Communicable diseases intelligence (2018)最新文献

Abstract: In November 2016, herpes zoster (HZ) vaccination for older adults, using the live-attenuated zoster vaccine (Zostavax; ZVL) was added to the Australian National Immunisation Program (NIP) with the aim of reducing morbidity from HZ and its complications, particularly for people at increased risk. Prior to the program, there were on average 5.6 cases of HZ per 1,000 persons annually in Australia, with highest risk of disease in older and in immunocompromised people. The burden of complications of HZ, such as post-herpetic neuralgia (PHN), was also highest in older and immunocompromised groups. No formal comprehensive program evaluation has been undertaken since program commencement. This review examined published literature and available vaccine administration data to summarise the evidence and considerations underpinning current use of HZ vaccines and potential future program directions in Australia. There have been modest reductions in the incidence of HZ and its complications since program introduction. However, five years into the program, challenges remain, including suboptimal vaccine coverage and significant safety concerns arising from inadvertent use of ZVL in immunocompromised people, who are contraindicated to receive this vaccine. This reduces opportunities to offset the burden of HZ-related disease. The recombinant subunit zoster vaccine (Shingrix; RZV), first registered in Australia in 2018, became available on the Australian market in June 2021. This vaccine has higher efficacy than ZVL and, as a non-live vaccine, can be used in both immunocompetent and immunocompromised people. RZV has potential to address the unmet needs of at-risk population groups. However, it has not yet demonstrated cost-effectiveness for inclusion as a funded vaccine under the NIP. The Australian HZ vaccination program has had limited effectiveness in meeting its aim in highest risk groups. Future options and challenges anticipated in using vaccination to reduce the burden of HZ and its complications are discussed in this review.

Abstract: In 2020 and 2021, in the context of nationwide efforts to suppress SARS CoV-2 virus transmission while awaiting a vaccine, public health teams were responsible for finding and isolating all cases and quarantining their contacts. The success of this strategy required very high case ascertainment and thus, by inference, ready access to PCR testing, even in large rural areas such as Hunter New England in New South Wales. 'Silent area' analysis entailed the scheduled regular comparison of case and testing rates at local-government-area resolution against larger area and state-wide rates. This analysis provided an easily understood metric for identifying areas with lower testing rates, and for direction of surging of local testing capacity in such areas, by the local health district in partnership with public health services and private laboratory services. Complementary intensive community messaging was also utilised to promote increased testing in identified areas.

Abstract: The overarching goal of the Australian coronavirus disease 2019 (COVID-19) vaccination program has been to protect all people in Australia from the harm caused by the novel coronavirus SARS-CoV-2. This review reflects on the role of the Australian Technical Advisory Group on Immunisation (ATAGI) in the national COVID-19 vaccination program, in terms of the initial programmatic and clinical recommendations in the evolving context of evidence relating to the disease and vaccines, epidemiology, and the program rollout. To fulfil the obligation to provide evidence-based advice to the Minister for Health and Aged Care on the safe, effective and equitable use of COVID-19 vaccines, ATAGI has worked closely with other agencies and committees such as the Therapeutic Goods Administration (TGA) and the Communicable Diseases Network Australia. ATAGI recommendations have sought to optimise the use of the available vaccine doses in achieving the objectives of preventing serious illness and death from COVID-19 while addressing any emerging safety signals following program commencement on 22 February 2021. As of mid-November 2021, the use of COVID-19 vaccines in children aged 5 to 11 years was being considered by the TGA and ATAGI; and emerging evidence, in areas such as use of heterologous vaccine schedules and co-administration with other vaccines, was under review. Despite unprecedented challenges which the delivery of mass COVID-19 vaccination presented to health systems globally, in Australia much was achieved in 2021 with over 90% coverage for primary doses in the vaccine-eligible population. Evaluation, using high quality data and assessment methods, of vaccination program outcomes-such as coverage, vaccine effectiveness and impact-is key to determine whether program objectives have been achieved and where gaps remain. Reflecting on the lessons learned so far would help further improve the national COVID-19 vaccination program and would also benefit programs for other routine vaccines and planning for future pandemics.

Background: Childcare centres can be high-risk settings for SARS-CoV-2 transmission due to age, vaccination status, and infection control challenges. We describe the epidemiology and clinical characteristics of a childcare SARS-CoV-2 Delta outbreak. When the outbreak occurred, little was known about the transmission dynamics of SARS-CoV-2 ancestral and Delta strains among children. Vaccinations for coronavirus disease 2019 (COVID-19) were not mandatory for childcare staff, and children (< 12 years) were ineligible.

Methods: A retrospective cohort design of childcare attendees was used to investigate age-cohorts exposure and transmission of SARS-CoV-2. We defined a case as a person who tested positive to SARS-CoV-2; we defined a close contact as a person who attended the childcare during 16-20 August 2021. Childcare centre exposures were defined by three cohorts: younger children (0-< 2.5 years) with designated staff; older children (2.5-5 years) with designated staff; and a staff-only group that moved between both age cohorts. We calculated the number and proportion of SARS-CoV-2 Delta infections, symptom profile and severity in children and adults, secondary attack rates, and relative risks (RR) with 95% confidence intervals (CIs) to compare age-cohort exposures and SARS-CoV-2 infection.

Results: There were 38 outbreak cases that tested positive to SARS-CoV-2 Delta infection, comprising one primary case, 11 childcare attendees and 26 household members. Child attendees were in two non-interacting groups, 0-< 2.5 years and 2.5-5 years, with designated staff, separate rooms, and independent ventilation. The greatest risk of infection to childcare attendees was in the < 2.5 years age cohort which had a secondary attack rate of 41% and were five times more likely to be infected with SARS-CoV-2 (RR = 5.73; 95% CI: 1.37-23.86; p ≤ 0.01). No identified transmission (n = 0/21) occurred in the ≥ 2.5 years age cohort.

Conclusion: Young children play an important role in SARS-CoV-2 Delta transmission to their peers and staff in childcare settings and to household members. Cohorting may be effective at limiting the propagation of SARS-CoV-2 in childcare settings. These findings highlight a need for multi-layered mitigation strategies and implementation support to manage respiratory infection control challenges at childcares. If prevention measures are not in place, this may facilitate ongoing transmission in these settings and into the broader community.