Event-based surveillance: Providing early warning for communicable disease threats.

The coronavirus disease 2019 pandemic served as a compelling modern-day reminder of the value of early warning against communicable disease threats in public health. As countries exit the acute phase of the pandemic, there remains a continued need to be vigilant for potential communicable disease threats, particularly as the risk of animal-to-human spillover events is increasing due to climate and land use change. Early warning of emerging threats facilitates earlier public health response, which affords more time to implement public health measures that can help minimize the impact of a particular health threat and protect the health and well-being of the population. One approach to providing early warning for communicable disease and other threats is through event-based surveillance (EBS). However, EBS is not often discussed in the context of public health surveillance. This overview introduces EBS and how it might contribute to providing early warning for communicable disease threats.

Cryptosporidiosis Outbreak Investigation in a Canadian Correctional Facility Using Novel Case Finding Tools.

Eliminating Cryptosporidium oocysts is particularly challenging in prison environments, and limited information is available on best practices for outbreak control. This report aims to expand the evidence base through the lessons learned from an outbreak at a Canadian federal penitentiary in 2013. The outbreak investigation methods included inmate and staff case finding, hypothesis-generating questionnaires, and environmental investigation. A clear source of Cryptosporidium into the facility could not be identified; however, there were a number of possible sources of ongoing propagation within the facility. There were difficulties obtaining valid data on inmate and staff cases and exposures. This report discusses the novel epidemiological tools used in this investigation to address the complex challenges of a correctional setting.

A case of active tuberculosis in a cabin crew: the results of contact tracing.

INTRODUCTION: Transmission of communicable diseases on board aircraft is of considerable concern for passengers and aircrew. Previously published estimates of risk of tuberculosis (TB) transmission have been highly variable. Furthermore, very few studies have been published for active TB in aircrew. METHODS: The public health authorities advised the Medical Advisor of an airline that a cabin crewmember had been diagnosed with active TB. Contact tracing was done for the cabin crew who worked with the index case for more than 8 h. Cabin crewmembers were divided in two groups according to their exposure and had one tuberculin skin test (TST) more than 8 wk after the last exposure. Those with a TST > or = 5 mm have been recommended to have a QuantiFERON-TB Gold In-Tube (QFT) assay. RESULTS: Among the 56 identified contacts, 32 agreed to be evaluated, of whom 6 (19%) had a TST > or = 5 mm. Of those six, four underwent a QFT with one positive result. None had active TB. The percentages of positives in the two exposure groups were similar. All the positive contacts were born in Canada in the period when the childhood Bacille Calmette-Guérin (BCG) vaccination program was in effect. DISCUSSION: The same percentage of positives in the two exposure groups, the proportion of positive contacts below the expected rate in Canadians, and the high proportion of QFT negative among the TST positive contacts suggest that transmission of TB to the cabin crew is unlikely.