Assessment of trachoma prevalence in a mobile population in Central Australia

Leaving no one behind: targeting mobile and migrant populations with health interventions for disease elimination-a descriptive systematic review

BACKGROUND

Mobile and migrant populations (MMPs) pose a unique challenge to disease elimination campaigns as they are often hard to survey and reach with treatment. While some elimination efforts have had success reaching MMPs, other campaigns are struggling to do so, which may be affecting progress towards disease control and elimination. Therefore, this paper reviews the literature on elimination campaigns targeting MMPs across a selection of elimination diseases-neglected tropical diseases, malaria, trypanosomiasis, polio, smallpox, and rinderpest.

METHODS

Through a systematic review process following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a three-person review team identified papers from databases, conference records, and citation searches using inclusion/exclusion criteria. Papers were divided into three key outcome domains during the synthetization process: (1) MMP movement patterns in East Africa including reasons for movement and consequences in terms of health outcomes and healthcare access; (2) MMP contribution to the transmission of disease across all geographies; (3) surveillance methods and treatment interventions used to implement programming in MMPs across all geographies. Experts in the field also provided supplemental information and gray literature to support this review.

RESULTS

The review identified 103 records which were descriptively analyzed using the outcome domains. The results indicate that in East Africa, there are various motivations for migration from economic opportunity to political unrest to natural disasters. Regardless of motivation, mobile lifestyles affect health service access such that MMPs in East Africa report barriers in accessing healthcare and have limited health knowledge. Often lower service delivery to these populations has resulted in higher disease prevalence. A minority of articles suggest MMPs do not pose challenges to reaching disease control and elimination thresholds. Finally, the literature highlighted surveillance methods (e.g., using satellite imagery or mobile phone data to track movement, participatory mapping, snowball sampling) and intervention strategies (e.g., integration with animal health campaigns, cross-border coordination, alternative mass drug administration [MDA] methods) to implement health interventions in MMPs.

CONCLUSIONS

Ultimately, the literature reviewed here can inform programmatic decisions as the community attempts to reach these never treated populations.

SYSTEMATIC REVIEW REGISTRATION

The protocol for this manuscript was registered with the International Prospective Registry of Systematic Reviews (PROSPERO) (No. CRD42021214743).

A global perspective of Indigenous child health research: a systematic review of longitudinal studies

BACKGROUND

Rigorously designed longitudinal studies can inform how best to reduce the widening health gap between Indigenous and non-Indigenous children.

METHODS

A systematic review was performed to identify and present the breadth and depth of longitudinal studies reporting the health and well-being of Indigenous children (aged 0-18 years) globally. Databases were searched up to 23 June 2020. Study characteristics were mapped according to domains of the life course model of health. Risk of bias was assessed using the National Institutes of Health (NIH) Study Quality Assessment Tools. Reported level of Indigenous involvement was also appraised; PROSPERO registration CRD42018089950.

RESULTS

From 5545 citations, 380 eligible papers were included for analysis, representing 210 individual studies. Of these, 41% were located in Australia (n = 88), 22.8% in the USA (n = 42), 11.9% in Canada (n = 25) and 10.9% in New Zealand (n = 23). Research tended to focus on either health outcomes (50.9%) or health-risk exposures (43.8%); 55% of studies were graded as 'good' quality; and 89% of studies made at least one reference to the involvement of Indigenous peoples over the course of their research.

CONCLUSIONS

We identified gaps in the longitudinal assessment of cultural factors influencing Indigenous child health at the macrosocial level, including connection to culture and country, intergenerational trauma, and racism or discrimination. Future longitudinal research needs to be conducted with strong Indigenous leadership and participation including holistic concepts of health. This is critical if we are to better understand the systematic factors driving health inequities experienced by Indigenous children globally.

Eye health service access and utilization in the National Indigenous Eye Health Survey

BACKGROUND

To determine access to and utilization of eye health services for indigenous Australians.

DESIGN

A national, stratified, random cluster sample was drawn from 30 communities across Australia that each included about 300 indigenous people.

PARTICIPANTS

A total of 1189 indigenous adults aged 40 and above were examined, representing 79% of the target population.

