Intestinal helminthic infections in schoolchildren in Cambodia

During the period January to December 1998, the National Malaria Center (CNM) carried out a parasitological survey of schoolchildren in rural and semi-urban areas, to assess intestinal helminthic infections in schoolchildren in the central parts of Cambodia. In the rural areas, there were four schools in Stung Treng Province (all situated along the Mekong River), five schools in Kratie Province (around rubber plantations), six schools in Kampong Chhnang Province (along Tonle Sap Lake); and in the semi-urban areas, three schools in Beng Tumpon Commune and five schools in Chbar Ampeou Commune (Mean Chey District) were selected for study. By Kato-Katz technique, the prevalence of soil-transmitted helminthic infections in schoolchildren in both the rural and urban areas was high. The infection rate was between 10-40% for Ascaris, 2-17% for Trichuris and 5-65% for hookworm. Schistosomiasis and opisthorchiasis were found in the schoolchildren living along the Mekong River (Stung Treng Province); the infection rate of S. mekongi ranged from 12 to 43%. These infections in children were with hepatomegalies. An intervention in an urban area (Chraing Chamres) showed that after repeated treatment with mebendazole 500 mg single dose every 6 months, the prevalence of all parasites had dropped to about one third of the initial level.     

A six-year follow-up of schoolchildren for urinary and intestinal schistosomiasis and soil-transmitted helminthiasis in Northern Tanzania

Two cross-sectional studies with a 6-year interval were undertaken in two primary schools in neighbouring villages in Mwanga District, Tanzania, to determine the prevalence of schistosome and soil-transmitted helminth infections before and 6 years after treatment. Within this interval, health-related interventions such as one mass treatment of the villagers, health education, improvement of sanitation and access to safe water were undertaken in the villages. In 1996, urinary schistosomiasis occurred in Kileo (n=284) and Kivulini (n=350) in 37.0 and 86.3% of the schoolchildren. Intestinal schistosomiasis was found in 22.9 and 43.5% of the children. The infection with soil-transmitted helminths ranged between 2.7 and 18.1% in both villages. After 6 years, the prevalence of urinary schistosomiasis in schoolchildren remained nearly constant in Kileo (33.5%; n=544), but dropped from 86.3% to 70.0% in Kivulini (n=514). In the latter village the proportion of children heavily infected with Schistosoma haematobium (> or = 50 eggs/10 ml urine) decreased from 53.8% to 34.4%. With the exception of hookworm infection, soil-transmitted helminthiasis and intestinal schistosomiasis were significantly less seen in 2002 compared to the baseline. The previous chemotherapy of schoolchildren and villagers in 1996 and 1998, respectively, might have led to a reduced transmission of schistosomiasis in the following years. However, the reduction of prevalence of soil-transmitted helminthiasis is more likely to be the result of health-related interventions.     

Urinary schistosomiasis among schoolchildren in Ibadan, an urban community in south-western Nigeria

The current status of urinary schistosomiasis was assessed in Ibadan, an urban community in south-western Nigeria. Of 1331 children examined for eggs of S. haematobium in their urine, 17.4% were infected. Prevalence in postprimary schoolchildren was significantly (P < 0.01) higher (22.4%) than in primary schoolchildren (12.0%). Intensity of infection based on geometric mean egg count per 10 ml of urine was also higher in postprimary (36.7 eggs/10 ml urine) than primary pupils (29.9 eggs/10 ml urine). Boys had a significantly (P < 0.01) higher infection rate (24.1%) than girls (8.5%), and the intensity of infection was also higher (P < 0.01) in males (39.0 eggs/10 ml urine) than in females (22.1 eggs/10 ml urine). The overall geometric mean intensity of infection was highest (38.8 eggs/10 ml urine) in the 11-15 years age group. 42% of infected children excreted > 50 eggs/10 ml urine. 2.2% excreted S. mansoni eggs in urine. Water contact activities were more frequent (P < 0. 01) in males (31.8%) than females (38.2%). Nine species of snails were encountered, with B. (p) globosus being the the most abundant and widespread. These results show that urinary schistosomiasis is still being actively being transmitted in Ibadan.     

