Serological and epidemiological analysis of an outbreak of gastroenteritis among military recruits in Germany caused by Cryptosporidium parvum.

BACKGROUND: Cryptosporidium spp. cause enteritic disease worldwide. Besides those patients with an impaired immune system, the general population is also at risk. PATIENTS AND METHODS: Stool samples from participants of a military field exercise were tested for enteritic pathogens and sera were analyzed for Cryptosporidium-antibodies. All participants received a questionnaire for assessing possible risk factors. RESULTS: After a 5-day field training, 201 of a total of 450 soldiers (45%) developed acute gastroenteritis. Immediate microbiological analysis ruled out enteropathogenic bacteria and viruses as the cause of the disease. Only after hospitalization of one of the patients diagnostic procedures were expanded to the identification of parasites and Cryptosporidium parvum was identified. In addition, 14 fecal samples of 217 specimens were subsequently identified in a Cryptosporidium antigen ELISA. A serological analysis of 214 sera revealed 72% positive for specific IgG antibodies compared with 17% of a control group of soldiers who had not participated in the field training (relative risk 3.38; 95% CI 2.39-4.77; p < 0.001). Analysis of specific IgM levels was less conclusive. Epidemiological analysis of questionnaires correlated drinking of tap water, or consumption of various meals with gastroenteritis. However, the source of contamination could not be identified. CONCLUSION: Cryptosporidium spp. can cause acute enteritis even in healthy, young adults as demonstrated by this outbreak. Using serological methods, the extent of the outbreak could be estimated in a retrospective analysis.

Humoral immune response in IL-12 and IFN-gamma deficient mice after infection with Cryptosporidium parvum.

Infection with Cryptosporidium spp. causes diarrhoeal disease and has become an important medical and veterinary problem especially in the immunocompromised host. The importance of the adaptive immune response, with CD4+ T-lymphocytes being the major players, has been clearly demonstrated. The requirement of IL-12 and IFN-gamma identifies this response as a Th1-dominated reaction. IFN-gamma is also important in the early phase of the host-parasite interaction. We analysed the outcome of infection in IL-12p40 (IL-12KO) and IFN-gamma (GKO) deficient C57BL/6 mice after primary and secondary challenge with the parasite and, for the first time, we demonstrate the resulting Ig response in sera and vaginal lavages. Although showing differences in the extent and the time course both strains of mice were able to clear infection and developed an almost complete resistance to re-infection. While GKO mice mounted prolonged parasite-specific IgG and IgA responses after primary infection, in IL-12KO mice IgG and IgA titres dropped over time. Re-challenge of mice 5 weeks after primary infection led to a booster effect in Ig response despite the absence of oocyst shedding. The data from infection and re-challenge experiments suggest that in IL-12- or IFN-gamma-deficient mice the development of resistance involves other protective immune responses.

[Clinical presentation and management of the severe acute respiratory syndrome (SARS)]. / Klinik und Behandlung des schweren akuten respiratorischen Syndroms.

BACKGROUND AND OBJECTIVE: In February 2003, a newly emerged infectious disease was described, the etiology of which was initially unknown. It is referred to under the term SARS. In the beginning, it spread in some regions South-East Asia. Import infections appeared in many other parts of the world. Based on the first cases in Germany, this report illustrates the clinical appearance, the diagnostic results and the management of this new disease. PATIENTS AND METHODS: We analysed the data of two patients with SARS and one suspected patient. The results of radiological, laboratory, microbiological and physical examinations were abstracted and compared with the data obtained in other regions. RESULTS: Two of the three patients under our care developed SARS disease. This is characterised by fever of sudden onset lasting for more than 5 days, rapidly changing consolidations in chest x-ray not affected by antimicrobial therapy, leuko-, lympho- as well as thrombopenia with a compromised pulmonary function later in the course. Close contacts with SARS patients does not regularly result in full development of the disease. Secretion of a coronavirus could be detected in respiratory samples during the febrile phase and in feces for a longer time. It is still an open question whether bedrest and antibiotic prophylaxis by themselves or an additional administration of ribavirin and corticosteroids can improve the outcome. CONCLUSION: SARS is a new and highly contagious lung disease. It is crucial to be able to recognize the clinical appearance and the diagnostic features of this disease at an early stage, in order to prevent a further dissemination of the disease.