Publications by authors named "Njiokou Flobert"

Article Synopsis
  • - The study investigates the prevalence of a specific bacterium in mosquito populations as a potential method for controlling malaria, focusing on co-infections with the malaria parasite in Cameroon.
  • - Researchers collected and analyzed 864 adult mosquitoes from two locations during both dry and wet seasons, using real-time qPCR to assess bacterial and malaria parasite densities.
  • - Results indicated a higher prevalence of the bacterium in one species of mosquito compared to another, influenced by seasonal changes, but no correlation was found between the bacterium and malaria infections, suggesting the need for further experimental studies.
View Article and Find Full Text PDF
Article Synopsis
  • - This study investigates the gut microbiota of the blackfly Simulium damnosum s.l. to understand its role in the transmission of the parasite Onchocerca volvulus, which causes river blindness.
  • - Adult female blackflies were collected from various regions in Cameroon, and their gut microbiota was analyzed using advanced sequencing techniques to identify dominant bacterial taxa and assess microbiota diversity.
  • - Findings revealed significant variations in the gut microbiota related to certain factors like the blackfly's reproductive status and geographic origin, with specific bacteria associated with the absence of O. volvulus infection, indicating a complex relationship between the microbiota and parasite transmission.
View Article and Find Full Text PDF

Novel vector control tools against African trypanosomiases require a deep understanding of the factors driving tsetse vector fitness or population resilience in their ecosystems. Following evidence of microbiota-mediated host fitness or traits shaping, including insecticide resistance in arthropod populations, we undertook a comparative study of the microbiota in wild-caught tsetse flies during vector control with deltamethrin-impregnated traps called Tiny Targets. The bacterial microbiome composition of tsetse flies collected before and after 6, 12, and 18 months of vector control were characterized using high-throughput sequencing of the V3-V4 hypervariable region of the bacterial 16S rRNA gene and compared.

View Article and Find Full Text PDF
Article Synopsis
  • Surveillance of "silent" human African Trypanosomiasis (HAT) foci in Cameroon is crucial for meeting the World Health Organization's goal of interrupting disease transmission by 2030, prompting a study on trypanosome species present in Bafia and Manoka island.
  • Using georeferenced traps, researchers captured 1683 tsetse flies and employed molecular methods to identify trypanosome species and examine blood meal sources, highlighting areas at high risk for transmission.
  • The study found a notable difference in tsetse fly density and infection rates between the two regions, with a 7.34% overall infection rate and mixed infections primarily involving Trypanozoon and T. congolense
View Article and Find Full Text PDF
Article Synopsis
  • - The white-bellied pangolin faces serious trafficking threats, and a study analyzed 562 pangolins in central Africa to understand its population genetics and the domestic trade dynamics.
  • - Findings revealed overlapping genetic lineages with minimal introgression and suggested a significant decline in population size, likely due to historical factors and current trade routes radiating up to 600 km from markets in Cameroon.
  • - The study recommends improved monitoring of key trade hubs like the Yaoundé market and emphasizes the need for better enforcement of CITES regulations in Europe to help protect pangolin populations.
View Article and Find Full Text PDF
Article Synopsis
  • Vector control is essential for preventing trypanosome infections in humans and livestock, which is crucial for eliminating African sleeping sickness.
  • Researchers in Cameroon updated the identification and distribution of tsetse fly species by capturing specimens and performing morphological and DNA analysis.
  • The study revealed distinct morphologic features for different tsetse species, confirmed through DNA sequencing, and updated their geographic distribution, noting changes in species presence in specific regions.
View Article and Find Full Text PDF

The effectiveness of the "Slash and Clear" method in reducing blackfly populations in low transmission areas is established, but its impact in high transmission settings with large rivers and dense vectors is yet to be proven. A community-based intervention study was conducted in the Mbam Valley, Centre Cameroon, involving two sites: Bayomen (control) and Biatsota (intervention). In each arm, baseline blackfly densities were collected over one year using the human landing method.

View Article and Find Full Text PDF

Background: Significant progress has been made towards African sleeping sickness elimination in the last decade. Indeed, the World Health Organization (WHO) global goal of eliminating the chronic form of the disease as a public health problem was achieved in 2020 (i.e.

View Article and Find Full Text PDF

Malaria molecular surveillance remains critical in detecting and tracking emerging parasite resistance to anti-malarial drugs. The current study employed molecular techniques to determine species prevalence and characterize the genetic diversity of and molecular markers of sulfadoxine-pyrimethamine resistance in humans and wild mosquito populations in Cameroon. mosquito collections and parasitological survey were conducted in villages to determine species infection, and genomic phenotyping of anti-folate resistance was accomplished by sequencing the dihydrofolate-reductase () and dihydropteroate-synthase () genes of naturally circulating and isolates.

View Article and Find Full Text PDF

Pangolins form a group of scaly mammals that are trafficked at record numbers for their meat and purported medicinal properties. Despite their conservation concern, knowledge of their evolution is limited by a paucity of genomic data. We aim to produce exhaustive genomic resources that include 3,238 orthologous genes and whole-genome polymorphisms to assess the evolution of all eight extant pangolin species.

View Article and Find Full Text PDF

Background: The increasing reports of resistance to pyrethroid insecticides associated with reduced efficacy of pyrethroid-only interventions highlight the urgency of introducing new non-pyrethroid-only control tools. Here, we investigated the performance of piperonyl-butoxide (PBO)-pyrethroid [Permanet 3.0 (P3.