Questionnaire survey and prevalence of intestinal helminthic infections in Barru, Sulawesi, Indonesia

A questionnaire survey with parasitological study was carried out on the inhabitants of 4 villages in Barru district, Sulawesi, Indonesia from 1994 to 1995. The questionnaire dealt with life style and sanitary conditions. In 482 houses in the 4 villages, interviews for the items of the questionnaire were conducted with the owner, housekeeper and children of the same family. In Pancana and Lalolang, 37.7% and 50% respectively of man inhabitants surveyed were fishermen, while in Lompo Riaja and Pattappa, 38.6% and 65.5% respectively were farmers. The highest proportion of official workers was 33.7% in Lompo Riaja. Educational level was low; 88.4% in Pancana, 90.4% in Lalolang, 62.1% in Lompo Riaja and 91.2% in Pattappa had elementary or below elementary school education. In Lompo Riaja, 30.8% of the inhabitants graduated from senior high school or university. The percentage of families having their own latrine was 30.3% in Pancana, 13.2% in Lalolang, 31.9% in Pattapa and 60% in Lompo Riaja. The people without latrines usually defecated in rice fields, seaside or riverside. A total of 654 fecal samples was examined by the modified Kato-Katz thick smear method. Five nematode species, Ascaris lumbricoides, Trichuris trichiura, Necator americanus, Strongyloides stercoralis and unidentified Rhabditoids of free-living nature were detected. Cestode, Hymenolepis nana infection was confirmed. All the hookworms examined by the modified Harada-Mori culture technic were Necator americanus. Trichuris infection was most common, followed by hookworm and Ascaris infections, both in young (aged 4-14) and older (aged over 15) age groups. The prevalence of hookworm infection was significantly higher in males than in females of older age. Among the older age group, the prevalence of Trichuris infection was significantly lower in Lompo Riaja, while hookworm infection was the highest in Pattappa. Among all the inhabitants examined for parasite infection, 17.4% had 3 kinds of nematode, Ascaris, Trichuris and hookworm. However, egg counts revealed that most of the inhabitants with Trichuris or hookworm had light infections. The inhabitants with higher education background had significantly lower infection rates of Ascaris and Trichuris. The prevalence of hookworm infection was not significantly different between the inhabitants owning latrine and without it, but the prevalence of Ascaris and Trichuris, differed significantly.     

Albendazole in the treatment of opisthorchiasis and concomitant intestinal helminthic infections

A total of 52 adult patients with opisthorchiasis with or without concomitant intestinal helminthic infections were treated with albendazole at dosage regimens of 400 mg twice daily for 3 days (group I with 25 patients) and 7 days (group II 27 patients). By concentration method with four examinations from two faecal specimens of each patient the cure rates and percentage egg reduction on day 30 in group I and group II were 12% and 33%, 94 and 95 respectively; by Stoll method the cure rates and percentage egg reduction were 40% and 63%, 92 and 92 in group I and group II, respectively. There were no statistically significant differences between the results of the two regimens. Twenty six patients with hookworm and 9 patients with S. stercolaris infections were cured. Opisthorchis viverrini, N. americanus, A. duodenale, A. ceylanicum, E. malayanum, E. ilocanum, S. stercolaris, E. vermicularis, and T. saginata segments were expelled in stools, mostly on days 1 to 4. Most of the patients felt relieved from symptoms of pain in the right hypochondrium and epigastrium. The side effects were mild and transient. There were no evidence of toxic effects on the bone marrow, heart, liver or kidneys. Albendazole was shown to be effective against Opisthorchis viverrini infection as well as other concomitant intestinal helminthic infections; but the optimal dosage and duration of treatment have not yet been achieved.     

