Prevalence of Strongyloides stercoralis infection and associated clinical symptoms among schoolchildren living in different altitudes of Amhara National Regional State, northwest Ethiopia

Background: Strongyloides stercoralis is a parasite that causes strongyloidiasis in humans. It is prevalent in the tropics and sub-tropics where poor sanitation is a common problem. The true prevalence of S. stercoralis in Ethiopia is underestimated due to the lack of a "Gold" standard diagnostic method. Moreover, its prevalence across altitudinal gradient in Amhara Region has not been studied. Methods: A cross-sectional study was conducted among 844 schoolchildren in Amhara Region from April to December 2019. A stool sample was collected from each study participant and processed using formol ether concentration technique (FECT), spontaneous tube sedimentation technique (STST), Baermann concentration technique (BCT), agar plate culture (APC) and real-time polymerase chain reaction (RT-PCR). Data were entered using EpiData and analyzed by SPSS version 23 statistical software. Prevalence of S. stercoralis infection was determined using a single diagnostic technique and combination of techniques. Association of clinical variables with S. stercoralis infection was assessed by logistic regression and independent variables with p<0.05 were considered statistically significant. Results: Prevalence of soil-transmitted helminths (STHs) and S. mansoni infections was 38.0% and 20.4%, respectively. Among STHs, the prevalence of hookworm infection was 32.8%. Prevalence of S. stercoralis infection was 39.0%, 28.8%, 10.9%, 10.3%, 4.0% and 2.0% by the respective, combinations of the five methods, RT-PCR, APC, BCT, STST and FECT. The highest prevalence rates, 48.2%, 45.0% and 41.1% of S. stercoralis were recorded in the age group of 12-14 years, males and rural dwellers, respectively. Prevalence rates of S. stercoralis infection in highland, semi-highland and lowland areas were 40.4%, 41.8% and 25.9%, respectively. Having abdominal pain (AOR = 2.48; 95% CI:1.65-3.72), cough (AOR = 1.63;95%CI:1.09-2.42), urticaria (AOR = 2.49;95%CI:1.50-4.01) and being malnourished (AOR = 1.44;95%:1.10-2.01) were significantly associated with strongyloidiasis. Conclusion: Prevalence of S. stercoralis infection was high and varied across different altitudes in Amhara Region. Some clinical syndromes were found to be significantly associated with S. stercoralis infection. Therefore, proper diagnosis and preventive strategies against S. stercoralis infection are highly recommended to be devised and implemented in Amhara Region.This study was funded by the Bahir Dar University (https://www.bdu.edu.et), Mundo Sano Foundation (https://www.mundosano.org/es/) and the National Center of Tropical Medicine, from the Institute of Health Carlos III (https://www.isciii.es/QuienesSomos/CentrosPropios/CNMT/Paginas/default.aspx), which supported the implementation by providing material support. We received materials and reagents but not a specific budget from funders to this project. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.S

Deletion patterns, genetic variability and protein structure of pfhrp2 and pfhrp3: implications for malaria rapid diagnostic test in Amhara region, Ethiopia

Background: Although rapid diagnostic tests (RDTs) play a key role in malaria-control strategies, their efficacy has been threatened by deletion and genetic variability of the genes pfhrp2/3. This study aims to characterize the deletion, genetic patterns and diversity of these genes and their implication for malaria RDT effectiveness, as well as their genetic evolution in the Amhara region of Ethiopia. Methods: The study included 354 isolates from symptomatic patients from the Amhara region of Ethiopia who tested positive by microscopy. Exon 1-2 and exon 2 of genes pfhrp2 and -3 were amplified, and exon 2 was sequenced to analyse the genetic diversity, phylogenetic relationship and epitope availability. Results: The deletion frequency in exon 1-2 and exon 2 was 22 and 4.6% for pfhrp2, and 68 and 18% for pfhrp3, respectively. Double deletion frequency for pfhrp2 and pfhrp3 was 1.4%. High genetic diversity, lack of clustering by phylogenetic analysis and evidence of positive selection suggested a diversifying selection for both genes. The amino-acid sequences, classified into different haplotypes, varied widely in terms of frequency of repeats, with novel amino-acid changes. Aminoacidic repetition type 2 and type 7 were the most frequent in all the sequences. The most frequent epitopes among protein sequences were those recognized by MAbs 3A4 and C1-13. Conclusion: Deletions and high amino acidic variation in pfhrp2 and pfhrp3 suggest their possible impact on RDT use in the Amhara region, and the high genetic diversity of these genes could be associated with a diversifying selection in Ethiopia. Surveillance of these genes is, therefore, essential to ensure the effectiveness of public health interventions in this region.This work was supported by the project TRPY 111/18 funded by the Institute of Health Carlos III; and IMF received a research fellowship from the University of Alcalá that enables her to develop this study.S

