CHAPTER SEVEN 302 there are 13.5 trachoma blind for every 1,000 persons. The Far West regions (i.e., A and B) have 17.3 trachoma blindness cases per 1,000 trachoma cases, while the remainder of Nepal has only 7.2 trachoma blind per 1,000 cases. The ratio of trachoma blindness to trachoma cases also varies by sex and age, as might be expected. Females have 16.6 trachoma blind for every 1,000 trachoma cases compared to a ratio of 9.1 for males. By age, the ratio increases from 4.6 trachoma blind per 1,000 trachoma cases for persons under age 30 to 16.2 per 1,000 trachoma cases for ages 30 to 49 and 46.7 per 1,000 for persons age 50 or older. That is, there is ten times the ratio of trachoma blind to trachoma cases for persons 50 and older as for persons under age 30. Given the natural history of the disease, such a finding is to be expected. Finally, the case ratio of trachoma blind to trachoma also shows variability across various ethnic groups. The Tharu community has a ratio of 15.2 per 1,000 trachoma cases, higher than the national average. Similarly, the Magar group has a ratio higher than the national average at 19.0 per 1,000. The Chhetri ethnic group has the highest ratio of trachoma blindness to trachoma, 27.7 per 1,000, despite the finding that they have a lower prevalence of trachoma blindness than either the Tharu or Magar communities (i.e., 1.8 per 1,000 persons versus 2.9 per 1,000 for the Magar and 4.2 per 1,000 for the Tharu groups). These findings primarily confirm previous conclusions about the distribution of trichiasis and entropion and trachoma blindness in Nepal. Females, persons ages 50 and older, and residents of the Far West regions are apparently at increased risk of these serious consequences of trachoma when only persons with trachoma are considered. On the other hand, although the Magar and Tharu ethnic groups have higher prevalence rates for trichiasis and entropion and trachoma blindness than the Chhetri group, the Chhetris have a higher trachoma blindness to trachoma case ratio. The Chhetri are thus likely to require a special intervention strategy to reduce the rate of blindness due to trachoma among Chhetris having the disease. 7.5 A Profile of the Trachoma Hyperendemic Area Of all the diseases and conditions related to blindness that have been studied in the Nepal Blindness Survey, trachoma is by far the least uniformly distributed. Trachoma has been shown to cluster geographically, demographically, and socially, and trachoma se- quelae such as trichiasis and entropion or blindness are often even