METHODS

Eye health services data including nature and availability of facilities and workforce supply were collected for comparison with eye health prevalence data. The data were collected in 2008.

MAIN OUTCOME MEASURES

Low vision prevalence and coverage rate for distance refractive correction.

RESULTS

The full-time equivalent availability of an optometrist working in an Aboriginal Medical Service was significantly associated with both a decrease in the prevalence of low vision (t = -2.41, P = 0.02) and an increase in the coverage rate for distance refractive correction (t = 2.99, P = 0.006). These associations were not replicated when comparing availability of private or hospital-based optometry in each community. Regional eye health coordinators appeared to provide an improved utilization of Aboriginal Health Services and therefore improved access to Aboriginal medical service optometry.

CONCLUSIONS

Eye health services for indigenous Australians need to be provided in culturally appropriate facilities with clear links to the indigenous community to optimize access to care and reduce the prevalence of vision impairment. The adequate provision of accessible eye care services is an important component in 'closing the gap' in vision loss for indigenous Australians.

Barriers to the implementation of the SAFE strategy to combat hyperendemic trachoma in Australia

OBJECTIVE

Australia is the only developed country in the world that still has endemic levels of blinding trachoma. The SAFE (Surgery, Antibiotics, Facial cleanliness, Environmental improvement) strategy is an effective public health intervention that has been successfully used to eliminate blinding trachoma in some of the poorest countries of the world. Yet the SAFE strategy has not been systematically implemented in Australia. We undertook semi-structured interviews to identify some of barriers to the implementation of the SAFE strategy within remote indigenous communities of Australia.

METHODS

Health care professionals who were responsible for delivering trachoma control programs throughout the Northern Territory were asked to participate in a semi-structured interview. Quantitative analysis was performed using an existing strategic management framework.

RESULTS

Fourteen individuals were interviewed. Responses were grouped into 19 categories; 12 from the existing strategic management framework and 7 additional categories that were created for ideas unique to the trachoma control program in Australia.

CONCLUSIONS

A number of key themes emerged from the interview and are presented in a literary style. From these key themes critical success factors for the implementation of a sustainable trachoma control program were identified. With the election of the Rudd government there has been a renewed interest in "closing the gap" between the health of indigenous and non-indigenous Australians. A federal government funding package of $58 million over four years has just been announced to tackle trachoma. It is hoped that the findings of this research can assist in making sure that money achieves its goal.

Trachoma control in two Central Australian Aboriginal communities: a case study

This prospective case study assessed the additional impact of environmental changes (E) within the SAFE strategy in controlling trachoma in two Aboriginal communities (populations 315 and 385) in Central Australia. Baseline levels for trachoma, facial cleanliness, and nasal discharge were measured in children <15 years old. Health and facial cleanliness promotion were initiated in each community and housing and environmental improvements were made in one community. Azithromycin was distributed to all members of each community (coverage 55-73%). Assessments of trachoma and facial cleanliness were made at 3, 6, and 12 months post-intervention. Baseline trachoma rates were similar for the two communities (48 and 50%). Rates were significantly lower at 3, 6, and 12 months compared to baseline, but there was no significant difference between the two communities. The A/F components of the SAFE strategy significantly reduced the prevalence of trachoma; however, while the E intervention did not bring any apparent benefits, several factors might have masked them.

Prevalence and associations of blinding trachoma in indigenous Australians within central Australia: the Central Australian Ocular Health Study

PURPOSE

To determine the prevalence and associations of blinding trachoma within the indigenous Australian population living in central Australia.

METHODS

A total of 1884 individuals aged 20 years or older, living among 30 remote communities within the statistical local area of 'Central Australia', were recruited for this study. This equated to 36% of those aged 20 years or older and 67% of those aged 40 years or older within this district. Participants were recruited as they presented to the eye clinic at each remote community. Anterior segment examination was performed and the rates of trachomatous trichiasis (TT) and trachomatous corneal opacification (CO) were documented. The prevalence of TT and CO in one or both eyes was presented.

