title: Molecular characterization of human Cryptosporidium spp. isolates after an unusual increase in late summer 2012.
abstract: BACKGROUND
  During the late summer 2012, a number of medical microbiological laboratories (MMLs) reported an unusual increase in cases of cryptosporidiosis, a gastrointestinal infection caused by the protozoan parasites Cryptosporidium spp. Prompted by this signal, the National Institute of Public Health and the Environment (RIVM) started an epidemiological investigation into possible causes. Simultaneously, samples diagnosed at MMLs were sent to RIVM for genotyping, aiming to further identify the possible source of the increase.
  
  
  METHODS
  Genotyping was performed by sequencing a fragment of the GP60 gene. Additional genotyping was performed on a subset of samples using six microsatellite markers. Population genetic analysis was performed using BEAST.
  
  
  RESULTS
  The majority of the samples were typed as C. hominis, and a single GP60 genotype (IbA10G2) largely predominated. Genotyping microsatellite markers further supported the circulation of a single genetic type. Population genetic analysis with genotypes found in previous years is inconsistent with a decrease in effective population size.
  
  
  CONCLUSIONS
  The conclusion of this finding is that the rise reflects more an overall increase and not a common source outbreak.
authors.affiliation: Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands. jeroen.roelfsema@rivm.nl.
authors.forename: Jeroen H
authors.initials: JH
authors.lastname: Roelfsema
authors.affiliation: Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Hein
authors.initials: H
authors.lastname: Sprong
authors.affiliation: Department of Infectious, Parasitic and Immunomediated Diseases Istituto Superiore di Sanità, Rome, Italy.
authors.forename: Simone M
authors.initials: SM
authors.lastname: Cacciò
authors.affiliation: Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Takumi
authors.affiliation: Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Michiel
authors.initials: M
authors.lastname: Kroes
authors.affiliation: Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Wilfrid
authors.initials: W
authors.lastname: van Pelt
authors.affiliation: Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Laetitia M
authors.initials: LM
authors.lastname: Kortbeek
authors.affiliation: Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Joke W B
authors.initials: JW
authors.lastname: van der Giessen
mesh_terms: D003457:Cryptosporidiosis / Q000453:epidemiology* / Q000469:parasitology; D003458:Cryptosporidium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D014644:Genetic Variation; D005838:Genotype; D060005:Genotyping Techniques; D006801:Humans; D018895:Microsatellite Repeats; D015800:Protozoan Proteins / Q000235:genetics
chemical_list: D015800:Protozoan Proteins
keywords: Cryptosporidium; GP60; Gastroenteritis; Genotyping; Parasite; Population genetics