Reactive strategies for containing developing outbreaks of pandemic influenza

Abstract

BackgroundIn 2009 and the early part of 2010, the northern hemisphere had to cope with the first waves of the new influenza A (H1N1) pandemic. Despite high-profile vaccination campaigns in many countries, delays in administration of vaccination programs were common, and high vaccination coverage levels were not achieved. This experience suggests the need to explore the epidemiological and economic effectiveness of additional, reactive strategies for combating pandemic influenza.MethodsWe use a stochastic model of pandemic influenza to investigate realistic strategies that can be used in reaction to developing outbreaks. The model is calibrated to documented illness attack rates and basic reproductive number (R0) estimates, and constructed to represent a typical mid-sized North American city.ResultsOur model predicts an average illness attack rate of 34.1% in the absence of intervention, with total costs associated with morbidity and mortality of US$81 million for such a city. Attack rates and economic costs can be reduced to 5.4% and US$37 million, respectively, when low-coverage reactive vaccination and limited antiviral use are combined with practical, minimally disruptive social distancing strategies, including short-term, as-needed closure of individual schools, even when vaccine supply-chain-related delays occur. Results improve with increasing vaccination coverage and higher vaccine efficacy.ConclusionsSuch combination strategies can be substantially more effective than vaccination alone from epidemiological and economic standpoints, and warrant strong consideration by public health authorities when reacting to future outbreaks of pandemic influenza.

Simulation of strategies for containing pandemic influenza

“…Workers contact all of the persons in their workgroups. Employment rates are based on available employment statistics as well as census statistics on the geographical distribution of workers; details are given in Andradóttir et al (2010).…”

“…Now we discuss the economic analysis, where we use methods described by Meltzer, Cox, and Fukuda (1999) to quantify most medical and work loss costs (see also Medlock and Galvani 2009). The economic analysis is based on three tables, all of which are described in full detail in Andradóttir et al (2010): (i) the proportions of cases at high risk for complications (by age group); (ii) the rates of outpatient visits, hospitalizations, and death for people having complications; and (iii) frequency and costs associated with outpatient visits, hospitalizations, and deaths, e.g., the average number of visits per case, average copayment per outpatient visit, average copayment per prescription, average value of total days of work lost, etc. In the latter table, all the costs have been adjusted for inflation using 2008 consumer price and medical price indexes.…”

“…Section 5 deals with output analysis, both epidemiological and economic, and Section 6 offers some conclusions. Parts of this paper are taken from Andradóttir et al (2010).…”

Pandemic influenza: A global challenge for social marketing marketing

“…While H5N1 did not spread at the rate that was predicted by many, it was followed by a pandemic of H1N1 in 2009/10 [4][5][6][7]. There are wide-ranging estimates of the number of deaths from H1N1; for example it has been stated that the 18,500 laboratory-confirmed deaths for the period April 2009-April 2010 is a gross underestimation given that many deaths would have occurred in countries without routine reporting [4].…”

“…Further, there is often a reluctance to undertake vaccination due to concerns about lack of effectiveness or potential side effects, even among health care workers [6].  Related to the barriers to adequate vaccination levels, and the virulent nature of the disease, effective prevention strategies require a combination of medical approaches (such as vaccination and anti-virals) and environmental/policy approaches (such as school closures) [7].  While pandemic influenza would have a disproportion impact on developing countries, the developed countries would also be affected with low income persons within these countries being at highest risk [10].…”