Epidemiology and Infection

Original Papers

Gastroenteritis

Molecular epidemiology and clinical manifestations of human cryptosporidiosis in Sweden

M. INSULANDERa1, C. SILVERLÅSa2, M. LEBBADa3, L. KARLSSONa4, J. G. MATTSSONa5 and B. SVENUNGSSONa6 c1

a1 Department of Communicable Disease Control and Prevention, Stockholm County, Sweden

a2 Department of Animal Health and Antimicrobial Strategies, National Veterinary Institute, Uppsala, Sweden

a3 Department of Diagnostics and Vaccinology, Swedish Institute for Communicable Disease Control, Solna, Sweden

a4 Department of Clinical Microbiology, Karolinska University Hospital, Stockholm, Sweden

a5 Department of Virology, Parasitology and Immunobiology, National Veterinary Institute and Swedish University of Agricultural Sciences, Uppsala, Sweden

a6 Department of Medicine, Unit of Infectious Diseases, Karolinska Institutet, Stockholm, Sweden

SUMMARY

This study describes the epidemiology and symptoms in 271 cryptosporidiosis patients in Stockholm County, Sweden. Species/genotypes were determined by polymerase chain reaction–restriction fragment-length polymorphism (PCR–RFLP) of the Cryptosporidium oocyst wall protein (COWP) and 18S rRNA genes. Species were C. parvum (n=111), C. hominis (n=65), C. meleagridis (n=11), C. felis (n=2), Cryptosporidium chipmunk genotype 1 (n=2), and a recently described species, C. viatorum (n=2). Analysis of the Gp60 gene revealed five C. hominis allele families (Ia, Ib, Id, Ie, If), and four C. parvum allele families (IIa, IIc, IId, IIe). Most C. parvum cases (51%) were infected in Sweden, as opposed to C. hominis cases (26%). Clinical manifestations differed slightly by species. Diarrhoea lasted longer in C. parvum cases compared to C. hominis and C. meleagridis cases. At follow-up 25–36 months after disease onset, 15% of the patients still reported intermittent diarrhoea. In four outbreaks and 13 family clusters, a single subtype was identified, indicating a common infection source, which emphasizes the value of genotyping for epidemiological investigations.

(Received January 23 2012)

(Revised June 19 2012)

(Accepted July 11 2012)

(Online publication August 09 2012)

Key words

  • Clinical manifestations;
  • cryptosporidiosis;
  • molecular epidemiology

Correspondence

c1 Author for correspondence: B. Svenungsson M.D., Ph.D., Associate Professor, Smittskydd Stockholm, Box 17533, 118 91 Stockholm, Sweden. (Email: bo.svenungsson@gmail.com)

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