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Schistosomiasis remains a public health major problem and little is known in many areas, mainly in Sub-Saharan Africa.To assess the burden and risk factors of schistosomiasis and intestinal parasitic helminthes in the children of Cubal, Angola, and to compare different diagnostic approaches for urinary schistosomiasis under field conditions.A cross...
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Background
Urinary schistosomiasis has been a major public health problem in Zambia for many years. However, the disease profile may vary in different locale due to the changing ecosystem that contributes to the risk of acquiring the disease. The objective of this study was to quantify risk factors associated with the intensity of urinary schistoso...
Schistosomiasis is one of the neglected diseases in tropical Africa that continues to plague inhabitants of sub-urban and rural areas where there are little or no safe water outlets. This study investigated urinary schistosomiasis infection in relation to knowledge, attitudes and practices of people in Buruku and Katsina-Ala Local Government Areas...
Schistosoma haematobium infection is one of the parasitic diseases of public health importance affecting 100 million people worldwide; more than 75% live in sub-Sahara Africa. This study sought to determine the prevalence of urinary schistosomiasis among secondary school students in Lafia and the risk factors associated to it. One hundred and sixty...
Background: Schistosomiasis is a debilitating disease, infects millions of people in
tropical and subtropical regions. This study assessed the situation of the urinary
schistosomiasis among schoolchildren of the Alsaial Alsagair village, Sudan.
Methods: A cross-sectional survey was carried out in 2016, in the Alsaial Alsagair
village, and 385 sampl...
Citations
... prevalence among Angolan children found in three prior studies. [32][33][34] Limited utility for pelvic X-ray in chronic schistosomiasis diagnosis It was postulated that pelvic X-ray may be a useful diagnostic tool for chronic schistosomiasis, particularly in resource-limited settings. The presence of a calcified bladder on X-ray is pathognomonic for chronic urinary tract schistosomiasis infection and has been previously discussed in the literature. ...
Objective
To assess the association between chronic schistosomiasis infection, determined by bladder biopsies, and vesicovaginal (VVF) repair outcomes at an urban hospital in Angola. Other objectives were to quantify the prevalence of chronic schistosomiasis among patients with VVF and to assess agreement between pelvic X‐rays and bladder biopsies for chronic schistosomiasis diagnosis.
Methods
In this retrospective chart review, data were collected on patients who underwent VVF repair between 1 June 2022 and 30 November 2022 including: age, number of previous fistula repairs, Goh classification of fistula, X‐ray and biopsy results, fistula repair outcome, perioperative complications and postoperative incontinence. Age and number of previous repairs were described using means with standard deviations. Goh classification, X‐ray and biopsy results, fistula repair outcome, perioperative complications, and postoperative incontinence were described using frequencies. Parametric and nonparametric tests and Cohen's κ were calculated using R software and Excel.
Results
Of the 76 charts retrieved, 60 met inclusion criteria. The overall fistula repair failure rate was 26.7% (n = 16). There was no difference in the fistula repair failure rate between those with (26.9%) and without (26.5%) evidence of chronic schistosomiasis infection (χ² = 2.33 e‐31, 95% confidence interval [CI]: −0.30, 0.28). The prevalence of chronic schistosomiasis was 43.3%. There was no agreement between X‐ray and biopsy in diagnosing chronic schistosomiasis infection (Cohen's κ = 0.23, 95% CI: −0.001, 0.47).
Conclusion
There was no difference in the chance of fistula repair failure between those with evidence of chronic schistosomiasis infection and those without.
... A recent study has shown a prevalence of almost 20% among SAC in the province of Benguela [8]. Previous investigations in the municipality of Cubal (Benguela) showed a prevalence of 61% among SAC and 85.3% of pathologic ultrasound findings, being the irregularities of the bladder wall, the distorted shape of bladder and the thickening of the wall the most common lesions [9,10]. The high prevalence of the disease at that age, along with the significant associated morbidity and the high percentage of people who are in contact with waterbodies in their daily activities, call for a better understanding of its epidemiology and its effects on the paediatric population. ...
