Prevalence of Cryptosporidium spp. and Giardia spp. in five marine mammal species.

Cryptosporidium spp. and Giardia spp. are protozoan parasites that are often associated with severe diarrheal disease in a variety of mammals. Although these parasites have been extensively studied in terrestrial ecosystems, little is known about either parasite in the marine environment. Therefore, the objective of this study was to determine the prevalence of both Cryptosporidium spp. and Giardia spp. in 5 marine mammal species. Fecal samples were collected from 39 bowhead whales (Balaena mysticetus), 49 North Atlantic right whales (Eubalaena glacialis), 31 ringed seals (Phoca hispida), 22 bearded seals (Erignathus barbatus), and 18 beluga whales (Delphinapterus leucas) between 1998 and 2003. Using an immunofluorescent assay, parasites were detected in the feces of bowhead whales, right whales, and ringed seals, while neither parasite was detected in samples from bearded seals or beluga whales. Overall, prevalences were highest in ringed seals (Cryptosporidium spp., 22.6%; Giardia spp., 64.5%) and right whales (Cryptosporidium spp., 24.5%; Giardia spp., 71.4%) and lowest in bowhead whales (Cryptosporidium spp., 5.1%; Giardia spp., 33.3%). To our knowledge, this is the first report of Cryptosporidium spp. and Giardia spp. in either whale species and of Cryptosporidium spp. in the ringed seal.

Campylobacter-induced enteritis and diarrhea in captive cotton-top tamarins (Saguinus oedipus) during the first year of life.

A prospective study of 43 cotton-top tamarins, from infancy to 6 to 17 months of age, was conducted to determine the epidemiology of Campylobacter spp. infection. Nine infants followed for one year in an isolation unit, where attendants wore protective clothing, did not become infected. In the main facility where 32 of 34 animals had repeated infections with C. coli, 6% of the infections developed initially in incubators, 66% in the nursery room, and 28% after transfer to the main colony. Fifteen of these tamarins also were infected with C. jejuni. Twenty percent of the infections developed initially in the nursery room and 80% in the colony. Polyacrylamide gel electrophoresis analysis of C. jejuni cultures revealed multiple reinfections with different strains. Both types of infections were most prevalent between 3 and 9 months of age. Campylobacterjejuni infection developed most frequently between April and June and C. coli infection developed between October and December. In the nursery, diarrhea developed most frequently at times when there was no infection with Campylobacter spp. Forty percent of animals with diarrhea in the nursery had C. coli and none had C. jejuni, whereas, in the colony, 49% had C. jejuni and 11% had C. coli infections. There was no association between these infections and diet or idiopathic colitis.

A review of chemically-induced alterations in thyroid and vitamin A status from field studies of wildlife and fish.

This paper reviews 22 published field studies that have found an association between exposure to environmental contaminants and alterations in thyroid gland structure, circulating thyroid hormones and vitamin A (retinoid) status in free-ranging populations of wildlife and fish. Vitamin A and thyroid hormones play critical roles during development, growth and function 'throughout life. Studies of captive wildlife and laboratory studies support a relationship between alterations in thyroid hormones and vitamin A status and exposure to dioxins, furans, and planar polychlorinated biphenyls, which bind to the aryl hydrocarbon receptor. Some studies have found adverse health effects in wildlife associated with exposure to polyhalogenated aromatic hydrocarbons and altered thyroid and retinoid status including: decreased reproductive success, immune system changes, dermatologic abnormalities and developmental deformities. A direct causal relationship between these effects and thyroid and retinoid changes has not been demonstrated. Field researchers studying the responses to these synthetic chemicals in wildlife and fish should include measurement of thyroid hormones and retinoids and histological examination of the thyroid gland in their study design as biomarkers of exposure to these chemicals in the environment.

Antibiotic-resistant bacteria in wild primates: increased prevalence in baboons feeding on human refuse.

We examined three groups of wild baboons (Papio cynocephalus) in Amboseli National Park, Kenya, to determine the prevalence of aerobic antibiotic-resistant fecal bacteria in nonhuman primates with and without contact with human refuse. Using standard isolation and replica plating techniques, we found only low numbers of antibiotic-resistant gram-negative enteric bacteria in two groups of baboons leading an undisturbed existence in their natural habitat and having limited or no contact with humans. However, resistance was significantly higher among enteric bacteria from the third group of baboons living in close proximity to a tourist lodge and having daily contact with unprocessed human refuse. Conjugation studies and analysis of the cell DNA by gel electrophoresis showed that in many cases resistance was plasmid-borne and transferable. These data suggest that wild nonhuman primates in frequent contact with human debris have a higher proportion of antibiotic-resistant enteric bacteria than do conspecifics without this contact. The findings further suggest that such groups of wild animals may constitute a heretofore overlooked source of antibiotic resistance in the natural environment.

Five spontaneous deaths associated with Clostridium difficile in a colony of cotton-top tamarins (Saguinus oedipus).

Clostridium difficile toxin was detected in the feces of five cotton-top tamarins (Saguinus oedipus) that died spontaneously over a period of 10 weeks. Deaths occurred subsequent to antibiotic therapy for infectious diarrhea associated with Campylobacter spp. Relevant clinical signs of disease prior to death included weight loss, watery diarrhea, hematochezia, weakness, and sudden collapse. On histologic examination of the colon at necropsy, pseudomembranous colitis was evident in two cases, a lesion consistent with C. difficile lesions in humans. This finding prompted submission of feces for C. difficile toxin analysis from these five cases. Four of the tamarins were from a single room, and the fifth was housed nearby. The proximity of the cases raises the possibility of environmental contamination by resistant C. difficile spores or fecal spread of the organism as reported in hospitals, day-care centers, and nurseries. The relative importance of C. difficile and its potential role as an unrecognized cause of enteric disease secondary to antibiotic therapy in nonhuman primates is discussed.