Dataset Information

Multiplex serology demonstrate cumulative prevalence and spatial distribution of malaria in Ethiopia.

ABSTRACT:

Background

Measures of malaria burden using microscopy and rapid diagnostic tests (RDTs) in cross-sectional household surveys may incompletely describe the burden of malaria in low-transmission settings. This study describes the pattern of malaria transmission in Ethiopia using serological antibody estimates derived from a nationwide household survey completed in 2015.

Methods

Dried blood spot (DBS) samples were collected during the Ethiopian Malaria Indicator Survey in 2015 from malarious areas across Ethiopia. Samples were analysed using bead-based multiplex assays for IgG antibodies for six Plasmodium antigens: four human malaria species-specific merozoite surface protein-1 19kD antigens (MSP-1) and Apical Membrane Antigen-1 (AMA-1) for Plasmodium falciparum and Plasmodium vivax. Seroprevalence was estimated by age, elevation and region. The seroconversion rate was estimated using a reversible catalytic model fitted with maximum likelihood methods.

Results

Of the 10,278 DBS samples available, 93.6% (9622/10,278) had valid serological results. The mean age of participants was 15.8 years and 53.3% were female. National seroprevalence for antibodies to P. falciparum was 32.1% (95% confidence interval (CI) 29.8-34.4) and 25.0% (95% CI 22.7-27.3) to P. vivax. Estimated seroprevalences for Plasmodium malariae and Plasmodium ovale were 8.6% (95% CI 7.6-9.7) and 3.1% (95% CI 2.5-3.8), respectively. For P. falciparum seroprevalence estimates were significantly higher at lower elevations (ConclusionUsing multiplex serology assays, this study explored the cumulative malaria burden and regional dynamics of the four human malarias in Ethiopia. High malaria burden was observed in the northwest compared to the east. High transmission in the Gambela and Benishangul-Gumuz Regions and the neglected presence of P. malariae and P. ovale may require programmatic attention. The use of a multiplex assay for antibody detection in low transmission settings has the potential to act as a more sensitive biomarker.

SUBMITTER: Assefa A

PROVIDER: S-EPMC6647069 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Multiplex serology demonstrate cumulative prevalence and spatial distribution of malaria in Ethiopia.

Assefa Ashenafi A Ali Ahmed Ahmed A Deressa Wakgari W Sime Heven H Mohammed Hussein H Kebede Amha A Solomon Hiwot H Teka Hiwot H Gurrala Kevin K Matei Brian B Wakeman Brian B Wilson G Glenn GG Sinha Ipsita I Maude Richard J RJ Ashton Ruth R Cook Jackie J Shi Ya Ping YP Drakeley Chris C von Seidlein Lorenz L Rogier Eric E Hwang Jimee J

Malaria journal 20190722 1

<h4>Background</h4>Measures of malaria burden using microscopy and rapid diagnostic tests (RDTs) in cross-sectional household surveys may incompletely describe the burden of malaria in low-transmission settings. This study describes the pattern of malaria transmission in Ethiopia using serological antibody estimates derived from a nationwide household survey completed in 2015.<h4>Methods</h4>Dried blood spot (DBS) samples were collected during the Ethiopian Malaria Indicator Survey in 2015 from ...[more]

