Long-term care facilities: a cornucopia of viral pathogens

Abstract

Objectives: To determine the frequency and types of respiratory viruses circulating in Boston long-term care facilities (LTCFs) during a 3-year period.

Design: Observational.

Setting: Thirty-three Boston-area LTCFs over a 3-year period.

Participants: Residents of long-term care who had previously participated in a trial of vitamin E supplementation and had paired serum samples available for viral analysis.

Measurements: Viral antibody titers to eight respiratory viruses (influenza A and B, respiratory syncytial virus (RSV), parainfluenza virus serotype three (PIV-3), PIV-2, human metapneumovirus (hMPV), and coronaviruses 229E and OC43) were measured using enzyme immunoassay at baseline and 53 weeks. Infection was defined as a more than quadrupling of viral titers. Clinical data on respiratory illnesses were collected throughout the study period.

Results: A total of 617 persons were enrolled in the trial. Of these, 382 (62%) had sera available for viral analysis. A total of 204 viral infections were documented in 157 subjects. Serological responses to all eight viruses were documented, with hMPV (12.8%) and coronavirus 229E (10.5%) being the most common and PIV-2 (2.4%) the least common. The occurrence of bronchitis (P=.007), pneumonia (P=.02), and any lower respiratory tract infection (P=.002) was significantly associated with having a viral diagnosis.

Conclusion: A wide range of respiratory viruses cocirculates in LTCFs and contributes to respiratory illness morbidity in these populations.

Figure 1

Number of viral infections diagnosed serologically during the 3‐year period. The individual nursing homes which participated in each year are shown on the horizontal axis with the number of individuals tested indicated. Each type of viral infection is expressed by a different shade in the bar graph. Some nursing homes participated in more than 1 year.RSV = respiratory syncytial virus; Flu A = influenza A virus; Flu B = influenza B virus; HMPV = human metapneumovirus; OC43 = coronavirus OC43; 229E = coronavirus 229E; PIV‐3 = parainfluenza virus serotype 3; PIV‐1 = parainfluenza virus serotype 1.