Performance of a rapid human metapneumovirus antigen test during an outbreak in a long-term care facility

Clinical Features of Human Metapneumovirus Pneumonia in Non-Immunocompromised Patients: An Investigation of Three Long-Term Care Facility Outbreaks

Background

Several studies have reported outbreaks due to human metapneumovirus (hMPV) in long-term care facilities (LTCF) for the elderly. However, most of these reports are epidemiological studies and do not investigate the clinical features of hMPV pneumonia.

Methods

Three independent outbreaks of hMPV occurred at separate LTCF for intellectually challenged and elderly residents. A retrospective evaluation of hMPV pneumonia and its clinical and radiological features was conducted using available medical records and data.

Results

In 105 hMPV infections, 49% of patients developed pneumonia. The median age of pneumonia cases was significantly higher than non-pneumonia cases (P < .001). Clinical manifestations of hMPV pneumonia included high fever, wheezing in 43%, and respiratory failure in 31% of patients. An elevated number of white blood cells as well as increased levels of C-reactive protein, creatine phosphokinase, and both aspartate and alanine transaminases was also observed among pneumonia cases. Evaluation of chest imaging revealed proximal bronchial wall thickenings radiating outward from the hilum in most patients.

Conclusions

The aforementioned characteristics should be considered as representative of hMPV pneumonia. Patients presenting with these features should have laboratory testing performed for prompt diagnosis.

Outbreak of Human Metapneumovirus in a Nursing Home: A Clinical Perspective

Objectives

To describe a human metapneumovirus (hMPV) outbreak occurring in a nursing home for older adults and to identify the risk factors associated with the clinical infection.

Design

A retrospective, case-controlled study.

Setting and participants

A French nursing home for older adults between December 27, 2014 and January 20, 2015. Probable cases were residents presenting at least 1 respiratory symptom or 1 constitutional symptom. Confirmed cases identified in the same way as probable cases but with a positive RT-PCR test for hMPV. Controls were residents with no symptoms of respiratory infection.

Measures

Identification of hMPV was realized on nasal swab samples by RT-PCR.

Results

Seventy-eight older people were resident at the time of the outbreak. Three of the 4 tested were positive for hMPV by RT-PCR and negative for 13 other viruses or bacteria. All probable infected residents presented cough; other symptoms were scarcer. An inflammatory response was present, with median C-reactive protein at 50 mg/L. The median duration of the illness was 7 days. The rate of infection among residents was high (51%), with 5 hospitalizations (12.5%) and 1 death (2.5%). In multivariate analysis, vaccination against influenza virus appeared to emerge as associated with a probable hMPV infection, but this might be an artifact, as the proportion of unvaccinated residents was low (15%). A clear infected population profile was hard to define, although limited autonomy and low ADL score may play a role. Basic hygiene precautions were reinforced, but droplet precautions seemed difficult to apply rigorously to this population.

Conclusions/Implications

Clinical and biological presentations were nonspecific. The rate of infection was high, highlighting the need for the rapid introduction of strict precautions to contain the infection.

Severe respiratory failure due to co-infection with human metapneumovirus and Streptococcus pneumoniae

A 64-year-old male patient was admitted with respiratory failure, although chest X-rays revealed only mild bronchiolitis. Streptococcus pneumoniae, which usually presents as massive lobular pneumonia, was isolated from sputum, however, pan-pathogen screening using a next-generation sequencer also detected human metapneumovirus genome fragments.