StrongNet: An International Network to Improve Diagnostics and Access to Treatment for Strongyloidiasis Control

Strongyloidiasis is a disease caused by an infection with a soil-transmitted helminth that affects, according to largely varying estimates, between 30 million and 370 million people worldwide [1,2]. Not officially listed as a neglected tropical disease (NTD), strongyloidiasis stands out as particularly overlooked [3]. Indeed, there is a paucity of research and public health efforts pertaining to strongyloidiasis. Hence, clinical, diagnostic, epidemiologic, treatment, and control aspects are not adequately addressed to allow for an effective management of the disease, both in clinical medicine and in public health programs [4]. The manifold signs and symptoms caused by Strongyloides stercoralis infection, coupled with the helminth’s unique potential to cause lifelong, persistent infection, make strongyloidiasis relevant beyond tropical and subtropical geographic regions, where, however, most of the disease burden is concentrated. Indeed, strongyloidiasis is acquired through contact with contaminated soil, and the infection is, thus, primarily transmitted in areas with poor sanitation, inadequate access to clean water, and lack of hygiene

Prevalence of Strongyloides stercoralis and Other Intestinal Parasite Infections in School Children in a Rural Area of Angola: A Cross-Sectional Study

Intestinal Parasite; School Children; AngolaParàsit Intestinal; Escolars; AngolaParásito Intestinal; Escolares; AngolaStrongyloides stercoralis is widely distributed in the tropics and subtropics. The aim of this study was to determine the prevalence of S. stercoralis and other intestinal parasites and identify the risk factors for infection with S. stercoralis in a rural area of Angola. A cross-sectional study was conducted in school-age children (SAC) in Cubal, Angola. A questionnaire collecting clinical and epidemiological variables was used, and two stool samples were collected. A concentration technique (Ritchie) and a technique for detection of larvae migration (Baermann) were performed. Of 230 SAC, 56.1% were female and the mean age was 9.3 years (SD 2.45). Severe malnutrition, according to body mass index (BMI)-for-age, was observed in 20.4% of the SAC, and anemia was found in 59.6%. Strongyloides stercoralis was observed in 28 of the 230 (12.8%) SAC. Eggs of other helminths were observed in 51 (22.2%) students: Hymenolepis spp. in 27 students (11.7%), hookworm in 14 (6.1%), Schistosoma haematobium in four (1.7%), Enterobius vermicularis in four (1.7%), Ascaris lumbricoides in three (1.3%), Taenia spp. in two (0.9%), and Fasciola hepatica in one (0.4%). Protozoa were observed in 17 (7.4%) students. Detection of S. stercoralis was higher using the Baermann technique versus using formol-ether (11.3 vs. 3%). Overall prevalence of S. stercoralis in the school population of 16 studied schools in the municipal area of Cubal was greater than 10%. This fact must be considered when designing deworming mass campaigns. The use of specific tests in larvae detection is needed to avoid overlooking this parasite

COVID-19 Severity and Survival over Time in Patients with Hematologic Malignancies: A Population-Based Registry Study