RESULTS

There were 6.1% (95% CI 5.0-7.2) (8.3% of those aged 40 years or older) who had TT and 3.3% (95% CI 2.5-4.1) (4.4% of those aged 40 years or older) who had CO. Both TT and CO were associated with advancing age and female sex. Prevalence varied widely between communities, from 0% to 33% for TT and 0% to 27% for CO.

CONCLUSION

Our study has shown that blinding trachoma remains endemic among indigenous Australians in central Australia. However, compared with previous estimates, the prevalence of TT and CO appears to be decreasing.

The prevalence and causes of vision loss in Indigenous Australians: the National Indigenous Eye Health Survey

AIM

To determine the prevalence and causes of vision loss in Indigenous Australians.

DESIGN, SETTING AND PARTICIPANTS

A national, stratified, random cluster sample was drawn from 30 communities across Australia that each included about 300 Indigenous people of all ages. A sample of non-Indigenous adults aged > or = 40 years was also tested at several remote sites for comparison. Participants were examined using a standardised protocol that included a questionnaire (self-administered or completed with the help of field staff), visual acuity (VA) testing on presentation and after correction, visual field testing, trachoma grading, and fundus and lens photography. The data were collected in 2008.

MAIN OUTCOME MEASURES

VA; prevalence of low vision and blindness; causes of vision loss; rates of vision loss in Indigenous compared with non-Indigenous adults.

RESULTS

1694 Indigenous children and 1189 Indigenous adults were examined, representing recruitment rates of 84% for children aged 5-15 years and 72% for adults aged > or = 40 years. Rates of low vision (VA < 6/12 to > or = 6/60) were 1.5% (95% CI, 0.9%-2.1%) in children and 9.4% (95% CI, 7.8%-11.1%) in adults. Rates of blindness (VA < 6/60) were 0.2% (95% CI, 0.04%-0.5%) in children and 1.9% (95% CI, 1.1%-2.6%) in adults. The principal cause of low vision in both adults and children was refractive error. The principal causes of blindness in adults were cataract, refractive error and optic atrophy. Relative risks (RRs) of vision loss and blindness in Indigenous adults compared with adults in the mainstream Australian population were 2.8 and 6.2, respectively. By contrast, RRs of vision loss and blindness in Indigenous children compared with mainstream children were 0.2 and 0.6, respectively.

CONCLUSION

Many causes of vision loss in our sample were readily avoidable. Better allocation of services and resources is required to give all Australians equal access to eye health services.

Blinding Trachoma in the Northern Provinces of Vietnam—A Cross Sectional Survey

INTRODUCTION

A prevalence study was conducted in 2001 as part of the SAFE Trachoma Control initiatives in twelve districts of eight northern provinces of Vietnam. The authors present the magnitude and some risk factors of trachomatous trichiasis (TT), trachomatous scarring (TS) and trachomatous corneal opacity (TCO).

METHODS

Ophthalmologists examined 43,677 people of more than 34 years of age, randomly selected. Ophthalmic loupe, torchlight and the trachoma grading card recommended by WHO were used for this examination.

RESULTS

The prevalence of TT was 7.31% (95% CI 7.07-7.55) and 382,950 persons with TT were included in the study population. The rate was higher in females (8.92%) than in males (5.35%). The rate was 13.7% in the district of Me Linh in Vinh Phuc province and in the districts of Ha Tay and Khoai Chau in Hung Yen province, while in the districts of Na Ri (Bac Kan province), Cam Xuyen (Ha Tinh province) and Van Yen (Yen Bai province), the prevalence of TT was less than 2%. The TT rate in the plains was 13%, while in mountainous, coastal and delta terrains, the rate fell to 2.4%, 3.5% and 9.4% respectively. The prevalence of TS and TCO was 8.42% (95% CI 8.21-8.61) and 1.1% (95% CI 1.00-1.20) respectively.

CONCLUSION

Although the magnitude of TT is high, the problem of TCO seems to be less serious. The goal of eliminating blinding trachoma from the study area by 2010 represents a big challenge. Based on these survey estimates, the national program could plan resources for the 'S' strategy of trachoma control (surgery for those at immediate risk of blindness).

