1.Contact tracing of in-flight measles exposures: lessons from an outbreak investigation and case series, Australia, 2010
Frank Beard ; Lucinda Franklin ; Steven Donohue ; Rodney Moran ; Stephen Lambert ; Marion Maloney ; Jan Humphreys ; Jessica Rotty ; Nicolee Martin ; Michael Lyon ; Thomas Tran ; Christine Selvey
Western Pacific Surveillance and Response 2011;2(3):25-33
OBJECTIVE: To describe a 2010 outbreak of nine cases of measles in Australia possibly linked to an index case who travelled on an international flight from South Africa while infectious.
METHODS: Three Australian state health departments, Victoria, Queensland and New South Wales, were responsible for the investigation and management of this outbreak, following Australian public health guidelines. Results: An outbreak of measles occurred in Australia after an infectious case arrived on a 12-hour flight from South Africa. Only one of four cases in the first generation exposed to the index case en route was sitting within the two rows recommended for contact tracing in Australian and other guidelines. The remaining four cases in subsequent generations, including two health care workers, were acquired in health care settings. Seven cases were young adults. Delays in diagnosis and notification hampered disease control and contact tracing efforts.
CONCLUSION: Review of current contact tracing guidelines following in-flight exposure to an infectious measles case is required. Alternative strategies could include expanding routine contact tracing beyond the two rows on either side of the case’s row or expansion on a case-by-case basis depending on cabin layout and case and contact movements in flight. Releasing information about the incident by press release or providing generic information to everyone on the flight using e-mail or text messaging information obtained from the relevant airline, may also be worthy of consideration. Disease importation, inadequately vaccinated young adults and health care-related transmission remain challenges for measles control in an elimination era.
2.Population compliance with COVID-19 directions in December 2021, Queensland, Australia
Marguerite Dalmau ; Ramim Sourjah ; Ross Andrews ; Emma Field ; Stephen Lambert
Western Pacific Surveillance and Response 2023;14(4):04-06
The Queensland Border Restrictions Direction (No. 56) was introduced in December 2021 as part of the COVID-19 pandemic response. We assessed direction compliance among new and returning Queensland residents. A registered COVID-19 PCR test could be identified for 58% of people, and 89% had received the required vaccines.
3.Re-positive testing, clinical evolution and clearance of infection: results from COVID-19 cases in isolation in Viet Nam
Ngoc-Anh Hoang ; Thai Quang Pham ; Ha-Linh Quach ; Khanh Cong Nguyen ; Samantha Colquhoun ; Stephen Lambert ; Huy Luong Duong ; Dai Quang Tran ; Cong Dinh Phung ; Nhu Duong Tran ; Duy Nghia Ngu ; Anh Tu Tran ; Hue Bich Thi Nguyen ; Duc-Anh Dang ; Florian Vogt
Western Pacific Surveillance and Response 2021;12(4):82-92
Objectives:
Asymptomatic infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and test re-positivity after a negative test have raised concerns about the ability to effectively control the coronavirus disease 2019 (COVID-19) pandemic. We aimed to investigate the prevalence of COVID-19 asymptomatic and pre-symptomatic infections during the second wave of COVID-19 in Viet Nam, and to better understand the duration of SARS-CoV-2 infection and the dynamics between the evolution of clinical symptoms and SARS-CoV-2 test positivity among confirmed COVID-19 cases.
Methods:
We conducted a cohort analysis on the first 50 confirmed cases during the second COVID-19 wave in Viet Nam using clinical, laboratory and epidemiological data collected from 9 March to 30 April 2020. Kaplan-Meier estimates were used to assess time to clearance of SARS-CoV-2 infection, and log-rank tests were used to explore factors related to time to SARS-CoV-2 infection clearance.
Results:
Most cases (58%) had no typical signs or symptoms of COVID-19 at the time of diagnosis. Ten cases (20%) were re-positive for SARS-CoV-2 during infection. Eight cases (16%) experienced COVID-19 symptoms after testing negative for SARS-CoV-2. The median duration from symptom onset until clearance of infection was 14 days (range: 6–31); it was longer in re-positive and older patients and those with pre-existing conditions.
Conclusion
Asymptomatic and pre-symptomatic infections were common during the second wave of COVID-19 in Viet Nam. Re-positivity was frequent during hospitalization and led to a long duration of SARS-CoV-2 infection.