Integration of Genomic and Other Epidemiologic Data to Investigate and Control a Cross-Institutional Outbreak of Streptococcus pyogenes.

Chalker VJ., Smith A., Al-Shahib A., Botchway S., Macdonald E., Daniel R., Phillips S., Platt S., Doumith M., Tewolde R., Coelho J., Jolley KA., Underwood A., McCarthy ND.

Single-strain outbreaks of Streptococcus pyogenes infections are common and often go undetected. In 2013, two clusters of invasive group A Streptococcus (iGAS) infection were identified in independent but closely located care homes in Oxfordshire, United Kingdom. Investigation included visits to each home, chart review, staff survey, microbiologic sampling, and genome sequencing. S. pyogenes emm type 1.0, the most common circulating type nationally, was identified from all cases yielding GAS isolates. A tailored whole-genome reference population comprising epidemiologically relevant contemporaneous isolates and published isolates was assembled. Data were analyzed independently using whole-genome multilocus sequencing and single-nucleotide polymorphism analyses. Six isolates from staff and residents of the homes formed a single cluster that was separated from the reference population by both analytical approaches. No further cases occurred after mass chemoprophylaxis and enhanced infection control. Our findings demonstrate the ability of 2 independent analytical approaches to enable robust conclusions from nonstandardized whole-genome analysis to support public health practice.

DOI

10.3201/eid2206.142050

Type

Journal article

Journal

Emerg Infect Dis

Publication Date

06/2016

Volume

22

Pages

973 - 980

Keywords

Group A Streptococcus, Streptococcus pyogenes, bacteria, epidemiologic data, genome, genomic data, iGAS, infection control, invasive group A streptococcal infection, investigation, outbreak, streptococci, whole-genome sequencing, Alleles, Computational Biology, Cross Infection, Disease Outbreaks, Drug Resistance, Bacterial, Genome, Bacterial, Genomics, Health Facilities, Humans, Phylogeny, Polymorphism, Single Nucleotide, Streptococcal Infections, Streptococcus pyogenes, United Kingdom, Virulence, Whole Genome Sequencing

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