Egg-positive Children Research Articles

Urogenital schistosomiasis prevalence and diagnostic performance of urine filtration and urinalysis reagent strip in schoolchildren, Ethiopia.

BackgroundUrogenital schistosomiasis has been known to be endemic in several lowland areas of Ethiopia. It is caused by Schistosoma haematobium and causes considerable public health problems to schoolchildren. Ethiopia, after mapping the distribution of the disease (2013 to 2015), launched school-based mass deworming program to treat schoolchildren for schistosomiasis and soil-transmitted helminthiasis (STH) across the country since 2015. However, there is no recent information about the prevalence of the disease among schoolchildren in the current study areas. Diagnostic performance of urine filtration method and urinalysis reagent strip is also lacking. Therefore, this study aimed to determine the prevalence of urogenital schistosomiasis in schoolchildren, and to evaluate diagnostic performance of urine filtration and urinalysis reagent strip in Amibara, Kurmuk and Abobo districts, Ethiopia.MethodsAcross-sectional study was conducted involving 1,171 schoolchildren in Abobo, Amibara and Kurmuk districts from October, 2020 to January, 2021. The study participants were selected using random sampling technique. From each study participant, 10 ml urine samples were collected and examined using urine filtration method and urinalysis reagent strip. Data obtained from the survey were entered into Microsoft Excel 2010 and analysed with SPSS version 20.0. Data was summarized using descriptive statistics. Chi-square, bivariate and multivariable logistic regression and Pearson correlation test were used to measure associations between urogenital schistosomiasis, age, sex and haematuria. Odds ratio was used to measure strengths of association between variables. Agreement between urine filtration method and urinalysis reagent strip was determined using Kappa statistics. P-value < 0.05 at 95% CI was considered as statistically significant.ResultsAmong the 1,171 urine samples from schoolchildren examined by urine filtration method, 143 (12.2%) were S.haematobium egg positive. Out of 143 positive children 126(88.1%) were lightly infected and 17 (11.9%) were heavily infected. Among the total of 1,171 urine samples tested by dipstick, 264(22.5%) were positive for haematuria. Prevalence of urogenital schistosomiasis by both urine filtration and urinalysis reagent strip method was higher in Abobo than Hassoba (Amibara) and Kurmuk (P< 0.001). The number of egg counts (intensity of infections) were significantly correlated with intensity of haematuria (r = 0.6, P < 0.001). Egg-positive children had significantly higher risk of having haematuria compared to S. haematobium egg negative children (OR; 6.96; 95%CI: 4.98, 8.940). Compared to urine filtration method, the sensitivity, specificity, positive predictive value (PPV) and negative predictive values (NPV) of urinalysis reagent strip were 99.3%, 88.1%, 53.8% and 99.8%, respectively. Furthermore, its positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were 8.34 and 0.008, respectively. The accuracy index and diagnostic odds ratio (DOR) of reagent strip were 0.89 and 1054, respectively. The agreement level between urine filtration methods and urinalysis reagent strip for detecting urogenital schistosomiasis was substantial (Kappa = 0.64).ConclusionThis study showed that urogenital schistosomiasis was prevalent in schoolchildren in Abobo, Hassoba and Kurmuk districts. Urogenital schistosomiasis prevalence in Hassoba-bure and Kurmuk falls under low category whereas moderate in Abobo and is almost four times compared to Kurmuk and Hassoba-bure. Chemotherapy is needed in schoolchildren in such endemic areas and other measures like access to safe water, improved sanitation, hygiene, and health education should be implemented to control and prevent schistosomiasis effectively. The sensitivity, specificity, positive and negative predictive values of urinalysis reagent strip were higher and could serve as alternative for mass screening of urogenital schistosomiasis, for surveillance and evaluation of schistosomiasis intervention programs.

Evaluation of morbidity in Schistosoma mansoni-positive primary and secondary school children after four years of mass drug administration of praziquantel in western Kenya

