Schistosoma mansoni‐related morbidity on Ukerewe Island, Tanzania: clinical, ultrasonographical and biochemical parameters

Abstract

SummaryOne thousand six hundred and ninety-five inhabitants of 3 rural villages on Ukerewe Island, Lake Victoria, Tanzania, were examined by clinical, parasitological, ultrasonographic and-in part-serological means to evaluate Schistosoma (S.) mansoni-related morbidity on a community level. Villagers frequently complained of typical colitis symptoms (abdominal pain 80.1%, bloody stools 43.1%, diarrhoea 35.1%); haematemesis, on the other hand, was rare (and reports doubtful in most cases). 16.9% of the population had been given praziquantel previously. Overall S. mansoni prevalence was 86.3%, with a median egg output of 176 eggs per gram (e.p.g.) and a maximum output of 17 984 e.p.g. Children and adolescents were infected more severely than adults, men more severely than women. Pretreated individuals excreted significantly fewer ova (median 124 vs 192e.p.g., P<0.001).Hepatomegaly (determined by ultrasonography) was present in 35%, splenomegaly in 80%. Organomegaly was significantly related to egg output. Pretreated persons had lower rates of splenomegaly and left lobe hepatomegaly. Low-degree periportal fibrosis was common, while severe grades of fibrosis (MANAGIL score II and III) were present in about 6%. About 10% had other abnormalities on liver sonography (irregular parenchymal texture and/or shape); these persons passed significantly more S. mansoni ova than others. Clear sonographic signs of portal hypertension were seen in 2.1%. Serum procollagen-IV-peptide and -glutamyl-transferase levels were increased in persons with severe periportal fibrosis, irregular liver texture or portofugal collateral vessels.Thus, S. mansoni infection in the western part of Ukerewe Island is frequent and often severe, leading to a high prevalence of gastrointestinal symptoms. Hepatosplenic involvement does occur, although symptomatic cases of portal hypertension were not identified beyond doubt. The overall level of schistosomal morbidity is thus considered intermediate. Serum procollagen-IV-peptide may be a promising marker of schistosomal liver disease. Our data suggest that S. mansoni infection may also be related to diffuse liver parenchyma alterations in this area.

Two-year impact of praziquantel treatment for Schistosoma japonicum infection in China: re-infection, subclinical disease and fibrosis marker measurements

“…Decreases in the thickness of portal vein walls and in echogenic bands have been detected after praziquantel therapy (HOMEIDA et al, 1988;DOEHRING-SCHWERDTFEGER et al, 1989: OH-MAE et al, 1992WIEST et al, 1993;CAI>~ al., i997;GERSPACHER-LARA et aI, 1997;BOISIER et al, 1998). Assay of serum levels of fibrosis markers may be a useful supplementary tool for monitoring changes in liver fibrosis (SHAHIN et aZ., 1992;KARDORFF et al, 1997;OBERTI et al, 1997;ESTERRE et al, 1998;RICARD-BLUM et al, 1999).…”

A feasibility study to determine if minimally trained medical students can identify markers of chronic parasitic infection using bedside ultrasound in rural Tanzania

“…These morbidities have shown a strong relationship. [19] In this study we determined if minimally trained practitioners can use ultrasound to identify acute pathology of chronic infections in rural Tanzania.…”

“…[20] Use of portable ultrasound improves accessibility and removes some of the constraints of upkeep. Studies [15][16][17][18][19][20] have shown that the introduction of ultrasound can significantly alter treatment plan. In 43% of cases in Rwanda, ultrasound changed the initial management plan, involving surgical procedure, medication, clinic referral and others.…”

“…[9][10][11][12] In these studies, schistosomiasis infection was associated with hepatomegaly, splenomegaly, periportal fibrosis, portal vein dilation, portal hypertension, and calcifi cation of the bladder. These studies demonstrated that ultrasound is useful for monitoring long-term pathological changes in chronically infected individuals and may also be useful in detecting both acute pathology and chronic effects from high parasite burden.…”

“…These studies demonstrated that ultrasound is useful for monitoring long-term pathological changes in chronically infected individuals and may also be useful in detecting both acute pathology and chronic effects from high parasite burden. [9][10][11][12] However, there is little value of using ultrasound for screening for schistosomiasis since stool sample analysis is more economical and has a high specificity. [13] We believe that these scans can be easily taught and performed in rural and underserved settings with transportable ultrasound machines.…”