Blinding Trachoma in Postconflict Southern Sudan

Abstract

Background

Trachoma is a leading cause of preventable blindness. Reports from eye surgery camps and anecdotal data indicated that blinding trachoma is a serious cause of visual impairment in Mankien payam (district) of southern Sudan. We conducted this study to estimate the prevalence of trachoma, estimate targets for interventions, and establish a baseline for monitoring and evaluation.

Methods and Findings

A population-based cross-sectional survey was conducted in May 2005. A two-stage cluster random sampling with probability proportional to size was used to select the sample population. Participants were examined for trachoma by experienced graders using the World Health Organization simplified grading scheme. A total of 3,567 persons were examined (89.7% of those enumerated) of whom 2,017 were children aged less than 15 y and 1,550 were aged 15 y and above. Prevalence of signs of active trachoma in children aged 1–9 y was: trachomatous inflammation-follicular (TF) = 57.5% (95% confidence interval [CI], 54.5%–60.4%); trachomatous inflammation-intense (TI) = 39.8% (95% CI, 36.3%–43.5%); and TF and/or TI (active trachoma) = 63.3% (95% CI, 60.1%–66.4%). Prevalence of trachomatous trichiasis was 9.6% (95% CI, 8.4%–10.9%) in all ages, 2.3% (95% CI, 1.6%–3.2%) in children aged under 15 y, and 19.2% (95% CI, 17.0%–21.7%) in adults. Men were equally affected by trichiasis as women: odds ratio = 1.09 (95% CI, 0.81%–1.47%). It is estimated that there are up to 5,344 persons requiring trichiasis surgery in Mankien payam.

Conclusions

Trachoma is a serious public health problem in Mankien, and the high prevalence of trichiasis in children underscores the severity of blinding trachoma. There is an urgent need to implement the surgery, antibiotics, facial cleanliness, and environmental change (SAFE) strategy for trachoma control in Mankien payam, and the end of the 21-y civil war affords an opportunity to do this.

Abstract

A population-based, cross-sectional survey with two-stage cluster random sampling, conducted in Sudan's Mankien district, found a high prevalence of trachoma, with many patients in need of surgery for trachomatous trichiasis.

Editors' Summary

Background.

Trachoma is an infectious disease that it is cased by a bacterium, Chlamydia trachomatis. The infection can be passed from one person to another through contact with hands and clothes, and by flies. The disease develops gradually—while children are most susceptible to infection, they may not note its effects until adulthood, when scarring from repeated infections causes the eyelashes to turn inward (“trichiasis”). The cornea—the transparent front part of the eye—becomes damaged by the eyelashes and develops ulcers, and eventually blindness results. Trachoma is most common in poor rural communities living in overcrowded conditions with limited access to water and health care. As improved living conditions, better hygiene, and early treatment of the infection with antibiotics can prevent the disease—and surgery for trichiasis is very effective—trachoma is regarded as a preventable type of blindness. It is also described as a “neglected disease”; over seven million people have trichiasis and it causes an estimated 3.6% of the world's blindness, but it does not receive the attention that such a widespread and serious condition demands. The World Health Organization recommends a strategy for trachoma control known as SAFE—surgery, antibiotics, facial cleanliness, and environmental change.

Why Was This Study Done?

The environment and living conditions in the southern Sudan are such that trachoma is likely to be common; there have been reports that this is the case, but reliable information has not been available. In part, this is because of the serious conflict in the country that lasted many years. In 2005 when the region became more peaceful, planning began in order to expand health programmes there. Good planning must be based on reliable information as to how many people are affected by different health conditions, including trachoma.

What Did the Researchers Do and Find?

They focused on just one district of southern Sudan (Mankien), where they also conducted a survey that looked for all types of blindness. They selected 22 villages at random and sent people to conduct the survey who were experienced in recognizing trachoma and in using the WHO's system for grading the various stages of the disease, from early infection to blindness. Once in the village, the survey teams selected homes at random and examined the people there. A total of 3,567 people were examined, of whom 2,017 were children aged less than 15 years. The earliest stages of infection were very common indeed, particularly in children aged 1–9, over half of whom had some sign of infection. In adults, one in five had trichiasis caused by trachoma.

What Do These Findings Mean?

The very high proportion of children with early stages of trachoma is of great concern and, based on the survey, over 5,000 people in Mankien are estimated to be in need of trichiasis surgery. The survey suggests that other parts of the southern Sudan are also likely to have similar problems. This is a particularly disturbing situation for a disease that should be very easy to prevent. Antibiotic treatment and preventive measures are also needed. The SAFE strategy must be urgently put into action. Further discussion of the implications of this study and of the methods the researchers used are found in two “Perspective” articles in this issue of PLoS Medicine (by Buchan and by Kuper and Gilbert).

Additional Information.

Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0030478.

• Basic information on trachoma may be found on Wikipedia, an internet encyclopaedia that anyone can edit

• More detailed information is available from the International Trachoma Initiative and Medline Plus

• The Carter Center implements trachoma control activities in Africa

• The SAFE strategy is described in detail in a document available on the Web site of the Carter Center