BackgroundWorld Health Organization guidelines recommend preventive chemotherapy with praziquantel to control morbidity due to schistosomiasis. The primary aim of this cross-sectional study was to determine if 4 years of annual mass drug administration (MDA) in primary and secondary schools lowered potential markers of morbidity in infected children 1 year after the final MDA compared to infected children prior to initial MDA intervention.MethodsBetween 2012 and 2016 all students in two primary and three secondary schools within three kilometers of Lake Victoria in western Kenya received annual mass praziquantel administration. To evaluate potential changes in morbidity we measured height, weight, mid-upper arm circumference, hemoglobin levels, abdominal ultrasound, and quality of life in children in these schools. This study compared two cross-sectional samples of Schistosoma mansoni egg-positive children: one at baseline and one at year five, 1 year after the fourth annual MDA. Data were analyzed for all ages (6–18 years old) and stratified by primary (6–12 years old) and secondary (12–18 years old) school groups.ResultsThe prevalence of multiple potential morbidity markers did not differ significantly between the egg-positive participants at baseline and those at 5 years by Mann Whitney nonparametric analysis and Fisher’s exact test for continuous and categorical data, respectively. There was a small but significantly higher score in school-related quality of life assessment by year five compared to baseline by Mann Whitney analysis (P = 0.048) in 13–18 year olds where malaria-negative. However, anemia was not positively impacted by four annual rounds of MDA, but registered a significant negative outcome.ConclusionsWe did not detect differences in morbidity markers measured in a population of those infected or re-infected after multiple MDA. This could have been due to their relative insensitivity or a failure of MDA to prevent morbidity among those who remain infected. High malaria transmission in this area and/or a lack of suitable methods to measure the more subtle functional morbidities caused by schistosomiasis could be a factor. Further research is needed to identify and develop well-defined, easily quantifiable S. mansoni morbidity markers for this age group.

Effect of Mass Drug Administration with a Single Dose of Albendazole on Ascaris lumbricoides and Trichuris trichiura Infection among Schoolchildren in Yangon Region, Myanmar

Soil-transmitted helminths, including Ascaris lumbricoides and Trichuris trichiura, are important intestinal parasites mostly affecting younger people in developing countries. In 2014–2015, we performed mass fecal examinations targeting a total of 2,227 schoolchildren in 3 districts (South Dagon, North Dagon, and Hlaing-thar-yar) of Yangon Region, Myanmar, using the Kato-Katz thick smear technique. The egg positive children were subjected to a mass drug administration (MDA) using a single oral dose of 400 mg albendazole. The pre-treatment egg positive rate (EPG/person) of A. lumbricoides averaged 17.2% (15,532); it was 25.2% (21,796), 14.2% (11,816), and 12.8% (12,983) in 3 districts, respectively, and that of T. trichiura averaged 19.4% (1,074), and was 24.1% (1,040), 12.3% (852), and 21.2% (1,330) in 3 districts, respectively. Follow-up fecal examinations performed 4 months post-MDA revealed considerable decreases of A. lumbricoides prevalence (EPG/person) to av. 8.3% (12,429), and 13.7% (17,640), 8.0% (7,797), and 4.5% (11,849) in 3 districts, respectively. However, T. trichiura did not show any recognizable decrease in the prevalence (EPG/person) remaining at av. 18.2% (862), and 18.5% (888), 11.5% (812), and 23.3% (887) in 3 districts, respectively. The results demonstrated difficulty in short-term control of T. trichiura by MDA using albendazole and suggested necessity of either a long-term MDA (>10 years) or changing the albendazole regimen into 2~3-day course (total 800 or 1,200 mg), or using an alternative drug/drug combination.

Schistosomiasis Burden and Its Association With Lower Measles Vaccine Responses in School Children From Rural Cameroon.

Background and Methods: Schistosomiasis is debilitating and reported to impair immune responsiveness of infected hosts. In Cameroon, mass drug administration (MDA) is used in schoolchildren to reduce transmission of S. haematobium and S. mansoni. The effects of MDA and the impact of schistosomiasis on the titers of antibodies in vaccinated children have been poorly studied. We therefore assessed the prevalence of schistosomiasis in schoolchildren, eight months after MDA, in two locations: Barombi Koto (BK), endemic for S. haematobium (N = 169) and Yoro (Y), endemic for S. mansoni (N = 356). Age, gender, residence time and frequency of contact with river water were assessed as risk factors for infection and morbidity in both localities. In 70 schoolchildren from BK and 83 from Y, ultrasound was used to assess morbidity according to the WHO guidelines. Evaluation of measles antibodies was performed in previously vaccinated schoolchildren (14 with S. haematobium and 12 egg-negative controls from BK and 47 with S. mansoni and12 egg-negative controls from Y).Principal Findings and conclusions: The prevalence of S. haematobium was 25. 4% in BK (43/169) and 34.8% for S. mansoni in Y (124/356), indicating the persistent transmission of schistosomiasis despite MDA. Older age (AOR 1.31; 95%CI 1.12–1.54) and higher frequencies of exposure to river water (AOR 1.99; 95%CI 1.03–3.86) were identified as risks for infection in BK whereas only older age (OR 1.15; 95%CI 1.04–1.27) was a risk for infection in Y. Bladder pathology (score 2 to 5) was observed in 29.2% (7/24) of egg-positive children in BK and liver pathology (pattern C) in 31.1% (19/61) of egg-positive children in Y. There was a positive correlation between S. haematobium egg burden and bladder pathology (AOR 1.01; 95% CI 0.99–1.02) and positive correlation between S. mansoni-driven liver pathology and female gender (AOR 3.01; 95% CI 0.88–10.26). Anti-measles antibodies in vaccinated children were significantly lower in S. mansoni-infected when compared to egg-negative controls (p = 0.001), which was not observed in the S. haematobium-infected group from BK. Our results demonstrate a questionable efficacy of MDA alone in halting schistosomiasis transmission and confirm a possible immunomodulatory effect of S. mansoni on response to vaccines.

