Lessons from History: Methodological Problems arising from Comparing the Influenza A (H1N1) Pandemic 2009-10 to Seasonal Influenza 2010-2019 at the United States

Pandemics of human influenza are when influenza viruses that have little or no immunity become capable of transmitting from one person to another. A novel H1N1 influenza virus was discovered in children in the southwest United States in April 2009. Retroactively, it was shown that these cases were the result of an ongoing epidemic in Mexico. A number of national vaccination programs were established in response to the pandemic. Surprisingly early clinical trials data from humans have shown that one dose of nonadjuvanted pandemic flu A (H1N1) 2009 monovalent, inactivated vaccine (pMIV), has resulted in a significant seroprotective response. This is despite previous studies showing no cross-reactivity between pandemic and seasonal H1N1 viruses.

Biological Hazards

This chapter describes various biological hazards and their impact on workers and others. A major focus of the chapter is biological hazards in healthcare and laboratory settings, including exposure to bloodborne pathogens and prevention of diseases related to them. Sections deal with sharps injuries, HIV/AIDS, hepatitis B virus, hepatitis C virus, tuberculosis, and other infectious diseases that can be acquired in the work environment via direct contact, droplet or airborne spread, or fecal-oral transmission. In addition, infectious agents spread by animal contact or arthropod vectors in a broad range of settings will be addressed. Newly emerging infectious or re-emerging infections, such as those due to H5N1 and novel H1N1 influenza, Middle Eastern respiratory syndrome (MERS), and Ebola Virus Disease (EVD) as well as agents associated with bioterrorism are discussed.

Two Aircraft Carriers’ Perspectives: A Comparative of Control Measures in Shipboard H1N1 Outbreaks

BackgroundThe USS George Washington (GW) and the USS Ronald Reagan (RR), 2 US Navy aircraft carriers, experienced almost simultaneous outbreaks of novel H1N1 influenza A in the summer of 2009. We compared the respective epidemic control measures taken and subsequent lessons learned.MethodsData were collated from both outbreaks to assess various elements including attack rate, isolation/quarantine protocols, and treatment methods. The respective duration of each outbreak was compared with survival curve analysis. The number of personnel affected in each outbreak was compared using χ2 analysis.ResultsDifferences were found in the protocols used on the 2 ships. The GW treated about two-thirds of the patients with oseltamivir through day 14 and quarantined all patients meeting case definition throughout the outbreak. Face masks were used throughout. The RR used oseltamivir and quarantined many fewer patients (through days 5 and 3, respectively). No face masks were used after day 5. The outbreaks were similar in duration (GW = 25 days, RR = 27 days, P = .38), but the RR had significantly more cases (n = 253 vs 142, P < .0001). A portion of each group had samples that were confirmed H1N1 by polymerase chain reaction.ConclusionsGW's protocol, including aggressive oseltamivir treatment of two-thirds of the cases and quarantine throughout the duration decreased the overall number of personnel affected, likely reducing the overall control reproduction number. Both outbreaks were similar in duration. Even though the GW expended significantly more resources than the RR, if the 2009 pandemic H1N1 strain had been as clinically severe as the 1918 pandemic, a more stringent treatment protocol may have been the only way to prevent significant operational impact.(Disaster Med Public Health Preparedness. 2013;7:29-35)