Risk factors for Cryptosporidiosis in United Kingdom.

Our results confirm previous reports of a high rate of relapse of gastrointestinal symptoms following recovery from an acute episode of cryptosporidiosis and show that C. hominis but not C. parvum is associated with an increased risk of nonintestinal sequelae. This study demonstrates that the impact of cryptosporidiosis on public health extends beyond that of the acute diarrheal illness and can lead to significant health sequelae.

Cataracts were the most common finding, present in 64% of Macaroni Penguins, and 68% of Rockhopper Penguins. There were anterior segment anomalies in all eyes with cataracts consistent with lens-induced uveitis. The mean modified PTT for the Macaronis was 24.7 ± 6.37 mm/15 s and 25.1 ± 7.07 mm/15 s in the Rockhoppers. The mean STT value for the Macaronis was 12.1 ± 5.43 mm/min and 11.0 ± 3.96 mm/min in the Rockhoppers. Mean intraocular pressure (IOP) for the Macaronis was 21.9 ± 7.05 mmHg measured by applanation tonometry and 29.1 ± 7.16 mmHg using rebound tonometry. The Rockhoppers had a mean IOP of 20.0 ± 5.77 mmHg and 24.1 ± 5.09 mmHg for applanation and rebound tonometry, respectively. In both populations, there was a significant difference in IOP measurement between the two instruments. In the Macaroni penguins, the presence of cataracts correlated significantly with increased age and lower IOP readings. Anterior chamber distance and axial globe length were significantly greater in males than in females in both penguin species.

Complete ophthalmic examinations were performed on 160 Macaroni penguins ( Eudyptes chrysolophus ) and 90 Rockhopper penguins ( Eudyptes chrysocome ) at eight North American zoological institutions. Cataract prevalence in the Macaroni population was 46.5% (n = 74) of penguins and 42.3% (135/319) of eyes. Cataract prevalence in the Rockhopper population was 45.5% (n = 40) of penguins and 40.6% (73/180) of eyes. The mean age of Macaroni penguins without ocular disease was 7.4 ± 5.8 yr, while that of Rockhoppers was 9.8 ± 6.4 yr. Risk factors for cataract were examined through husbandry surveys completed by each institution and by evaluation of light intensity and ultraviolet (UV) light measurements acquired in each penguin exhibit. Risk factors associated with cataract in Macaroni penguins included age, dietary smelt, hand-feeding, and fluorescent exhibit lighting. Risk factors associated with cataract in Rockhopper penguins included age, dietary capelin, increasing population density, and increasing length of minimum photoperiod. Factors associated with decreased odds of cataract in Macaroni penguins included saltwater pool, monitoring of water quality for salinity, pH, and alkalinity; use of water additives; presence of pool filtration and sterilization systems; use of metal halide lightbulbs; increasing light intensity; and UV spectrum lighting. Factors associated with decreased odds of cataract in Rockhoppers included dietary herring and krill, increasing exhibit land area, pool temperature monitoring, increasing maximum photoperiod, and increasing minimum UV light.

During 2001, a large outbreak of foot and mouth disease occurred in the United Kingdom, during which approximately 2,030 confirmed cases of the disease were reported, >6 million animals were slaughtered, and strict restrictions on access to the countryside were imposed. We report a dramatic decline in the reported incidence of human cryptosporidiosis in northwest England during weeks 13–38 in 2001, compared with the previous 11 years. This decline coincided with the period of foot and mouth restrictions. No similar reduction occurred in the other 26 weeks of the year. We also noted a substantial decline in the proportion of human infections caused by the bovine strain (genotype 2) of Cryptosporidium parvum during weeks 13–38 that year but not during the other weeks.