Ultrasonic and X-ray tomographic findings of schistosomiasis japonicum

Imaging diagnosis of schistosomiasis japonica--the use in Japan and application for field study in the present endemic area

For detecting lesions-related schistosomiasis japonica, X-rays, scintillation scanning, ultrasonography (US), computed tomography (CT), magnetic resonance (MR) and endoscopic examinations with biopsies have been used in Japan. Liver fibrosis and calcified changes are detected by US and CT. Most of the lesions that are detected by endoscopic examinations are due to deposited ova of Schistosoma japonicum. Portal hypertension is detected by US, CT and gastroscopic examination. Because schistosome infection decreased rapidly in Japan, most of the studies on imaging diagnosis were performed on chronic lesions or sequelae of schistosomiasis. Most of the techniques were used on admitted patients in well-equipped hospitals. US was introduced in the 1970s as a safe, rapid, non-invasive and inexpensive technique and has been used for diagnosis in hospitals and screening in the fields. As a typical US image of the liver, septal formation by high echogenic bands like mosaic was described, and this network pattern was reported in the other endemic countries; China and Philippines. As an appropriate technique, US has been broadly used in developing countries. Not only for diagnosis in a hospital, but also for monitoring changes of morbidity, US is used in the community level. Network pattern related to the severity of S. japonicum infection, has not been described in S. mansoni or S. haematobium infection. Appearance of network pattern depends on pathological changes such as periportal fibrosis, postnecrotic fibrosis and calcified ova. For advanced studies on morbidity of schistosomiasis japonica, further research on pathological basis of network pattern and standardization of US diagnosis are necessary.

Laparoscopic diagnosis and clinical course of chronic schistosomiasis japonica

Laparoscopic findings of nine patients with chronic schistosomiasis japonica were analyzed and compared to hepatic ultrasonograms, computed tomography (CT) scans and histological findings from the same patients. In all nine patients laparoscopy revealed yellowish, small speckles, approximately 50 microm in diameter, sparse or clustered over the liver surface, which were later found to represent subcapsular calcified ova of Schistosoma japonicum. While the liver surface was almost smooth in mild schistosomiasis, multiple whitish markings and irregular, relatively wide, groove-like septums were seen in more advanced cases. In severe schistosomiasis block-like formations of variable size, separated by groove-like depressions, made the liver surface appear like a tortoise shell. In moderate or severe schistosomiasis ultrasonography revealed spotted high echoes and CT scans demonstrated network patterns and lineal calcified spots. The liver surface of chronic schistosomiasis japonica without re-infection appeared stable without change over time but with a tendency to improve. Hepatocellular carcinoma was initially recorded in two of the nine patients and follow-up revealed a further two with the same diagnosis. However, all these four cases also had chronic hepatitis C (HCV). Hepatocellular carcinoma was not detected in patients without viral hepatitis, indicating that hepatic viral infection is more important than schistosomiasis in promoting the development of hepatocellular carcinoma.

Schistosomiasis japonica on Jishan Island, Jiangxi Province, People's Republic of China: persistence of hepatic fibrosis after reduction of the prevalence of infection with age

Hepatic fibrosis due to schistosomiasis japonica was examined by ultrasonography in a cross-sectional community study of 825 individuals on Jishan Island, Jiangxi Province, China. The prevalence of active infection was 39.4% with peak infection in the 10-19.9 years age group followed by a significant decline. A similar pattern was observed for intensity of infection. The prevalence of hepatomegaly in the midsternal line > or = 6 cm peaked at 60% in the fourth decade and remained elevated. A progressive increase in the severity of hepatic periportal fibrosis was observed with age, with advanced fibrosis peaking in the fifth decade. The proportion of individuals with advanced fibrosis was significantly greater in males than in females despite equivalent prevalence and intensity of schistosome infection. In addition, a positive association (P < 0.01) was found between periportal fibrosis and both hepatomegaly > or = 6 cm and splenomegaly. This study suggests that the natural history of schistosomiasis japonica in this hyperendemic community in China is marked by persistence of hepatomegaly and schistosome-induced periportal fibrosis in adults despite a decrease in the prevalence of infection.