Sustained outbreak of measles in New South Wales, 2012: risks for measles elimination in Australia

"No jab, no pay": catch-up vaccination activity during its first two years

OBJECTIVES

To assess catch-up vaccination of older children and adolescents during the first two years of the "No jab, no pay" policy linking eligibility for federal family assistance payments with childhood vaccination status.

DESIGN, SETTING, PARTICIPANTS

Cross-sectional analysis of Australian Immunisation Register data on catch-up vaccination of children aged 5 to less than 7 years before (January 2013 - December 2014; baseline) and during the first two years of "No jab, no pay" (December 2015 - December 2017), and of children aged 7 to less than 10 years and young people aged 10 to less than 20 years ("No jab, no pay" period only).

MAIN OUTCOMES

Catch-up vaccination rates for measles-mumps-rubella vaccine second dose (MMR2), by age group, Indigenous status, and socio-economic status; catch-up vaccination of children aged 5 to less than 7 years (third dose of diphtheria-tetanus-pertussis vaccine [DTPa3], MMR1), before and after introduction of "No jab, no pay".

RESULTS

The proportion of incompletely vaccinated children aged 5 to less than 7 years who received catch-up DTPa3 was higher under "No jab, no pay" than during the baseline period (15.5% v 9.4%). Of 407 332 incompletely vaccinated people aged 10 to less than 20 years, 71 502 (17.6%) received catch-up MMR2 during the first two years of "No jab, no pay", increasing overall coverage for this age group from 86.6% to 89.0%. MMR2 catch-up activity in this age group was greater in the lowest socio-economic status areas than in the highest status areas (29.1% v 7.6%), and also for Indigenous than for non-Indigenous Australians (35.8% v 17.1%). MMR2 catch-up activity in 2016 and 2017 peaked mid-year.

CONCLUSIONS

Linking family assistance payments with childhood vaccination status and associated program improvements were followed by substantial catch-up vaccination activity, particularly in young people from families of lower socio-economic status.

Migration Health: Highlights from Inaugural International Society of Travel Medicine (ISTM) Conference on Migration Health

PURPOSE OF REVIEW

International migration is a global phenomenon that is growing in scope, complexity and impact. The inaugural International Society of Travel Medicine (ISTM) International Conference on Migration Health provided a forum to discuss scientific evidence on the broad issues relevant to migration health. This review summarises the key health issues, with a focus on infectious diseases, current effective strategies and future considerations presented at this forum and in the recent literature.

RECENT FINDINGS

Migrants face health disparities for both communicable and non-communicable diseases. Their heightened infectious disease risks, compared to host populations, are related to pre-migration exposures, the circumstances of the migration journey and the receptivity and access to health services in their receiving countries. While the prevalence of infectious diseases identified through screening programmes are generally low, delays in diagnosis and treatment for a range of treatable infectious diseases result in higher morbidity and mortality among migrants. Barriers to care in host countries occur at the patient, provider and health systems levels. Coordinated and inclusive health services, healthcare systems and health policies, responsive to patient diversity reduce these barriers. Structural barriers to healthcare provision impede equitable care to migrants and refugees. Public health and medical professionals have a role in advocating for policy reforms.

Public health responses during measles outbreaks in elimination settings: Strategies and challenges

In late September 2016, the Americas became the first region in the world to have eliminated endemic transmission of measles virus. Several other countries have also verified measles elimination, and countries in all six World Health Organization regions have adopted measles elimination goals. The public health strategies used to respond to measles outbreaks in elimination settings are thus becoming relevant to more countries. This review highlights the strategies used to limit measles spread in elimination settings: (1) assembly of an outbreak control committee; (2) isolation of measles cases while infectious; (3) exclusion and quarantining of individuals without evidence of immunity; (4) vaccination of susceptible individuals; (5) use of immunoglobulin to prevent measles in exposed susceptible high-risk persons; (6) and maintaining laboratory proficiency for confirmation of measles. Deciding on the extent of containment efforts should be based on the expected benefit of reactive interventions, balanced against the logistical challenges in implementing them.

Sub-national variation in measles vaccine coverage and outbreak risk: a case study from a 2010 outbreak in Malawi

BACKGROUND

Despite progress towards increasing global vaccination coverage, measles continues to be one of the leading, preventable causes of death among children worldwide. Whether and how to target sub-national areas for vaccination campaigns continues to remain a question. We analyzed three metrics for prioritizing target areas: vaccination coverage, susceptible birth cohort, and the effective reproductive ratio (R_E) in the context of the 2010 measles epidemic in Malawi.

