annual ivermectin (IVM) distributions are unable to interrupt transmission. The aim of this study was to accelerate progress towards elimination in the Massangam health district, West Region of Cameroon where impact...

Background The reduction of the contacts between humans and blackflies can lead to the interruption of the onchocerciasis transmission. Esperanza window trap (EWT) has been shown to be effective in reducing blackfly densities. Several shape-based improvements to this trapping system have been developed to optimize its performance. However, the opti...

Background Infection with resistant Pseudomonas aeruginosa (RPA) in the intensive care unit (ICU) is known to be either endogenous or exogenous or both, but the roles of each of these contamination routes are yet to be clarified. Data regarding prevalence, risk factors, and environmental factors associated with RPA in ICU are very scanty and even w...

Background Points of Entry (POEs) are at the frontline for prevention, detection and response to international spread of diseases. The objective of this assessment was to ascertain the current level of existing International Health Regulations (IHR) core capacities of designated airports, ports and ground crossings in Cameroon and identify critical...

Assuming the causality relationship between Onchocerca volvulus infection and epilepsy onset, preventive chemotherapy for the control onchocerciasis can result to a significant impact on epilepsy burden. This study aimed at assessing the prevalence of epilepsy in an onchocerciasis endemic area under annual CDTI for 16 years. A cross-sectional surve...

(1) Background: Schistosomiasis remains a public health issue in Cameroon. Snail control using Niclosamide can prevent schistosome transmission. It is safe to determine lethal concentrations for the population. This study aimed at assessing the toxicity of Niclosamide on different developmental stages of snail populations; (2) Methods: Snails were...

The health security planning process transforms recommendations from various evaluations into priority actions to strengthen countries' capacity for emergency preparedness using the One Health approach. Although the World Health Organization (WHO) has developed many tools to facilitate the planning process of a National Action Plan for Health Secur...

Entomological indicators of onchocerciasis transmission and the effect of climatic variables on the vector population dynamics were investigated in two first-line villages after more than two decades of mass drug administration with ivermectin. Female blackflies were collected in two villages (Bayomen and Biatsota) using human landing method for a...

The SD Bioline® IgG4 rapid diagnostic test (RDT) detects IgG4 antibodies induced by the Onchocerca volvulus-specific antigen Ov16. We evaluated the stability of the RDT results over 1 month, at different time points after completion of each assay, using eluted dried blood spots collected in central Cameroon. Agreement coefficients regarding positiv...

Background Alternative strategies are recommended to accelerate onchocerciasis elimination in problematic areas including areas where annual ivermectin (IVM) distributions are unable to interrupt transmission. The aim of this study was to accelerate progress towards elimination in the Massangam health district, West Region of Cameroon where impact...

Background Onchocerciasis elimination currently relies on repeated ivermectin-based preventive chemotherapy. Current World Health Organization's guidelines strongly recommend, though with low evidence of certainty, the use of Ov16 serology testing in children younger than 10 years old to assess whether mass drugs administration can be safely stoppe...

Background: The current mainstay for control/elimination of onchocerciasis and soil-transmitted helminthiasis (STH) relies on ivermectin- and mebendazole/albendazole-based preventive chemotherapies. However, children under five years of age have been excluded in both research activities and control programs, because they were believed to have insi...

Vector control using larvicides is the main alternative strategy to address limits of preventive chemotherapy using ivermectin for the control of onchocerciasis. However, it remains substantially limited by implementation difficulties, ecological concerns and the resistance of vector populations. Therefore, efficient and environmentally safe altern...

Background Intestinal parasitic infections remain of public health concern worldwide, especially among rural and poorest populations as a consequence of precariousness, lack of sanitation, non-availability of potable water and poor hygiene conditions. The present study aimed to better understand the epidemiology of intestinal parasitic infections i...

Background The onchocerciasis focus surrounding the lower Mbam and Sanaga rivers, where Onchocerca volvulus is transmitted by Simulium damnosum s.l. (Diptera: Simuliidae), was historically the largest in the southern regions of Cameroon. Annual community-directed treatment with ivermectin (CDTI) has been taking place since 2000, but recent studies...

Background and objectives: Preventive chemotherapy (PCT) is the main strategy currently used to control and/or eliminate onchocerciasis, lymphatic filariasis (LF) and soil transmitted helminthiasis (STH), and community participation (through implementation or adherence to PCT) is critical. This study aimed at investigating knowledge/perceptions of...

Background Despite high black fly densities in persisting onchocerciasis foci in Cameroon, no vector control has ever been carried out to complement Community-Directed Treatment with Ivermectin (CDTI). As a prelude to community-based vector control, this study explored knowledge/perception and attitude/practice (KAP) of populations of two first-lin...

Community-Directed Treatment with Ivermectin (CDTI) is the strategy of choice to fight onchocerciasis in Africa. In areas where loiasis is endemic, onchocerciasis control and/or elimination is hindered by severe adverse events (SAEs) occurring after ivermectin mass treatments. This study aimed at (i) investigating the impact of two decades of CDTI...

