Differentiation of Brugia malayi and Brugia pahangi by PCR-RFLP of ITS1 and ITS2.

Lymphatic filariasis has been targeted by the World Health Organization for elimination by the year 2020. Malayan filariasis, caused by Brugia malayi, is endemic in southern Thailand where domestic cats serve as a major reservoir host. However, in nature, domestic cats also carry B. pahangi infection. In addition to chemotherapy and vector control, control in reservoir hosts is necessary to achieve the elimination of the disease. Therefore, differentiation between B. malayi and B. pahangi in the cat reservoir will help the lymphatic control program to monitor and evaluate the real disease situation. It is difficult to differentiate these two Brugia species by microscopic examination. The technique is also time-consuming and requires expertise. We employed the polymerase chain reaction-linked restriction fragment length polymorphism (PCR-RFLP) technique of internal transcribed spacer regions, ITS1 and ITS2, of ribosomal DNA (rDNA) to differentiate B. malayi from B. pahangi species. Among the restriction enzymes tested, only the PCR product of ITS1 digested with Ase I could differentiate B. malayi from B. pahangi. This PCR-RFLP technique will be useful for lymphatic filariasis control programs for monitoring and evaluating animal reservoirs.

Enterobius vermicularis infection among pre-school children in Karen hilltribe villages in Chiang Mai, Thailand.

We surveyed Karen hilltribe villages in the Mae Chaem District of Chiang Mai Province between April and May 2001. Two hundred and forty-nine pre-school children were selected by stratified sampling from 10 villages and were examined for Enterobius vermicularis eggs by the Scotch tape perianal examination technique. One hundred and thirteen (53 boys and 60 girls) were found to have E. vermicularis eggs, giving an overall infection rate of 45.38%. We were able to determine that E. vermicularis infection is prevalent among the children of these hilltribe villages.

Malaria among hilltribe communities in northern Thailand: a review of clinical manifestations.

Malaria is an important vector-borne disease in the tropics. Northern Thailand is endemic for malaria. We reviewed the clinical manifestations presented by patients with malaria; our data were drawn from the database of Mae Chaem Hospital, Chiang Mai Province. Mae Chaem district is hilly and rural. More than 80% of the district's population are members of hilltribes. The database showed that between July 2000 and April 2001, a final diagnosis of malaria was made in 94 cases. The commonest clinical manifestation was fever (in 91 cases; 96.8%), followed by chills (in 57 cases; 60.6%). Interestingly, some unusual presentations such as petechiae, abnormal menstruation, and jaundice were also found.

Brugia malayi in a naturally infected cat from Narathiwat Province, southern Thailand.

Brugia malayi-like from an infected cat from Narathiwat Province, southern Thailand was identified intensively by microfilarial morphometry, acid phosphatase activity, and adult morphology. The results indicated that both microfilarial and adult characteristics conformed to the topotypic B. malayi.