This is the first report of an epidemic of human infection with Trichinella pseudospiralis. An outbreak of trichinellosis affecting 59 individuals, of whom one died, occurred in southern Thailand during 1994 -1995. The source of this epidemic was raw pork from a wild pig that was distributed to villagers by a local hunter. The most striking clinical features among 50 individuals who could be followed were muscular swelling, myalgia, and asthenia persisting for ú4 months. These were associated with significant elevations of creatine phosphokinase and lactate dehydrogenase levels. All patients had Trichinella-specific IgG antibodies in an enzyme-linked immunosorbent assay. Muscle biopsies, performed in six cases, showed nonencapsulated, actively migrating Trichinella larvae. Experimental infection of mice with larvae from human biopsies revealed nonencapsulated muscle larvae consistent with T. pseudospiralis. The identification of muscle larvae from a human specimen by random amplified polymorphic DNA analysis confirmed the causative agent to be T. pseudospiralis. Patients seemed to respond best to treatment with albendazole.

Preservation of Cryptosporidium oocysts in faecal specimens containing 75% ethanol is suitable for subsequent morphometric and molecular analysis. No significant morphologic alteration occurred after storage at ambient temperatures, ranging from 22 to 38 degrees C, for more than 2 years. After washing, sugar floatation and DNA extraction, a nested polymerase chain reaction targeting the small subunit ribosomal RNA gene successfully amplified Cryptosporidium DNA in all 15 isolates examined. The sensitivity of detection by polymerase chain reaction (PCR) was found to be as high as 1.25 oocysts per reaction (mean=3.01, SD=1.14). Importantly, a 2.2-kb of the complete DNA sequence of a gene encoding Cryptosporidium thrombospondin-related adhesive protein (TRAP-C1) was also consistently amplified by PCR in all isolates. The PCR-amplified product can be used as a good template for sequencing. Therefore, this simple procedure should be useful for epidemiological analysis of clinical samples from outbreaks, endemic or sporadic cases of cryptosporidiosis when long-term storage of oocysts is required.