Ongoing outbreak of human adenovirus-associated acute respiratory illness in the Republic of Korea military, 2013 to 2018

Abstract

0000-0002-7464-9780 *These authors contributed equally to this work. Background/Aims: Human adenovirus type 55 (HAdV-55), an emerging epidemic strain, has caused several large outbreaks in the Korean military since 2014, and HAdV-associated acute respiratory illness (HAdV-ARI) has been continuously reported thereafter. Methods: To evaluate the epidemiologic characteristics of HAdV-ARI in the Korean military, we analyzed respiratory virus polymerase chain reaction (RV-PCR) results, pneumonia surveillance results, and severe HAdV cases from all 14 Korean military hospitals from January 2013 to May 2018 and compared these data with nationwide RV surveillance data for the civilian population. Results: A total of 14,630 RV-PCRs was performed at military hospitals. HAdV (45.4%) was the most frequently detected RV, followed by human rhinovirus (12.3%) and influenza virus (6.3%). The percentage of the military positive for HAdV was significantly greater than the percentage of civilians positive for HAdV throughout the study period, with a large outbreak occurring during the winter to spring of 2014 to 2015. The outbreak continued until the end of the study, and non-seasonal detections increased over time. The reported number of pneumonia patients also increased during the outbreak. Case fatality rate was 0.075% overall but 15.6% in patients with respiratory failure. The proportion of severe patients did not change significantly during the study period. Conclusions: A large HAdV outbreak is currently ongoing in the Korean military, with a trend away from seasonality, and HAdV-55 is likely the predominant strain. Persistent efforts to control the outbreak, HAdV type-specific surveillance, and vaccine development are required.

Early cidofovir administration might be associated with a lower probability of respiratory failure in treating human adenovirus pneumonia: a retrospective cohort study

“…Fatal HAdV pneumonia in adults has been reported, but an effective treatment modality has not been well evaluated [13,22]. Among currently available antiviral agents, cidofovirda cytosine nucleotide analogue inhibiting DNA polymerasedis recommended for the treatment of severe HAdV infections based on in vitro and case reports [14,16,22,23].…”

“…In addition, its high cost and potential adverse effects hinder general use of the drug [22]. Since winter 2014, the Korean military has experienced an explosion of cases of severe HAdV pneumonia due to the ongoing outbreak of HAdV-55 and tried cidofovir for potentially severe HAdV pneumonia patients based on previous experience [6,13,17,18]. Since we treated most potentially severe HAdV cases with cidofovir after the outbreak, a comparison between treated and non-treated patients was not feasible.…”

“…Lastly, HAdV typing was not performed in all included patients. Although the major HAdV type during the study period was type 55 [6,13,17], other types of HAdV might have been included in the study cohort. Since in vitro data on cidofovir activity against various HAdV types are limited [14,27,28], careful interpretation of the study result is required, and further studies evaluating the effect of cidofovir on various HAdV types need to be conducted.…”

“…All included patients first visited the hospital after pneumonia development and were admitted on the same day. HAdV infections were confirmed by multiplex respiratory virus polymerase chain reaction (PCR) tests using patients' sputum samples, as previously described [13]. Pneumonia was defined as the presence of parenchymal infiltration on chest x-ray or CT with respiratory symptoms.…”

“…HAdV-55 has also been noticed in the Korean military from 2012 and caused a large outbreak beginning in the winter of 2014 [6,11e13]. This nonvaccine-type HAdV outbreak is currently ongoing in the Korean military, with a high burden of morbidity and mortality [13]. In managing severe HAdV pneumonia patients in the Korean military, we tried cidofovir based on previous case reports and in vitro studies [14e16], and we experienced several successes with early administration of cidofovir [17].…”