Cryptosporidiosis 2003

Table 1. Cryptosporidiosis Cases by Race and Sex, Indiana, 2003

  2003 1999-2003
Cases Rate* Cases
Total 126 2.00 409
Race
   White 108 2.00 295
   Black 3 0.60 18
   Other 5 3.10 15
   Not Reported 10 - 81
Sex
   Male 59 1.90 188
   Female 67 2.10 217
   Not Reported 0 - 4

*Rate per 100,000 population based on the U.S. Census Bureau’s population data as of July 1, 2003

Cryptosporidiosis is a parasitic infection usually transmitted by fecal-oral contact, most commonly through contaminated water. Other routes of transmission include foodborne, person to person, and animal to person. Outbreaks have been associated with contaminated drinking water, recreational water venues, consumption of unpasteurized apple cider, and daycare centers. Populations at most risk of developing severe infection include young children, the elderly, and those with weakened immune systems.

In 2003, 126 cases of cryptosporidiosis were reported in Indiana, for a rate of 2.0 cases per 100,000 population. This represents a marked increase from 2002 and surpasses the total number of cases reported in 2001. Figure 1 shows the number of reported cases each year for 1999-2003. Disease incidence was greatest during the summer and fall months (Figure 2). As shown in Figure 3, age-specific rates were greatest for preschoolers aged 1-4 years (6.1), followed by adults aged 80 years or older (4.2), and children aged 5-9 years (3.0). Females (2.1) were slightly more likely to be reported than males (1.9). The rate for other races (3.1) was higher than that for whites (2.0) and blacks (0.6); however, 10 cases (8%) did not report race data.

The incidence rates were highest among the following counties reporting five or more cases:
Porter (33.2), LaGrange (14.1), and Dubois (12.5). Figure 4 shows counties reporting five or more cases of cryptosporidiosis in 2003.

In 2003, the Porter County Health Department reported a historically high number of cases. In early 2004, the Centers for Disease Control and Prevention released information regarding a recall of a laboratory testing kit commonly used by hospitals and reference laboratories to test clinical specimens for Cryptosporidium. Certain kit lot numbers were yielding high numbers of false positive tests. The hospital laboratory that reported the majority of positive tests in Porter County had used a recalled kit lot number. Once those lot numbers were replaced, the number of positive laboratory tests generated from this hospital laboratory greatly decreased. There were no outbreaks of cryptosporidiosis reported in 2003.

You can learn more about cryptosporidiosis by visiting the following Web site:
http://www.cdc.gov/ncidod/dpd/parasites/cryptosporidiosis/factsht_cryptosporidiosis.htm.