... Our study confirms that the high prevalence of urogenital schistosomiasis infection in PSAC also extends to the endemic areas of Angola with a prevalence of 30.2% (CI 95%; 24.5-35.9) in Cubal. It is within the expected values considering other prevalence studies in PSAC and previous research in the SAC group that was carried out in Cubal in 2014, where a prevalence of 61% was found [9]. The likelihood of infection increases with age, since older children have been in contact with infested water for a longer time. ...
Background
Schistosomiasis is one of the most important neglected tropical diseases, with a great impact on public health and more than 200,000 deaths annually. Schistosoma haematobium causes urinary tract (UT) morbidity. Since schistosomiasis morbidity control programs focus on children older than 5 years, pre-school age children (PSAC) morbidity is not well known.
Methods
We conducted a cross-sectional study in Cubal (Angola) among 245 PSAC with the objective of evaluating the prevalence of S . haematobium infection, the intensity of infection, and associated morbidity. For this purpose, urine filtration test followed by microscopic visualization and ultrasound examinations were performed.
Results
The estimated overall prevalence of urogenital schistosomiasis was 30.2% (CI 95%; 24.5–35.9), with 20.3% (CI 95%; 15.3–25.3) of the samples analysed showing a high intensity of infection. A total of 54.5% (CI 95%; 47.6–61.8) of infected children presented UT lesions, showing a significant association between schistosomiasis infection and UT morbidity ( p -value < 0.001). Bladder wall thickening was the most common lesion, being present in 100% of abnormal ultrasounds. We found that anaemia and severe malnutrition were not significantly associated with the development of UT lesions.
Conclusions
S . haematobium infection in PSAC causes great UT detectable morbidities. Therefore, there is an evident need of including them in mass drug administration (MDA) campaigns and consequently the development of an adapted praziquantel treatment dosage for children under 2 years of age.
... In Angola, the current epidemiological information about S. stercoralis is still scarce. A limited number of microscopy-based studies in Cubal, a rural area in South Angola, focusing on school-age children reported a strongyloidiasis prevalence of 0.07% [25] and 12.2% [26]. A more recent study determined a considerably higher prevalence rate of 21.4% in children when samples were analysed by qPCR in a reference laboratory [27]. ...
... The better sensitivity of Baermann obtained compared to DSM is not surprising as it is well known and has been evidenced in many different studies [10]. The pooled parasitological prevalence value in our study (9.3%) was slightly lower than the infection rate (12.2%) previously reported in an Angolan children population by using formol ether concentration technique (FECT) and Baermann [26] but higher than 0.07% also reported in school-children population of Cubal, Angola, by only FECT [25]. In general, our data are higher than the pooled low prevalence of strongyloidiasis reported by different African countries across different parasitological diagnostic methods (mainly DSM, FECT and Baermann) and study settings (schools, health institutions and rural communities) in a recent review by Hailu et al. [24]. ...
Background
Strongyloides stercoralis infection is a common neglected tropical disease distributed worldwide, mainly in tropical and subtropical climates. The impact of S. stercoralis infections on human health ranges from mild asymptomatic infections to chronic strongyloidiasis unnoticeable until the host is immunosuppressed. In severe strongyloidiasis, a syndrome of hyperinfection and larval dissemination to various organs can occur with high mortality rates. The diagnosis of strongyloidiasis is challenging because of the absence of a single standard reference test with high sensitivity and specificity, which also makes it difficult to estimate the accuracy of other diagnostic tests. This study aimed to evaluate, for the first time, the use of an easy-to-perform loop-mediated isothermal amplification (LAMP) colorimetric assay (named Strong-LAMP) for the molecular screening of strongyloidiasis in stool samples from patients in a low-resource endemic area in Cubal, Angola. To compare different LAMP application scenarios, the performance of the Strong-LAMP under field conditions in Angola was reassessed in a well-equipped reference laboratory in Spain and compared with a quantitative polymerase chain reaction (qPCR) method.
Methods
A total of 192 stool samples were collected from adult population in Cubal, Angola, and examined by parasitological methods (direct saline microscopy and Baermann’s technique). DNA was extracted from each stool sample using a commercial kit and tested by the colorimetric Strong-LAMP assay for the detection of Strongyloides spp. under field conditions. Furthermore, all samples were shipped to a well-equipped laboratory in Spain, reanalysed by the same procedure and compared with a qPCR method. The overall results after testing were compared.