PMID: 31331340

Similar Datasets

Project description:BackgroundUniversal coverage with long-lasting insecticidal nets (LLINs) is a primary control strategy against Plasmodium falciparum malaria. However, its impact on the three other main species of human malaria and lymphatic filariasis (LF), which share the same vectors in many co-endemic areas, is not as well characterized. The recent development of multiplex antibody detection provides the opportunity for simultaneous evaluation of the impact of control measures on the burden of multiple diseases.Methodology/principal findingsTwo cross-sectional household surveys at baseline and one year after a LLIN distribution campaign were implemented in Mecubúri and Nacala-a-Velha Districts in Nampula Province, Mozambique. Both districts were known to be endemic for LF; both received mass drug administration (MDA) with antifilarial drugs during the evaluation period. Access to and use of LLINs was recorded, and household members were tested with P. falciparum rapid diagnostic tests (RDTs). Dried blood spots were collected and analyzed for presence of antibodies to three P. falciparum antigens, P. vivax MSP-119, P. ovale MSP-119, P. malariae MSP-119, and three LF antigens. Seroconversion rates were calculated and the association between LLIN use and post-campaign seropositivity was estimated using multivariate regression. The campaign covered 68% (95% CI: 58-77) of the population in Nacala-a-Velha and 46% (37-56) in Mecubúri. There was no statistically significant change in P. falciparum RDT positivity between the two surveys. Population seropositivity at baseline ranged from 31-81% for the P. falciparum antigens, 3-4% for P. vivax MSP-119, 41-43% for P. ovale MSP-119, 46-56% for P. malariae MSP-119, and 37-76% for the LF antigens. The seroconversion rate to the LF Bm33 antigen decreased significantly in both districts. The seroconversion rate to P. malariae MSP-119 and the LF Wb123 and Bm14 antigens each decreased significantly in one of the two districts. Community LLIN use was associated with a decreased risk of P. falciparum RDT positivity, P. falciparum LSA-1 seropositivity, and P. malariae MSP-119 seropositivity, but not LF antigen seropositivity.Conclusions/significanceThe study area noted significant declines in LF seropositivity, but these were not associated with LLIN use. The MDA could have masked any impact of the LLINs on population LF seropositivity. The LLIN campaign did not reach adequately high coverage to decrease P. falciparum RDT positivity, the most common measure of P. falciparum burden. However, the significant decreases in the seroconversion rate to the P. malariae antigen, coupled with an association between community LLIN use and individual-level decreases in seropositivity to P. falciparum and P. malariae antigens show evidence of impact of the LLIN campaign and highlight the utility of using multiantigenic serological approaches for measuring intervention impact.

Project description:BackgroundG6PD enzyme deficiency is a common enzymatic X-linked disorder. Deficiency of the G6PD enzyme can cause free radical-mediated oxidative damage to red blood cells, leading to premature haemolysis. Treatment of Plasmodium vivax malaria with primaquine poses a potential risk of mild to severe acute haemolytic anaemia in G6PD deficient people. In this study, the prevalence and distribution of G6PD mutations were investigated across broad areas of Ethiopia, and tested the association between G6PD genotype and phenotype with the goal to provide additional information relevant to the use of primaquine in malaria treatment.MethodsThis study examined G6PD mutations in exons 3-11 for 344 febrile patient samples collected from seven sites across Ethiopia. In addition, the G6PD enzyme level of 400 febrile patient samples from Southwestern Ethiopia was determined by the CareStart™ biosensor. The association between G6PD phenotype and genotype was examined by Fisher exact test on a subset of 184 samples.ResultsMutations were observed at three positions of the G6PD gene. The most common G6PD mutation across all sites was A376G, which was detected in 21 of 344 (6.1%) febrile patients. Thirteen of them were homozygous and eight were heterozygous for this mutation. The G267+119C/T mutation was found in 4 (1.2%) individuals in South Ethiopia, but absent in other sites. The G1116A mutation was also found in 4 (1.2%) individuals from East and South Ethiopia. For the 400 samples in the south, 17 (4.25%) were shown to be G6PD-deficient. G6PD enzyme level was not significantly different by age or gender. Among a subset of 202 febrile patients who were diagnosed with malaria, 11 (5.45%) were G6PD-deficient. These 11 infected samples were diagnosed with Plasmodium vivax by microscopy. Parasitaemia was not significantly different between the G6PD-deficient and G6PD-normal infections.ConclusionsThe prevalence of G6PD deficiency is modest among febrile patients in Ethiopia. G6PD deficiency testing is thus recommended before administrating primaquine for radical cure of P. vivax infected patients. The present study did not indicate a significant association between G6PD gene mutations and enzyme levels.

