From the Guidelines
Human metapneumovirus (HMPV) infection should be managed with supportive care, including rest, hydration, and fever control, as there is currently no specific antiviral treatment recommended. HMPV is a paramyxovirus that causes upper and lower respiratory tract infections, commonly diagnosed by nucleic acid testing (NAT), with rates ranging from 2.5% to 9% during the first 2 years after allogeneic hematopoietic stem cell transplantation (HSCT) 1. The infection can present with flu-like symptoms, and in HSCT patients with pneumonia, HMPV is frequently codetected with other pathogens, making it challenging to determine the attributable morbidity 1. Some key points to consider in the management of HMPV infection include:
- Asymptomatic and prolonged shedding has been reported in HSCT patients 1
- Recipient cytomegalovirus seropositivity is a risk factor for HMPV infection in HSCT patients 1
- Single cases of severe disease and fatal outcome have been reported, highlighting the importance of close monitoring and supportive care 1
- Some centers consider treating HMPV lower respiratory tract infection with ribavirin and/or intravenous immunoglobulin (IVIG), although there is a lack of supporting studies 1. Prevention measures, such as regular handwashing, avoiding close contact with sick individuals, and covering coughs and sneezes, are essential to reduce the transmission of HMPV 1.
From the Research
Human Metapneumovirus Overview
- Human metapneumovirus (hMPV) is a common respiratory pathogen that can cause both upper and lower respiratory tract infections, particularly in children, elderly adults, and immunocompromised hosts 2, 3.
- hMPV is a leading cause of acute respiratory tract infections (ARTIs) worldwide, responsible for about 5% to 10% of hospitalizations of children suffering from ARTIs 2.
- The virus has a seasonal variation, circulating in late winter to early spring in temperate climates and late spring and summer in tropical regions 3.
Transmission and Diagnosis
- hMPV transmission occurs through droplets, direct contact, and surface contamination, with crowded spaces and healthcare facilities serving as key environmental amplifiers 4.
- Reverse transcription polymerase chain reaction (RT-PCR) is the most sensitive test for detecting hMPV infection, as the virus is difficult to culture 2, 3, 5.
- Direct detection of hMPV antigens with an immunofluorescent antibody test is available but is less sensitive than PCR 3.
Clinical Manifestations and Treatment
- Symptoms of hMPV infection range from mild upper respiratory tract infections to severe lower respiratory tract infections, such as bronchiolitis and pneumonia 2, 3, 6.
- The main risk factors for severe disease upon hMPV infection are the presence of a high viral load, coinfection with other agents, being between 0 and 5 months old or older than 65 years, and immunodeficiency 6.
- Currently, available treatments for hMPV infections are only supportive, and antiviral drugs are employed in cases of severe disease as a last resort 6.
Vaccine Development and Future Directions
- Several vaccine candidates have been shown to be effective in preventing clinical disease, but none are yet commercially available 2, 6.
- Promising innovations, including AI-guided vaccine design and portable diagnostic tools, highlight the potential for future breakthroughs in hMPV prevention and treatment 4.
- Further studies are required to define the best treatment and prevention strategies for hMPV infection 6, 5.