Trachoma prevalence in rural areas of eastern Iran.

We investigated the prevalence of trachoma in rural areas of eastern Iran. We collected swabs from 150 children in three areas. Results of PCR showed presence of chlamydia in four boys (5.97%) and nine girls (10.84%). We suggest that in assessing the elimination of trachoma, WHO must consider border areas between countries.

Trachoma is the most common infectious cause of blindness. Trachoma, caused by the obligate intracellular parasite Chlamydia trachomatis, remains a leading cause of blindness throughout the world [1]. The infection is transmitted through contact with eye and nose discharge of infected people, particularly young children who are the principal reservoir of infection. It is also spread by flies that have been in contact with the eyes and noses of infected people [2], [3]. Trachoma rates increase greatly with crowding and poor living standards [4], [5]. Environmental risk factors influencing the transmission of the disease include poor hygiene, crowded households, water shortage and inadequate sanitation. Trachoma is hyperendemic in many of the poorest and most rural areas of 51 countries of Asia, Africa, Central and South America, Australia and the Middle East. Zabol is a city in the Sistan and Baluchistan Province, in Iran. It borders Afghanistan to the north, the Chehl-dokhtaran (Forty girls) and Malek-siah-kuh (Black King) Mountains to the west and southwest, and Pakistan to the south and southeast. Zabol lies within a dry-temperate zone in the de Martonne climatic zonation system; it is located near Lake Hamun and the region is irrigated by the Hirmand River. Lake Hamun is a seasonal lake that is often dry. The Zabol area is well known for its ‘120-day wind’ (bād-e sad-o-bist-roz), a highly persistent dust storm in the summer that blows from north to south.

During a visit to the Zabol rural areas near the Afghanistan border in June 2014, we observed that several of the children showed signs of follicular conjunctivitis. To confirm the suspicion that this was due to trachoma, swabs were collected from 150 children (67 male and 83 female) with age range 6–11 years in three areas near the border with Afghanistan. The upper eyelid was everted using a sterile cotton bud and the eyelid was swabbed three times using a nasopharyngeal swab. The swab was placed in a dry DNA-free tube. Sampling was performed using precautions to prevent transfer of agents between participants in the study [6]. Amplicor PCR analysis [7], showed the presence of chlamydia in four boys (5.97%) and nine girls (10.84%). More than 70% of the participants had access to clean water, sanitation and facial cleanliness during the study, but 85% lived near uncovered wastelands, kept animals close to their houses and had frequent contact with flies.

In the current study, the prevalence of trachoma in these older people was surprisingly high. WHO reported that seven countries had achieved the elimination of trachoma, and had progressed to the surveillance phase [2]. These countries are Gambia, Ghana, Morocco, Myanmar, Oman, Vietnam and, importantly. Iran.

One reason for the persistence of trachoma in this study may be the interaction with people in Afghanistan. Study participants said that they frequently communicated with the Afghan people living near the border. Therefore, it is very important that the elimination of trachoma from a country considers the effect that migration can have on the incidence of disease. The Afghan people who live near the Iran border have much poorer living conditions than Iranians living on the other side of the border. Furthermore, the continuing prevalence of trachoma in the rural areas near Zabol can be related to the absence of a specific trachoma control programme in these areas. Another factor that may have contributed to the high prevalence of infection in these areas is the presence of dust storms. A dry dust climate has long been important as a factor in high prevalence of trachoma [8]. Further study is needed to better understand the importance and threshold of each factor.

We suggest that in assessing the elimination of trachoma, WHO must consider border areas between countries. In conclusion, the results of this study demonstrate that trachoma is still a disease with public health importance in the population living in the Zabol rural areas near to the Afghanistan border and additional elimination efforts need to continue to satisfy the target set by the World Health Assembly resolution, which is elimination of trachoma as a public health problem by 2020.

Conflict of Interest

None declared.