Comparison of two diagnostic techniques to determine the prevalence of Schistosoma mansoni infections in Cameroonian school children

Background: The Kato-Katz technique is recommended for diagnosis of Schistosoma mansoni infection by the World Health Organization. However, egg counts are subject to variability. The aim of this study is to determine the prevalence of S. mansoni infection in school children using two different techniques and to recommend the technique that should be routinely used in the diagnosis of this infection. Methodology: Field investigations on faecal samples from 299 Cameroonian school children were carried out in 2016 to compare the effectiveness of the Kato-Katz and Formalin-ether techniques in diagnosis of S. mansoni infections. Results: Schistosome eggs were detected in 37 (12.3%) samples with the Kato-Katz technique and 61 (20.4%) samples with the Formalin-ether technique. The difference between the prevalence observed for the two techniques was significant in males and age group 10 - 12 years (p < 0.5). Conclusion: The Formalin-ether technique was more sensitive than the Kato-Katz method for detecting S. mansoni eggs in faecal matter. Despite its cost, the Formalin-ether technique can be routinely used in the laboratory for epidemiological studies of intestinal schistosomiasis

Epidemiology of soil-transmitted helminths, schistosoma mansoni, and haematocrit values among school children in Ethiopia

Introduction: This study aimed to determine the prevalence of intestinal helminths; risk factors and haematocrit values among primary schoolchildren. Methodology: Across-sectional study was conducted in 12 primary schools in March 2011. Stool samples were randomly selected from 778 children and were microscopically examined using Kato-Katz and formal-ether concentration methods. Haematocrit values were measured using heparinized capillary tubes. Results: The overall prevalence of intestinal helminths was 51.5 (rural = 68.3; urban = 36.2). Hookworm spp.; Schistosoma mansoni and Schistosoma stercoralis were more prevalent in rural schools; whereas Hymenolepis nana was higher in urban schools (p = 0.0001). With regard to haematocrit; 34 of rural and 21.7 of urban schoolchildren had haematocrit values below the median (40.5) (p=0.001). Hookworm spp. and S. mansoni infected children had lower haematocrit values than non-infected children (p = 0.001). Lack of footwear was positively associated with intestinal helminths infection in rural schools [OR = 2.5 (95 CI: 1.5-4.1)]; and having dirty fingernails and untrimmed fingernails were positively associated with the prevalence of intestinal helminths in urban samples [OR = 1.58 (95 CI: 1.03-2.5)]. Conclusion: The prevalence of soil-transmitted helminths and S. mansoni differs by geographical area of the schools and social determinants. Primary school de-worming and health education on proper hygiene are recommended

Evidence of Long Term Benefit of Praziquantel Treatment Against Schistosoma mansoni in Kigungu Fishing Village of Entebbe, Uganda

Praziquantel (PZQ) is efficacious against all species of schistosome: Schistosoma mansoni; Schistosoma haematobium; Schistosoma japonicum and other parasites like the Taenia species. This cross-sectional cohorts study was carried out in Kigungu fishing village along Lake Victoria shore in Entebbe Uganda. Our analysis was based on examining microscopically three slides from a single stool specimen from each of base line cohorts 945.These included children and adults; participants from both sexes in Kigungu fishing village in Entebbe Uganda. Nine hundred and one (901) of the cohorts were re-examined after six months and 625 of the same cohorts who were examined at the baseline and after six months were re-examined 18 months later. The slides were prepared using modified Kato/Katz (Odongo-Aginya) method. The infection proportion with Schistosoma mansoni at baseline was 448 (47.5) but this was reduced to 244 (25.8) 18 months after treatment with a single oral dose of praziquantel at 40mg/kg. However 495 (52.5) were negative at the baseline study. The cure proportion after six was significant ///{(P=0.00); (OR4.63) CI at 95(3.53-6.06)///}. Similarly the cure proportion after 18 months was significant ///{(P=0.00); (OR2.2) CI at 95(1.87-3.34)///}. The force of re-infection after six months was significant ///{(P=0.0001); (OR 0.47) CI at 95(0.31-0.71)///}. Nevertheless the force of re-infection was not significant after 18 months ///{(P=0.766); (OR 0.95) CI at 95(0.68-1.34)///} eggs excretion did not reach the level of the pre-treatment intensity. The egg reduction was 69.3. This was associated with age and pre-treatment intensity 400 eggs per gram (epg) of faeces and age groups ? 30 years. The egg reduction also resulted in marked decrease in clinical symptoms in the participants. Our study suggests evidence of long-term benefit of praziquantel in Kigungu and that the re-infection occurred more commonly in younger age group than in the older patients

Evidence of long term benefit of morbidity reduction due to praziquantel treatment against schistosoma mansoni in Kigungu fishing village in Entebbe, Uganda

