Subject(s)
Disease Outbreaks , Mumps/epidemiology , Adolescent , Adult , Competitive Behavior , Female , Humans , Middle Aged , Sports , Texas/epidemiology , Young AdultABSTRACT
BACKGROUND: A second dose of varicella vaccine was recommended for U.S. children in 2006. We investigated a suspected varicella outbreak in School District X, Texas to determine 2-dose varicella vaccine effectiveness (VE). METHODS: A varicella case was defined as an illness with maculopapulovesicular rash without other explanation with onset during April 1-June 10, 2011, in a School District X student. We conducted a retrospective cohort in the two schools with the majority of cases. Lesion, saliva, and environmental specimens were collected for varicella-zoster virus (VZV) PCR testing. VE was calculated using historic attack rates among unvaccinated. RESULTS: In School District X, 82 varicella cases were reported, including 60 from Schools A and B. All cases were mild, with a median of 14 lesions. All 10 clinical specimens and 58 environmental samples tested negative for VZV. Two-dose varicella vaccination coverage was 66.4% in Schools A and B. Varicella VE in affected classrooms was 80.9% (95% CI: 67.2-88.9) among 1-dose vaccinees and 94.7% (95% CI: 89.2-97.4) among 2-dose vaccinees in School A, with a second dose incremental VE of 72.1% (95% CI: 39.0-87.3). Varicella VE among School B students did not differ significantly by dose (80.1% vs. 84.2% among 1-dose and 2-dose vaccinees, respectively). CONCLUSION: Laboratory testing could not confirm varicella as the etiology of this outbreak; clinical and epidemiologic data suggests varicella as the likely cause. Better diagnostics are needed for diagnosis of varicella in vaccinated individuals so that appropriate outbreak control measures can be implemented.
Subject(s)
Chickenpox Vaccine/administration & dosage , Chickenpox Vaccine/immunology , Chickenpox/diagnosis , Chickenpox/epidemiology , Disease Outbreaks , Adolescent , Chickenpox/pathology , Child , Child, Preschool , Clinical Medicine/methods , Environmental Microbiology , Female , Herpesvirus 3, Human/isolation & purification , Humans , Male , Molecular Diagnostic Techniques/methods , Polymerase Chain Reaction/methods , Retrospective Studies , Saliva/virology , Skin/virology , Texas/epidemiologyABSTRACT
BACKGROUND: Shigella outbreaks often continue for months and are linked frequently to poor hygiene and hand washing. Such outbreaks are found often in day care facilities, but rarely are reported in schools. We present the investigation of an outbreak in autumn 2007 at a building that housed an elementary school and a middle school in separate wings in a small Texas city north of Dallas-Fort Worth. METHODS: We canvassed local hospitals, school attendance records, and physician offices for cases. Ill individuals were interviewed using a standard questionnaire for symptoms, disease onset, and the presence of the illness in an ill person's household. RESULTS: A music teacher was the index case for this outbreak of gastrointestinal illness caused by S. sonnei. Ten percent of the students in the school building were ill, and 15 households had secondary cases. Installing liquid soap in dispensers in student restrooms was the initial control measure, followed by sustained instruction in hand washing, scheduled hand washing times, and monitored cleaning and disinfection procedures for surfaces and inanimate objects. Enhanced surveillance detected no new cases in the school district. CONCLUSIONS: Appropriate soap supplies and repeated instruction in hand washing and its monitoring were needed to control the outbreak.
