A new rapid immunochromatographic test for malaria diagnosis, Determine^™ Malaria Pf, was evaluated. This diagnostic kit is an antigen capture assay based on the detection of histidine-rich protein 2 (HRP-2) of Plasmodium falciparum. Positive test results are read visually, with the formation of red bands within 30 min. 438 patient samples were tested from malaria endemic areas in Palawan, Philippines and non-endemic areas, the Research Institute for Tropical Medicine in Metro Manila and the Komagome Hospital and Keio University Hospital in Tokyo. Of 136 malaria samples, 101 was P. falciparum, 33 P. vivax and 2 mixed infection. There were 302 other diseases, 26 of infectious nature, 201 non-infectious, and 75 working normals. Using microscopy as the gold standard, . sensitivity for Determine^™ Malaria Pf, ICT Malaria P.f ^™ and ParaSight^™ F was 100%, 99% and 100%, respectively, and specificity was 96.7%, 99.1%, and 93.4%, respectively. The positive predictive value for Determine^™ Malaria Pf was 90.4%, 97.1% for ICT Malaria P.f^™ and 82.4% for ParaSight^™ F. The negative predictive value was 100% for Determine^™ Malaria Pf, 99.7% for ICT Malaria P.f^™ and 100% for ParaSight^™ F. Determine^™ Malaria Pf had an analytical sensitivity for Parasite detection as low as 30-50 Parasites/μl. Antigenemia was seen to persist until about9 days in patients treated with the second line drug sulfadoxine-pyrimethamine (Fansidar ^®) despite a negative blood film. It was longer in chloroquine-treated patients, 14-21 days, only to give a strong positive signal on the day some patients recrudesce, also with a positive blood film. Following of HRP-2 antigen clearance might be used to predict early treatment failures or drug resistance. Determine^™ Malaria Pf is a very simple 2-step rapid and convenient procedure with excellent sensitivity and specificity. Its marked simplicity and reliability makes it ideal for field use where remote health centers are minimally equipped and staffed, and malaria diagnosis urgently needed.

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The variation of Paraguayan Trypanosoma cruzi isolates was examined using the unweighted pair group method analysis (UPGMA) based on the resulting matrix of the Dice similarity coefficients of random amplified polymorphic DNA (RAPD) profiles. These isolates were also compared with the established strains isolated from Brazil, Chile and Colombia in South America. Of 9 Paraguayan isolates, 3 isolates were similar to the Berenice, Y and Sao Felipe strains (zymodeme type; Brazilian Z2), respectively, isolated from Brazil, and 4 strains were similar to the Tulahuen strain from Chile. There was no isolate similar to the Colombiana I strain (Z1) from Colombia.

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In order to increase our knowledge of the epidemiology for our patient population, we retrospectively analyzed the data obtained from stool samples received at Tropical Disease Research Center, Airlangga University during a five year period. Isolation frequency of enteropathogens from diarrheal stools from 1993 to 1997 were examined in Surabaya, Indonesia. A total of 1, 477 hospitalized pediatric patients under 2 years of age with acute diarrhea were enrolled. Bacterial enteropathogens other than Campylobacter jejuni and Clostridium difficile were positive cumulatively in 1, 086 cases out of 1, 477 (73.5%), and the annual isolation frequency ranged from 61.1% to 82.4%. Rotavirus was detected cumulatively in 408 cases out of 1, 184 examined (34.5%), and 210 cases of 408 (51.5%) were co-infected with diarrheagenic Escherichia coli. Generally, diarrheagenic E. coli were dominant isolates (53.8%) while Vibrio cholerae Ol, Aeromonas hydrophila, Salmonella spp. and Shigella spp. were also isolated from the patients with lower frequencies.

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