Mumps Outbreak in a Marshallese Community - Denver Metropolitan Area, Colorado, 2016-2017.

In January 2017, the Colorado Department of Public Health and Environment (CDPHE) identified four epidemiologically linked cases of mumps among persons from a Marshallese community who were members of the same church in the Denver metropolitan area. During 2016-2017, sizable outbreaks of mumps reported in Arkansas, Hawaii, and Washington also affected the Marshallese population (1). CDPHE, the Tri-County Health Department (TCHD), and Denver Public Health collaborated to conduct an outbreak investigation during January-March 2017 using active and passive surveillance that identified 17 confirmed and 30 probable cases. Public health actions included conducting measles-mumps-rubella (MMR) vaccination clinics at local Marshallese churches; these resulted in the vaccination of 126 persons with ≥1 doses of MMR vaccine. Implementation of active surveillance and support from local Marshallese church leaders in promoting vaccination programs likely contributed to interruption of the outbreak.

Public Health Economic Burden Associated with Two Single Measles Case Investigations - Colorado, 2016-2017.

During July 2016-January 2017, two unrelated measles cases were identified in the Denver, Colorado area after patients traveled to countries with endemic measles transmission. Each case resulted in multiple exposures at health care facilities and public venues, and activated an immediate and complex response by local and state public health agencies, with activities led by the Tri-County Health Department (TCHD), which serves Adams, Arapahoe, and Douglas counties. To track the economic burden associated with investigating and responding to single measles cases, personnel hours and supply costs incurred during each investigation were tracked prospectively. No secondary cases of measles were identified in either investigation. Postexposure prophylaxis (PEP) was administered to 31 contacts involving the first case; no contacts of the second case were eligible for PEP because of a delay in diagnosing measles disease. Public health costs of disease investigation in the first and second case were estimated at $49,769 and $18,423, respectively. Single measles cases prompted coordinated public health action and were costly and resource-intensive for local public health agencies.

Outbreak of Human Pneumonic Plague with Dog-to-Human and Possible Human-to-Human Transmission--Colorado, June-July 2014.

On July 8, 2014, the Colorado Department of Public Health and Environment (CDPHE) laboratory identified Yersinia pestis, the bacterium that causes plague, in a blood specimen collected from a man (patient A) hospitalized with pneumonia. The organism had been previously misidentified as Pseudomonas luteola by an automated system in the hospital laboratory. An investigation led by Tri-County Health Department (TCHD) revealed that patient A's dog had died recently with hemoptysis. Three other persons who had contact with the dog, one of whom also had contact with patient A, were ill with fever and respiratory symptoms, including two with radiographic evidence of pneumonia. Specimens from the dog and all three human contacts yielded evidence of acute Y. pestis infection. One of the pneumonia cases might have resulted through human-to-human transmission from patient A, which would be the first such event reported in the United States since 1924. This outbreak highlights 1) the need to consider plague in the differential diagnosis of ill domestic animals, including dogs, in areas where plague is endemic; 2) the limitations of automated diagnostic systems for identifying rare bacteria such as Y. pestis; and 3) the potential for milder plague illness in patients taking antimicrobial agents. Hospital laboratorians should be aware of the limitations of automated identification systems, and clinicians should suspect plague in patients with clinically compatible symptoms from whom P. luteola is isolated.

Outbreak of shiga toxin-producing Escherichia coli serotype O26: H11 infection at a child care center in Colorado.

BACKGROUND: Shiga toxin-producing Escherichia coli (STEC) O26:H11 is an emerging cause of disease with serious potential consequences in children. The epidemiology and clinical spectrum of O26:H11 are incompletely understood. We investigated an outbreak of O26:H11 infection among children younger than 48 months of age and employees at a child care center. METHODS: Every employee at the center (n = 20) and every child <48 months (n = 55) were tested for STEC and administered a questionnaire. Thirty environmental health inspections and site visits were conducted. A cohorting strategy for disease control was implemented. RESULTS: Eighteen confirmed and 27 suspect cases were detected. There were no hospitalizations. The illness rate was 60% for children and employees. The risk of being a case in children <36 months was twice the risk among children of 36 to 47 months (risk ratio: 2.10; 95% confidence interval: 1.00, 4.42). The median duration of shedding among symptomatic confirmed cases was 30.5 days (range: 14-52 days). Four (22%) confirmed cases were asymptomatic and 3 (17%) shed intermittently. Nearly half (49%) of the household contacts of confirmed cases developed a diarrheal illness. The outbreak was propagated by person-to-person transmission; cohorting was an effective disease control strategy. CONCLUSIONS: This was the largest reported outbreak of O26:H11 infection in the United States and the largest reported non-O157 STEC outbreak in a US child care center. Non-O157 STEC infection is a differential diagnosis for outbreaks of diarrhea in child care settings. Aggressive disease control measures were effective but should be evaluated for outbreaks in other settings.