Informing the public health management of typhoid and paratyphoid: the Australian context.

OBJECTIVE: To examine outcomes of public health management of notified enteric fever cases in South-East Queensland over the past five years. METHODS: Notification records of typhoid and paratyphoid infection in South-East Queensland 2008-2012 (inclusive) were reviewed to determine likelihood of cases and contacts adhering to present or previous recommendations for faecal clearance/screening, duration of infectiousness of cases and extent of local transmission to contacts. RESULTS: Sixty-nine of 85 cases and 218 of 265 contacts submitted at least one faecal specimen. Cases were 2.7 (95%CI 1.2-6.0) and contacts were 4.4 (95%CI 3.0-6.4) times more likely to complete recommended faecal clearance/screening under previous compared to present guidelines (requiring more specimens). In ten cases with positive post-treatment specimens, last recorded infectiousness was 19 days to six months after notification. The documented rate of local transmission of infection was 18/1,000 contacts submitting at least one faecal specimen (95%CI 6-48/1,000). CONCLUSIONS: Local transmission risk of enteric fever in South-East Queensland is low, although small numbers of cases may have prolonged bacilli excretion post-treatment. More complex clearance/screening regimens are associated with decreased compliance. IMPLICATIONS: Pursuing extensive faecal clearance/screening regimens is unlikely to be effective in terms of public health management of enteric fever in South-East Queensland. We suggest a unified national approach focussing on cases/contacts at high risk of disease transmission.