Australian Trachoma Surveillance Report 2014

Discussion

Page last updated: 30 October 2015

Screening coverage was measured as both the proportion of at-risk communities screened and the proportion of 5- 9-year-old children screened in at-risk communities. A higher screening coverage provides confidence that those screened are representative of the community at risk therefore providing a more accurate reflection of the prevalence of disease within the community. The revised Guidelines for the public health management of trachoma in Australia reference 1 guide communities to focus resources on treatment without annual screening where trachoma prevalence is already well established. Communities with non-endemic levels of trachoma are not required to screen annually, unless resources are available to do so. In response to the 2014 revised guidelines, the annual report has shifted focus from screening coverage to the extent of implementation of the guidelines with respect to screening, treatment and health promotion activities. For communities that undertake screening for trachoma, the guidelines recommend screening coverage of 85%. Screening for trachoma is predominantly undertaken through primary school-based initiatives where the focus is on the 5-9-year-old age group. Screening of older (10-14 years) and younger (0-4 years) children also takes place, but less consistently and treatment strategies are informed by the prevalence in the 5-9-year age group. In 2014, population estimates provided by jurisdictions were used to calculate proportions.

In 2014, all communities in all regions that required screening for trachoma received screening. All regions except Alice Springs Remote and the two NSW regions achieved 85% or over screening coverage with a national coverage level of 89%.

The number of at-risk communities screened has decreased marginally in the NT, and decreased seemingly more substantially in SA and WA. However, taking into consideration both SA and WA aggregated 9 and 10 previously distinct communities respectively into one single reporting community, the actual decrease in SA and WA is also marginal. Figure 1.8 illustrates that some communities in all jurisdictions have reached the threshold for being considered no longer at risk for trachoma. Jurisdictions will assess other factors including known travel exchange of the population with areas that are hyperendemic to establish if these communities should be removed from the at risk register. It is expected that this decreasing trend will continue in future years. The Trachoma Surveillance and Control Reference Group will formulate advice on the ongoing monitoring of communities that were previously at risk. A number of NSW communities screened for the first time in 2014 did not have trachoma, and therefore will not be considered as being at risk for future years.Top of page

Trachoma prevalence

Endemic trachoma is defined by the WHO as a prevalence of active trachoma of 5% or greater in children aged 1-9 years. In past years, the National Trachoma Surveillance and Reporting Unit (NTSRU) had been able to estimate the prevalence using population weights. Due to the limited screening coverage of the 1-4-year age group, it was considered that the results reported were not representative of that age group.

Across all four jurisdictions in 2014, the prevalence of trachoma in 5-9-year-old children was 4.7%, which includes data projected forward in communities that did not screen due to implementation of the revised guidelines (see methodology, data analysis). This percentage is a slight increase from the 2013 national prevalence of trachoma in 5- 9-year-old children of 4%. The observed trachoma prevalence in communities that were screened in 2014 was 3.7%. At a regional level in 2014, the prevalence of trachoma in children aged 5-9 years ranged from 0 % in Western and Far Western NSW to 24.3% in the Barkly region of the NT.

Trachoma prevalence in 2014 has slightly increased in SA and the NT and decreased in WA and NSW. At the regional level, large increases in prevalence were recorded in Alice Springs Remote, Barkly and Midwest regions. Of some concern is the increase in trachoma prevalence in several communities that had previous prevalence rates under 5%, and the consequent increase in the number of communities recording endemic levels of trachoma. In interpreting these changes it is important to keep in mind that many of the communities have small populations and are not monitored on an annual basis. Therefore, fluctuations in rates at the community level can occur for statistical reasons. Another factor may be the inevitable variation in diagnostic accuracy between individuals, as trachoma detection depends on a clinical judgment. The continued need for health promotion programs that focus on facial cleanliness and environmental improvements may also be a contributing factor. The Trachoma Surveillance and Control Reference Group (TSCRG) will continue to monitor changes in trachoma prevalence and consider the impact of possible variables. Nevertheless, the ongoing presence of trachoma in many communities is a timely reminder of the need for all jurisdictions to maintain their commitment to national control strategies in all of their aspects. Advice will be sought from the Trachoma Surveillance and Control Reference Group on whether treatment strategies decisions should take more account of regional groupings of communities, given the potential for re-infection to occur through movement between communities. The target set by WHO for the elimination of blinding trachoma is defined as a community prevalence of trachoma in children aged 1-9 years of less than 5% over a period of 5 years; in Australia, the Communicable Diseases Network Australia (CDNA) target is defined as a prevalence in children aged 5-9 years of less than 5% over a period of 5 years. Several communities designated as at risk have reported a prevalence of less than 5% over the past 5 years, or have a baseline prevalence of 0% and are therefore designated not at risk. The NTSRU will be working closely with jurisdictions to appropriately designate at-risk status for communities for future program delivery.

