Cryptosporidium oocysts in stool specimens submitted to routine ova & parasite examination: 38 months survey.

The fecal samples submitted for routine ova and parasite examination in Children's Hospital, Bangkok, Thailand, between October 1984 and November 1987, were investigated for Cryptosporidial oocysts, indicated that the prevalence was 1.61 per cent. The infection played an important role in aetiology of gastroenteritis and/or diarrhea. Because the children, particularly those less than 2 years of age who had watery and non-bloody stools and accompanied with gastrointestinal symptoms were found to have Cryptosporidium oocysts, almost (84.31%) of the infected children were hospitalized. Suggestively, Cryptosporidiosis should be included in the diagnosis of diarrheal disease in children and diarrheal illness in immunocompetent patients. In this report, the source of infection and the route of transmission was not identified but 80.39 per cent of children with cryptosporidiosis children were admitted with primary diagnosis of diarrhea together with pneumonia. The medication was Furazolidone or the combination of Trimethoprime and Sulphamethoxazone.

In vitro studies on the sensitivity of local Entamoeba histolytica to anti-amoebic drugs.

The in vitro activity of drugs, namely dehydroemetine, ornidazole, metronidazole and tinidazole were determined against the locally isolated strains of E. histolytica in Thailand. The test was performed in liquid monophasic medium, i.e. liver marmite serum medium. In all, locally isolated strains from thirty hosts studied, the minimal inhibitory concentration (MIC) for dehydroemetine ranged from 0.125 to 1 microgram/ml, ornidazole ranged from 0.0625 to 0.25 microgram/ml, metronidazole ranged from 0.0625 to 0.125 microgram/ml, and tinidazole ranged from 0.0625 microgram/ml to 0.25 microgram/ml. The MIC of dehydroemetine was significantly different from ornidazole, metronidazole and tinidazole. Metronidazole was superior to that of dehydroemetine but was not significantly different among ornidazole, metronidazole and tinidazole.

Detection of antibodies in cats infected with filarial parasites by the indirect immunofluorescence technique.

The indirect immunofluorescence technique in cats infected with filarial parasites, Brugia malayi, B. pahangi and D. repens were studied. The antibody level in infected microfilaraemic cats was higher than that in infected amicrofilaraemic cats and uninfected cats. Papain-treated whole microfilariae appeared to be more sensitive than the sonicated antigen. The comparative IFA titres using papain-treated and sonicated microfilarial antigen, in the serodiagnosis of filariasis is presented.

In vivo and in vitro studies of tinidazole in Trichomonas vaginalis infection.

A total 787 patients with complaints of vaginal discharges were examined, of which 106 patients were found to be positive for Trichomonas vaginalis by the normal saline method, and 114 patients were positive by the culture method. In the in vivo series, 55 patients were treated with a single dose of 1.8 gm of tinidazole, and with a follow-up examination 7 days there after. For the in vitro study 55 swab specimens were cultured to study the tinidazole sensitivity of Trichomonas vaginalis. The survival of Trichomonas vaginalis at each concentration of tinidazole was presented as a cumulative frequency. At the concentration of 1 microgram/ml, none of the organisms were killed; but at the concentration of 6 micrograms/ml, the mortality rate was 100%. In the in vivo series a 100% cure rate was obtained with tinidazole with no side effects, and in vitro series the mean minimum trichomonicidal concentration (MCC) at 24 hours was 3.76 +/- 1.25 micrograms/ml, with the range of 2--6 micrograms/ml. These studies revealed the sensitivity of Trichomonas vaginalis to tinidazole in Thailand and that tinidazole at a single oral dose of 1.8 gm perferably after a meal is effective, safe and cheap for the treatment of Trichomonas vaginalis.

A study on the diagnostic methods for Trichomonas vaginalis infection.

A comparison of the sensitivity of the wet smear, Papanicolaou's stained smear, and culture in Cystein-Peptone-Liver-Maltose (CPLM) medium for the diagnosis of T. vaginalis infection was undertaken in 1, 197 female subjects, both with and without gynaecological disorders. The wet smear method gave 15.5% positives, culture method, 16.5% positives and Papanicolaou's stained smear 6.7% positives. All positive cases by Papanicolaou's method or wet smear method were positive by the culture method. These findings indicate that the wet smear and culture in CPLM medium were better than the Papanicolaou's method.

In vivo and in vitro studies of quinine sensitivity of Plasmodium falciparum in Thailand.

Forty-four patients with falciparum malaria were studied. Nine patients were given quinine orally at a daily dose of 1.5 gm base for a period of 14 days. The mean parasite clearance in all 9 patients was 3.3 days, and none had recrudescence in follow-up examinations for 31 days. The in vivo study of these 9 patients showed sensitivity to quinine which correlated with the in vitro test, with concentration of quinine base 2.5-5.8 microgram/ml of blood that inhibited the maturation of Plasmodium falciparum parasites. The results of the in vitro test of 35 patients showed concentrations of quinine base 2.1-5.4 microgram/ml of blood were able to inhibit the maturation of P. falciparum parasites. Therefore, these studies indicate that Plasmodium falciparum are still sensitive to quinine and quinine remains to be the drug of choice for the treatment of falciparum malaria in Thailand.

Studies on coagulation and fibrinolysis in cases of Falciparum malaria.

Coagulation and fibrinolytic studies were conducted in 18 cases of severe falciparum malaria including cases with parasitaemia above 5% and with pernicious manifestations such as coma, jaundice, anuria, pulmonary oedema, bleeding tendency, etc., irrespective of parasitaemia. Marked changes in blood coagulograms and high levels of serum fibrin degradation products appeared only in cases with very severe cerebral involvement and also in cases with very high parasitaemia alone. These investigations indicated that intravascular coagulation occurs only in patients suffering from falciparum malaira who develop cerebral manifestations and in cases with high parasitaemia.