Prevalence of gastrointestinal helminthic infections and associated risk factors among schoolchildren in Tilili town,northwest Ethiopia

Objective:To determine the prevalence of gastrointestinal helminthes and associated risk factors among schoolchildren in Tilili town,northwest Ethiopia.Methods:A cross-sectional study involving 383 schoolchildren was conducted between November 2011 to February 2012.Each student was selected using systematic random sampling method.Questionnaire and observation were used to identify socio-demographic and associated risk factors.Fresh stool samples were observed using formal-ether concentration technique.Data were analyzed using SPSS 16.0statistical software.Results:Four species of intestinal helminthes were identified with an overall prevalence of 44.2%(170 of 385 schoolchildren).The predominant parasites were Ascaris lumbricoides(A.lumbricoides)153(39.7%)and Trichuris trichiura(T.trichiura)30(7.8%).One hundred thirty five(35.1%)had single infections and 35(9.2%)were infected with more than one helminthic parasites in which 32(8.4%)were double infections and 3(0.8%)were triple infections.Significant associations were observed between intestinal helminth infection and those of age,grade level,and school variables.Prevalence of hookworm infection was significant in children who did not wear shoes regularly(P0.05).Conclusions:intervention programs and education on personal and environmental hygiene should be implemented for the prevention and control of helminthic infections in the study area.     

Chemotherapy in the control of urinary schistosomiasis in Nigeria

Praziquantel (Biltricide, Bayer AG), which has been found to be very effective in the treatment of schistosomiasis, was evaluated to formulate the minimal cost-effective dose in selective chemotherapy of 135 school children aged 6-15 years. Side effects were minimal. The drug had no effect on the heavy load of intestinal helminths found in 78.1% of the subjects. However, it cleared the urinary schistosomiasis in all but 0.9% of the subjects at the dosages used and after 18 months only 0.59% of the entire school population had new infections. The targetted chemotherapy reduced the prevalence rate from 16.0% to 0.59%. The lowest dose of 1 X 20 mg/kg body weight was able to clear the light infections of 52 subjects. This has a great economic advantage because the drug is expensive and most of the infections in Nigeria are light to moderate.     

Survey of urinary schistosomiasis and trichomoniasis in a rural community in Edo State,Nigeria

Survey of urinary schistosomiasis and trichomoniasis was conducted among 830 inhabitants of Ikao village, in Owan local government area of Edo State, Nigeria Between October, 1999 and February, 2000. Of these, 178 (21.4%) excreted Schistosoma haematobium ova in their urine. School children were more infected than the farmers and petty traders. Males were more infected than the female counterparts, These differences were statistically significant using Chi-square test analysis (chi 2). Most of the inhabitants had light infections. In all, urinary schistosomiasis and trichomoniasis co-infection occurred in the genito-urinary tract of 14 (6.3%) females inhabitants. The highest Trichomonas vaginalis infection 16 (40.0%) occurred in female subjects within 20-25 years old.     

Micro-epidemiology of urinary schistosomiasis in Zanzibar: Local risk factors associated with distribution of infections among schoolchildren and relevance for control

Although it is well recognised that both behavioural and environmental factors play a role in determining small-scale heterogeneities in schistosomiasis transmission, empirical evidence of their relative importance is often limited. A study was conducted around Chaani, a village in northern Unguja (Zanzibar) where urinary schistosomiasis is endemic, in order to shed light upon the micro-epidemiology of Schistosoma haematobium and patterns of infection within schoolchildren and the intermediate host snail Bulinus globosus, that may help in adjusting recently implemented control programmes. Malacological surveys were conducted to identify transmission foci and questionnaires were devised to assess recalled water-contact patterns of 150 schoolchildren who had been screened for S. haematobium infection, finding an overall prevalence of 50.6%. Boys were more frequently and more heavily infected than girls and, accordingly, mean exposure scores were significantly higher for boys than girls. Univariate statistics revealed significant associations between infection and specific water-contact activities, including washing/bathing (odds ratio [OR]=3.01, 95% confidence interval [CI]=1.36-6.67) and playing (OR=4.03, 95% CI=1.51-10.70) in streams/ponds. In multivariate analysis, however, the strongest predictor of infection was proximity of the child's home to a site harbouring S. haematobium-infected B. globosus (P<0.001), suggesting that geography may be a better proxy for exposure than self-reported water contact. Surveillance programmes may therefore wish to prioritise evaluation of environmental risk to pinpoint transmission at the micro-geographical level, although water-contact questionnaires are also recommended as a complementary tool to rapidly identify the behaviour patterns of children at most risk of infection in the rural communities of Zanzibar. Such knowledge is a prerequisite for focusing and improving schistosomiasis control at the local level.     

