Epidemiologic analysis of respiratory viral infections among Singapore military servicemen in 2016

Abstract

BackgroundRespiratory illnesses have been identified as a significant factor leading to lost training time and morbidity among Singapore military recruits. A surveillance programme has been put in place to determine etiological agents responsible for febrile, as well as afebrile respiratory illnesses in a military camp. The goal of the study is to better understand the epidemiology of these diseases and identify potential countermeasures to protect military recruits against them.MethodsFrom Jan 2016 - Jan 2017, a total of 2647 respiratory cases were enrolled into the surveillance programme. The cases were further stratified into Febrile Respiratory Illness (FRI, with body temperature > 37.5 °C) or Acute Respiratory Illness (ARI, with body temperature < 37.5 °C). Nasal washes were collected and tested by multiplex PCR to detect 26 different pathogens.ResultsOne thousand ninety five cases (41% of total cases) met the criteria of FRI in which 932 cases (85% of FRI cases) were screened positive for at least one virus. The most common etiological agents for FRI mono-infection cases were Adenovirus E and Rhinovirus. Recruits infected with H3N2 influenza, Influenza B and Adenovirus E viruses were most likely presented as FRI cases. Notably, H3N2 influenza resulted in the greatest rise in body temperature. The remaining 1552 cases (59% of total cases) met the criteria of ARI in which 1198 cases (77% of ARI cases) were screened positive for at least one virus. The most common etiological agent for ARI mono-infection was Rhinovirus. The distribution pattern for dual infections was different for ARI and FRI cases. Maximum number of pathogens detected in a sample was five for both groups.ConclusionPrevious studies on respiratory diseases in military focused largely on FRI cases. With the expanded surveillance to ARI cases, this study allows unbiased evaluation of the impact of respiratory disease pathogens among recruits in a military environment. The results show that several pathogens have a much bigger role in causing respiratory diseases in this cohort.Electronic supplementary materialThe online version of this article (10.1186/s12879-018-3040-x) contains supplementary material, which is available to authorized users.

Respiratory Viruses and Atypical Bacteria Co-Infection in Children with Acute Respiratory Infection

“…Several recent studies have analysed the epidemiologic pattern of respiratory viral infections; Rhinovirus is usually the most common single pathogen found in ARI surveillances samples with prevalence range 24. -50% followed by RSV 22-25% and influenza viruses 7.2-8% either by detection in nasal washes or nasopharyngeal swabs [ 21 ] [ 22 ] [ 23 ], which comes in accordance with an Egyptian study by Amin et al, 2012 RSV virus was detected with a high predominance (51.9%) in Egyptian asthmatic children with acute respiratory tract infection [ 24 ].…”

Evidence for Cross-Protection Against Subsequent Febrile Respiratory Illness Episodes From Prior Infections by Different Viruses Among Singapore Military Recruits 2009–2014

“…Given the relative ranking of virus families in conferring cross-protection, we suggest focusing the search for mechanisms on common factors induced by both adenovirus and influenza virus. Notably, our previous studies suggest that infections with these 2 infections may be more severe, because they are more likely to present with febrile illness [26] and higher temperatures (≥38°C) than infections due to other common circulating virus families [16]. This again supports a cytokine-mediated antiviral effect.…”

Pertussis in the Association of Southeast Asian Nations: epidemiology and challenges

“…Nine studies containing descriptive epidemiology data from ASEAN countries were identified: two hospital-based studies of children with severe pertussis (Kowalzik et al, 2007;Sadiasa et al, 2017), two hospital-based studies of adults with prolonged cough (Siriyakorn et al, 2016;Koh et al, 2016), two seroepidemiology surveys (Wanlapakorn et al 2016;Son et al 2018), and three studies of multiple etiologies of respiratory illness (Wertheim et al 2015;Barger-Kamate et al 2016;Lau et al 2018) (Table 3). Pertussis disease in ASEAN countries is poorly characterized, partly demonstrated by the fact that only six out of ten countries are represented by these nine studies.…”

“…None of the 224 pneumonia cases tested positive for pertussis by PCR while three (0.34%) cases (two clinically and one PCR-confirmed case) were found in the control group. The Singaporean Army performed respiratory disease surveillance of multiple etiologies of acute respiratory illness (ARI) in servicemen at an army clinic (Lau et al, 2018). Seven out of 2647 (0.264%) cases tested positive for pertussis between 2016 and 2017.…”