Trachoma treatment

The 2014 CDNA guidelines recommend the treatment of active cases and their household contacts when trachoma prevalence is under 5% (not endemic levels). When prevalence is greater than 5% in 5-9-year olds and cases are not clustered within a few households, community-wide treatment is recommended. This approach includes treatment to all people living in households with children younger than 15 years of age annually for a period of 3 years. The guidelines also recommend 6-monthly treatments over a period of 3 years for all people living in households with children younger than 15 years of age in hyperendemic communities (prevalence in 5-9-year olds at least 20%).

Nationally, 92% of active cases that were identified in 2014 were treated for trachoma. Contact and community treatment coverage using estimates provided by the jurisdictions was 90%. Total doses of azithromycin administered in 66 communities were 9803.

Trichiasis

Previous annual trachoma reports have described trichiasis screening coverage. The previous at-risk population was estimated using the current year’s trachoma at-risk community adult population, which does not account for changing endemic areas that have occurred over time, and transiency into non-endemic regions. It was therefore decided that estimating an at-risk population for trichiasis is not feasible as it cannot capture the actual potential risk for trichiasis.

The number of adults aged 40 years and older reported to be screened for trichiasis decreased in 2014 with 3783 reported in 2014, and 3856 screened in 2013. Screening for trichiasis is believed to be greatly under-reported. Of the adults aged older than 40 years who were screened, 1% (37/3783) prevalence levels of trichiasis were reported. In 2014, 16 cases of trichiasis surgery were reported in NT (12), SA (3) and WA (1). These cases may have been identified from previous years’ screening activities. The reporting of trichiasis data regarding referral and surgery undertaken is limited due to incomplete data collection and compilation.Top of page

Facial cleanliness

Promoting facial cleanliness is a component of the SAFE strategy, recognising that the presence of nasal and ocular discharge is significantly associated with the risk for acquiring, transmitting and potential presence of trachoma. The proportion of 5-9-year-old children screened who had clean faces increased in all jurisdictions except in SA.

Program delivery and monitoring

Improvements in program delivery have been reported in 2014 with increased coverage of screening and treatment delivery and health promotion activities in all jurisdictions. Data quality also improved in all jurisdictions. One issue that will need to be considered when Australia comes to assess trachoma elimination against international standards is the lack of information on 1-4-year olds, who are considered in many populations to be at higher risk than 5-9-year olds.

The revised CDNA guidelines have strengthened the trachoma control program planning in all jurisdictions by reducing ambiguity experienced in previous guidelines and providing clear guidance on screening and treatment methods. The impact of the new strategies, in particular treatment and screening schedules, may not be evident for several years.

Progress towards Australia’s elimination target

The Australian Government’s commitment to the WHO Alliance of the Global Elimination of Blinding Trachoma by the Year 2020 (GET 2020) continues with funding provided to jurisdictions to deliver rigorous trachoma screening and treatment programs. Ongoing efforts are required to ensure high quality control in diagnosing active cases and that all intervention systems are being applied appropriately. The small increases in trachoma prevalence in 2014 are a timely reminder that trachoma trends and elimination may be unpredictable, especially in small local populations, and that local outbreaks must be managed under close adherence to the guidelines.

The Trachoma Surveillance and Control Reference Group has a significant role in the near future in reviewing surveillance procedures under the 2014 guidelines, considering the next phase of monitoring communities no longer considered at risk, and advising on strengthening elimination monitoring systems and future surveillance once blinding trachoma has been eliminated from Australia.Top of page