Praziquantel (PZQ) is efficacious against Schistosoma mansoni. This was prospective cohort study. This study was carried out at Kigungu fishing village, Entebbe, Uganda. The goal of the study was to establish cost effective regiment for mass drug administration (MDA) of Praziquentel in the morbidity reduction of S.mansoni infection. In January 2004, nine hundred and forty five (945) participants were registered in this study. Our analysis was based on examining microscopically three slides prepared from each of 945 stool specimens delivered by each of the participant using modified Kato/Katz method. These included male and female, children and adults living in Kigungu fishing village in Entebbe Uganda. In total 901, cohorts were re-examined for infections clearance six months later in July 2004 and 18 months later in June 2005, 625 cohorts were again re-evaluated for S.mansoni infections after the baseline study. At baseline, (448) of 945 (47.5%) cohorts were S. mansoni positive. All these participants were treatment with a single oral dose of praziquantel at 40mg/kg. At the same time, 495 (52.5%) were S. mansoni negative. Of the 625 (66.3%) cohorts who came back for final review, 80 (12.8%) were still positive for S. mansoni while 210 (33.6%) remained negative after the base line treatment with praziquantel. On the other hand 103 (16.3%) of cohorts who were initially negative at the base line became S.mansoni positive after 18 months and 213(34.1%) remained negative for S.mansoni. The force of re-infection after six months was significant {(P=0.0001),(OR 0.47) CI at 95% (0.31-0.71)}. Nevertheless the force of reinfection was not significant after 18 months {(P=0.766), (OR 0.95) CI at 95% (0.68-1.34)}.The geometric mean eggs excretion of the 80 cohorts who were S.mansoni positive at 18 months was 151.967.This did not reach the geometric mean egg excreted by the same cohorts at baseline which was 285.05. The egg excretion was reduced by 46.8%. Similarly there was marked decrease in clinical symptoms amongst the cohorts. Our study suggests evidence of long-term benefit of praziquantel in Kigungu and that a yearly administration of praziquantel to the community could be a regiment for mass drug administration (MAD) for this community to control schistosomiasis morbidity

Transmission of Schistosoma Mansoni in Tikur Wuha Area; Southern Ethiopia

Background: Although the epidemiology of schistosomiasis is well established and the disease distribution has also been mapped in Ethiopia; discovery of new foci has continuously been reported. Objectives: The objective of this study was to assess the establishment of transmission of schistosomiasis mansoni in Tikur Wuha area; southern Ethiopia. Methods: A cross-sectional epidemiological study involving 375 school children in Tikur Wuha Elementary School was conducted in December 2007 and January 2008. Stool specimens were collected and microscopically examined using Kato-Katz method. Snail survey was also conducted using scoop in Tikur Wuha River and littoral zone of Lake Awassa on the side of Tikur Wuha Kebele (administrative unit). The snails collected were checked for trematode infection by shedding. Laboratory-bred mice were exposed to schistosome cercariae and definite identification of the schistosome was made using eggs and adult worm morphology. Results: The prevalence and intensity of schistosomiasis mansoni was 12and 69 eggs per gram (epg) of stool; respectively. Biomphalaria sudanica collected in Tikur Wuha River shed schistosome cercariae. Adult S. mansoni worms were harvested from laboratory-bred mice after 6 weeks of laboratory maintenance. Conclusion: The prevalence and intensity of schistosomiasis mansoni among school children was low and the area represents low-risk community. The finding of S. mansoni infected young children; the collection of B. sudanica infected with schistosome cercariae; and the establishment of infection in lab-bred mice all confirmed the transmission of schistosomiasis mansoni in Tikur Wuha area. Appropriate intervention measures need to be in place to reduce morbidity and transmission of intestinal schistosomiasis in the area. [Ethiop. J. Health Dev. 2010;24(3):180-184]

Epidemiology; of Bilharzias (schistosomiasis) in Uganda from 1902 until 2005

Background: Schistosoma mansoni was observed and reported in Kuluva hospital Arua District in north western Uganda as early as 1902. S. mansoni is widely distributed in Uganda along permanent water bodies. Objective: To review the litreture on scistosomiasis in Uganda; since 1902. Method: The core literature for this short review was searched from reports and publications by the British colonial Ministry of Health Districts Medical officers and Entomologists. Additional information was obtained from Makerere University Medical School library archives; London School of Hygiene and Tropical Medicine library archives; University of Antrwap; and post independence publications on schistosomiasis in Uganda in various journals. Results: Since it was first detected in 1902 Schistosoma (S) mansoni is more widely distributed in Uganda than S. haematobium. However Schistosoma mansoni and S. haematobium are of public health importance in Uganda and the importance of migrants and fishermen in disseminating infections into non-infested areas and intensifying infection in areas already infested have been reported. Conclusion: S. mansoni has been on the increase in Uganda whereas S. haematobium is localized in sporadic foci in the north of Uganda. Treatment with praziquantel the drug of choice in Uganda used in schistosomiasis control programme has reduced development of severe schistosomiasis

Dynamique des schistosomoses intestinales au Cameroun: evolution de la trasmission dans le foyer mixte de Nkolmebanga; Lekie