Effect of four rounds of annual school-wide mass praziquantel treatment for schistosoma mansoni control on schistosome-specific immune responses.

SummaryThis study evaluated potential changes in antischistosome immune responses in children from schools that received 4 rounds of annual mass drug administration (MDA) of praziquantel (PZQ). In a repeated cross‐sectional study design, 210 schistosome egg‐positive children were recruited at baseline from schools in western Kenya (baseline group). Another 251 children of the same age range were recruited from the same schools and diagnosed with schistosome infection by microscopy (post‐MDA group). In‐vitro schistosome‐specific cytokines and plasma antibody levels were measured by ELISA and compared between the 2 groups of children. Schistosome soluble egg antigen (SEA) and soluble worm antigen preparation (SWAP) stimulated higher IL‐5 production by egg‐negative children in the post‐MDA group compared to the baseline group. Similarly, anti‐SEA IgE levels were higher in egg‐negative children in the post‐MDA group compared to the baseline group. Anti‐SEA and anti‐SWAP IgG4 levels were lower in egg‐negative children in the post‐MDA group compared to baseline. This resulted in higher anti‐SEA IgE/IgG4 ratios for children in the post‐MDA group compared to baseline. These post‐MDA immunological changes are compatible with the current paradigm that treatment shifts immune responses to higher antischistosome IgE:IgG4 ratios in parallel with a potential increase in resistance to reinfection.

Parasitological and malacological surveys reveal urogenital schistosomiasis on Mafia Island, Tanzania to be an imported infection

To confirm the local endemicity of Schistosoma haematobium on Mafia Island, Tanzania, conjoint parasitological and malacological surveys were undertaken in July 2006 with parasitological investigations supplemented with case-history questionnaires. A total of 238 children (125 girls and 113 boys, mean age of 13.9 years) across 9 primary schools were examined. The prevalence of micro-haematuria and egg-patent infection was 18.1% (CI95=9.6–33.6) and 4.2% (CI95=1.9–7.6), respectively but a strong female bias was observed for micro-haematuria (5.6F:1M) contrasting with a strong male bias for the presence of eggs (1F:4M). All egg-patent infections were of light-intensity (<10eggs/10ml). No clear associations between infection prevalence and local water-contact, by school, were found and all 10 of the egg-positive children had a travel history to the nearby mainland or Zanzibar. Inspection of community diagnostic registers at Kilindoni Hospital revealed a low proportion (<2%) of egg-patent infection for 20,306 samples tested in the 2000–2005 period. A total of 43 freshwater sites, a third of which were previously sampled in 1999 and 2002, were surveyed and 11 species of freshwater mollusc were found. Four species of Bulinus (B. nasutus, B. forskalii, B. barthi and B. sp.) were encountered across 13 sites with B. nasutus restricted to 3 of these towards the north of the island. No collected snail was observed to shed schistosome cercariae. Further characterisation of B. nasutus and S. haematobium included infection challenge on two occasions, with miracidia obtained from egg-patent children from Mafia and Unguja islands as well as DNA barcoding of snails and schistosomes. B. nasutus was shown refractory to infection. With the substantial travel to and from Mafia, the refractory nature of local snails and evidence from DNA barcoding in schistosomes and snails, we conclude that urogential schistosomiasis is an imported infection.