Results
Strongyloides stercoralis larvae were identified by direct saline microscopy and Baermann in a total of 10/192 (5.2%) and 18/192 (9.4%) stool samples, respectively. Other helminth and protozoan species were also identified. The Strong-LAMP-positive results were visually detected in 69/192 (35.9%) stool samples. The comparison of Strong-LAMP results in field conditions and at a reference laboratory matched in a total of 146/192 (76.0%) samples. A total of 24/192 (12.5%) stool samples tested positive by qPCR.
Conclusions
This is the first study in which colorimetric Strong-LAMP has been clinically evaluated in a resource-poor strongyloidiasis endemic area. Strong-LAMP has been shown to be more effective in screening for strongyloidiasis than parasitological methods under field conditions and qPCR in the laboratory. Our Strong-LAMP has proven to be a field-friendly and highly accurate molecular test for the diagnosis of strongyloidiasis.
Graphical Abstract
... Benguela is one of the 18 Angolan provinces and is ranked as the second most prevalent province in the country [14]. In Cubal, a municipality of Benguela, a 61% urogenital schistosomiasis prevalence among SAC was previously described [15]. ...
... Nonetheless, 93.6% had prior knowledge about the existence of schistosomiasis. This high percentage could probably be due to the high prevalence of the disease in that area [15]. While only one person (0.4%) scored high knowledge, 105 (42%) ...
Background
Urogenital schistosomiasis is one of the most prevalent parasitic diseases in sub-Saharan Africa. It is a poverty-related disease conditioned by behavioural practices.
Methods
Our objective is to evaluate the awareness, mindset and habits about urogenital schistosomiasis in the community of Cubal (Angola), as well as its association with infection and urinary tract morbidity in pre-school age children. A cross-sectional study of knowledge, attitudes and practices at home was conducted between February and May 2022 with 250 participants.
Results
Overall, 93.6% of those surveyed had some prior knowledge about schistosomiasis and, among all the symptoms associated with this disease, blood in the urine was the best known (54.4%). Nevertheless, 57.6% obtained a medium knowledge score. Regarding attitude, the majority of respondents had a high attitude score (79.2%) with 96.0% willing to participate in mass drug administration campaigns. Laundry in the river was the most common risk practice (61.2%) and 55.2% out of the total were classified with a low practice score.
Conclusion
Low knowledge about symptoms and transmission by caregivers was the outstanding risk factor for infection in pre-school age children (OR = 16.93, 95%CI: 3.93–72.82), and lack of knowledge that avoiding entering the river prevents schistosomiasis was the main risk factor for morbidity in PSAC (OR = 8.14, 95%CI: 1.14–58.25).
... Schistosomiasis and STH infections are long recognized public health problems in Angola [9,10]. The Angolan Ministry of Health, in conjunction with the MENTOR Initiative and the END Fund, initiated a school-based PC programme for the control of STH infections in 2013 and schistosomiasis in 2014 in Huambo, Uige and Zaire provinces. ...
Schistosomiasis and soil-transmitted helminth (STH) control programs require target population engagement, assessed through knowledge, attitudes and practices (KAP) surveys. We report the results of a KAP survey of Angolan schoolchildren supported by a school preventive chemotherapy (PC) programme, without or with a school water, sanitation and hygiene (WASH) programme (PC+/WASH− and PC+/WASH+, respectively); and schoolchildren without a school PC or WASH program (PC−/WASH−). Schoolchildren from PC+/WASH− (N = 218), PC+/WASH+ (N = 250) and PC−/WASH− (N = 254) schools were interviewed. Descriptive statistics were used to report demographics and survey responses. Chi-square or Fisher's exact test was used to compare PC+/WASH− schoolchildren with (i) PC+/WASH+ and (ii) PC−/WASH− schoolchildren. A lower proportion of PC+/WASH− schoolchildren used latrines and a higher proportion practised open defecation at school compared with PC+/WASH+ schoolchildren. A lower proportion of PC+/WASH− schoolchildren always washed their hands after toileting and before meals at school compared with PC+/WASH+ schoolchildren. However, the PC+/WASH− schoolchildren reported better toileting and handwashing practices at school compared to PC−/WASH− schoolchildren. Over 90% of PC+ schoolchildren agreed with schistosomiasis and STH control and accepted schoolteacher PC delivery. Expanding the integration of both school PC and WASH programs will improve health behaviours relevant to reduce the risk of schistosomiasis and STHs in schoolchildren.