Project description:BackgroundSince 2005, Ethiopia has aggressively scaled up malaria prevention and case management. As a result, the number of malaria cases and deaths has significantly declined. In order to track progress towards the elimination of malaria in Amhara Region, coverage of malaria control tools and current malaria transmission need to be documented.MethodsA cross-sectional household survey oversampling children under 5 years of age was conducted during the dry season in 2013. A bivalent rapid diagnostic test (RDT) detecting both Plasmodium falciparum and Plasmodium vivax and serology assays using merozoite antigens from both these species were used to assess the prevalence of malaria infections and exposure to malaria parasites in 16 woredas (districts) in Amhara Region.Results7878 participants were included, with a mean age of 16.8 years (range 0.5-102.8 years) and 42.0% being children under 5 years of age. The age-adjusted RDT-positivity for P. falciparum and P. vivax infection was 1.5 and 0.4%, respectively, of which 0.05% presented as co-infections. Overall age-adjusted seroprevalence was 30.0% for P. falciparum, 21.8% for P. vivax, and seroprevalence for any malaria species was 39.4%. The prevalence of RDT-positive infections varied by woreda, ranging from 0.0 to 8.3% and by altitude with rates of 3.2, 0.7, and 0.4% at under 2000, 2000-2500, and >2500 m, respectively. Serological analysis showed heterogeneity in transmission intensity by area and altitude and evidence for a change in the force of infection in the mid-2000s.ConclusionsCurrent and historic malaria transmission across Amhara Region show substantial variation by age and altitude with some settings showing very low or near-zero transmission. Plasmodium vivax infections appear to be lower but relatively more stable across geography and altitude, while P. falciparum is the dominant infection in the higher transmission, low-altitude areas. Age-dependent seroprevalence analyses indicates a drop in transmission occurred in the mid-2000s, coinciding with malaria control scale-up efforts. As malaria parasitaemia rates get very low with elimination efforts, serological evaluation may help track progress to elimination.

Project description:ObjectiveAlthough the rate of stillbirth has decreased globally, it remains unacceptably high in developing countries. Today, only 10 countries share the burden of more than 65% of the global rate of stillbirth and these include Ethiopia. Ethiopia ranks seventh in terms of high rate of stillbirths. Exploring the spatial distribution of stillbirth is critical to developing successful interventions and monitoring public health programmes. However, there is no study on the spatial distribution and the associated factors of stillbirth in Ethiopia. Therefore, this study aimed to explore the spatial distribution and the associated factors of stillbirth.MethodsSecondary data analysis was conducted based on the 2016 Ethiopian Demographic and Health Survey data. A total weighted sample of 11 375 women were included in the analysis. The Bernoulli model was fitted using SaTScan V.9.6 to identify hotspot areas and ArcGIS V.10.6 to explore the spatial distribution of stillbirth. For associated factors, a multilevel binary logistic regression model was fitted using STATA V.14 software. Variables with a p value of less than 0.2 were considered for the multivariable multilevel analysis. In the multivariable multilevel analysis, adjusted OR (AOR) with 95% CI was reported to reveal significantly associated factors of stillbirth.ResultsThe spatial analysis showed that stillbirth has significant spatial variation across the country. The SaTScan analysis identified significant primary clusters of stillbirth in the Northeast Somali region (log likelihood ratio (LLR)=13.4, p<0.001) and secondary clusters in the border area of Oromia and Amhara regions (LLR=8.8, p<0.05). In the multilevel analysis, rural residence (AOR=4.83, 95% CI 1.44 to 16.19), primary education (AOR=0.39, 95% CI 0.20 to 0.74), no antenatal care (ANC) visit (AOR=2.77, 95% CI 1.70 to 4.51), caesarean delivery (AOR=5.07, 95% CI 1.65 to 15.58), birth interval <24 months (AOR=1.95, 95% CI 1.20 to 3.10) and height <150 cm (AOR=2.73, 95% CI 1.45 to 4.97) were significantly associated with stillbirth.Conclusion and recommendationIn Ethiopia, stillbirth had significant spatial variations across the country. Residence, maternal stature, preceding birth interval, caesarean delivery, education and ANC visit were significantly associated with stillbirth. Therefore, public health interventions that enhance maternal healthcare service utilisation and maternal education in hotspot areas of stillbirth are crucial to reducing stillbirth in Ethiopia.