Trachoma survey methods: a literature review

Reliable population-based prevalence data are essential for planning, monitoring and evaluating trachoma control programmes and understanding the scale of the problem, yet they are not currently available for 22 out of 56 trachoma-endemic countries. Three survey methods have been advocated for trachoma: cluster random sampling (CRS); trachoma rapid assessment (TRA); and acceptance sampling trachoma rapid assessment (ASTRA). Our review highlights the benefits of CRS being simple, efficient, repeatable and giving population-based prevalence estimates of all signs of trachoma. There are limitations to TRA, which include: non-representative sampling; does not estimate prevalence; and lacks consistency and accuracy. ASTRA advocates small sample sizes but it is relatively complex, may result in imprecise prevalence estimates and does not estimate cicatricial signs of trachoma. We conclude that CRS should therefore remain the 'gold' standard for trachoma surveys. However, among the CRS surveys reviewed, we also found several methodological deficiencies of sample-size calculations, standardization of trachoma graders, reporting of confidence intervals of prevalence estimates, variability of age groups for presentation of age-specific prevalence, and lack of estimation of district prevalence estimates. Properly conducted surveys will be crucial if the objective of global elimination of blinding trachoma is to be charted and realized. Harmonization of survey methods will enhance the conduct and comparability of trachoma surveys needed for reliable mapping of prevalence within endemic countries. Consistent with WHO recommendations, we advocate for continued use of CRS as the survey design of choice for trachoma control programmes and propose ways of improving future surveys based on this method.

The burden of trachoma in Ayod County of Southern Sudan

Background

Blindness due to trachoma is avoidable through Surgery, Antibiotics, Facial hygiene and Environmental improvements (SAFE). Recent surveys have shown trachoma to be a serious cause of blindness in Southern Sudan. We conducted this survey in Ayod County of Jonglei State to estimate the need for intervention activities to eliminate blinding trachoma.

Methodology and Findings

A cross-sectional two-stage cluster random survey was conducted in November 2006. All residents of selected households were clinically assessed for trachoma using the World Health Organization (WHO) simplified grading scheme. A total of 2,335 people from 392 households were examined, of whom 1,107 were over 14 years of age. Prevalence of signs of active trachoma in children 1–9 years of age was: trachomatous inflammation follicular (TF) = 80.1% (95% confidence interval [CI], 73.9–86.3); trachomatous inflammation intense (TI) = 60.7% (95% CI, 54.6–66.8); and TF and/or TI (active trachoma) = 88.3% (95% CI, 83.7–92.9). Prevalence of trachomatous trichiasis (TT) was 14.6% (95% CI, 10.9–18.3) in adults over 14 years of age; 2.9% (95% CI, 0.4–5.3) in children 1–14 years of age; and 8.4% (95% CI, 5.5–11.3) overall. The prevalence of corneal opacity in persons over 14 years of age with TT was 6.4% (95% CI, 4.5–8.3). No statistically significant difference was observed in the prevalence of trachoma signs between genders. Trachoma affected almost all households surveyed: 384/392 (98.0%) had at least one person with active trachoma and 130 (33.2%) had at least one person with trichiasis.

Conclusions

Trachoma is an unnecessary public health problem in Ayod. The high prevalence of active trachoma and trichiasis confirms the severe burden of blinding trachoma found in other post-conflict areas of Southern Sudan. Based on WHO recommended thresholds, all aspects of the SAFE strategy are indicated to eliminate blinding trachoma in Ayod.

Trachoma, a neglected tropical disease, is the leading cause of infectious blindness and is targeted for global elimination by the year 2020. We conducted a survey in Ayod County of Jonglei State, Southern Sudan, to determine whether blinding trachoma was a public health problem and to plan interventions to control this disease. We found the burden of trachoma in Ayod to be one of the most severe ever documented. Not only were adults affected by the advanced manifestations of the disease as is typical for older age groups, but young children were also affected. At least one person with clinical signs of trachoma was found in nearly every household, and 1 in 3 households had a person with severe blinding trachoma. Characteristics previously identified as risk factors were ubiquitous among surveyed households, but we were unable to identify why trachoma is so severe in this location. Surgical interventions are needed urgently to improve vision and prevent irreversible blindness in children and adults. Mass antibiotic distribution may alleviate current infections and transmission of trachoma may be reduced if communities adopt the behavior of face washing and safe disposal of human waste. Increasing access to improved water sources may not only improve hygiene but also reduce the spread of guinea worm and other water-borne diseases.

