Persistence of IgG, IgM, and IgE antibodies in human trichinosis.

An enzyme-linked immunosorbent assay (ELISA) was used to detect serum IgG, IgM, and IgE antibodies against Trichinella spirals s. str. following an outbreak of human trichinosis in 1989 in Chiang Rai Province, Thailand, for two years and seven months in order to observe diagnostic sensitivity of ELISA as well as the persistence of antibodies. It was found that the sensitivity of IgG-ELISA, as determined from biopsy-positive cases, reached 100% on the 50th day of infection. For IgM-ELISA, peak sensitivity was 93.33% at the 57th and IgE-ELISA 100% at the 85th day of infection. Two years and seven months after infection, the diagnostic sensitivity of IgG-ELISA was 88.24%, and that of IgE-ELISA was 47.06%, while the sensitivity of IgM-ELISA was only 11.76%. It was suggested from the data that IgM-ELISA is a helpful indicator of infection within three years. Other two groups of trichinosis cases, i.e., high-titer and seroconversion cases, were also studied. Antibody response curves were constructed from mean ELISA values from each group. It was revealed that all curves were similar in shape, independent of the group studied. The only exception was IgG-antibody response in the high-titer group, which showed the highest antibody level at the first collection of blood samples, i.e., 23 days after infection.

A modified agar plate method for detection of Strongyloides stercoralis.

The agar plate method is a new technique with high detection rates for coprological diagnosis of human strongyloidiasis. This report details modifications of the technique and establishes a standardized procedure. We recommend that all plates should be carefully observed using a microscope because macroscopic observation can lead to false negative results. It is also advisable to pour formalin solution directly into microscopically positive dishes to collect worms by sedimentation. This procedure enables one to observe worms otherwise hidden. Sealing dishes with adhesive tape prevents larvae from crawling out of the dishes, eliminating any possibility in the reduction of detection rates, and greatly improves the safety conditions for the technician performing the procedure. We consider the agar plate method to be superior to the filter paper method in detecting Strongyloides, and we believe that it will eventually become the technique of choice.

Bancroftian filariasis in Tambol Na-Sai, Amphoe Li, Lamphun Province: a preliminary survey for microfilaraemia.

A preliminary survey for Bancroftian filariasis in villagers of Ban Prabat Heuy Tom, Tambol Na-Sai, Amphoe Li, Lamphun Province was performed between July 12, 1986 and March 19, 1987. A total of 1,435 villagers comprising 668 females and 767 males were examined for microfilaraemia in peripheral blood. Microfilariae were found in five males of which two cases were found to have developed hydrocele at a lesser degree and all of them had formerly resided in an endemic area of Tak Province. Microfilarial periodicity was studied in two cases, and it was shown to be nocturnally subperiodic.

The relative importance of various enteropathogens as a cause of diarrhoea in hospitalized children in Chiang Mai, Thailand.

PIP: A study of 208 children aged under 15 hospitalized with diarrhea and 108 matched controls was conducted at Chiang Mai University Hospital, Chiang Mai, Thailand from May 1983 to April 1984 to investigate the incidence, seasonal distribution, and causative agents of diarrhea. 1 or more enteropathogens were isolated from 121 (58%) diarrhea patients and from 32 (30%) controls. In diarrhea patients, Shigella spp. were most frequently isolated (22%) followed by enteropathogenic Escherichia coli (EPEC) (20%), rotavirus (18%), Campylobacter jejuni (7%), Salmonella (4%), Aeromonas (1%) and Plesiomonas shigelloides (1%). No Yersinia enterocolitica were found. Pathogens such as Norwalk agent, adenovirus, and enterotoxigenic E. coli (ETEC) were not sought. A concurrent study revealed ETEC in 3.2% of diarrheal children and 1.5% of controls. Parasites were identified in 11% of diarrhea patients; Giardia lamblia was most commonly found. In 32% of positive diarrhea and 19% of positive control cases more than 1 pathogen was isolated. Shigella was the least involved in cases with multiple infections. Only Shigella and rotavirus were found significantly more often in diarrhea cases than controls and their relation with age, season, and clinical presentation are reported. A high incidence of EPEC among control patients suggests common asymptomatic carriage. 2 diarrhea peaks occurred in the hot and cold seasons; the peak of Shigella diarrhea occurs in the summer, and may be related to the shortage of water at this time of year. Both shigellosis and rotavirus diarrhea patients had an acute onset of symptoms: cramps, convulsions, mucoid and bloody stools with high numbers of white and red blood cells were signficantly more common in shigellosis patients.^ieng