This article is part of the theme issue ‘Challenges and opportunities in the fight against neglected tropical diseases: a decade from the London Declaration on NTDs’.
... Overall, urine reagent strips have shown higher positive rates than UM when using the same urine specimens (Tables 2 and 3). Among SAC, the MicH rate ranged from 13.6% with a 5.0% UM positivity [6], while it was 65.7% MicH among 1283 SAC with a 61.2% UM positivity in Angola [7]. In a mapping study of SAC in Ethiopia, the positive MicH rate was 2.8% compared to a 0.13% UM positivity [21], and among 12,102 SAC and adults, MicH was detected in 2.4% of individuals with a UM positivity of 0.2% [22]. ...
... Generally, the MacH rates were reported to be 1/10 or less compared to the positive rates of UM or MicH. In a hyperendemic area, however, Bocanegra et al. (2015) [7] reported a high MacH positivity rate of 17.1% among SAC in Angola, where the egg-positive rate was 61.2% by UM and 65.7% by MicH. The diagnostic sensitivity of MacH was estimated at 27.1%, while the specificity was 97.5% in the study [7]. ...
... Generally, the MacH rates were reported to be 1/10 or less compared to the positive rates of UM or MicH. In a hyperendemic area, however, Bocanegra et al. (2015) [7] reported a high MacH positivity rate of 17.1% among SAC in Angola, where the egg-positive rate was 61.2% by UM and 65.7% by MicH. The diagnostic sensitivity of MacH was estimated at 27.1%, while the specificity was 97.5% in the study [7]. ...
Human schistosomiasis is one of neglected tropical diseases that remain highly prevalent in sub-Saharan Africa (SSA). Human schistosomiasis is mainly caused by two species, Schistosoma haematobium and S. mansoni, leading to urogenital and intestinal schistosomiasis, respectively. The World Health Organization (WHO) recommends mass drug administration (MDA) with praziquantel as the primary method of global intervention. Currently, MDA with praziquantel covers over half of the target population in endemic SSA countries. However, an accurate diagnosis is crucial for monitoring and evaluating the effectiveness of MDA. The standard diagnosis of both urogenital and intestinal schistosomiasis relies on the microscopic identification of eggs. However, the diagnostic sensitivity of this approach is low, especially for light or ultra-light infections. This is because Schistosoma eggs are laid inside of the venous plexus of the urinary bladder or mesenteric vein, where the adult flukes live. Approximately half of the eggs circulate in the blood vessels or are packed in neighboring tissues, while the remaining half are expelled into the lumen of the urinary bladder or intestine intermittently when the blood vessels are ruptured. In the field setting, the accuracy of any diagnostic method is critical for proper management of the intervention. The present article reviews the recent prevalence of urogenital schistosomiasis in SSA and highlights the practical limitations of diagnostic methods such as urine microscopy, urine reagent strips, molecular diagnosis, and ultrasound scanning in the field setting. Despite continuous global efforts to eliminate schistosomiasis over the past 20 years, many areas still remain endemic in SSA. No single diagnostic approach achieves acceptable sensitivity and specificity in the field setting. Therefore, any field survey should employ a combination of these methods based on the purpose of the study to accurately monitor and evaluate urogenital schistosomiasis. Based on diagnostic values and a cost–benefit analysis, a urine reagent strip test can replace urine microscopy in the field setting. The WHO criteria by ultrasound diagnosis should be updated including the echogenic snow sign and contour distortion.
