Changing spatial patterns and increasing rurality of HIV prevalence in the Democratic Republic of the Congo between 2007 and 2013

The Democratic Republic of the Congo (DRC) has one of the lowest HIV prevalence in sub-Saharan Africa, estimated at 1.1% [0.9-1.3] of adults aged 15-49 in 2013 (UNAIDS). Within the 2 million km2 country, however, there exists spatial variation in HIV prevalence, with the highest HIV prevalence observed in the large cities of Kinshasa and Lubumbashi. Globally, HIV is an increasingly rural disease, diffusing outwards from urban centers of high HIV prevalence to places where HIV was previously absent or present at very low levels. Utilizing data collected during Demographic and Health Surveillance (DHS) in 2007 and 2013 in the DRC, we sought to update the map of HIV prevalence in the DRC as well as to explore whether HIV in the DRC is an increasingly rural disease or remains confined to urban areas. Bayesian kriging and regression indicate that HIV prevalence in rural areas of the DRC is higher in 2013 than in 2007 and that increased distance to an urban area is no longer protective against HIV as it was in 2007. These findings suggest that HIV education, testing and prevention efforts need to diffuse from urban to rural areas just as HIV is doing

Malaria surveillance in the Democratic Republic of the Congo: comparison of microscopy, PCR, and rapid diagnostic test

Malaria surveillance is critical for control efforts, but diagnostic methods frequently disagree. Here we compare microscopy, PCR, and a Rapid Diagnostic Test in 7,137 samples from children in the Democratic Republic of the Congo using Latent Class Analysis. PCR had the highest sensitivity (94.6%) and microscopy had the lowest (76.7%)

Low prevalence of Plasmodium malariae and Plasmodium ovale mono-infections among children in the Democratic Republic of the Congo: a population-based, cross-sectional study

Abstract Background In an effort to improve surveillance for epidemiological and clinical outcomes, rapid diagnostic tests (RDTs) have become increasingly widespread as cost-effective and field-ready methods of malaria diagnosis. However, there are concerns that using RDTs specific to Plasmodium falciparum may lead to missed detection of other malaria species such as Plasmodium malariae and Plasmodium ovale. Methods Four hundred and sixty six samples were selected from children under 5 years old in the Democratic Republic of the Congo (DRC) who took part in a Demographic and Health Survey (DHS) in 2013–14. These samples were first tested for all Plasmodium species using an 18S ribosomal RNA-targeted real-time PCR; malaria-positive samples were then tested for P. falciparum, P. malariae and P. ovale using a highly sensitive nested PCR. Results The prevalence of P. falciparum, P. malariae and P. ovale were 46.6, 12.9 and 8.3 %, respectively. Most P. malariae and P. ovale infections were co-infected with P. falciparum—the prevalence of mono-infections of these species were only 1.0 and 0.6 %, respectively. Six out of these eight mono-infections were negative by RDT. The prevalence of P. falciparum by the more sensitive nested PCR was higher than that found previously by real-time PCR. Conclusions Plasmodium malariae and P. ovale remain endemic at a low rate in the DRC, but the risk of missing malarial infections of these species due to falciparum-specific RDT use is low. The observed prevalence of P. falciparum is higher with a more sensitive PCR method

Evaluation du niveau de connaissance et des facteurs prédisposant aux hépatites B et C chez les patients suivis en consultations externes des trois hôpitaux de Kinshasa : étude transversale multicentrique: Assessment of level of knowledge and factors predisposing on hepatitis B and C in patients followed by external consultations of the three hospitals of Kinshasa: a multicenter cross-sectional study

Context and objective. Knowledge on prevention and risk factors for HBV and HCV in the community is essential in order to fight against efficiently the spread of HBV and HCV. The aim of this study was to assess the extent of the risk factors for hepatitis B and C virus infection in Congolese community settings through outpatients. Methods. A multicentric cross-sectional study was conducted from May to October 2016. It consisted directly in collecting information on hepatitis B and C from outpatients in 3 hospitals of Kinshasa: Clinique d’Or, CUK and CHEM. Data collection was done consecutively. Results. 133 patients were interviewed (male 66.9%, mean age 33.9 ± 7.8 years). Knowledge of hepatitis B or C was found in 58.6% patients. The predisposing factors of hepatitis B and C were on average 4 factors in the same person and 24.8% of the respondents had at least 4 predisposing factors. The high level of study was the major factor associated with best knowledge of hepatitis B and C (aOR: 15.81, 95% CI: 4.90-18.01, p <0.001). Conclusion. The frequency of predisposing factors for hepatitis B and C is high in our environment; sufficient information on the harmful effects of these viruses would reduce this frequency and increase knowledge about hepatitis B and C. Contexte et objectif. La connaissance par la population des moyens de prévention et des facteurs prédisposant est indispensable en vue de lutter efficacement contre la propagation des virus de l’hépatite B et C. L’objectif de cette étude était d’évaluer l’ampleur des facteurs prédisposant l’acquisition de l’infection par le virus de l’hépatite B et C en milieu communautaire congolais. Méthodes. Etude transversale multicentrique, ayant inclus des patients recrutés, par convenance en consultation externe des trois formations hospitalières de Kinshasa ; entre mai et octobre 2016. Elle avait consisté à recueillir directement par entretiens dirigés, des informations sur les connaissances des hépatites B et C. Résultats. Au total 133 sujets ont été interviewés (hommes 66,9%, âge moyen était de 33,9±7,8 ans). Près de 59% des patients avaient avoué avoir des connaissances sur les hépatites B et C. Les facteurs prédisposant aux hépatites B et C étaient en moyenne de 4 chez la même personne. Le niveau d’étude élevé a émergé comme seul facteur associé de manière indépendante, à la connaissance de l’hépatite B et C (ORa : 15,81 ; IC 95% : 4,90-18,01, p<0,001). Conclusion. La fréquence des facteurs prédisposant à l’hépatite B et C est élevée dans nos milieux, une information suffisante sur les méfaits de ces virus, permettrait de diminuer cette fréquence et d’augmenter la connaissance sur les hépatites B et C

