The natural history of cryptosporidiosis was investigated during a waterborne outbreak among 1731 members of a drug rehabilitation community in Italy; 19.6% of the members were positive for human immunodeficiency virus (HIV). Demographic and clinical information and pre-outbreak serum samples were available. Clinical data were analyzed, stratifying the study population by HIV serostatus and CD4 cell count. The attack rate of clinical cryptosporidiosis was 13.6% among HIV-negative individuals and 30.7% among HIV-positive individuals, although in the latter, it varied according to CD4 cell count. Clinical symptoms and their duration were also related to CD4 cell count. Chronic symptoms were observed in only 16 individuals (15.4%), who all had <150 CD4 cells at the onset of the illness. Among a systematic sample of 198 individuals, 14.1% already had anti-Cryptosporidium antibodies before the outbreak, and 51.2% developed specific antibodies during the outbreak. The development and clinical manifestations of cryptosporidiosis were strongly influenced by the level of HIV-induced immunosuppression.

Trichinella spiralis larvae infective for laboratory mice were collected from muscle biopsies performed at different times (from 1 day to 16 months) following the end of treatment, indicating the failure of mebendazole to kill Trichinella parasites when they are encapsulating in muscles.

No abstract

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.