Background The District Health Information Software (DHIS2), adopted as national health information system by the ministry of public health in Cameroon, did not integrate neglected tropical diseases (NTD) program data. Integrating NTD program data into the national DHIS2 might require more than technical skills. Our study aimed to explore the fact...

The control of soil-transmitted helminthiasis (STH) in Cameroon is focused on large-scale deworming through annual mass drug administration (MDA) of albendazole or mebendazole to at-risk groups, principally preschool and school-age children. After a decade of intervention, prevalence and intensity of infection have been significantly lowered, encou...

AIM: This study aimed to determine the prevalence and risk factors of HIV, HBV, and HCV among refugees of the Mbile camp in the East Region of Cameroon. MATERIALS AND METHODS: This was a cross-sectional study conducted in 2019 in the Mbile refugee camp. All recruited subjects were interviewed and provided blood samples for the screening of Hepatit...

Le traitement des morsures de serpents est sujet à plusieurs recours thérapeutiques au sein desquels figure la médecine dite traditionnelle. Les tradipraticiens, sont parfois les premiers consultés avant le transfert des patients vers les formations sanitaires. Face à l’importance du problème des morsures de serpents, le Ministère de la Santé Publi...

The standard techniques for diagnosis of human filariasis are the microscopic examination of blood smears or skin biopsies, which are relatively invasive and poorly sensitive at low levels of infection. Recently, filarial DNA has been detected in fecal samples from non-human primates in Central Africa. The aim of this study was to demonstrate proof...

Background: The diagnostic gold standard for onchocerciasis relies on identification and enumeration of (skin-dwelling) Onchocerca volvulus microfilariae (mf) using the skin snip technique (SST). In a recent study, blood-borne Loa loa mf were found by SST in individuals heavily infected with L. loa, and microscopically misidentified as O. volvulus...

Socioeconomic and socio-demographic factors have been considered as critical in disease epidemiology and need to be taken into consideration when designing health interventions. It is therefore strongly recommended to investigate population ownership to ensure sustainability of a given intervention. To this end, a household-based cross sectional su...

Introduction The first visceral and cutaneous leishmaniasis cases were reported in Cameroon since more than six decades. However, interest in the disease has decreased over time and data on its epidemiology across the country are scanty. This systematic review aims to update data on what is known and done so far on leishmaniasis in Cameroon. Metho...

Background: Infection with resistant Pseudomonas aeruginosa (RPA) in Intensive Care Unit (ICU) is known to be either endogenous or exogenous or both, but the roles of each of these contamination routes is yet to be clarified. Data regarding prevalence, risk factors and environmental factors associated with RPA in ICU are very scanty and even when t...

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is responsible for the development of a highly contagious disease called coronavirus disease (COVID-19). Ten months after the onset of the pandemic, America and Europe remain the most affected regions. Initially, experts predicted that Africa, the poorest continent with the most vulne...

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is responsible for the development of a highly contagious disease called coronavirus disease (COVID-19). Ten months after the onset of the pandemic, America and Europe remain the most affected regions. Initially, experts predicted that Africa, the poorest continent with the most vulne...

Ivermectin (IVM) is a broad spectrum endectocide whose initial indication was onchocerciasis. Although loiasis is not among its indications, IVM also exhibits antiparasitic activity against Loa loa. IVM-based preventive chemotherapies (PCs), so-called community-directed treatment with ivermectin (CDTI), have led to the interruption of transmission...

Background Mass drug administration (MDA) with ivermectin is the main strategy for onchocerciasis elimination. Ivermectin is generally safe but associated with serious adverse events in individuals with high Loa loa microfilarial densities (MFD). Therefore, ivermectin MDA is not recommended in areas where onchocerciasis is hypo-endemic and L. loa i...

Background Mass drug administration (MDA) with ivermectin is the main strategy for onchocerciasis elimination. Ivermectin is generally safe but associated with serious adverse events in individuals with high Loa loa microfilarial densities (MFD). Therefore, ivermectin MDA is not recommended in areas where onchocerciasis is hypo-endemic and L. loa i...

Aside the direct effect of the COVID-19 on infected patients, this infectious disease outbreak has various psychological consequences. These mental health repercussions pertain to the general population of uninfected individuals, and particularly families of isolated or deceased COVID-19 patients. This aspect is of substantial interest amid sub-Sah...

Background Lymphatic filariasis (LF) is a debilitating neglected tropical disease which is targeted for elimination through co-administration of a single dose of ivermectin and albendazole in the affected population. Following implementation of such a treatment campaign over a period of years, control programmes are urged to conduct a transmission...

Background Soil-transmitted helminth (STH) infections remain a public health concern in sub-Saharan Africa. School-based mass drug administration (MDA) using the anthelminthic drug Mebendazole/Albendazole have succeeded in controlling morbidity associated to these diseases but failed to interrupt their transmission. In areas were filarial diseases...