... In recognition of the public health problems posed by schistosomiasis and STHs in Angola [6,7], a school PC program for STH control was initiated in the provinces of Huambo, Uige and Zaire in 2013, which was integrated with PC for schistosomiasis control from 2014. This program was subsequently informed by a prevalence survey conducted in 2014, which found a prevalence of any STH infection in Huambo of 13.1% (municipality range 0.8-33.2%), ...
Background:
A school preventive chemotherapy (PC) program for soil-transmitted helminths (STHs) and schistosomiasis has operated in Huambo, Uige and Zaire provinces, Angola, since 2013 and 2014, respectively; complemented by a school water, sanitation and hygiene (WASH) program in a subset of schools from 2016. Conducted in 2021, this is the first impact assessment of the school program for the control of schistosomiasis and STHs.
Methodology/principal findings:
A two-stage cluster design was used to select schools and schoolchildren for parasitological and WASH surveys. The rapid diagnostic tests (RDTs), point of care circulating cathodic antigen (POC-CCA) and Hemastix, were used to estimate Schistosoma mansoni and Schistosoma haematobium prevalence, respectively. Kato Katz was used to detect STHs, and quantify STH and S. mansoni infections. Urine filtration was used to quantify S. haematobium infections. Prevalence, infection intensity, relative prevalence reduction and egg reduction rates were calculated for schistosomiasis and STHs. Cohen's Kappa co-efficient was used to assess agreement between RDTs and microscopy. Chi-square or Fisher's exact test was used to compare WASH indicators in WASH-supported and WASH-unsupported schools. Overall, 17,880 schoolchildren (599 schools) and 6,461 schoolchildren (214 schools) participated in the schistosomiasis and STH surveys, respectively. Prevalence of any schistosomiasis in Huambo was 29.6%, Uige 35.4%, and Zaire 28.2%. Relative reduction in schistosomiasis prevalence from 2014 for Huambo was 18.8% (95% confidence interval (CI) 8.6, 29.0), Uige -92.3% (95%CI -162.2, -58.3), and Zaire -14.0% (95%CI -48.6, 20.6). Prevalence of any STH in Huambo was 16.3%, Uige 65.1%, and Zaire 28.2%. Relative reduction in STH prevalence for Huambo was -28.4% (95%CI -92.1, 35.2), Uige -10.7% (95%CI -30.2, 8.8), and Zaire -20.9% (95%CI -79.5, 37.8). A higher proportion of WASH-supported schools had improved water sources, and toilet and handwashing facilities compared to WASH-unsupported schools.
Conclusions/significance:
The limited impact this school program has had in controlling schistosomiasis and STHs identifies the need for a comprehensive understanding of individual, community, and environmental factors associated with transmission, and consideration for a community-wide control program.
... Schistosomiasis and STH infections are recognised public health problems in Angola [18,19]. In 2005, United Nations Children's Fund (UNICEF), WHO, Angolan Ministry of Health and other partners conducted a national prevalence survey of schistosomiasis and STH infection, which demonstrated a prevalence of intestinal parasites (STH species and S. mansoni) ranging from 26.5% to 75.9% and a prevalence of haematuria (as a proxy for S. haematobium) ranging from 11.8% to 40.6% across ecological zones (unpublished data). ...
... Keywords: Schistosomiasis, Soil-transmitted helminths, Circulating cathodic antigen, Rapid diagnostic test, Water, sanitation and hygiene school-age children; and the prevalence of microhaematuria (as a proxy for S. haematobium) as 10.0% and 16.6% in preschool and school-age children respectively [18]. A cross-sectional survey (2013-2014) in children in Cubal estimated a crude prevalence of urinary schistosomiasis (by the presence of haematuria) of 61.2% [19]. Recognising the burden of schistosomiasis and STH infection, the Ministry of Health in Angola undertook a school-based preventive chemotherapy program with albendazole in 2013 followed by a school-based preventive chemotherapy program with praziquantel and albendazole from 2014. ...
