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 school closure intervention in the Madang model is found to be approximately 5 times less effective compared to that of the Albany model. Simulation results suggest a 9.4% reduction (46.6% to 42.2%) in the illness attack rate can be achieved in Madang due to school closure whereas a 48.6% reduction (31.7% to 16.3%) can be achieved in Albany (see Table 1 ). For the Madang-nnh (no neighbourhood hub) model, school closure is approximately 3.5 times less effective compared to the Albany model. Table 2 (middle panel) indicates an illness attack rate of ~15,000 in Madang compared to ~4,800 in Albany. Much higher case numbers occur in households, workplaces and the wider community (including neighbourhood hubs) than in Albany, highlighting the poorer efficacy of this intervention strategy in a PNG setting. The Madang-nnh model also results in higher household and workplace transmission than the Albany model. Note that while there is a significantly higher proportion of under 17 year old children in Madang (40%) compared to Albany (28%), our field survey indicates that 50% of school age children in Madang do not attend school, hence school closure is less effective in disrupting the transmission chain (i.e., household 1-to-school-to-household 2) compared to Australia. This feature is also present in the rigorous social distancing intervention.