This report describes Pennsylvania’s 9-year experience in implementing training programs to strengthen public health response to emerging infectious diseases. During the biannual 3–5-day-long Pennsylvania Public Health Institute (PHI) events, which have been held since 2000, courses have covered topics such as emerging infectious disease outbreaks, monitoring of antimicrobial-resistant pathogens in retail food, and zoonotic diseases commonly associated with companion animals. Core competency courses include the legal basis for public health and epidemiology for nonepidemiologists. Emerging infectious disease seminars offered to clinicians since 2005 have focused on the emergence of community-associated methicillin-resistant Staphylococcus aureus and Clostridium difficile antibiotic-associated diarrhea. Complementing the PHI, the Pennsylvania Department of Health’s monthly Epidemiology Journal Club offers additional interactions with presenters from academic institutions and federal agencies. Lunch-time forums also provide a venue for health department staff to share their work with colleagues. Innovative use of modern communication technology increases participation of frontline health workers in Journal Club events, and video conference capability offers flexibility in the selection of presenters. Pennsylvania’s experience over the past 9 years demonstrates that with political will, commitment from content experts, and adequate administrative support, modest state and federal resources can be used to sustain public health training programs tailored to local needs.

Background

In April 2009, a new pandemic strain of influenza infected thousands of persons in Mexico and the United States and spread rapidly worldwide. During the ensuing summer months, cases ebbed in the Northern Hemisphere while the Southern Hemisphere experienced a typical influenza season dominated by the novel strain. In the fall, a second wave of pandemic H1N1 swept through the United States, peaking in most parts of the country by mid October and returning to baseline levels by early December. The objective was to determine the seroprevalence of antibodies against the pandemic 2009 H1N1 influenza strain by decade of birth among Pittsburgh-area residents.

Methods and Findings

Anonymous blood samples were obtained from clinical laboratories and categorized by decade of birth from 1920–2009. Using hemagglutination-inhibition assays, approximately 100 samples per decade (n = 846) were tested from blood samples drawn on hospital and clinic patients in mid-November and early December 2009. Age specific seroprevalences against pandemic H1N1 (A/California/7/2009) were measured and compared to seroprevalences against H1N1 strains that had previously circulated in the population in 2007, 1957, and 1918. (A/Brisbane/59/2007, A/Denver/1/1957, and A/South Carolina/1/1918). Stored serum samples from healthy, young adults from 2008 were used as a control group (n = 100). Seroprevalences against pandemic 2009 H1N1 influenza varied by age group, with children age 10–19 years having the highest seroprevalence (45%), and persons age 70–79 years having the lowest (5%). The baseline seroprevalence among control samples from 18–24 year-olds was 6%. Overall seroprevalence against pandemic H1N1 across all age groups was approximately 21%.

Conclusions

After the peak of the second wave of 2009 H1N1, HAI seroprevalence results suggest that 21% of persons in the Pittsburgh area had become infected and developed immunity. Extrapolating to the entire US population, we estimate that at least 63 million persons became infected in 2009. As was observed among clinical cases, this sero-epidemiological study revealed highest infection rates among school-age children.

This report describes Pennsylvania's 9-year experience in implementing training programs to strengthen public health response to emerging infectious diseases. During the biannual 3-5-day-long Pennsylvania Public Health Institute (PHI) events, which have been held since 2000, courses have covered topics such as emerging infectious disease outbreaks, monitoring of antimicrobial-resistant pathogens in retail food, and zoonotic diseases commonly associated with companion animals. Core competency courses include the legal basis for public health and epidemiology for nonepidemiologists. Emerging infectious disease seminars offered to clinicians since 2005 have focused on the emergence of community-associated methicillin-resistant Staphylococcus aureus and Clostridium difficile antibiotic-associated diarrhea. Complementing the PHI, the Pennsylvania Department of Health's monthly Epidemiology Journal Club offers additional interactions with presenters from academic institutions and federal agencies. Lunch-time forums also provide a venue for health department staff to share their work with colleagues. Innovative use of modern communication technology increases participation of frontline health workers in Journal Club events, and video conference capability offers flexibility in the selection of presenters. Pennsylvania's experience over the past 9 years demonstrates that with political will, commitment from content experts, and adequate administrative support, modest state and federal resources can be used to sustain public health training programs tailored to local needs.