304 CHAPTER SEVEN include any of the three priority areas shown in Figure 7.4, depend- ing on how much of the disease one wishes to include. In this sec- tion, one portion of these hyperendemic areas, which accounts for almost half of the trachoma, trichiasis and entropion, and trachoma blindness in Nepal, will be examined: Bheri and Seti zones. These two zones roughly correspond to priority zones 1 and 2 in Figure 7.9. Administratively these zones represent units well-known to persons in the field and hence they may serve as convenient units for operationalizing the hyperendemic area as an objective for trachoma intervention activities. With a hyperendemic area identified epidemiologically, ad- ministratively, and operationally, it is possible to do two important things. First, the trachoma programme can be focused sharply and resources targeted to the location of the problem. Second, it is possible to explore various hypotheses about factors related to trachoma blindness in a hyperendemic area in order to develop effective intervention strategies. Thus, it is the purpose of this section to examine further the dis- tribution and determinants of trachoma, trichiasis and entropion, trachoma blindness, and other characteristics within two zones representing the hyperendemic area: Bheri and Seti. Since these two zones represent a large share of the trachoma, trichiasis and entropion, and trachoma blindness in the country, the distribution of these characteristics will be similar to those observed in Section 7.3. Thus, the discussion in this section will briefly review findings and intervention criteria for these two zones as a means of summarizing trachoma in Nepal. 7.5.1 Trachoma From the estimated 909,834 cases of trachoma in Nepal, an estimated 433,751 occurred in Bheri and Seti zones, for an overall prevalence of 26.6 cases per 100 persons. That is, an estimated one-quarter (26.6%) of the persons in Bheri and Seti zones have signs of trachoma infection. The age and sex distribution of trachoma cases in Bheri and Seti zones is shown in Table 7-48. Females have slightly more than half (54.1%) of the trachoma in the two zones and, except for two age groups (i.e., 30-39 and 40- 49 years), females have a higher age-specific prevalence rate than males for all ages. Over all ages, females have a trachoma prevalence rate of 28.3 per 100 persons while males have a slightly lower rate at 24.7 per 100 persons. With respect to age, there is a drop in prevalence rates for the adolescent years (i.e., 10-19 years), and the decrease is more marked for males than for females. These
