BACKGROUND: Human adenoviruses (HAdVs) comprise 7 species (A-G) and over 50 types. HAdV infections cause different clinical syndromes and specific types have been associated with community and healthcare-associated outbreaks. In 2014, the Centers for Disease Control and Prevention (CDC) launched a passive surveillance system, the National Adenovirus Type Reporting System (NATRS) to collect information on HAdV types.
METHODS: NATRS collects HAdV type data generated by CDC, state public health and other laboratories on a quarterly basis. Data includes patient age, gender, state of residence, HAdV type, specimen type, specimen collection date, typing method, coinfections detected, and whether the specimen was associated with an outbreak. During the launch of NATRS, contributors were asked to report 2014 data and historic data from the previous 10 years.
RESULTS: Since 2014, 8 laboratories reported data to NATRS including the CDC’s Respiratory Virology Laboratory, 6 state health departments, and the Naval Health Research Center. For 2013-2015, NATRS received information on 890 specimens; 521 had complete typing information; 364 only had species information and were classified as species (B/E or C) by the GenMark eSensor® respiratory viral panel; 5 specimens were unable to be typed. Nasopharyngeal and oropharyngeal swabs/washes were the most prominent specimen type (n=720, 81%). Patient ages ranged between <1 month to 89 years (median age= 2 years). The most common typing method was serum neutralization (n=206, 23.2%), hexon and/or fiber gene sequencing (n=186, 21.0%) and real time PCR that detects specific HAdV types 3, 4, 7, 11, 14, 16 and 21 (n=132, 14.8%). GenMark eSensor® was used for species determination (n=364, 41.0%). Of the 885 specimens with species information, species C HAdVs (57%) were most frequently detected followed by species B (22.3%), species B/E (11.0%), species E (7.7%), species D (2.0%), species A (0.1%). During 2013-2015, of the 521 specimens with complete typing information, the five most frequently detected HAdV types were, HAdV-2 (21.0%), HAdV-3 (17.5%), HAdV-1 (16.9%), HAdV-7 (14.2%) and HAdV-4 (13.8%). Other HAdVs detected included 5, 6, 8, 14, 15, 19, 21, 22, 31, 35 and 37 and accounted for 16.7% of NATRS reports. The most frequently detected type was HAdV-2 (16%) in 2013, HAdV-7 (14.3%) in 2014 and HAdV-4 (13%) in 2015.
CONCLUSIONS: NATRS has enabled public and private health agencies in the US to share HAdV typing data resulting in timely identification of predominant HAdV types, assessment of temporal trends in circulating HAdVs, and improved guidance for outbreak investigations.