Spatial and social factors drive anemia in Congolese women

Anemia is common in women of child-bearing age in the Democratic Republic of the Congo (DRC). As part of the 2007 DRC Demographic and Health Survey (DHS), 4,638 women of childbearing age (including 526 pregnant women) were tested for HIV and had the hemoglobin content of their blood recorded. We assessed malaria prevalence using laboratory methods. The DHS provided extensive information for individuals, as well as household cluster coordinates which enabled us to derive several spatial variables. Multilevel analyses were conducted to determine individual and contextual risk factors for anemia. Prevalence varied geographically and was associated with both one's ethnic group and the amount and type of nearby agriculture. In contrast, prevalence was not affected by HIV or malaria status

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

Local Differences in Human Immunodeficiency Virus Prevalence: A Comparison of Social Venue Patrons, Antenatal Patients, and Sexually Transmitted Infection Patients in Eastern Kinshasa

This study compares the sexual behavior and HIV prevalence of men and women at social venues where people meet new sexual partners in Eastern Kinshasa with the HIV prevalence and behavior of STI treatment and antenatal clinic patients in the same area

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

Low knowledge about hepatitis B prevention among pregnant women in Kinshasa, Democratic Republic of Congo

Infants infected perinatally with hepatitis B (HBV) are at the highest risk of developing chronic hepatitis and associated sequelae. Prevention of mother-to-child transmission (PMTCT) of HBV requires improved screening and awareness of the disease. This study evaluated existing HBV knowledge among pregnant mothers (n = 280) enrolled in two HBV studies in urban maternity centers in Kinshasa, Democratic Republic of the Congo. All mothers responded to three knowledge questions upon study enrollment. Baseline levels of knowledge related to HBV transmission, treatment, prevention, and symptoms were low across all participants: 68.8% did not know how HBV was transmitted, 70.7% did not know how to prevent or treat HBV MTCT, and 79.6% did not know signs and symptoms of HBV. Over half of participants responded “I don’t know” to all questions. HBV-positive women who participated in both studies (n = 46) were asked the same questions during both studies and showed improved knowledge after screening and treatment, despite no formal educational component in either study (p < 0.001). These findings highlight the need for intensified education initiatives in highly endemic areas to improve PMTCT efforts

Pooled Amplicon Deep Sequencing of Candidate Plasmodium falciparum Transmission-Blocking Vaccine Antigens

Polymorphisms within Plasmodium falciparum vaccine candidate antigens have the potential to compromise vaccine efficacy. Understanding the allele frequencies of polymorphisms in critical binding regions of antigens can help in the designing of strain-transcendent vaccines. Here, we adopt a pooled deep-sequencing approach, originally designed to study P. falciparum drug resistance mutations, to study the diversity of two leading transmission-blocking vaccine candidates, Pfs25 and Pfs48/45. We sequenced 329 P. falciparum field isolates from six different geographic regions. Pfs25 showed little diversity, with only one known polymorphism identified in the region associated with binding of transmission-blocking antibodies among our isolates. However, we identified four new mutations among eight non-synonymous mutations within the presumed antibody-binding region of Pfs48/45. Pooled deep sequencing provides a scalable and cost-effective approach for the targeted study of allele frequencies of P. falciparum candidate vaccine antigens

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

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

Population, behavioural and environmental drivers of malaria prevalence in the Democratic Republic of Congo

<p>Abstract</p> <p>Background</p> <p>Malaria is highly endemic in the Democratic Republic of Congo (DRC), but the limits and intensity of transmission within the country are unknown. It is important to discern these patterns as well as the drivers which may underlie them in order for effective prevention measures to be carried out.</p> <p>Methods</p> <p>By applying high-throughput PCR analyses on leftover dried blood spots from the 2007 Demographic and Health Survey (DHS) for the DRC, prevalence estimates were generated and ecological drivers of malaria were explored using spatial statistical analyses and multilevel modelling.</p> <p>Results</p> <p>Of the 7,746 respondents, 2268 (29.3%) were parasitaemic; prevalence ranged from 0-82% within geographically-defined survey clusters. Regional variation in these rates was mapped using the inverse-distance weighting spatial interpolation technique. Males were more likely to be parasitaemic than older people or females (p < 0.0001), while wealthier people were at a lower risk (p < 0.001). Increased community use of bed nets (p = 0.001) and community wealth (p < 0.05) were protective against malaria at the community level but not at the individual level. Paradoxically, the number of battle events since 1994 surrounding one's community was negatively associated with malaria risk (p < 0.0001).</p> <p>Conclusions</p> <p>This research demonstrates the feasibility of using population-based behavioural and molecular surveillance in conjunction with DHS data and geographic methods to study endemic infectious diseases. This study provides the most accurate population-based estimates to date of where illness from malaria occurs in the DRC and what factors contribute to the estimated spatial patterns. This study suggests that spatial information and analyses can enable the DRC government to focus its control efforts against malaria.</p