Molecular detection and species identification of Plasmodium spp. infection in adults in the Democratic Republic of Congo: A population-based study.

BackgroundIn efforts to control malaria infection, the Democratic Republic of Congo has implemented several strategies. Studies assessing their efficiency mainly involved at-risk groups, especially children under five years of age. This study aimed to determine the prevalence and identify the risk factors associated with Plasmodium spp. infection.MethodsFrom October 2014 to March 2015, individuals aged at least 15 years were selected randomly and enrolled in a cross-sectional study conducted throughout the country. Microscopy and polymerase chain reaction (PCR) analysis were used for the detection of Plasmodium ssp.ResultsFrom 2286 individuals recruited, 1870 with valid laboratory results were included in the study for further analysis. The prevalence of Plasmodium spp. infection assessed by microscopy (355/ 1870 (19%) was lower than that estimated by PCR (580/1870 (31%). In addition, the difference between the two results was statistically significant (P ConclusionIn this study, the molecular detection and species identification of Plasmodium spp. showed that, despite all efforts for malaria control, malaria remains a public health problem in the Democratic Republic of Congo. The high prevalence and parasite density of Plasmodium spp. in adults make this age group a potential parasitic infectious reservoir for the at-risk groups and supports the need to include this age group in further programs for malaria control

Absence de détection de Plasmodium simien au sein de la population vivant dans la forêt équatorienne de RDC

Background Malaria remains the most deadly parasitic disease to date, especially in sub-Saharan Africa, which comprises the majority of cases collected per year. It has long been accepted that four species of Plasmodium (P. falciparum, P. vivax, P. malariae and P. ovale) were responsible for the disease in humans. But quite recently, a fifth species, Plasmodium Knowlesi, has been identified as naturally infecting humans. Indeed, known for decades as naturally parasitizing the monkey Macaca fascicularis, P. knowlesi has long been confused, in terms of its evolutionary stage, with P. malariae or P. falciparum, which it resembles morphologically and it was not possible to properly differentiate them until the advent of molecular biology. To date, P. Knowlesi has only been identified in Southeast Asia and a similar phenomenon of natural transmission of simian plasmodium to humans has not been reported elsewhere. We therefore conducted this study to investigate the possible transmission of simian plasmodium to humans in populations living near the rainforest of the Democratic Republic of Congo (DRC) where several species of primates lives. Methods & Materials Three villages (Wenji-Secli, Bongonde, and Bolenge) in the Province of Ecuador (North-eastern DRC) were selected because of their geographical location. Blood samples spotted on filter paper were collected from 100 people randomly taken in each village. Two successive RT- PCR were performed. A first one using a single probe able to diagnose all plasmodium spp. and a second using four species-specific probes for the diagnosis of the four conventional human plasmodium species. Positivity in the first RT- PCR with negativity in the second RT- PCR would suggest the presence of plasmodium species other than the four conventional. Results P. falciparum was correctly identified in 44.6 % of samples. No other species of human plasmodium or not has been identified. Conclusion This preliminary study did not detect the presence of simian plasmodium in human populations living in the rainforest of the DRC. Studies with larger samples and with more advanced techniques should still be conducted. Keywords: Malaria, simian plasmodium, DR Cong

Mosquito-borne viruses circulating in Kinshasa, Democratic Republic of the Congo

Background: Diseases caused by mosquito-borne viruses are among the most important emerging diseases that threaten human and animal health, particularly in Africa. However, little attention has been paid to these diseases in the Democratic Republic of the Congo (DRC). The present cross-sectional study was undertaken between March and May 2014 to investigate the presence of mosquito-borne viruses in mosquitoes collected from five municipalities of Kinshasa, DRC. Methods: Mosquitoes were collected using BG-Sentinel traps and battery-powered aspirators. Female mosquitoes were pooled according to their genera and sampling locations, preserved in RNAlater, and later screened for viruses using reverse transcription PCR (RT-PCR) assays. Results: A total of 2922 mosquitoes were collected and 29 pools of female mosquitoes, containing approximately 30 mosquitoes each, were tested. Twelve of the 29 (41.4%) mosquito pools were found to be infected with at least one arbovirus, with eight (27.5%) pools positive for Alphavirus, nine (31%) for Flavivirus, and five (17.2%) for Bunyaviridae. Chikungunya, o’nyong’nyong, and Rift valley fever viruses were detected. Conclusions: The present study shows that mosquitoes in Kinshasa carry mosquito-borne viruses that may have serious public health implications. Further investigations on the presence of mosquito-borne viruses in the human and livestock populations of Kinshasa and DRC are recommended

Surveillance moléculaire de la résistance de Plasmodium falciparum aux associations thérapeutiques à base d'artémisinine

Malaria is a major public health problem in the Democratic Republic of Congo. Despite progress achieved over the past decade in the fight against malaria, further efforts have to be done such as in the surveillance and the containment of Plasmodium falciparum resistant strains. We investigated resistance to artemisinin-based combination therapies currently in use in Democratic Republic of Congo by surveying molecular polymorphisms in three genes: pfcrt, pfmdr1 and pfk13 to explore possible emergence of amodiaquine, lumefantrine or artemisinin resistance in Democratic Republic of Congo. This study essentially revealed that resistance to chloroquine is still decreasing while polymorphism related to amodiaquine resistance seems to be not present in Democratic Republic of Congo, that three samples, located in the east of the country, harbor Pfmdr1 amplification and that none of the mutations found in South-East Asia correlated with artemisinine resistance have been found in Democratic Republic of Congo. But new mutations have been identified, especially the M476K, occurred in the same position that the M476I previously identified in the F32-ART strain, strongly resistant to artemisinine. Antimalarial first-line treatments currently in use in Democratic Republic of Congo are not associated with emergence of molecular markers of resistance

High Prevalence of Plasmodium falciparum Infection in Asymptomatic Individuals from the Democratic Republic of the Congo

Malaria remains a major public health problem in the Democratic Republic of Congo (DRC) with 14 million cases reported by the WHO Malaria Report in 2014. Asymptomatic malaria cases are known to be prevalent in endemic areas and are generally untreated, resulting in a significant source of gametocytes that may serve as reservoir of disease transmission. Considering that microscopy certainly underestimates the prevalence of Plasmodium infections within asymptomatic carriers and that PCR assays are currently recognized as the most sensitive methods for Plasmodium identification, this study was conducted to weigh the asymptomatic carriage in DRC by a molecular method. Six provinces were randomly selected for blood collection in which 80 to 100 individuals were included in the study. Five hundred and eighty blood samples were collected and molecular diagnosis was performed. Globally, almost half of the samples collected from asymptomatic individuals (280/580; 48.2%) had Plasmodium infections and the most species identified was P. falciparum alone in combination with P. malariae. The high prevalence reported here should interpellate the bodies involved in malaria control in DR Congo to take into account asymptomatic carriers in actions taken and consider asymptomatic malaria as a major hurdle for malaria elimination

Distribution of mutations found in the k13 gene across DRC.

<p>New mutations are in green and already described mutations are presented in blue.</p