The New Zealand Ministry of Health needs to assess the risk of Covid-19 infection among international travellers arriving in Aotearoa New Zealand, principally by air.

The model described here assesses country level infection risk using daily infection rates among recent arrivals, and daily disease incidence in the country of origin.

This model is a robust and practical tool for forecasting the disease arrival risk at the New Zealand border. It relies only on readily available data (reported incidence rate in the source countries, together with counts of arrivals and cases by week and country). The forecasts are in the form of expected rates and counts by country, and are accompanied with suitable measures of uncertainty. Combined with other information (effective reproduction number, death rates, testing rates etc) policy makers can make informed decisions about disease risk among source countries.