Diarrheal disease in Cambodian children at a camp in Thailand

The etiology of acute diarrhea (less than or equal to 3 days duration) and persistent diarrhea (greater than or equal to 14 days duration) was determined in Cambodian children under age 5 years in a refugee camp on the Thai-Cambodian border between May and October 1989; potential risk factors associated with persistent diarrhea were examined in an age-matched case-control study. Specimens collected from children and environmental sources were examined by standard microbiologic methods; Escherichia coli isolates were examined for hybridization with specific DNA probes and in tissue culture adherence assays. The same bacterial, viral, or parasitic agents were identified in 79 children with persistent diarrhea and in 408 children with acute diarrhea. Only one of nine children with persistent diarrhea excreted the same organism, Cryptosporidium, for that extended period. The most important risk factors identified for developing persistent diarrhea were living with other young children (odds ratio (OR) = 2.0, 95% confidence interval (Cl) 1.2-3.4) and being undernourished (OR = 2.6, 95% Cl 1.2-5.7). Persistent diarrhea in children in this camp was associated with several different agents rather than persistent infections with a single organism.

Amebiasis at an evacuation site on the Thai-Cambodian border

Symptomatic intestinal amebiasis was highly endemic among the Cambodians living at Green Hill, an evacuation site on the Thai-Cambodian border between June 1987 through May 1989. Monthly incidence rates of intestinal amebiasis were determined to be inversely proportional to cumulative monthly rainfall. The highest incidence of amebic dysentery was 63/1000 in children 12-23 months old. Behavioral risk factors were investigated by conducting a case-control study. A questionnaire was administered to 73 families, each having at least one member with confirmed intestinal amebiasis within the past 3 months, and to 95 randomly selected control families having no individual with diarrhea for at least 3 months. Individuals from families with greater than 4 members were at higher risk for acquiring intestinal amebiasis. No significant differences in behavioral risk factors were identified between case and control families. Eighty-six percent of 51 water samples drawn from wells where amebiasis patients obtained their drinking water had greater than 10 coliforms/100 ml. The main route of transmission of E. histolytica was not identified, but was most likely via the fecal-oral route.

Microscopic examination of stools and a latex slide agglutination test for the rapid identification of bacterial enteric infections in Khmer children

Eighty-five stools collected from 50 children with diarrhea at an evacuation site on the Thai-Kampuchean border were (1) examined microscopically for fecal leukocytes, (2) tested after 24 hr enrichment in brain/heart infusion broth by a latex slide agglutination test for detection of Salmonella and Shigella, and (3) examined with microbiological techniques to identify bacterial, viral, and parasitic pathogens. If the 65 specimens in which one or no pathogens are considered, 6 or more fecal leukocytes/hpf were found on microscopic examination of stools in both children infected with Shigella spp., the one child infected with Salmonella spp., and three of eight children infected with Campylobacter spp. Less than or equal to 5 leukocytes/hpf were found in 70% (7/10) of children infected with rotavirus, 100% (2/2) infected with Cryptosporidium, 100% (2/2) infected with Giardia, 89% (8/9) infected with enterotoxigenic Escherichia coli, and 77% (24/31) with diarrhea in whom no etiologic agent was identified. The Salmonella slide latex test had a sensitivity of 50%, a specificity of 92%, and a positive predictive value of 12%. The Shigella slide latex test had a sensitivity of 0%, a specificity of 95%, and a positive predictive value of 0%. Forty-five percent of the latex slide agglutination tests from enrichment cultures were nonspecific. Microscopic examination of diarrheal stools for fecal leukocytes, though nonspecific, appears to be the best way to differentiate Shigella spp. from rotavirus and parasitic infections. Examining stools for fecal leukocytes was less helpful in differentiating Shigella from other bacterial infections.

Treatment of falciparum malaria with quinne and tetracycline or combined mefloquine/sulfadoxine/pyrimethamine on the Thai-Kampuchean border

Three different regimens were compared for treatment of falciparum malaria in displaced Kampucheans living in encampments on the Thai-Kampuchean border in 1983: single dose 750 mg mefloquine, 1.5 g sulfadoxine, 75 mg pyrimethamine (MSP); 600 mg quinine 8-hourly for 3 days and 500 mg tetracycline 8-hourly for 7 days (Q3T7); or 600 mg quinine 8-hourly for 7 days and 500 mg tetracycline 8-hourly for 7 days (Q7T7). Radical cure rates were 98% (40/41) for MSP, 76% (32/42) for Q3T7 and 92% (33/36) for Q7T7. The criterion for treatment failure was reappearance of parasites by 35 days after commencement of treatment or no parasite clearance. Treatment failures comprised one case of reduction but no clearance of parasites (RII resistance) for MSP, 10 recrudescences (RI) for Q3T7 and 3 recrudescences (RI) for Q7T7. The radical cure rate for Q3T7 was significantly lower than that for MSP (P less than 0.01), whilst Q7T7 significantly from the other groups. Parasite clearance time was shorter (2.4 days) with MSP than with Q3T7 (3.5 days) and Q7T7 (3.3 days). There was little difference in side effects between the regimens, and tolerance was good. The MSP and Q7T7 regimens are both effective for treatment, but the single dose of MSP is much easier to manage than 7 days of quinine and tetracycline.