This study was undertaken to evaluate the current status of shistosomiasis in the Nkolmebanga region (Lekie) of Cameroon; p rev i o u s ly determined to be a mixed zone harboring both Schistosoma mansoni and S. intercalatum. Study invo lved both malacology with collection and identifi c ation of fre s h water snails in four wat e rpools and para s i t o l ogy with collection and analysis of stools from schoolchildren Five species of freshwater snails were identified including two that were intermed i ate host of Schistosomes; i.e.; Biomphalaria pfe i ffe ri and Bulinus fo rskalii. Only B. pfe i ffe ri species collected from the Momboh and Mbonsoh Rivers shed Schistosoma cercaria. A total of 347 schoolchildren were enrolled but only 200 provided stools for parasitological testing. There were 93 boys and 107 girls. Parisitology demonstrated S. intercalatum eggs in the stools of no children. S. mansoni eggs were identified in the stools of 10 children for a prevalence of 5. Parasitic load ranged from 24 to 1104 eggs per gram of stool. In this study both malacologic and parasitological findings suggested that S. mansoni persists in Nkolmebanga region but that S. intercalatum has disappeared probably as a result of deforestation and urbanization

Association leucemie lymphoide chronique-bilharziose mixte a schistosoma mansoni et a schistosoma haemotobium a propos d'un cas collige dans le service de Medecine interne du CHU de Treichville d'Abidjan (Revue de la Litterature)

Les associations Bilharzioses et neoplasies decrites dans la litterature ne sont pas rares. Les plus connues restent l'association Bilharziose-cancer de la vessie; Bilharziose-polype colique surtout observee dans la vallee du Nilten Egypte ou encore l'association Bilharziose-hepatocarcinome.Le lien physiopathologique et immunologique de ces associations reste cependant a prouver; ce qui a ce jour semble privilegier l'hypothese d'une association fortuite.Exegese: nous rapportons dans notre travail; un cas d'association Leucemie Lymphoide Chtonique-Bilharziose mixte a Schistosoma haematobium et Schistosoma mansoni chez une patiente de 51 ans hospitalisee dans le service de medecine interne du CHU de Treichville (Abidjan).Elle a ete revelee par une splenomegalie de type 5 et une polyadenopathie cervicale et inguinale. L'evolution est en regle pejorative

La bilharziose a Schistosoma intercalatum au Congo? [Lettre]

A ce jour; aucun foyer de Schistosoma intercalatum n'a jamais ete signale au Congo; en dehors de quelques cas sporadiques depistes chez les etrangers. A ce titre le Congo restait donc le seul pays de la sous-region de l'Afrique Centrale ou ce parasite n'etait pas decrit. Mais depuis quelques mois; des cas de Schistosoma intercalatum etaient regulierement declares par le secteur operationnel No6 de la Sangha a Ouesso (Nord Congo); dans le cadre de la surveillance epidemiologique

A preliminary study on intermediate snail hosts of schistosomes in Reiver enyau; Arua District; Uganda

A total of 1260 snail intermediate hosts of both Schistosoma mansoni and Schistosoma haemotobium were collected along the non-seasonal river enyau which lies half a kilometre west of Arya; north-western Uganda town. The snails collected were Biomphalaria pfeireri 709: Biomphalaria choanomphala 457; Bulinus tropicus 94. These were screened for cercariae shedding and 25 B. pfeifferi and 12 B. choabomphalal shed mammalian cercaricae while none of the Bulinus) tropicus shed any cercae. River enyau Biomphalaria snails were susceptible to a Schistosoma mansoni strain from Entebbe. Cercariae derived from these snails and also those found infected in the River Enyau were confirmed to be S. mansoni using laboratory mice

Preliminary study on Intermediate snail hosts of schistosomes in River Enyau; Arua District; Uganda

A total of 1260 snail intermediate hosts of both Schistosoma mansoni and Schistosoma haemotobium were collected along the non-seasonal River enyau which lies half a kilometre west of Arua; a north-western Uganda town. The snails collected were Biomphalaria pfeifferi 709: Biomphalaria choanomphala 457; Bulinus Bulinus tropicus 94. These were screened for cercarieae while none of the Bulinus (Bulinus) tropicus shed any cercariae. River Enyau Biomphalaria snails were susceptible to a Schistosoma mansoni strain from Entebbe. Cercariae derived from these snails and also those found infected in the river enyau were confirmed to be S. mansoni using laboratory mice

The intensity of Schistosoma mansoni in the fishing villages of Bugonga and Kitubulu in Entebbe peninsula; Uganda

The intensity of Schistosoma mansoni infection in the fishing villages of Bugonga and Kitubulu; and the occurrence of snail intermediate host population in the two villages are described and compared. A total of five hundred and six faecal samples from both villages were examined by modified Kato's technique and the prevalence infection rate at Kitubulu was 40.3with mean egg count of 187 eggs per gram (epg) while in Bugonga it was 32.4and 126 egg respectively. The snail intermediate host for S. mansoni in the two villages was 2;750 Biomphalaria choanomphala at Kitubulu and 1;268 at Bugonga. But at Kitubulu in the vicinity of the village 185 Biomphalaria peifferi occurred in small localized population. The cercarial screening test conducted on 4;018 B. choanomphala and 185 B. peifferi from the two villages revealed higher snail infection rate for both mammalian and non-mammalian cercariae at Kitubulu than Bugonga. Variations in infection rates both among the inhabitants and host snail populations in the two villages are discussed