Project description:BackgroundPrimaquine is essential for malaria control and elimination since it is the only available drug preventing multiple clinical attacks by relapses of Plasmodium vivax. It is also the only therapy against the sexual stages of Plasmodium falciparum infectious to mosquitoes, and is thus useful in preventing malaria transmission. However, the difficulties of diagnosing glucose-6-phosphate dehydrogenase deficiency (G6PDd) greatly hinder primaquine's widespread use, as this common genetic disorder makes patients susceptible to potentially severe and fatal primaquine-induced haemolysis. The risk of such an outcome varies widely among G6PD gene variants.MethodsA literature review was conducted to identify surveys of G6PD variant frequencies among representative population groups. Informative surveys were assembled into two map series: (1) those showing the relative proportions of the different variants among G6PDd individuals; and (2) those showing allele frequencies of G6PD variants based on population surveys without prior G6PDd screening.ResultsVariants showed conspicuous geographic patterns. A limited repertoire of variants was tested for across sub-Saharan Africa, which nevertheless indicated low genetic heterogeneity predominated by the G6PD A(-202A) mutation, though other mutations were common in western Africa. The severe G6PD Mediterranean variant was widespread across western Asia. Further east, a sharp shift in variants was identified, with high variant heterogeneity in the populations of China and the Asia-Pacific where no single variant dominated.ConclusionsG6PD variants exhibited distinctive region-specific distributions with important primaquine policy implications. Relative homogeneity in the Americas, Africa, and western Asia contrasted sharply with the heterogeneity of variants in China, Southeast Asia and Oceania. These findings will inform rational risk assessments for primaquine in developing public health strategies for malaria control and elimination, and support the future development of regionally targeted policies. The major knowledge gaps highlighted here strongly advocate for further investigation of G6PD variant diversity and their primaquine-sensitivity phenotypes.

Project description:BackgroundEchinococcosis is a zoonotic parasitic disease caused by larval stages of cestodes belonging to the genus Echinococcus. The infection affects people's health and safety as well as agropastoral sector. In China, human echinococcosis is a major public health burden, especially in western China. Echinococcosis affects people health as well as agricultural and pastoral economy. Therefore, it is important to understand the prevalence status and spatial distribution of human echinococcosis in order to advance our knowledge of basic information for prevention and control measures reinforcement.MethodsReport data on echinococcosis were collected in 370 counties in China in 2018 and were used to assess prevalence and spatial distribution. SPSS 21.0 was used to obtain the prevalence rate for CE and AE. For statistical analyses and mapping, all data were processed using SPSS 21.0 and ArcGIS 10.4, respectively. Chi-square test and Exact probability method were used to assess spatial autocorrelation and spatial clustering.ResultsA total of 47,278 cases of echinococcosis were recorded in 2018 in 370 endemic counties in China. The prevalence rate of human echinococcosis was 10.57 per 10,000. Analysis of the disease prevalence showed obvious spatial positive autocorrelation in globle spatial autocorrelation with two aggregation modes in local spatial autocorrelation, namely high-high and low-high aggregation areas. The high-high gathering areas were mainly concentrated in northern Tibet, western Qinghai, and Ganzi in the Tibetan Autonomous Region and in Sichuan. The low-high clusters were concentrated in Gamba, Kangma and Yadong counties of Tibet. In addition, spatial scanning analysis revealed two spatial clusters. One type of spatial clusters included 71 counties in Tibet Autonomous Region, 22 counties in Qinghai, 11 counties in Sichuan, three counties in Xinjiang Uygur Autonomous Region, two counties in Yunnan, and one county in Gansu. In the second category, six types of spatial clusters were observed in the counties of Xinjiang Uygur Autonomous Region, and the Qinghai, Gansu, and Sichuan Provinces.ConclusionThis study showed a serious prevalence of human echinococcosis with obvious spatial aggregation of the disease prevalence in China. The Qinghai-Tibet Plateau is the "hot spot" area of human echinococcosis in China. Findings from this study indicate that there is an urgent need of joint strategies to strengthen efforts for the prevention and control of echinococcosis in China, especially in the Qinghai-Tibet Plateau.

