1416. Molecular Epidemiology of Cryptosporidiosis — Idaho, 2012–2015
Session: Poster Abstract Session: Public Health
Friday, October 28, 2016
Room: Poster Hall
  • Molecular Epidemiology Poster.pdf (293.0 kB)
  • Background: During 2006–2012, Idaho cryptosporidiosis incidence rates (2.8–38.9/100,000 persons) were consistently higher than U.S. rates (2.1–3.7/100,000 persons). Because Cryptosporidium species are morphologically indistinguishable by traditional laboratory tests, molecular testing for species and subtype might help differentiate zoonotic from human sources and identify outbreaks. We explored molecular epidemiology of cryptosporidiosis in Idaho.

    Methods: We analyzed surveillance and laboratory records of cryptosporidiosis cases reported to Idaho Department of Health and Welfare during September 2012–August 2015. Available stool specimens from laboratory-confirmed cases were submitted to CDC’s CryptoNet for molecular testing using polymerase chain reaction-based restriction fragment length polymorphism analysis of the small ribosomal subunit RNA, and DNA sequencing of 60-kDa glycoprotein. We explored molecular profile of Cryptosporidium, and examined characteristics of sporadic cases by molecular profile.

    Results: Among 429 reported cryptosporidiosis cases, ≥2 potential exposures were suspected in 134 (31%); transmission mode was indeterminate in 305 (71%). Among 38 stool specimens tested, we detected 2 subtype families (Ib and If) of C. hominis in 8 (21%), and 1 subtype family (IIa) of C. parvum in 30 (79%), of which subtype A16G3R1 was detected in 17 (57%) and was present in 9 of 12 outbreak-associated cases. In sporadic cases, persons with C. parvum (n = 20) and C. hominis (n = 6) had varying characteristics, respectively, as follows: female (70% and 83%), Hispanic (15% and 0%), illness onset in summer (50% and 33%), child care association (5% and 33%), and private well exposure (30% and 17%).

    Conclusion: The cryptosporidiosis molecular profile in Idaho appears to be dominated by C. parvum. Increased molecular surveillance has potential to disentangle person-to-person, animal-to-person, waterborne, and foodborne Cryptosporidium transmission routes.

    Ahmed Kassem, MBBCh, MPH, PhD1, Kris Carter, DVM, MPVM2, Amanda Bruesch, MS2 and Dawn Roellig, MS, PhD3, (1)Centers for Disease Control and Prevention, Boise, ID, (2)Idaho Department of Health and Welfare, Boise, ID, (3)Centers for Disease Control and Prevention, Atlanta, GA


    A. Kassem, None

    K. Carter, None

    A. Bruesch, None

    D. Roellig, None

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