Influenza Outbreak in a Well-Vaccinated Nursing Home Population in Belgium

Abstract

Elderly people in nursing home communities are vulnerable to contagious infections, including the influenza virus. Systematic anti-influenza vaccination is an important preventive measure; however, vaccination does not provide absolute protection. We report an outbreak of influenza A infection in a well-vaccinated nursing home population. Several factors can facilitate the occurrence of this type of outbreak. This report mainly addresses the discrepancy between the circulating viral strain and strains present in the recommended vaccine.

Influenza outbreak control practices and the effectiveness of interventions in long‐term care facilities: a systematic review

“…The article selection criteria allowed for inclusion of outbreaks occurring in assisted living facilities and nursing homes, which typically house individuals of different functional abilities. Only two outbreaks occurred among residents living exclusively in an assisted living facility 40,41 and one outbreak occurred in a combined assisted living-nursing home facility, 30 which were consistent with the remaining 58 outbreaks that occurred among residents of nursing homes. Moreover, our results appeared robust as case definitions were not associated with attack rates, and prophylactic vaccination of residents and staff was not related to antiviral use.…”

A systematic review on the causes of the transmission and control measures of outbreaks in long-term care facilities: Back to basics of infection control

“…Fifteen studies reported outbreaks caused by bacteria [15-17, 20, 22, 24, 27, 32-39] and 22 studies were outbreaks by viruses [14,18,19,21,23,25,26,[28][29][30][31][40][41][42][43][44][45][46][47][48][49][50]. The largest number of a single pathogen was influenza viruses [40][41][42][43][44][45], followed by group A streptococcus (GAS) [17,20,24,37,38]. The most affected site was respiratory tract (n = 12) [32, 35, 36, 39-45, 48, 50], followed by gastrointestinal (GI) tract (n = 10) [14,16,23,26,27,31,33,46,47,49].…”

“…Three studies analyzed the data of multiple outbreaks of viral gastroenteritis and influenza-like illness that occurred in multiple facilities for a certain period of time [14,46,48]. The outbreaks in 23 studies affected both the residents and HCWs [14,20,22,23,25,26,29,31,33,[35][36][37][38][39][40][41][43][44][45][46][47][48][49], and the outbreaks of 14 studies affected only the residents [15-19, 21, 24, 27, 28, 30, 32, 34, 42, 50].…”

“…The most commonly reported route of transmission was person-to-person [17, 22-24, 26, 31, 33, 35, 38, 41, 43, 46, 47, 49]. Of these studies, the human source of transmission was identified as the HCWs in six outbreaks [22,24,26,38,41,49] and the residents in two outbreaks [17,33]. The skin of a HCW was a reservoir for Methicillin-resistant Staphylococcus aureus (MRSA) outbreaks, leading to cross-infection, in the study by Maltezou et al [22].…”

2012/13 influenza vaccine effectiveness against hospitalised influenza A(H1N1)pdm09, A(H3N2) and B: estimates from a European network of hospitals

“…Influenza outbreaks have been regularly documented in long-term care facilities, including outbreaks of vaccine-matched influenza strains among highly vaccinated institutional populations. [202][203][204][205] Summer outbreaks of influenza also occur among elderly populations in long-term care facilities, [206][207][208] highlighting the year-round risk of transmission in institutionalized settings.…”