... Given the comparatively low detection of schistosomiasis on microscopy compared to RDTs, there is concern for the low sensitivity of microscopy methods in our survey, which hinders the ability to make more definitive conclusions as to whether RDT trace readings reflect true infection or not. The low sensitivity of microscopy methods in field surveys is well recognized, particularly in low-prevalence and light-intensity settings, which has prompted an increasing reliance on RDTs to estimate schistosomiasis prevalence [13,16,17,19,[23][24][25]. This is in part due to the fluctuation in S. mansoni egg excretion and variable distribution of eggs in stool [26], with the variability in S. mansoni antigen excretion as detected by POC-CCA ® shown to be less pronounced than egg excretion in stool for detection by Kato-Katz [27][28][29]. ...
Background
Schistosomiasis and soil-transmitted helminths (STHs) contribute high disease burdens amongst the neglected tropical diseases (NTDs) and are public health problems in Angola. This study reports the prevalence, intensity and risk factors for schistosomiasis and STH infection in Huambo, Uige and Zaire provinces, Angola, to inform a school-based preventive chemotherapy program.
Methods
A two-stage cluster design was used to select schools and schoolchildren to participate in parasitological and water, sanitation and hygiene (WASH) surveys across Huambo, Uige, and Zaire provinces. Point-of-care circulating cathodic antigen and urinalysis rapid diagnostic tests (RDTs) were used to determine the prevalence of Schistosoma mansoni and S. haematobium , respectively. Kato-Katz was used to identify and quantify STH species and quantify and compare with RDTs for S. mansoni . Urine filtration was used to quantify and compare with RDTs for S. haematobium . Descriptive statistics were used for prevalence and infection intensity of schistosomiasis and STH infection. Performance of RDTs was assessed through specificity and Cohen’s Kappa agreement with microscopy. A multivariate regression analysis was used to determine demographic and WASH factors associated with schistosomiasis and STH infection.
Results
A total 575 schools and 17,093 schoolchildren participated in the schistosomiasis survey, of which 121 schools and 3649 schoolchildren participated in the STH survey. Overall prevalence of S. mansoni was 21.2% (municipality range 0.9–74.8%) and S. haematobium 13.6% (range 0–31.2%), with an overall prevalence of schistosomiasis of 31.4% (range 5.9–77.3%). Overall prevalence of Ascaris lumbricoides was 25.1% (range 0–89.7%), hookworm 5.2% (range 0–42.6%), and Trichuris trichiura 3.6% (range 0–24.2%), with an overall prevalence of STH infection of 29.5% (range 0.8–89.7%). Ecological zone and ethnicity were factors associated with schistosomiasis and STH infection, with older age and female sex additional risk factors for S. haematobium .
Conclusions
Most municipalities met World Health Organization defined prevalence thresholds for a schistosomiasis preventive chemotherapy program. A STH preventive chemotherapy program is indicated for nearly all municipalities in Uige and select municipalities in Huambo and Zaire. The association between ecological zone and ethnicity with schistosomiasis and STH infection necessitates further evaluation of home and school environmental, sociodemographic and behavioural factors to inform targeted control strategies to complement preventive chemotherapy programs.
... A cross-sectional survey in 2010 across three communes in Bengo province demonstrated the prevalence of at least one STH infection as 22.6% in preschool children and 31.6% in school-age children; and the prevalence of microhaematuria (as a proxy for S. haematobium) as 10.0% and 16.6% in preschool and school-age children respectively [13]. A crosssectional survey (2013)(2014) in children in Cubal estimated a crude prevalence of urinary schistosomiasis (by the presence of haematuria) of 61.2% [14]. ...
... Given the comparatively low detection of schistosomiasis on microscopy compared to RDTs, there is concern for the low sensitivity of microscopy methods in our survey, which hinders the ability to make more de nitive conclusions as to whether RDT trace readings re ect true infection or not. The low sensitivity of microscopy methods in eld surveys is well recognized, particularly in low-prevalence and light-intensity settings, which has prompted an increasing reliance on RDTs to estimate schistosomiasis prevalence [8, 11,12,14,[16][17][18]. This is in part due to the uctuation in S. mansoni egg excretion and variable distribution of eggs in stool [19], with the variability in S. mansoni antigen excretion as detected by POC-CCA® shown to be less pronounced than egg excretion in stool for detection by Kato-Katz [20][21][22]. ...
