Outbreak of acute respiratory disease caused by human adenovirus type 7 in a military training camp in Shaanxi, China

Abstract

Outbreaks of ARD associated with HAdV have been reported in military populations in many countries. Here, we report an ARD outbreak caused by HAdV-7 in a military training camp in Shaanxi Province, China, from February to March of 2012. Epidemic data and samples from the patients were collected, and viral nucleotides from samples and viral isolations were detected and sequenced. IgG and IgA antibodies against HAdV, and the neutralization antibodies against the viral strain isolated in this outbreak, were detected. Epidemiological study showed that all personnel affected were males with an average age of 19.1 years. Two peaks appeared on the epicurve and there was an 8-day interval between peaks. Laboratory results of viral nucleotide detection carried out with clinical specimens were positive for HAdV (83.33%, 15/18). Further study through serum antibody assay, virus isolation and phylogenetic analysis showed that HAdV-7 was the etiological agent responsible for the outbreak. IgA antibody began to appear on the 4th day after the onset and showed 100% positivity on the 8th day. The virus strain in the present outbreak was highly similar to the virus isolated in Hanzhong Shaanxi in 2009. We conclude that HAdV-7 was the pathogen corresponding to the outbreak, and this is the first report of an ARD outbreak caused by HAdV-7 in military persons in China. Vaccine development, as well as enhanced epidemiological and virological surveillance of HAdV infections in China should be emphasized. Key words

Severe Pediatric Adenovirus 7 Disease in Singapore Linked to Recent Outbreaks across Asia

“…A corresponding rise was noted among military personnel during October 2012-April 2013, but no statistically significant increase in Ad7 infections was detected by the NPHL community ILI surveillance program. Partial hexon gene sequences of the Singapore isolates had 100% nucleotide identity with sequences reported from outbreaks in Taiwan and China (2,3,10).…”

“…Recent reports have noted increased incidence of severe Ad7 disease in Asia: among the general population and pediatric inpatients in Taiwan; among persons in a military training camp in Shaanxi, China; and among those in a police training center in Kuala Lumpur, Malaysia (2)(3)(4). During January-June 2013, physicians in Singapore noted an increase in HAdV pediatric inpatients.…”

Adenoviral Infections in Singapore: Should New Antiviral Therapies and Vaccines Be Adopted?

“…Clinical epidemiological data regarding HAdV infections are relatively sparse for Southeast Asia (SEA). However, existing data suggest that HAdV-B3 is ubiquitous and more often associated with milder illness when compared with recent HAdV-B7 infections in Singapore, Malaysia, Taiwan, and China [7][8][9][10][11][12][13][14]. Unlike HAdV-B3 and HAdV-B7, outbreaks of HAdV-E4 have not been as commonly reported globally until recently.…”

Fatal Community-acquired Pneumonia in Children Caused by Re-emergent Human Adenovirus 7d Associated with Higher Severity of Illness and Fatality Rate

“…Of the seven HAdV species, species B (mostly HAdV-3, -7, -14, and -55) and species E (HAdV-4) are highly associated with ARD, which account for a high proportion of respiratory diseases both in children and adults throughout the world1211121314151617181920212223. HAdV-7 is one of the most important respiratory HAdVs and has been circulating both in military and civilian populations.…”

“…Recently, more and more ARD outbreaks with severe or even fatal cases caused by HAdV-7 have been reported in Asia, especially in China, which has a large and high-density population161113151628293031. The three recent isolates circulating in Southern China (DG01; 2011), Southwestern China (CQ1198; 2010), and Northwestern China (0901HZ/ShX; 2009) were identified as a re-emergent genome type 7d (HAdV-7d) after approximately 20-year absence in China1.…”