105. Burden and Epidemiology of Human Metapneumovirus (hMPV) Acute Respiratory Infection (ARI) among American Indian and Alaska Native (AI/AN) Children <5 years of Age, November 2019-May 2024

TL;DR

This study examines the burden of hMPV respiratory infections in young American Indian and Alaska Native children, finding hospitalization rates lower than RSV but comparable to general US rates.

Contribution

The study provides the first detailed epidemiological data on hMPV in AI/AN children under 5 years of age.

Findings

hMPV was detected in 14% of inpatient and 8% of outpatient children with ARI.

hMPV hospitalization rates in AI/AN children were lower than RSV but similar to general US RSV rates.

The pandemic disrupted hMPV circulation in 2021.

Abstract

hMPV is a common cause of medically attended ARI (MA-ARI) in US children aged < 5 years, but few data are available on disease burden in AI/AN children. For respiratory syncytial virus (RSV), another common cause of pediatric respiratory illness, hospitalization rates in AI/AN children < 5 years historically have been higher than for the general US population < 5 years (17-40/1000 in some remote AI/AN communities versus 4-6/1000). We describe the epidemiology of medically attended hMPV-associated ARI in AI/AN children and estimate incidence rates of hMPV-associated hospitalizations.

We conducted population-based surveillance for MA-ARI in hospitalized and outpatient AI/AN children aged < 5 years in the Southwest US (Navajo Nation and White Mountain Apache Tribal lands) and Alaska (Yukon Kuskokwim Delta and Anchorage) during November 2019-May 2024. Nasal swabs were tested by PCR for hMPV and RSV. We described the seasonality of hMPV and RSV detection and compared the clinical presentation of children with hMPV-positive versus hMPV-negative MA-ARI using Fisher’s exact test and Wilcoxon rank sum test. We used Poisson regression to estimate annual hMPV-associated hospitalization incidence per 1000 children stratified by age and site.

hMPV seasonality varied regionally but circulation typically followed the onset of the RSV season; the COVID-19 pandemic disrupted circulation during 2021 (Fig). Among the 2561 (90%) of 2836 enrollees with hMPV testing, hMPV was detected in 14% (1373/1591) of swabs from inpatient children and 8% (79/970) of swabs from outpatient children (Table 1). Clinical characteristics were generally similar in children with hMPV-positive compared to hMPV-negative MA-ARI. The incidence of HMPV-associated ARI hospitalization among children < 5 years ranged from 0-16.0/1000 and age-group patterns varied by site and year (Table 2).

hMPV-associated hospitalization incidence rates in AI/AN children < 5 years were lower than historical RSV-associated hospitalization rates in these same communities but similar to or greater than historical RSV rates in the general US child population. These findings provide a baseline for hMPV disease burden for assessments of future prevention products.

All Authors: No reported disclosures

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