SUMMARY This comprehensive review outlines the impact of military-relevant respiratory infections, with special attention to recruit training environments, influenza pandemics in 1918 to 1919 and 2009 to 2010, and peacetime operations and conflicts in the past 25 years. Outbreaks and epidemiologic investigations of viral and bacterial infections among high-risk groups are presented, including (i) experience by recruits at training centers, (ii) impact on advanced trainees in special settings, (iii) morbidity sustained by shipboard personnel at sea, and (iv) experience of deployed personnel. Utilizing a pathogen-by-pathogen approach, we examine (i) epidemiology, (ii) impact in terms of morbidity and operational readiness, (iii) clinical presentation and outbreak potential, (iv) diagnostic modalities, (v) treatment approaches, and (vi) vaccine and other control measures. We also outline military-specific initiatives in (i) surveillance, (ii) vaccine development and policy, (iii) novel influenza and coronavirus diagnostic test development and surveillance methods, (iv) influenza virus transmission and severity prediction modeling efforts, and (v) evaluation and implementation of nonvaccine, nonpharmacologic interventions.

IntroductionA novel A/H1N1 virus is the cause of the present influenza pandemic; vaccination is a key countermeasure, however, few data assessing prior seasonal vaccine effectiveness (VE) against the pandemic strain of H1N1 (pH1N1) virus are available.Materials and MethodsSurveillance of influenza-related medical encounter data of active duty military service members stationed in the United States during the period of April–October 2009 with comparison of pH1N1-confirmed cases and location and date-matched controls. Crude odds ratios (OR) and VE estimates for immunized versus non-immunized were calculated as well as adjusted OR (AOR) controlling for sex, age group, and history of prior influenza vaccination. Separate stratified VE analyses by vaccine type (trivalent inactivated [TIV] or live attenuated [LAIV]), age groups and hospitalization status were also performed. For the period of April 20 to October 15, 2009, a total of 1,205 cases of pH1N1-confirmed cases were reported, 966 (80%) among males and over one-half (58%) under 25 years of age. Overall VE for service members was found to be 45% (95% CI, 33 to 55%). Immunization with prior season's TIV (VE = 44%, 95% CI, 32 to 54%) as well as LAIV (VE = 24%, 95% CI, 6 to 38%) were both found to be associated with protection. Of significance, VE against a severe disease outcome was higher (VE = 62%, 95% CI, 14 to 84%) than against milder outcomes (VE = 42%, 95% CI, 29 to 53%).ConclusionA moderate association with protection against clinically apparent, laboratory-confirmed Pandemic (H1N1) 2009-associated illness was found for immunization with either TIV or LAIV 2008–09 seasonal influenza vaccines. This association with protection was found to be especially apparent for severe disease as compared to milder outcome, as well as in the youngest and older populations. Prior vaccination with seasonal influenza vaccines in 2004–08 was also independently associated with protection.

Capacity-building initiatives related to public health are defined as developing laboratory infrastructure, strengthening host-country disease surveillance initiatives, transferring technical expertise and training personnel. These initiatives represented a major piece of the Armed Forces Health Surveillance Center, Division of Global Emerging Infections Surveillance and Response System (AFHSC-GEIS) contributions to worldwide emerging infectious disease (EID) surveillance and response. Capacity-building initiatives were undertaken with over 80 local and regional Ministries of Health, Agriculture and Defense, as well as other government entities and institutions worldwide. The efforts supported at least 52 national influenza centers and other country-specific influenza, regional and U.S.-based EID reference laboratories (44 civilian, eight military) in 46 countries worldwide. Equally important, reference testing, laboratory infrastructure and equipment support was provided to over 500 field sites in 74 countries worldwide from October 2008 to September 2009. These activities allowed countries to better meet the milestones of implementation of the 2005 International Health Regulations and complemented many initiatives undertaken by other U.S. government agencies, such as the U.S. Department of Health and Human Services, the U.S. Agency for International Development and the U.S. Department of State.

A cornerstone of effective disease surveillance programs comprises the early identification of infectious threats and the subsequent rapid response to prevent further spread. Effectively identifying, tracking and responding to these threats is often difficult and requires international cooperation due to the rapidity with which diseases cross national borders and spread throughout the global community as a result of travel and migration by humans and animals. From Oct.1, 2008 to Sept. 30, 2009, the United States Department of Defense’s (DoD) Armed Forces Health Surveillance Center Global Emerging Infections Surveillance and Response System (AFHSC-GEIS) identified 76 outbreaks in 53 countries. Emerging infectious disease outbreaks were identified by the global network and included a wide spectrum of support activities in collaboration with host country partners, several of which were in direct support of the World Health Organization’s (WHO) International Health Regulations (IHR) (2005). The network also supported military forces around the world affected by the novel influenza A/H1N1 pandemic of 2009. With IHR (2005) as the guiding framework for action, the AFHSC-GEIS network of international partners and overseas research laboratories continues to develop into a far-reaching system for identifying, analyzing and responding to emerging disease threats.

The Armed Forces Health Surveillance Center (AFHSC), Division of Global Emerging Infections Surveillance and Response System conducts disease surveillance through a global network of US Department of Defense research laboratories and partnerships with foreign ministries of agriculture, health and livestock development in over 90 countries worldwide. In 2010, AFHSC supported zoonosis survey efforts were organized into four main categories: (i) development of field assays for animal disease surveillance during deployments and in resource limited environments, (ii) determining zoonotic disease prevalence in high-contact species which may serve as important reservoirs of diseases and sources of transmission, (iii) surveillance in high-risk human populations which are more likely to become exposed and subsequently infected with zoonotic pathogens and (iv) surveillance at the human-animal interface examining zoonotic disease prevalence and transmission within and between human and animal populations. These efforts have aided in the detection, identification and quantification of the burden of zoonotic diseases such as anthrax, brucellosis, Crimean Congo haemorrhagic fever, dengue fever, Hantaan virus, influenza, Lassa fever, leptospirosis, melioidosis, Q fever, Rift Valley fever, sandfly fever Sicilian virus, sandfly fever Naples virus, tuberculosis and West Nile virus, which are of military and public health importance. Future zoonotic surveillance efforts will seek to develop local capacity for zoonotic surveillance focusing on high risk populations at the human-animal interface.