Evaluation of circulating cathodic antigen (CCA) strip for diagnosis of urinary schistosomiasis in Hassoba school children, Afar, Ethiopia

A total of 206 urine samples collected from Hassoba Elementary schoolchildren, Afar, Ethiopia, a low Schistosoma haematobium endemic setting, was diagnosed to evaluate the performance of CCA strip using double references, urine filtration technique and urinalysis dipstick (Combur 1.0 Test) that detect schistosome eggs and blood in urine, respectively. The former was used as a gold standard reference method. Sensitivity, specificity, positive and negative predictive values for the CCA were 52%, 63.8%, 56.7% and 59% respectively, with reference to urine filtration technique whereas these parameters were 50.4%, 62.4%, 55.6% and 57.5% respectively, with reference to Combur 10 Test. 47 S. haematobium egg-positive children were found negative by CCA strip while 38 egg-negative children were found positive by CCA strip. Moreover, among the pre-tests done in duplicate, inconsistent results were also recorded. Assays were also compared with regard to the cost of equipment and reagents, speed and simplicity of use. Though CCA strip was found to be rapid and could be performed with minimal training, it was found to be expensive (US $ 4.95 per test) to use it for large-scale field use even if its diagnostic value would have been satisfactory. Further development and standardization of the CCA strip are required for its applicability for field use. It is also recommended that its cost per strip should be substantially cut down if it is to be used in poor schistosomiasis endemic countries.

Detailed clinical and ultrasound examination of children and adolescents in a Schistosoma mansoni endemic area in Kenya: hepatosplenic disease in the absence of portal fibrosis.

Hepatosplenic schistosomiasis involving organomegaly, portal fibrosis and portal hypertension has been observed in autopsy studies. Here, we have tested the hypothesis that hepatosplenic disease including organomegaly and markers of increased portal pressure can occur in school aged children in the absence of fibrosis. A case-only study of 96 children aged 7-20 years defined by ultrasound detectable hepatomegaly was undertaken in Makueni district, Kenya. A novel method of clinical examination that involved a consensus scoring by three or four examiners was used to classify children as presenting with severe or moderate hepatosplenic disease after palpation of livers and spleens. Ultrasound examination of livers and spleens was based on the Niamey protocol. Clinical measurements included spleen enlargement along the mid-clavicular and mid-axillary lines, liver enlargement along the mid-sternal (MSL) and mid-clavicular lines, as well as organ consistency. The clinical examination indicated that 9% and 60% of the children had severe or moderate hepatosplenomegaly, respectively. Amongst egg-positive children, all clinical measurements, except MSL liver enlargement, correlated with egg count, as did portal vein diameter, spleen length and liver length measured by ultrasound. Peri-portal fibrosis was not observed in any child, whereas 28% of the children were classified as having increased portal pressure according to World Health Organization criteria. There was no effect of malaria parasitaemia or hepatitis seropositvity on any of the observed parameters. These results indicate that hepatosplenic disease in school-aged children attributable to S. mansoni infection, involving hepatosplenomegaly and increased portal vein diameter, can occur in the absence of peri-portal fibrosis.

Urinary schistosomiasis in southern Ghana: 1. Prevalence and morbidity assessment in three (defined) rural areas drained by the Densu river

Epidemiological studies on urinary schistosomiasis were carried out in eight villages in the Ga and Akuapem South districts in Ghana. Single urine samples were collected from individuals aged 5 years and above between 10.00 and 14.00 h. The samples were examined for the presence of Schistosoma haematobium eggs using a filtration technique. Indirect morbidity was determined as the presence of microhaematuria and proteinuria using reagent strips, and macrohaematuria was recorded with the naked eye. Out of the study population of 3912 subjects, 2562 (65.5%) submitted urine samples. The prevalence of a Schistosoma haematobium infection ranged between 54.8 and 60.0%. Infection rates increased by age with a peak in the 10–19 years category, and decreased with increasing age. Disease prevalence was higher in males aged 15 years and above in Areas 2 (Ntoaso and Sansami Amanfro) and 3 (Dom Faase, Papase, Chento and Gidi Kope), whereas it was higher among males aged 10 years and above in Area 1 (Ayikai Doblo and Akramaman). The intensity of infection was highest among children aged 10–14 years in most of the villages. More than half of egg-positive children in this age group had a heavy infection (100 eggs and above in 10 ml of urine). Although both egg-positive and egg-negative individuals manifested variable degrees of macro- or micro-haematuria, microhaematuria was more prevalent among egg-positives (χ 2=918.5, d.f.=1, P<0.01). The degree of microhaematuria and proteinuria were significantly associated with the intensity of the infection. These results indicate a high transmission of disease in the study area.