Mortality rates for COVID-19 have declined over time in the general population, but data in patients with hematologic malignancies are contradictory. We identified independent prognostic factors for COVID-19 severity and survival in unvaccinated patients with hematologic malignancies, compared mortality rates over time and versus non-cancer inpatients, and investigated post COVID-19 condition. Data were analyzed from 1166 consecutive, eligible patients with hematologic malignancies from the population-based HEMATO-MADRID registry, Spain, with COVID-19 prior to vaccination roll-out, stratified into early (February–June 2020; n = 769 (66%)) and later (July 2020–February 2021; n = 397 (34%)) cohorts. Propensity-score matched non-cancer patients were identified from the SEMI-COVID registry. A lower proportion of patients were hospitalized in the later waves (54.2%) compared to the earlier (88.6%), OR 0.15, 95%CI 0.11–0.20. The proportion of hospitalized patients admitted to the ICU was higher in the later cohort (103/215, 47.9%) compared with the early cohort (170/681, 25.0%, 2.77; 2.01–3.82). The reduced 30-day mortality between early and later cohorts of non-cancer inpatients (29.6% vs. 12.6%, OR 0.34; 0.22–0.53) was not paralleled in inpatients with hematologic malignancies (32.3% vs. 34.8%, OR 1.12; 0.81–1.5). Among evaluable patients, 27.3% had post COVID-19 condition. These findings will help inform evidence-based preventive and therapeutic strategies for patients with hematologic malignancies and COVID-19 diagnosis.Depto. de MedicinaFac. de MedicinaTRUEFundación Madrileña de Hematología y HemoterapiaFundación Leucemia y LinfomaAsociación Madrileña de Hematología y Hemoterapiapu

Performance Evaluation of Diagnostic Methods for Schistosoma mansoni Detection in Amhara Region, Northwest Ethiopia

Background. Schistosoma mansoni is a parasitic worm that infects humans throughout the world. It is more prevalent in sub-Saharan Africa including Ethiopia. Proper detection of Schistosoma mansoni using sensitive diagnostic methods is crucial in the prevention and control era. Since direct wet mount microscopy with its low sensitivity has been used as a diagnostic technique in Ethiopia, searching alternative diagnostic methods which have better sensitivity should be a priority agenda. Objective. This study is aimed at evaluating the performance of diagnostic methods for Schistosoma mansoni in Amhara region. Methods. A cross-sectional study was conducted among 520 school children from October to December 2019 in Amhara region. The study participants were selected by a systematic random sampling technique. Stool samples were collected from each participant and processed via formol-ether concentration, Kato-Katz, and spontaneous tube sedimentation techniques. The data was entered into EpiData version 3.1, and analysis was done using SPSS version 20. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated against the combined result as “Gold” standard. A kappa value was computed to measure the strength of agreement of the diagnostic methods. Results. The overall prevalence of Schistosoma mansoni was 20.2% using a combination of three methods. The prevalence of 8.3%, 12.9%, and16.3%, respectively, was recorded by using formol-ether concentration, Kato-Katz, and spontaneous tube sedimentation. The spontaneous tube sedimentation method (81.0%) had better sensitivity compared to Kato-Katz (63.8%) and formol-ether concentration (41.0%) methods in Schistosoma mansoni detection. Conclusion. The spontaneous tube sedimentation technique is more sensitive and has better detection rate to Schistosoma mansoni infection followed by the Kato-Katz technique. Therefore, updating the current diagnostic methods for Schistosoma mansoni could be a priority agenda to take action in schistosomiasis prevention and control

Strongyloidiasis in Africa: Systematic Review and Meta-Analysis on Prevalence, Diagnostic Methods, and Study Settings