METHODS

Using case-based surveillance data from the 2010 measles outbreak in Malawi, we estimated vaccination coverage from the proportion of cases reporting with a history of prior vaccination at the district and health facility catchment scale. Health facility catchments were defined as the set of locations closer to a given health facility than to any other. We combined these estimates with regional birth rates to estimate the size of the annual susceptible birth cohort. We also estimated the effective reproductive ratio, R_E, at the health facility polygon scale based on the observed rate of exponential increase of the epidemic. We combined these estimates to identify spatial regions that would be of high priority for supplemental vaccination activities.

RESULTS

The estimated vaccination coverage across all districts was 84%, but ranged from 61 to 99%. We found that 8 districts and 354 health facility catchments had estimated vaccination coverage below 80%. Areas that had highest birth cohort size were frequently large urban centers that had high vaccination coverage. The estimated R_E ranged between 1 and 2.56. The ranking of districts and health facility catchments as priority areas varied depending on the measure used.

CONCLUSIONS

Each metric for prioritization may result in discrete target areas for vaccination campaigns; thus, there are tradeoffs to choosing one metric over another. However, in some cases, certain areas may be prioritized by all three metrics. These areas should be treated with particular concern. Furthermore, the spatial scale at which each metric is calculated impacts the resulting prioritization and should also be considered when prioritizing areas for vaccination campaigns. These methods may be used to allocate effort for prophylactic campaigns or to prioritize response for outbreak response vaccination.

Raising Rates of Childhood Vaccination: The Trade-off Between Coercion and Trust

Vaccination is a highly effective public health strategy that provides protection to both individuals and communities from a range of infectious diseases. Governments monitor vaccination rates carefully, as widespread use of a vaccine within a population is required to extend protection to the general population through "herd immunity," which is important for protecting infants who are not yet fully vaccinated and others who are unable to undergo vaccination for medical or other reasons. Australia is unique in employing financial incentives to increase vaccination uptake, mainly in the form of various childcare payments and tax benefits linked to timely, age-appropriate vaccination. Despite relatively high compliance with the childhood vaccination schedule, however, the Australian government has determined that rates should be higher and has recently introduced policy that includes removing certain tax and childcare benefits for non-vaccinators and formally disallowing conscientious objection to vaccination ("No Jab No Pay"). In addition, it has raised the possibility of banning unvaccinated children from childcare centres ("No Jab No Play"). This article examines the impact of coercive approaches to childhood vaccination and raises the question of the ethical justification of health policy initiatives based on coercion. We consider the current evidence regarding childhood vaccination in Australia, the small but real risks associated with vaccination, the ethical requirement for consent for medical procedures, and the potential social harms of targeting non-vaccinators. We conclude that the evidence does not support a move to an increasingly mandatory approach that could only be delivered through paternalistic, coercive clinical practices.

The changing epidemiology of measles in an era of elimination: lessons from health-care-setting transmissions of measles during an outbreak in New South Wales, Australia, 2012

Introduction

In countries where measles is rare, health-care-setting transmissions remain problematic. Australia experienced its largest measles outbreak in 15 years in 2012 with 199 cases reported nationally; 170 cases occurred in the state of New South Wales (NSW) with symptom onset between 7 April and 29 November 2012.

Methods

A descriptive study was conducted using measles case data obtained from metropolitan Sydney local health districts in NSW in 2012. Characteristics of measles source and secondary cases were described. Details of health-care presentations resulting and not resulting in measles transmission were also analysed.

Results

There were 168 confirmed and two probable cases resulting in 405 documented health-care presentations. Thirty-four secondary cases acquired in health-care settings were identified, including 29 cases resulting from 14 source cases and 5 cases whose source could not be identified. Health-care-acquired cases accounted for 20% of all cases in this outbreak. Source cases were more likely to be of Pacific Islander descent (P = 0.009) and to have had more presentations before diagnosis (P = 0.012) compared to other cases. The percentage of presentations to emergency departments was higher for presentations that resulted in transmission compared to those that did not (71.4% and 37.6%, respectively, P = 0.028). There were no significant differences between transmission and non-transmission presentations with respect to presence of rash and infection control measures (P = 0.762 and P = 0.221, respectively), although the power to detect these differences was limited. Rash was reported at 66% of the presentations.

Conclusion

Development of and adherence to protocols for the management of patients presenting to hospitals with fever and rash will minimize secondary transmission of measles.

Measles prevention in adolescents: lessons learnt from implementing a high school catch-up vaccination programme in New South Wales, Australia, 2014-2015

Introduction

In response to a significant increase of measles cases and a high percentage of unvaccinated adolescents in New South Wales, Australia, a measles high school catch-up vaccination programme was implemented between August and December 2014. This study aimed to explore the factors affecting school-based supplementary immunization activities (SIAs) and to inform future SIA and routine school-based vaccination programme implementation and service provision.