Eosinophilia and helminthic infections.

Among microbial agents, helminths are the most common cause of eosinophilia. An approach to the evaluation of a patient with eosinophilia is outlined, with particular emphasis on clues in the history, examination and routine laboratory data that can help with the diagnosis. Multiple helminthic infections have been associated with eosinophilia, and the characteristic modes of spread, clinical manifestations, diagnostic tests and therapeutic considerations of these infections are discussed.     

Geographical information system and predictive risk maps of urinary schistosomiasis in Ogun State,Nigeria

Background  

The control of urinary schistosomiasis in Ogun State, Nigeria remains inert due to lack of reliable data on the geographical distribution of the disease and the population at risk. To help in developing a control programme, delineating areas of risk, geographical information system and remotely sensed environmental images were used to developed predictive risk maps of the probability of occurrence of the disease and quantify the risk for infection in Ogun State, Nigeria.     

Efficacy of metrifonate in urinary schistosomiasis in light and heavy infections

In a prospective clinical trial, patients with urinary schistosomiasis from the Sudan and from other African countries were treated with two or three doses of metrifonate (10 mg/kg), respectively, in two weeks' intervals. Patients seen in the Sudan (n = 37) were followed up for 3 months, those seen in Hamburg (n = 17) up to 20 months. Each dose of metrifonate led to a decrease of almost 90% in egg excretion independently of the pretreatment intensity of infection so that after three doses a reduction of almost 99.9% was achieved. The estimated proportion of parasitological cure after two doses of metrifonate was in the order of 24% in the lightly infected patients seen in Hamburg, and in the order of 8% in the heavily infected Sudanese patients. Almost 59% of the patients who received a complete metrifonate treatment of three doses stopped to excrete ova of S. haematobium. Drug failure was found in almost the same proportion in the two patient groups (17.5% and 16.2%, respectively) and could not be overcome by additional doses of metrifonate. The considerable reduction in egg excretion after a single dose of metrifonate might have a remarkable benefit in large scale programmes where the aim is drastic reduction of worm burden rather than complete cure.     

Missed treatment opportunities for schistosomiasis mansoni, in an active programme for the treatment of urinary schistosomiasis in Plateau and Nasarawa states, Nigeria

Both Schistosoma haematobium and S. mansoni are endemic in Nigeria. Since 1999 the ministries of health of Plateau and Nasarawa states, assisted by The Carter Center, have provided mass drug administrations with praziquantel to villages where >20% of the school-aged children tested with urine dipsticks have been found to have haematuria (presumed to be caused by S. haematobium). The current extent of S. mansoni in Nigeria remains relatively unknown because the tests needed to detect human infection with this parasite are difficult to perform in many endemic areas. In a cross-sectional survey involving 924 children, the prevalence of S. mansoni was determined in 30 villages (in four local government areas) that had been excluded from mass praziquantel administrations because the prevalence of haematuria in their school-aged children had been found to be <20%. Seventeen (57%) of the surveyed villages had sufficient S. mansoni (i.e. prevalences of at least 10%) to warrant treatment. The results indicated that, if both S. haematobium and S. mansoni are taken into account, 81% of the villages in the four local government areas studied require treatment, compared with 50% if only S. haematobium is considered. At the moment, the costs of the village-by-village diagnosis of S. haematobium and S. mansoni would be greater than those of the presumptive treatment of the school-aged children in all villages. Until improved and cheaper rapid diagnostic methods for S. mansoni become available, the cheapest approach to the overall problem of schistosomiasis in this part of Nigeria would therefore be wide-spread mass drug distributions, without screening for at-risk populations.