Pandemic influenza in Papua New Guinea: a modelling study comparison with pandemic spread in a developed country

Milne, George J; Baskaran, Pravin; Halder, Nilimesh; Karl, Stephan; Kelso, Joel

'The interventions used in the present study are based on social distancing. Surveys have shown that a higher proportion of low-income countries have social distancing interventions planned in the case of a pandemic, compared to high income European countries due to their feasibility and cost-effectiveness, given that the supply of antiviral drugs will be difficult in developing nations [4, 8] .' 'Census data classified a significant proportion (16.2%) of adults as unemployed and do not attend a designated workplace [17] . Local knowledge indicated that these adults do have daytime contact with others outwith the home, such as working or visiting the two informal markets. To address this feature an additional daytime contact location (neighbourhood hub) was introduced, with unemployed adults in each census unit allocated to neighbourhood hubs of 10 individuals. In addition, these hubs also have 25% of all local school age pupils allocated to them, accounting for half of the 50% of school age children which do not attend school.' The seeding assumption of 1 case per day was chosen to reliably begin a local epidemic in every stochastic simulation. Analysis of the low transmissibility scenario shows that seeding at this rate for 7 days results in a sustained epidemic in >97% of the simulation runs and 100% with two weeks of seeding, with higher percentages for the higher transmissibility scenarios. Seeding at this rate is continued throughout the simulation in order to capture the case where an epidemic may be initially suppressed by a rigorous intervention strategy, but may subsequently break out if intervention measures are relaxed.