Methods

Focus group analysis was conducted among public health unit (PHU) staff responsible for implementing the SIA catch-up programme. Key areas discussed were pre-programme planning, implementation, resources, consent materials, media activity and future directions for school vaccination programme delivery. Sessions were audio recorded, transcribed verbatim and reviewed. Thematic analysis was conducted to identify the major themes.

Results

Two independent focus groups with 32 participants were conducted in January 2015. Barriers to the SIA implementation included lead time, consent processes, interagency collaboration, access to the targeted cohort and the impact of introducing a SIA to an already demanding curriculum and school programme immunization schedule. A positive PHU school coordinator rapport and experience of PHU staff facilitated the implementation. Consideration of different approaches for pre-clinic vaccination status checks, student involvement in the vaccination decision, online consent, workforce sharing between health districts and effective programme planning time were identified for improving future SIA implementation.

Conclusion

Although many barriers to school programme implementation have been identified in this study, with adequate resourcing and lead time, SIAs implemented via a routine school vaccination programme are an appropriate model to target adolescents.

Verification of measles elimination in Australia: Application of World Health Organization regional guidelines

BACKGROUND

The World Health Organization (WHO) Western Pacific Region (WPR) Guidelines on verification of measles elimination were established in 2012. This article outlines Australia's approach to addressing the guideline's five lines of evidence, which led to formal verification of elimination by the WHO Regional Verification Commission (RVC) in March 2014.

METHODS

The criteria were addressed using national measles notifications, data from selected laboratories, the national childhood immunization register, and three national serosurveys (1998/1999, 2002, 2007).

RESULTS

Australia met or exceeded all indicator targets with either national or sentinel data. Laboratory and epidemiological surveillance were of high quality, with 85% of cases documented as imported/import-related (target 80%); coverage with the first dose of measles vaccine was close to 94% in 2008-2012 and second dose coverage increased to 91% in 2012 (target >95%). There is ongoing commitment by the Australian Government to increase immunization coverage, and the absence of sustained transmission of any single measles genotype was demonstrated.

CONCLUSIONS

This is the first documentation of the successful application of the WPR RVC guidelines. The indicators afford some flexibility but appear to provide appropriate rigor to judge achievement of measles elimination. Our experience could assist other countries seeking to verify their elimination status.

The contribution of travellers visiting friends and relatives to notified infectious diseases in Australia: state-based enhanced surveillance

Immigrants and their children who return to their country of origin to visit friends and relatives (VFR) are at increased risk of acquiring infectious diseases compared to other travellers. VFR travel is an important disease control issue, as one quarter of Australia's population are foreign-born and one quarter of departing Australian international travellers are visiting friends and relatives. We conducted a 1-year prospective enhanced surveillance study in New South Wales and Victoria, Australia to determine the contribution of VFR travel to notifiable diseases associated with travel, including typhoid, paratyphoid, measles, hepatitis A, hepatitis E, malaria and chikungunya. Additional data on characteristics of international travel were collected. Recent international travel was reported by 180/222 (81%) enhanced surveillance cases, including all malaria, chikungunya and paratyphoid cases. The majority of cases who acquired infections during travel were immigrant Australians (96, 53%) or their Australian-born children (43, 24%). VFR travel was reported by 117 (65%) travel-associated cases, highest for typhoid (31/32, 97%). Cases of children (aged <18 years) (86%) were more frequently VFR travellers compared to adult travellers (57%, P < 0·001). VFR travel is an important contributor to imported disease in Australia. Communicable disease control strategies targeting these travellers, such as targeted health promotion, are likely to impact importation of these travel-related infections.

An assessment of measles vaccine effectiveness, Australia, 2006-2012

OBJECTIVE

Vaccine effectiveness analysis serves as a critical evaluation for immunization programmes and vaccination coverage. It also contributes to maintaining public confidence with the vaccine providers. This study estimated measles vaccine effectiveness at the population level using Australian national notifications data between 2006 and 2012.

METHODS

Notification data were obtained from the National Notifiable Diseases Surveillance System. Vaccination status was classified according to whether a case had received zero, one or two doses of measles-containing vaccine. Cases aged less than 1 year and those with unknown vaccination status were excluded. All children with disease onset between 1 January 2006 and 31 December 2012 who were born after 1996 were included. Cases were matched to controls extracted from the Australian Childhood Immunization Register according to date of birth and jurisdiction of residence. Vaccine effectiveness was estimated by conditional logistic regression. Sensitivity analyses were conducted to test data robustness.

RESULTS

Vaccine effectiveness was estimated at 96.7% (95% confidence interval [CI]: 94.5-98.0%) for one dose and 99.7% (95% CI: 99.2-99.9%) for two doses of measles vaccine. For at least one dose, effectiveness was estimated at 98.7% (95% CI: 97.9-99.2%). Sensitivity analyses did not significantly alter the base estimates.