Background. Strongyloidiasis is an intestinal parasitic infection mainly caused by Strongyloides stercoralis. Although it is a predominant parasite in tropics and subtropics where sanitation and hygiene are poorly practiced, the true prevalence of strongyloidiasis is not known due to low-sensitivity diagnostic methods. Objective. This systematic review and meta-analysis is aimed at determining the pooled prevalence of strongyloidiasis in African countries, stratified by diagnostic methods, study settings, and patients. Methods. Cross-sectional studies on strongyloidiasis published in African countries from the year 2008 up to 2018 in PubMed and Google Scholar databases and which reported at least one Strongyloides spp. infection were included. Identification and screening of eligible articles were also done. Articles whose focus was on strongyloidiasis in animals, soil, and foreigners infected by Strongyloides spp. in Africa were excluded. The random effects model was used to calculate the pooled prevalence of strongyloidiasis across African countries as well as by diagnostic methods and study settings. The heterogeneity between studies was also computed. Result. A total of 82 studies were included. The overall pooled prevalence of strongyloidiasis was 2.7%. By individual techniques, the pooled prevalence of strongyloidiasis was 0.4%, 1.0%, 3.4%, 9.3%, 9.6%, and 19.4% by the respective direct saline microscopy, Kato-Katz, formol ether concentration, polymerase chain reaction, Baermann concentration, and culture diagnostic techniques. The prevalence rates of strongyloidiasis among rural community, school, and health institution studies were 6.8%, 6.4%, and 0.9%, respectively. The variation on the effect size comparing African countries, diagnostic methods, study settings, and patients was significant (P≤0.001). Conclusions. This review shows that strongyloidiasis is overlooked and its prevalence is estimated to be low in Africa due to the use of diagnostic methods with low sensitivity. Therefore, there is a need for using a combination of appropriate diagnostic methods to approach the actual strongyloidiasis rates in Africa

Prevalence and Factors Associated with Intestinal Parasitic Infections among Pregnant Women in West Gojjam Zone, Northwest Ethiopia

Background. Intestinal parasitic infections are the major causes of morbidity and mortality in sub-Saharan countries. The disease burden of these parasites is significantly high among pregnant women in developing countries like Ethiopia. Poor living conditions, sanitation, and hygiene are believed to be the contributing factors. The aim of this study was to determine the magnitude of intestinal parasitic infection and factors associated with pregnant women. Methods. A cross-sectional study was conducted from February 2017 to June 2017. A structured questionnaire was used to obtain the sociodemographic and other explanatory variables via face-to-face interviews. Stool samples were collected and examined using formol ether concentration technique. The magnitude of parasitic infection was calculated using descriptive statistics. The association between intestinal parasitic infection and determinant factors was assessed by logistic regression. The differences were considered to be statistically significant if the p value was less than 0.05. Results. From a total of 743 pregnant women, the overall prevalence of intestinal parasitosis was 277 (37.3%). The prevalence of hookworm 138 (18.6%) was the leading cause of intestinal parasitosis followed by E. histolytica/dispar 113 (15.2%). Dwelling in rural area (AOR: 2.9 (95% CI: 1.85-4.85)), being a farmer (AOR: 1.91 (95% CI: 1.20-3.03)), eating raw vegetables (AOR: 1.45, 95% CI:0.09-0.24), lack of proper use of latrine (AOR: 2.89 (95%1.18-7.08)), poor environmental sanitation (AOR: 0.19 (95%: CI:0.08-0.47)), habit of soil eating (AOR: 0.42 (95% CI: 0.25-0.72)), having irrigation practice (AOR: 0.47 (95% CI: 0.29-0.77)), and lack of health education (AOR: 0.32 (95% CI: 0.13-0.77)) were significantly associated with intestinal parasitic infections. Conclusions. Intestinal parasitic infection is a major problem among pregnant women in the study area. High parasitic infection is associated with poor hygienic and sanitation practices. Therefore, awareness creation through health education should be given to pregnancy on intestinal parasitic infection and associated factors

Socio-demographic characteristics and STH co-infection among school-aged children participated in prazequantel efficacy testing in northwest Ethiopia, February to June 2023 (N = 110).

Socio-demographic characteristics and STH co-infection among school-aged children participated in prazequantel efficacy testing in northwest Ethiopia, February to June 2023 (N = 110).</p