Project description:BackgroundInstitutional delivery is an important indicator in monitoring the progress towards Sustainable Development Goal 3.1 to reduce the global maternal mortality ratio to less than 70 per 100,000 live births. Despite the international focus on reducing maternal mortality, progress has been low, particularly in Sub-Saharan Africa (SSA), with more than 295,000 mothers still dying during pregnancy and childbirth every year. Institutional delivery has been varied across and within the country. Therefore, this study aimed to investigate the individual and community level determinants, and spatial distribution of institutional delivery in Ethiopia.MethodsA secondary data analysis was done based on the 2016 Ethiopian Demographic and Health Survey (EDHS) data. A total weighted sample of 11,022 women was included in this study. For spatial analysis, ArcGIS version 10.6 statistical software was used to explore the spatial distribution of institutional delivery, and SaTScan version 9.6 software was used to identify significant hotspot areas of institutional delivery. For the determinants, a multilevel binary logistic regression analysis was fitted to take to account the hierarchical nature of EDHS data. The Intra-class Correlation Coefficient (ICC), Median Odds Ratio (MOR), Proportional Change in Variance (PCV), and deviance (-2LL) were used for model comparison and for checking model fitness. Variables with p-values<0.2 in the bi-variable analysis were fitted in the multivariable multilevel model. Adjusted Odds Ratio (AOR) with a 95% Confidence Interval (CI) were used to declare significant determinant of institutional delivery.ResultsThe spatial analysis showed that the spatial distribution of institutional delivery was significantly varied across the country [global Moran's I = 0.04 (p<0.05)]. The SaTScan analysis identified significant hotspot areas of poor institutional delivery in Harari, south Oromia and most parts of Somali regions. In the multivariable multilevel analysis; having 2-4 births (AOR = 0.48; 95% CI: 0.34-0.68) and >4 births (AOR = 0.48; 95% CI: 0.32-0.74), preceding birth interval ≥ 48 months (AOR = 1.51; 95% CI: 1.03-2.20), being poorer (AOR = 1.59; 95% CI: 1.10-2.30) and richest wealth status (AOR = 2.44; 95% CI: 1.54-3.87), having primary education (AOR = 1.47; 95% CI: 1.16-1.87), secondary and higher education (AOR = 3.44; 95% CI: 2.19-5.42), having 1-3 ANC visits (AOR = 3.88; 95% CI: 2.77-5.43) and >4 ANC visits (AOR = 6.53; 95% CI: 4.69-9.10) were significant individual-level determinants of institutional delivery while being living in Addis Ababa city (AOR = 3.13; 95% CI: 1.77-5.55), higher community media exposure (AOR = 2.01; 95% CI: 1.44-2.79) and being living in urban area (AOR = 4.70; 95% CI: 2.70-8.01) were significant community-level determinants of institutional delivery.ConclusionsInstitutional delivery was low in Ethiopia. The spatial distribution of institutional delivery was significantly varied across the country. Residence, region, maternal education, wealth status, ANC visit, preceding birth interval, and community media exposure were found to be significant determinants of institutional delivery. Therefore, public health interventions should be designed in the hotspot areas where institutional delivery was low to reduce maternal and newborn mortality by enhancing maternal education, ANC visit, and community media exposure.

Dataset Information

Multiplex serology demonstrate cumulative prevalence and spatial distribution of malaria in Ethiopia.

Background

Methods

Results

Publications

Multiplex serology demonstrate cumulative prevalence and spatial distribution of malaria in Ethiopia.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets