Influenza Outbreaks at Two Correctional Facilities — Maine, March 2011

On March 8, 2011, the Maine Center for Disease Control and Prevention (Maine CDC) received a laboratory report of a positive influenza specimen from an intensive-care unit patient who was an inmate at a prison (facility A). That same day, the state medical examiner notified Maine CDC of an inmate death suspected to be have been caused by influenza at another, nearby prison (facility B). On March 9, Correctional Medical Services (CMS), which provides health services to both facilities, notified Maine CDC that additional inmates and staff members from both facilities were ill with influenza-like illness (ILI). CMS reported that influenza vaccination coverage among inmates was very low (<10%), and coverage among staff members was unknown but believed to be low. Maine CDC assisted CMS and the Maine Department of Corrections (DOC) in conducting an epidemiologic investigation to gather more information about the two cases, initiate case finding, and implement control measures, which included emphasizing respiratory hygiene and cough etiquette, closing both facilities to new admissions and transfers, and offering vaccination and antiviral drugs to inmates and staff members. This report describes the public health response and highlights the importance of collaboration between public health and corrections officials to identify quickly and mitigate communicable disease outbreaks in these settings, where influenza can spread rapidly in a large and concentrated population. Correctional facilities should strongly consider implementing the following measures during each influenza season: 1) offering influenza vaccination to all inmates and staff members, 2) conducting education on respiratory etiquette, and 3) making documentation regarding the vaccination status of inmates and staff members accessible.

Case Reports and Outbreak Investigation

Facility A is a medium to maximum security prison that can house up to 916 inmates, employs up to 410 staff members, and is divided into three units with up to six pods per unit (each pod houses up to 112 inmates in either single cells or double cells). Facility B is a minimum security prison that can house up to 222 inmates, employs up to 65 staff members, and is divided into two units. The facilities are located on separate campuses but are under the same organizational structure. Staff members work at either facility to help cover staffing shortages or for overtime, but work hours are not documented by site. On March 8, Maine CDC learned that a male inmate in facility A, aged 55 years, with history of diabetes, congestive heart failure, and chronic obstructive pulmonary disease, was admitted to the intensive-care unit on March 5 with a severe acute respiratory illness and tested positive for influenza A (H1N1)pdm09 by real-time reverse transcriptase–polymerase chain reaction. Chest radiography ruled out pneumonia. Later that day, the state medical examiner notified Maine CDC of a second patient, a previously healthy male inmate in facility B, aged 29 years, with onset of rapidly progressive respiratory symptoms on March 7. The second patient died on March 8. Real-time reverse transcriptase–polymerase chain reaction testing of a nasopharyngeal swab and lung tissue detected influenza B. Autopsy results also revealed methicillin-resistant Staphylococcus aureus pneumonia. Neither patient had been vaccinated for influenza.

On March 9, CMS informed Maine CDC that approximately 40 inmates from facility A (from two of the three units and at least six different pods) and several from facility B (from both units) reported for sick call with respiratory symptoms. CMS did not have sufficient internal resources to screen inmates and staff members to determine the extent of illness spread. They also did not have enough staff to assess non-ill inmates and staff members for their degree of contact with the two patients because neither patient was in solitary confinement; either might have interacted with many inmates while ill. CMS reported a high prevalence of comorbid medical conditions among inmates in both facilities, but the lack of electronic medical records (EMRs) made it impractical to determine whether contacts of the ill inmates had high-risk conditions that would be indications for influenza prophylaxis. Without EMRs, it also was extremely difficult to determine which inmates had been vaccinated during the routine influenza clinic. Staff members also had been offered vaccine during the facilities' annual influenza clinics, but whether or not they received it was not documented at the workplace.

Public Health Response

Given the severity of illness in the first two patients, the high prevalence of comorbid medical conditions and low vaccination coverage among inmates reported by CMS, and the congregate living situation, both facilities were closed to new admissions and transfers. On March 10, six Maine CDC public health nurses (PHNs) assisted CMS in establishing temporary clinics at facilities A and B to identify ILI cases (fever ≥100.0°F [≥37.8°C] with cough and/or sore throat) among inmates and staff members and offer vaccination and antiviral drugs. Symptomatic persons received treatment doses (75 mg twice daily for 5 days) of oseltamivir, and all others were offered prophylactic doses (75 mg once daily for 10 days). Both facilities isolated ill inmates and excluded ill staff members from work until afebrile for 24 hours without antipyretics. Staff members collected nasopharyngeal swabs from symptomatic inmates and staff members, and Maine's Health and Environmental Testing Laboratory performed influenza testing. The correctional facilities did not have sufficient supplies of vaccine and antiviral drugs; therefore, Maine CDC supplied vaccine, and the state stockpile supplied antiviral drugs.

Facility A. During March 10–11, CMS and the PHNs screened all 802 inmates for ILI symptoms; 17 (2.1%) with ILI started treatment courses of oseltamivir, and 648 (80.8%) asymptomatic inmates started prophylactic courses (Table). The remaining 137 asympotomatic inmates (17.1%) refused antiviral prophylaxis. CMS and the PHNs vaccinated 333 inmates (33% in the close housing unit and 49% in the medium housing units). Of the 17 ILI patients, nine were tested for influenza (all from the same pod): specimens from six patients were positive for influenza A (five were H1N1pdm09 and one was unsubtypable), and three were negative. The nine inmates tested for influenza ranged in age from 24 to 57 years (mean: 37.3 years), and only one had been vaccinated previously.

CMS and the PHNs screened 184 staff members from facility A and vaccinated 68 (37%). Sixteen (8.7%) staff members with ILI started treatment courses of oseltamivir, and 166 (90.2%) started prophylactic courses. No staff members were tested for influenza.

Facility B. On March 10, CMS and the PHNs screened all 193 inmates at facility B for ILI symptoms; four (2.1%) with ILI started treatment courses of oseltamivir, and 184 (95.3%) asymptomatic inmates started prophylactic courses (Table). The remaining five asymptomatic inmates (2.6%) refused antiviral prophylaxis. CMS and the PHNs vaccinated 88 inmates (46%). Of the four ILI patients, two were tested for influenza; one tested positive for influenza B, and the other was negative. The vaccination status of the inmate who tested positive was unknown; the other inmate tested was unvaccinated.

CMS and the PHNs screened 51 staff members from facility B and vaccinated 13 (25%). Nine (17.6%) staff members with ILI started treatment courses of oseltamivir, and 42 (82.4%) started prophylactic courses. Of the nine symptomatic staff members at facility B, six were tested for influenza. Vaccine status for all six was unknown, and all six were negative for influenza.

On March 13, 2011, both facilities reported no new illnesses, and the facilities reopened to new admissions and transfers. CMS decided to end antiviral prophylaxis after 10 days instead of the recommended minimum of 14 days because they had distributed oseltamivir packages containing 10 doses to inmates to self-administer, and repackaging and distributing 4 more doses was not possible without a major disruption to routine work.

Reported by

Sara Robinson, MPH, Peter Smith, PhD, Stephen D. Sears, MD, Maine Dept of Health and Human Svcs; Joseph Shubert, MD, Maine Dept of Corrections. Carrie Reed, DSc, Influenza Div, National Center for Immunization and Respiratory Diseases; Susan E. Manning, MD, Career Epidemiology Field Officer Program, Office of Public Health Preparedness and Response, CDC. Corresponding contributor: Sara Robinson, sara.robinson@maine.gov, 207-287-4610.

Editorial Note

These outbreaks emphasize the importance of collaboration between public health and correctional officials to overcome the challenges in managing influenza outbreaks in prisons and jails. Correctional facilities face many unique challenges, and infection control is recognized to be difficult (1). These facilities often have high turnover of inmates and staff members, which can make routine disease surveillance and early identification of infectious diseases challenging. Some additional challenges encountered during these outbreaks included 1) insufficient staff to handle the medical surge, 2) no easily accessible medical records to establish vaccination status or determine underlying medical conditions, 3) lack of access to sufficient quantities of vaccine and antiviral drugs, and 4) lack of skilled personnel to administer a large volume of vaccine and antiviral drugs in a timely manner. Through collaboration between Maine CDC and Maine DOC, officials were able to screen and offer vaccination and antiviral drugs to approximately 1,000 inmates and 200 staff members.

At the end of 2009, approximately 7.2 million adults were under correctional supervision in the United States (2). In October 2007, Maine housed 2,161 inmates in state prisons (3). Persons in U.S. correctional facilities are likely to be poor, undereducated, and/or homeless before incarceration; they also are more likely to have substance dependency or mental illness and higher rates of infectious and chronic diseases than the general population (4–7). A high prevalence of preexisting comorbid conditions, combined with close living conditions, is likely to increase the risk for influenza infection. When inmates work in the community or are released, they can transmit influenza to the rest of the population. Corrections staff who reside in the community also might transmit influenza back into the facility. Published reports of influenza outbreaks in United States correctional settings are lacking.

Correctional facilities might have limited staff to support surges in demand for health care created by outbreaks, or limited access to vaccine (8). The facilities in Maine required the assistance of PHNs to complete screening and vaccination promptly. Determining which inmates have underlying conditions without EMRs requires a labor-intensive manual review, thereby delaying the provision of vaccine and antiviral drugs. EMRs would allow inmates' medical histories to travel with them between facilities and might facilitate more efficient outbreak management.

Correctional facilities can play an important role in detecting and preventing influenza transmission within a community (4). Transmission of disease between correction staff members, inmates, and the community is an important concern, and improved vaccination coverage in all three settings can reduce disease risk. The U.S. Department of Health and Human Services has issued the Correctional Facilities Pandemic Influenza Planning Checklist, which recommends routine influenza surveillance; however, it does not provide suggestions regarding how to accomplish this, or give specific guidance once an outbreak is identified (9). CDC offers guidance for use of antiviral drugs in institutions, but not specifically for correctional facilities (10). Guidance for routine surveillance as well as outbreak management in correctional facilities would be beneficial in guiding prevention and response activities.

Collaboration between public health and correctional facilities is necessary to identify quickly and mitigate communicable disease outbreaks in these high-risk settings. This collaboration should be established well before any outbreak occurs. Vaccination of inmates and staff members is a critical prevention measure, and vaccine should be provided in correctional settings, along with accessible documentation regarding the vaccination status of inmates and staff members.

Acknowledgments

Brian Castonguay, Correctional Medical Svcs; staff members at both facilities, Maine Dept of Corrections; Megan Kelley, Anne Sites, MPH, Jennifer Gunderman-King, MPH, public health nursing staff, Maine Immunization Program, Maine Dept of Health and Human Svcs. John Tegeris, Office of the Assistant Secretary for Preparedness and Response/Biomedical Advanced Research and Development Authority, US Department of Health and Human Services.

References

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