The geography of malaria genetics in the Democratic Republic of Congo: A complex and fragmented landscape

Understanding how malaria parasites move between populations is important, particularly given the potential for malaria to be reintroduced into areas where it was previously eliminated. We examine the distribution of malaria genetics across seven sites within the Democratic Republic of Congo (DRC) and two nearby countries, Ghana and Kenya, in order to understand how the relatedness of malaria parasites varies across space, and whether there are barriers to the flow of malaria parasites within the DRC or across borders. Parasite DNA was retrieved from dried blood spots from 7 Demographic and Health Survey sample clusters in the DRC. Malaria genetic characteristics of parasites from Ghana and Kenya were also obtained. For each of 9 geographic sites (7 DRC, 1 Ghana and 1 Kenya), a pair-wise RST statistic was calculated, indicating the genetic distance between malaria parasites found in those locations. Mapping genetics across the spatial extent of the study area indicates a complex genetic landscape, where relatedness between two proximal sites may be relatively high (RST > 0.64) or low (RST < 0.05), and where distal sites also exhibit both high and low genetic similarity. Mantel’s tests suggest that malaria genetics differ as geographic distances increase. Principal Coordinate Analysis suggests that genetically related samples are not co-located. Barrier analysis reveals no significant barriers to gene flow between locations. Malaria genetics in the DRC have a complex and fragmented landscape. Limited exchange of genes across space is reflected in greater genetic distance between malaria parasites isolated at greater geographic distances. There is, however, evidence for close genetic ties between distally located sample locations, indicating that movement of malaria parasites and flow of genes is being driven by factors other than distance decay. This research demonstrates the contributions that spatial disease ecology and landscape genetics can make to understanding the evolutionary dynamics of infectious diseases

Prevalence of Human African Trypanosomiasis in the Democratic Republic of the Congo

Human African Trypanosomiasis (HAT) is a major public health problem in the Democratic Republic of the Congo (DRC). Active and passive surveillance for HAT is conducted but may underestimate the true prevalence of the disease. We used ELISA to screen 7,769 leftover dried blood spots from a nationally representative population-based survey, the 2007 Demographic and Health Survey. 26 samples were positive by ELISA. Three of these were also positive by trypanolysis and/or PCR. From these data, we estimate that there were 18,592 people with HAT (95% confidence interval, 4,883–32,302) in the DRC in 2007, slightly more than twice as many as were reported

Impact of malaria diagnostic choice on monitoring of Plasmodium falciparum prevalence estimates in the Democratic Republic of the Congo and relevance to control programs in high-burden countries

Malaria programs rely upon a variety of diagnostic assays, including rapid diagnostic tests (RDTs), microscopy, polymerase chain reaction (PCR), and bead-based immunoassays (BBA), to monitor malaria prevalence and support control and elimination efforts. Data comparing these assays are limited, especially from high-burden countries like the Democratic Republic of the Congo (DRC). Using cross-sectional and routine data, we compared diagnostic performance and Plasmodium falciparum prevalence estimates across health areas of varying transmission intensity to illustrate the relevance of assay performance to malaria control programs. Data and samples were collected between March–June 2018 during a cross-sectional household survey across three health areas with low, moderate, and high transmission intensities within Kinshasa Province, DRC. Samples from 1,431 participants were evaluated using RDT, microscopy, PCR, and BBA. P. falciparum parasite prevalence varied between diagnostic methods across all health areas, with the highest prevalence estimates observed in Bu (57.4–72.4% across assays), followed by Kimpoko (32.6–53.2%), and Voix du Peuple (3.1–8.4%). Using latent class analysis to compare these diagnostic methods against an “alloyed gold standard,” the most sensitive diagnostic method was BBA in Bu (high prevalence) and Voix du Peuple (low prevalence), while PCR diagnosis was most sensitive in Kimpoko (moderate prevalence). RDTs were consistently the most specific diagnostic method in all health areas. Among 9.0 million people residing in Kinshasa Province in 2018, the estimated P. falciparum prevalence by microscopy, PCR, and BBA were nearly double that of RDT. Comparison of malaria RDT, microscopy, PCR, and BBA results confirmed differences in sensitivity and specificity that varied by endemicity, with PCR and BBA performing best for detecting any P. falciparum infection. Prevalence estimates varied widely depending on assay type for parasite detection. Inherent differences in assay performance should be carefully considered when using community survey and surveillance data to guide policy decisions

A melt blowing-electrospinning approach to fabricating nanofibers

A polymer drawing model for melt blowing-electrospinning is established. The fiber diameters are predicted and measured. The results show that the predicted diameters show good agreements with the measured diameters. Fibers fabricated with electrospinning are finer than those without electrospinning, giving a new way to the mass production of nanofibers

Correction to: Individual and household characteristics of persons with Plasmodium falciparum malaria in sites with varying endemicities in Kinshasa Province, Democratic Republic of the Congo

Unfortunately after publication of the original article [1], it came to the author’s attention that there is an error in the caption of Fig. 2