View Article and Find Full Text PDF

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 trapping system has been based most often on the shape of the trap, collection in areas of high black fly density and the addition of attractants, without considering transmission potentials and parity rates.

View Article and Find Full Text PDF

Background: The double burden of malaria and helminthiasis in children poses an obvious public health challenge, particularly in terms of anemia morbidity. While both diseases frequently geographically overlap, most studies focus on mono-infection and general prevalence surveys without molecular analysis. The current study investigated the epidemiological determinants of malaria, schistosomiasis, and geohelminthiasis transmission among children in the North Region of Cameroon.

View Article and Find Full Text PDF
Article Synopsis
  • Tsetse flies are key vectors for African Trypanosomiasis, which affects humans and animals, and controlling their populations is crucial for disease management.
  • The study focuses on analyzing protein changes in the midgut of wild tsetse flies infected with Trypanosoma congolense, comparing infected and non-infected specimens from Southern Cameroon.
  • Significant proteins linked to infection include those involved in metabolism, apoptosis, and immune response, which could inform future strategies for controlling the fly's ability to transmit the disease.
View Article and Find Full Text PDF

The objective of this work was to assess the anemic status and the use of an immunological test and PCR-based methods to determine the infection rates of trypanosomes species. Transhumance aims to provide cattle with greener pastures and greater water resources than in the Djerem region during the dry season. Two criteria were used to assess the health status of the animals, the prevalence of trypanosomiasis and the level of anemia.

View Article and Find Full Text PDF

Eliminating schistosomiasis as a public health problem by 2030 requires a better understanding of the disease transmission, especially the asymmetric distribution of worm burden in individuals living and sharing the same environment. It is in this light that this study was designed to identify human genetic determinants associated with high burden of S. mansoni and also with the plasma concentrations of IgE and four cytokines in children from two schistosomiasis endemic areas of Cameroon.

View Article and Find Full Text PDF

Assessing the genetic diversity of metabolic resistance genes, such as cytochrome P450s, helps to understand the dynamics and evolution of resistance in the field. Here, we analyzed the polymorphisms of and associated with pyrethroid resistance in and , to detect potential resistance markers. Field-caught resistant mosquitos and susceptible lab strains were crossed, and F4 was exposed to permethrin for 15 min and 90 min to discriminate highly susceptible (HS) and highly resistant (HR) mosquitos, respectively.

View Article and Find Full Text PDF
Article Synopsis
  • The study assessed the susceptibility of Simulium larvae to the insecticides temephos and Bacillus thuringiensis var israelensis (Bti) using both in vitro bio-assays and semi-natural tests in Cameroon and Germany.
  • Results indicated that Cameroonian Simulium species showed lower LC50 and LC90 values for temephos compared to those from Germany, suggesting higher susceptibility.
  • The research recommends monitoring for resistance genes to prevent potential resistance development, similar to what has been observed in Ivory Coast.
View Article and Find Full Text PDF

Prevention and control of Aedes-borne viral diseases such as dengue rely on vector control, including the use of insecticides and reduction of larval sources. However, this is threatened by the emergence of insecticide resistance. This study aimed to update the spatial distribution, the insecticide resistance profile of A.

View Article and Find Full Text PDF
Article Synopsis
  • The study aimed to evaluate knowledge, attitudes, and practices (KAP) related to malaria among communities in the equatorial forest region of south Cameroon, specifically in Olama and Nyabessan.
  • Interviews with 186 households revealed that a significant majority had good knowledge of malaria and high ownership of long-lasting insecticidal nets (LLINs), yet malaria prevalence remained high at 63.9% in Nyabessan and 48.65% in Olama.
  • Despite community awareness and use of preventive measures, malaria transmission persists, highlighting the need for additional control strategies to enhance malaria prevention efforts in the region.
View Article and Find Full Text PDF

(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.

View Article and Find Full Text PDF

Background: Schistosomiasis control relies mainly on mass drug administration of Praziquantel (PZQ) to school aged children (SAC). Although precision mapping has recently guided decision making, the sub-districts and the epidemiological differences existing between bio-ecological settings in which infected children come from were not taken into consideration. This study was designed to fill this gap by using POC-CCA and KK to comparatively determine the prevalence and infection intensities of Schistosoma mansoni (S.

View Article and Find Full Text PDF

Animal African Trypanosomiasis (AAT) remains an animal health problem in sub-Saharan Africa and in Cameroon in particular. Despite more than 40 years of fighting against AAT in some tsetse infested areas, the disease prevalence is still a concern. Improving the control strategies in different settings requires to understand the current epidemiological situation of AAT.

View Article and Find Full Text PDF

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 period of 12 months. Blackflies were dissected and entomological indices were computed.

View Article and Find Full Text PDF

Background: Long-lasting insecticidal nets (LLINs) are a vital tool in the fight against malaria vectors. However, their efficacy in the field can be impacted by several factors, including patterns of usage, net age, mosquito resistance and the delayed mortality effect, all of which could influence malaria transmission. We have investigated the effectiveness of the various brands of LLINs available in markets and households in Cameroon on pyrethroid-resistant mosquitoes and assessed their post-exposure effect.

View Article and Find Full Text PDF