Approaches to genotyping individual miracidia of Schistosoma japonicum.

Molecular genetic tools are needed to address questions as to the source and dynamics of transmission of the human blood fluke Schistosoma japonicum in regions where human infections have reemerged, and to characterize infrapopulations in individual hosts. The life stage that interests us as a target for collecting genotypic data is the miracidium, a very small larval stage that consequently yields very little DNA for analysis. Here, we report the successful development of a multiplex format permitting genotyping of 17 microsatellite loci in four sequential multiplex reactions using a single miracidium held on a Whatman Classic FTA indicating card. This approach was successful after short storage periods, but after long storage (>4 years), considerable difficulty was encountered in multiplex genotyping, necessitating the use of whole genome amplification (WGA) methods. WGA applied to cards stored for long periods of time resulted in sufficient DNA for accurate and repeatable genotyping. Trials and tests of these methods, as well as application to some field-collected samples, are reported, along with the discussion of the potential insights to be gained from such techniques. These include recognition of sibships among miracidia from a single host, and inference of the minimum number of worm pairs that might be present in a host.

[Mid-term evaluation on schistosomiasis control effect in Lushan earthquake-stricken areas in Sichuan Province].

OBJECTIVE: To evaluate the effect of schistosomiasis control in Lushan earthquake-stricken areas in Sichuan Province, so as to provide the evidence for formulating appropriate measures for schistosomiasis prevention and control. METHODS: According to the data of historical schistosomiasis prevalence, 5 villages were selected as research sites and field investigations were conducted. RESULTS: The average density of Oncomelania hupensis snails was 0.41 snails/0.1 m2, and there were no schistosome-infected snails. There were no acute schistosomiasis cases in these five villages. For local residents, the health education leaflets were more suitable than warning signs, and for migrant population, they were more concerned about the warning signs. CONCLUSION: After the implementation of effective prevention and control works, the epidemic risks of schistosomiasis have been controlled. However, the health education, surveillance, and prevention measures for schistosomiasis still need to be persisted in.

[Report on 55 cases of small intestine hookworm disease diagnosed by capsule endoscopy].

OBJECTIVE: To demonstrate the diagnostic value of capsule endoscopy for small intestine hookworm disease. METHODS: A retrospective study was carried out to analyze the clinical data and capsule endoscope image of 55 patients with small intestine hookworm disease in the hospital from June 2006 to June 2012. RESULTS: Among these patients, 40 cases manifested as gastrointestinal bleeding, 7 had iron deficiency anemia, 6 had chronic abdominal pain, and 2 showed abdominal distension or discomfort. Hookworm eggs were found in stool specimens of 2 cases, 6 cases showed peripheral eosinophilia, 46 cases were found to be fecal occult blood positive. Out of the 55 cases investigated, 44 showed anemia (11 severe, 26 moderate, and 7 mild). All patients were definitely diagnosed by capsule endoscopy. The hookworms were translucent and about 5-10 mm in length. Hookworms in most cases were diffusely distributed, but 12 patients suffered massive and severe hookworm infection. In most cases, hookworms were found in the proximal small intestine, and 6 in the distal intestine. Erosion and injury in intestinal mucosa around the hookworm were observed in several cases. CONCLUSION: Capsule endoscopy is an effective and safe diagnostic technique for hookworm disease in small intestine.

[Report on 16 cases of small intestine ascariasis diagnosed by capsule endoscopy].

The clinical data and capsule endoscopy image of 16 adult patients with small intestine ascariasis were reviewed and analyzed retrospectively from June 2006 to June 2012 in West China Hospital. Among the 16 patients, 15 cases manifested as gastrointestinal bleeding, 15 cases showed anemia (3 severe, 10 moderate, and 2 mild), 2 had hypoalbuminemia, 1 had peripheral blood eosinophilia. All the cases were found to be fecal occult blood positive, but no Ascaris eggs found in the feces. Capsule endoscopy showed they were infected with Ascaris worms. The worms were found in the proximal small intestine in 14 patients and 2 in the distal intestine. Mucosal erythema and erosions around the worm were observed in 3 cases, and 7 cases were found with active bleeding or old haemorrhage in small intestine.