PREVALENCE OF HUMAN SCHISTOSOMIASIS IN THE TAVETA AREA OF KENYA, EAST AFRICA

A total of 963 individuals in three villages were examined for schistosomiasis by both skin test and schistosome ova detection in stool and urine in 1974. The antigen used for skin test was VBS adult S. japonicum antigen (1 : 10, 000 dilution). Stool and urine samples were examined through the concentration methods. Egg-positive rate was 62.2 per cent in Jipe, 68.0 per cent in Eldoro, 69.6 per cent in Kivalwa. Jipe was infested mostly by S. mansoni, Kivalwa by S. haematobium and Eldoro by both two schistosomes. The egg-positive rate was higher in females than in males in Eldoro. In Jipe and Kivalwa, however, the differences in the rate between males and females were not statistically significant. The rate increased with age in children, reached a peak between the ages of 5 and 14 years and then decreased gradually. The positive rate of skin test was 76.4 per cent in total, higher than that of stool and urine examinations. The skin reaction was weak or absent among many egg-positive children. The skin-test-positive rate increased as the age advanced and reached 95 per cent in inhabitants from 40 years up. The positive rate of skin test was higher among males than females in Jipe. No significant difference in the rate between males and females was found in Eldoro and Kivalwa. Among the egg-positive subjects there was no significant difference in skin reaction between S. mansoni infection and S. haematobium infection. In 1975 stool and urine samples from Jipe, Kivalwa, Kuwahoma and Chala were examined. Kuwahoma proved to be infested by S. haematobium. In Chala schistosome infection was rare. There exist villages infested by S. mansoni and/or S. haematobium in the small area. It seems that VBS adult S. japonicum antigen for skin test and the concentration methods for stool and urine examinations are of use in the epidemiological survey in the areas where S. mansoni and/or S. haematobium infections are prevailing.

A CLINICAL STUDY CONCERNING THE EFFECT OF VITAMIN A ON THE PREVENTION OF ASCARIS RE-INFECTION

This is a clinical study conducted with a view to determining the effect of Vitamin A on the prevention of Ascaris re-infection. 692 school children were used as subjects of study. A strict preliminary examination was conducted from February to October, 1957, as a result of which 110 children were deliberately selected. Such 110 children were divided into two groups at random, one of which was given V. A.(10, 000 IU per capita daily) for a whole year, and the other served as a control group. Thus, during the period of V. A. administration and during the 9 months' follow-up period succeeding it, the occurrence of re-infection was closely observed for comparative study.A. Preliminary examination1) The cumulative rate of re-infection among school children during 6 months' time was 42.0%. 2) All the egg-positive children were subjected to mass anthelmintic treatment in February and in June. And, from among those whose conversion to negative was confirmed by the August stool examination, but who had previously been positive both in May and in June and also positive from February to April consecutively or who had become negative as a result of treament executed in February but had been infected again thereafter, 110 children were finally chosen at random for the purpose of this experiment. These 110 persons were divided at random into two groups;then it came out that they were of practically holomogous composition as to the sex distribution ratio and the severity of infection (number of eggs detected). 3) For caution's sake, these subjects were again given two courses of anthelmintic treatment before the experimental administration of V. A, i. e. in September and in October, so that the possible inclusion of such cases as those who had larvae circulating within one or other organ unnoticed or of false negative cases be eliminated.B. Results of experimental V. A. administration and follow-up results1) Re-infection rate during the period of V. A. administration: The rate of the V. A. administered group was markedly lower than that of the control group. 2) Transition of the cumulative re-infection rate: After 5 months of the commencement of the V. A. administration, marked difference was observed in the ascending rates of the two groups. At the termination of the V. A. admintration, the V. A. administered group showed 29.1% while the control group reached to 60.0%-significant difference was obtained between the two values. 3) Relationship between the severity of infection prior to treatment and the severity of re-infection that took place during the V. A. administration: No definite relationship was recognized. 4) Severer re-infection occurred more frequently in the control group. 5) Spontaneous conversion to negative during the V. A. administration period: No significant difference was seen between the two groups. 6) Transition of the cumulative rate of re-infection during the follow-up period: The two groups presented no particular difference. Rise of the re-infection rate in V. A. administered group was ascribed to the lack of long lasting effect of V. A. 7) No side effect was recognized in the administration of V. A.It is concluded that V. A. is effective in preventing round-worm re-infection, but its effect appeared not long lasting.