Background: Schistosomiasis and soil-transmitted helminths (STHs) contribute high disease burdens amongst the neglected tropical diseases (NTDs) and are public health problems in Angola. This study reports the prevalence, intensity and risk factors for schistosomiasis and STH infection in Huambo, Uige and Zaire provinces, Angola, to inform a school-based preventive chemotherapy program.
Methods: A two-stage cluster design was used to select schools and schoolchildren to participate in parasitological and water, sanitation and hygiene (WASH) surveys across Huambo, Uige, and Zaire provinces. Point-of-care circulating cathodic antigen and urinalysis rapid diagnostic tests (RDTs) were used to determine the prevalence of Schistosoma mansoni and S. haematobium, respectively. Kato-Katz was used to identify and quantify STH species and quantify and compare with RDTs for S. mansoni. Urine filtration was used to quantify and compare with RDTs for S. haematobium. Descriptive statistics were used for prevalence and infection intensity of schistosomiasis and STH infection. Performance of RDTs was assessed through specificity and Cohen’s Kappa agreement with microscopy. A multivariate regression analysis was used to determine demographic and WASH factors associated with schistosomiasis and STH infection.
Results: A total 575 schools and 17,093 schoolchildren participated in the schistosomiasis survey, of which 121 schools and 3,649 schoolchildren participated in the STH survey. Overall prevalence of S. mansoni was 21.2% (municipality range 0.9-74.8%) and S. haematobium 13.6% (range 0-31.2%), with an overall prevalence of schistosomiasis of 31.4% (range 5.9-77.3%). Overall prevalence of A. lumbricoides was 25.1% (range 0-89.7%), hookworm 5.2% (range 0-42.6%), and T. trichiura 3.6% (range 0-24.2%), with an overall prevalence of STH infection of 29.5% (0.8-89.7%). Ecological zone and ethnicity were factors associated with schistosomiasis and STH infection, with older age and female sex additional risk factors for S. haematobium.
Conclusions: Most municipalities met WHO-defined prevalence thresholds for a schistosomiasis preventive chemotherapy program. A STH preventive chemotherapy program is indicated for nearly all municipalities in Uige and select municipalities in Huambo and Zaire. The association between ecological zone and ethnicity with schistosomiasis and STH infection necessitates further evaluation of home and school environmental, sociodemographic and behavioural factors to inform targeted control strategies to complement preventive chemotherapy programs.
... The molecular pooled prevalence of strongyloidiasis obtained in our study was comparable to those studies performed in Angola (21.4%) and Ethiopia (20.7%), where there are wet and dry seasons with tropical grasslands [34]. Our results showed a direct relation between publication bias and the pooled prevalence in all assessed studies. ...
Strongyloides stercoralis is a neglected soil-transmitted helminth affects approximately 100-370 million people globally. The life cycle is unusual as only larvae can be found in stool specimens. Thecurrent review and meta-analysis represented the distribution of strongyloidiasis in general population of the world based on published papers. Five English databases (Science Direct, Scopus, PubMed, Web of Science, and Google Scholar(were explored for literature published before October 2019.Altogether 235 studies (862243 participants) was eligible. Regarding diagnostic method, the overall prevalence for studies performed microscopic, culture, immu-nological and molecular method was 1.47% (95% CI = 1.56%), 10.08% (95% CI = 8.99%-11.16%), 23.88% (95% CI = 20.82%-26.94%) and 9.3% (95% CI = 7.2%-11.3%), respectively. Based on microscopic methods, the highest prevalence was related to the Western Pacific region [9.47% (95% CI = 8.55%-10.39%)]. According to the culture method, Western Pacific region [21.36% (95% CI = 16.32%-26.39%)] had the highest estimated pooled prevalence. In immunological studies, Eastern Mediterranean Region [40.72% (95% CI = 36.74%-44.70%)] had the highest seroprevalence.Also in molecular surveys, the highest prevalence was related to the African region [19.72% (95% CI = 16.71%-22.73%)]. The current study indicated that strongyloidiasis is still considered a health problem in many parts of the world. Thus a comprehensive control program and improvement of public health sectors are required.