Trachoma surveys 2000-2005: results, recent advances in methodology, and factors affecting the determination of prevalence

With the advent of VISION 2020 and GET 2020 inaugurated by the World Health Organization, it is timely to provide an update of the methodology employed in trachoma surveys, given that a significant number of individuals in many undeveloped and developing countries still suffer from this ophthalmic disease. The advent of Trachoma Rapid Assessment and Asymmetrical Sampling Rapid Trachoma Assessment has enabled faster identification of trachoma-endemic areas, though population-based surveys are still required prior to intervention. Research into factors affecting prevalence determination has shown that mobility, clustering, and seasonality should all be taken into account regarding survey design. In addition, recent advances in laboratory testing have given us new insight into trachoma infection patterns and a better understanding of the disease course. In this review, we examine advances in survey methodology and the results of trachoma surveys since 1999, and other issues relevant to the determination of trachoma prevalence. Based on recent findings, we recommend that pooled nucleic acid amplification testing be used to augment clinical assessment in areas where trachoma prevalence is greater than 20%. Further, we suggest that trachoma follicular and trachoma follicular or trachoma intense, as markers of the disease, be reported separately.

Trachoma: transmission, infection, and control

Mass antibiotic treatment and facial cleanliness are central to WHO's strategy for the elimination of blindness caused by trachoma. Recent studies have highlighted the heterogeneous response of communities to mass treatment and the complex relation between infection with Chlamydia trachomatis and clinical disease. It is important to be able to explain these findings to predict and maximise the effect of treatment on active trachoma disease and blindness in the community. Here we review the immunobiology of trachoma and provide a simple conceptual model of disease pathogenesis. We show how incorporating this model into a mathematical framework leads to an explanation of the observed community distribution of infection, bacterial load, and disease with age. The predictions of the model and empirical data show some differences that underscore the importance of individual heterogeneity in response to infection. The implications of disease transmission and pathogenesis for trachoma control programmes are discussed.

An evaluation of a SAFE-style trachoma control program in Central Australia

OBJECTIVES

To evaluate the effectiveness of a trachoma control program in a remote community before and after major environmental health improvements.

DESIGN

Before-and-after cross-sectional design. The control program was in three rounds - each consisting of community census, screening of children < 13 years, health promotion activities and antibiotic treatment. There were two housing and infrastructure surveys.

INTERVENTIONS

Treatment of affected children and their households with azithromycin at baseline, 7 and 21 months, and health promotions. Housing and sewerage infrastructure improvements were completed at 12 months.

SETTING

Large, remote Central Australian Aboriginal community, 1998-2000.

PARTICIPANTS

All community residents.

MAIN OUTCOME MEASURES

Prevalence of active trachoma among children under 13 years; community population changes; and adequacy of housing facilities for healthy living practices.

RESULTS

The prevalence of trachoma among children was 40% (95% CI, 32%-46%) at baseline, 33% (95% CI, 26%-40%) at 7 months' follow-up and 37% (95% CI, 29%-46%) at 21 months. These proportions were neither clinically nor statistically significantly different. There was a high degree of population mobility over the study period, with only 32% of residents appearing in all three censuses. The proportion of houses with completely adequate facilities increased from 0 to 16%.

CONCLUSIONS

Population mobility (both within and between communities), inadequate housing and continued crowding (despite improvements), as well as uncertainty about compliance with antibiotic treatment, are the likely factors contributing to the lack of effect of this trachoma control program. Because of high population mobility, a region-wide approach is needed for effective trachoma control.

Vision impairment in the Pacific region

The Western Pacific region is one of great diversity, containing the most populous country, China, and many small Pacific island countries. This review describes the prevalence of blindness and vision loss, illustrates the changing trends in the important causes of vision loss and blindness, and the stages of development of the delivery of eye care services across this region.