Background: Ivermectin-based preventive chemotherapy (PC) is distributed annually to all at-risk populations eligible for ivermectin treatment to control and/or eliminate onchocerciasis. Information on the impact of mass ivermectin administration on onchocerciasis transmission is scanty, and it is tricky to appreciate the progress towards eliminat...

Background Ivermectin (IVM) is a broad spectrum endectocide whose initial indication was onchocerciasis. IVM-based preventive chemotherapies (PC), so-called Community-Directed Treatment with Ivermectin (CDTI), have led to the interruption of transmission of onchocerciasis in some foci. Although loiasis is not among its indications, IVM also exhibit...

Background Vector control using larvicides is the main alternative strategy to address limits of preventive chemotherapy using ivermectin to fight onchocerciasis. However, it remains substantially limited by implementation difficulties, ecological concerns and resistance of vector populations. Therefore, efficient and environmentally safe alternati...

Background: Epilepsy is a severe neurological disorder with huge psychological, social, and economic consequences, including premature deaths and loss of productivity. Sub-Saharan Africa carries the highest burden of epilepsy. The management of epilepsy in Cameroon remains unsatisfactory due to poor identification of cases and a limited knowledge...

Background Ivermectin-based preventive chemotherapy is distributed annually to all at risk eligible individuals to fight onchocerciasis. Data reporting the impact of mass ivermectin administration on onchocerciasis transmission are scanty, and it is tricky to appreciate the progress towards elimination and engage adapted corrective measures. To fil...

Background Ivermectin-based preventive chemotherapy (PC) is distributed annually to all at-risk individuals to control and/or eliminate onchocerciasis. Information on the impact of mass ivermectin administration on onchocerciasis transmission are scanty, and it is tricky to appreciate the progress towards elimination and engage corrective measures....

Background: Ivermectin-based preventive chemotherapy (PC) is distributed annually to all at-risk populations eligible for ivermectin treatment to control and/or eliminate onchocerciasis. Information on the impact of mass ivermectin administration on onchocerciasis transmission is scanty, and it is tricky to appreciate the progress towards eliminati...

Background: Many control methods have been implemented to tackle onchocerciasis and great successes have been achieved, leading to a paradigm shift from control of morbidity to interruption of transmission and ultimately elimination. The mandate of the African Programme for Onchocerciasis Control (APOC) ended in 2015, and endemic countries are to...

Background: A test-and-not-treat (TaNT) strategy has been developed to prevent people with high concentrations of circulating Loa loa microfilariae (>20 000 microfilariae per mL) developing serious adverse events after ivermectin treatment during mass drug administration to eliminate onchocerciasis. An important question related to cost and progra...

Background: In Cameroon, since the first epidemiological week held in 2015, snakebites have been registered among Potential Epidemic Diseases (PED). In the Centre Region, the most densely populated of the country, weekly reports of snakebites are generated at health districts level for monthly data updates. Methods: To contribute to the better m...

Background: Severe adverse events (SAEs) after treatment with ivermectin in individuals with high levels of Loa loa microfilariae in the blood preclude onchocerciasis elimination through Community-Directed Treatment with Ivermectin (CDTI) in Central Africa. We measured the cost of a community-based pilot using a test-and-not-treat (TaNT) strategy...

Background: Preventive chemotherapy (PCT) is the main strategy currently used to control and/or eliminate onchocerciasis (Oncho), lymphatic filariasis (LF) and Soil Transmitted Helminthiasis (STH), and community participation (through implementation of MDA or adherence to PCT) is critical to achieve this goal. However, these Neglected Tropical Dise...

Background Surveys conducted in 1991-1992 in the Mbam Valley (Cameroon) revealed that onchocerciasis was highly endemic, with community microfilarial loads (CMFL)>100 microfilariae/snip in some villages. Also in 1991-1992, a survey of suspected cases of epilepsy (SCE) found 746 SCE using a questionnaire administered to individuals identified by key...

The specificity of skin snips for onchocerciasis diagnosis is considered to be almost 100%. In this study, molecular methods revealed that microfilariae emerging from skin snips collected from highly microfilaremic Loa loa-infected individuals were largely misidentified as Onchocerca volvulus. This has important implications for onchocerciasis diag...

Abstract Background Loiasis is a vector-borne parasitic disease due to Loa loa and transmitted to humans by tabanids of the genus Chrysops. Loiasis has been historically considered as the second or third most common reason for medical consultation after malaria, and a recent study has reported an excess mortality associated with the infection. Howe...

The Global Program to Eliminate Lymphatic Filariasis (LF) relies on rapid diagnostic tests (RDTs) to determine where annual mass drug administration for LF is required and when it can be stopped. These tests detect a Wuchereria bancrofti glycoprotein in the blood of infected persons via a carbohydrate moiety recognized by the monoclonal antibodies...

Complete list of L. loa proteins identified from cross-reactive loiasis serum. (XLSX)