DISCUSSION

Vaccine effectiveness estimates suggested that the measles vaccine was protective at the population level between 2006 and 2012. However, vaccination coverage gaps may have contributed to recent measles outbreaks and may represent a serious barrier for Australia to maintain measles elimination status.

Associations Between Exposure to and Expression of Negative Opinions About Human Papillomavirus Vaccines on Social Media: An Observational Study

Background

Groups and individuals that seek to negatively influence public opinion about the safety and value of vaccination are active in online and social media and may influence decision making within some communities.

Objective

We sought to measure whether exposure to negative opinions about human papillomavirus (HPV) vaccines in Twitter communities is associated with the subsequent expression of negative opinions by explicitly measuring potential information exposure over the social structure of Twitter communities.

Methods

We hypothesized that prior exposure to opinions rejecting the safety or value of HPV vaccines would be associated with an increased risk of posting similar opinions and tested this hypothesis by analyzing temporal sequences of messages posted on Twitter (tweets). The study design was a retrospective analysis of tweets related to HPV vaccines and the social connections between users. Between October 2013 and April 2014, we collected 83,551 English-language tweets that included terms related to HPV vaccines and the 957,865 social connections among 30,621 users posting or reposting the tweets. Tweets were classified as expressing negative or neutral/positive opinions using a machine learning classifier previously trained on a manually labeled sample.

Results

During the 6-month period, 25.13% (20,994/83,551) of tweets were classified as negative; among the 30,621 users that tweeted about HPV vaccines, 9046 (29.54%) were exposed to a majority of negative tweets. The likelihood of a user posting a negative tweet after exposure to a majority of negative opinions was 37.78% (2780/7361) compared to 10.92% (1234/11,296) for users who were exposed to a majority of positive and neutral tweets corresponding to a relative risk of 3.46 (95% CI 3.25-3.67, P<.001).

Conclusions

The heterogeneous community structure on Twitter appears to skew the information to which users are exposed in relation to HPV vaccines. We found that among users that tweeted about HPV vaccines, those who were more often exposed to negative opinions were more likely to subsequently post negative opinions. Although this research may be useful for identifying individuals and groups currently at risk of disproportionate exposure to misinformation about HPV vaccines, there is a clear need for studies capable of determining the factors that affect the formation and adoption of beliefs about public health interventions.

Responding to a measles outbreak in a Pacific island community in western Sydney: community interviews led to church-based immunization clinics

INTRODUCTION

There are large Pacific island communities in western and south-western Sydney, New South Wales, Australia. In 2011 and 2012, measles outbreaks disproportionally affected children and youth within these communities. The objectives of this study were to explore barriers to immunization in a Pacific island community from the perspectives of community members and health professionals and to conduct a pilot programme whereby immunization catch-up clinics were held in a Samoan church in western Sydney.

METHODS

Interviews were conducted with Pacific island community members (n = 12) and health professionals connected with the Pacific island community (n = 7) in 2013. A partnership with a local Samoan church was established to provide an accessible venue for immunization catch-up clinics.

RESULTS

Among the community members there were high levels of belief in the importance of immunization and a positive view regarding the protection offered by immunization. A key barrier reported by community members was being busy and therefore having limited time to get children immunized. The important role of the church within the community was emphasized in the interviews, and as a result, two immunization catch-up clinics were held in a Samoan church in western Sydney. The age range of attendees was 7-33 years. A total of 31 measles, mumps and rubella doses and 19 meningococcal C doses were given during the two clinics.

DISCUSSION

The outcomes of the interviews and the subsequent clinics highlighted the potential of churches as a venue for providing public health interventions such as catch-up immunization.

New South Wales annual vaccine-preventable disease report, 2012

We aim to describe the epidemiology of selected vaccine-preventable diseases in New South Wales (NSW) for 2012. Data from the NSW Notifiable Conditions Information Management System were analysed by: local health district of residence, age, Aboriginality, vaccination status and organism, where available. Risk factor and vaccination status data were collected by public health units for cases following notification under the NSW Public Health Act 2010. The largest outbreak of measles since 1998 was reported in 2012. Pacific Islander and Aboriginal people were at higher risk as were infants less than 12 months of age. Notifications of invasive pneumococcal disease (IPD) in children less than five years declined; however, the overall number of notifications for IPD increased. Mumps case notifications were also elevated. There were no Haemophilus influenzae type b case notifications in children less than five years of age for the first time since the vaccine was introduced. Invasive meningococcal disease case notifications were at their lowest rates since case notification began in 1991. Case notification rates for other selected vaccine-preventable diseases remained stable. Vaccine-preventable disease control is continually strengthening in NSW with notable successes in invasive bacterial infections. However, strengthening measles immunization in Pacific Islander and Aboriginal communities remains essential to maintain measles elimination.