High Prevalence of Intestinal Capillariasis in Chronic Diarrhea Patients in Thailand: Serological Screening Using a Rapid Lateral-Flow Immunochromatographic Assay.

Intestinal capillariasis is an emerging fish-borne helminthic disease caused by the round worm Capillaria philippinensis. Chronic infection may lead to death if the disease is misdiagnosed and inappropriate treatment is given. We used a rapid lateral-flow immunochromatographic test for screening of intestinal capillariasis in patients with chronic diarrhea. We screened 292 chronic diarrhea patients who had visited hospitals in Thailand. Sixty-six (22.6%) cases were positive according to the kit. All positive patients received mebendazole at 200 mg twice per day for 30 consecutive days or albendazole at 200 mg twice per day for 10 consecutive days. Later, stool concentration techniques, used to examine stool samples from all serologically positive individuals on three consecutive days, revealed C. philippinensis eggs, larvae, and/or adults. The kit is useful for screening and rapid diagnosis of intestinal capillariasis in chronic diarrhea patients in an endemic area for prevention of serious disease and facilitates treatment.

An Alternative Method for Extracting Plasmodium DNA from EDTA Whole Blood for Malaria Diagnosis.

Molecular techniques have been introduced for malaria diagnosis because they offer greater sensitivity and specificity than microscopic examinations. Therefore, DNA isolation methods have been developed for easy preparation and cost effectiveness. The present study described a simple protocol for Plasmodium DNA isolation from EDTA-whole blood. This study demonstrated that after heating infected blood samples with Tris-EDTA buffer and proteinase K solution, without isolation and purification steps, the supernatant can be used as a DNA template for amplification by PCR. The sensitivity of the extracted DNA of Plasmodium falciparum and Plasmodium vivax was separately analyzed by both PCR and semi-nested PCR (Sn-PCR). The results revealed that for PCR the limit of detection was 40 parasites/µl for P. falciparum and 35.2 parasites/µl for P. vivax, whereas for Sn-PCR the limit of detection was 1.6 parasites/µl for P. falciparum and 1.4 parasites/µl for P. vivax. This new method was then verified by DNA extraction of whole blood from 11 asymptomatic Myanmar migrant workers and analyzed by Sn-PCR. The results revealed that DNA can be extracted from all samples, and there were 2 positive samples for Plasmodium (P. falciparum and P. vivax). Therefore, the protocol can be an alternative method for DNA extraction in laboratories with limited resources and a lack of trained technicians for malaria diagnosis. In addition, this protocol can be applied for subclinical cases, and this will be helpful for epidemiology and control.