Population screening and mass chemoprophylaxis in Kiribati

International Journal of Leprosy and Other Mycobacterial Diseases, Dec 1999 by Daulako, E C

Kiribati is a country of 33 coral atolls and one volcanic island spread over a million square miles of the Pacific Ocean. Twenty-one of the islands are inhabited; the population projected for 1996 was 77,853. The Gilbert group consists of 16 inhabited islands, and the Line group of three; Phoenix Island and Banaba Island stand alone. Tarawa, in the Gilbert group, which is the capital island, contains about 40 percent of the population of the country.

Leprosy has been highly endemic in Kiribati (The Figure). When leprosy elimination activities were intensified in 1996, the number of new cases detected suddenly increased to 78, giving a new-case detection rate of 100 per 100,000 population. This situation prompted the government of Kiribati and its partners in leprosy elimination-the World Health Organization (WHO) and the Pacific Leprosy Foundation-to implement a project in which the entire population of the country was to be screened and chemoprophylaxis was to be administered to selected communities-- those with very high endemicity and those which are geographically isolated. The project was implemented in order to accelerate progress toward the elimination of leprosy by the year 2000.

The project was implemented by the formation of three special teams. One team was led by the WHO Short-Tenn Consultant and each of the remaining two teams was led by a Leprosy Control Officer assigned by the Ministry of Health. The members of the teams were recruited from the health staff of the areas in which the teams were operating. The plan was to start with the Gilbert group of islands and subsequently to extend the activity to the Line group and Phoenix Island.

The project was preceded and accompanied by regular broadcasts on Radio Kiribati to inform the general public of what was being done and the expected outcome. Listeners were also told where the teams would be working during the week, to alert them to present themselves for examination.

The population was screened by houseto-house visits, and visits to schools and places of work; in addition, anyone encountered in the market place or along the roadside during the visit to a locality was examined. Diagnosis was made by the team leader at the time of screening, based on clinical examination. For newly detected patients, a record was opened and treatment was administered immediately.

For chemoprophylaxis, a combination of 600 mg rifampin, 400 mg ofloxacin, and 100 mg minocycline (ROM) was administered to adults (those above age 14 years), and rifampin alone was administered to children (those under 15 years of age); the dosage for children 10 to 14 years of age was 600 mg, for those 5 to 9 years 300 mg, for those 2 to 4 years of age 150 mg, and for children no older than I year 100 mg. Patients with leprosy, pregnant women, people with kidney or liver disease, and patients with tuberculosis whose treatment included rifampin were not administered chemoprophylaxis.

On Tarawa atoll, screening was begun 22 May and completed 31 July 1997. One to two weeks were required to complete the screening on each of the remaining islands. South Tarawa was screened for the second time between August and October 1998, one year after the first round of screening.

Chemoprophylaxis was administered to the entire population of South Tarawa and the Christmas Islands-the former, which contributed 73 percent of the active cases of leprosy in the country, because of high endemicity, and the latter because of its geographic isolation. Chemoprophylaxis was administered on South Tarawa at the time of the second round of screening; on Christmas Island, chemoprophylaxis was administered between 20 April and 6 May 1998, at the time of the first round of screening.

Screening of the population has been completed on 19 of the 21 inhabited islands-on all 19 islands of the Gilbert and Line groups of islands. The two remaining islands, Banaba and Phoenix, represent only 0.2 percent of the entire population of the country, according to the census of 7 November 1990; therefore, approximately 99.8 percent of the population of the country has been included. The population of the 19 islands covered by the project was estimated to be 76,624, of whom 70,638 (92.2 percent) were screened. The population of South Tarawa was screened for a second time; of the estimated population of 29,374, 26,536 (90.3 percent) were screened.

In the course of the first round of screening, 135 new cases were detected, yielding a new-case detection rate of 191 per 100,000 population. The highest rate was in South Tarawa, with 315 per 100,000, representing 69.6 percent of all detected cases, whereas five islands had no cases. The numbers of cases in the remaining islands ranged from one to seven. Of the new cases detected, 26 (19.3 percent) were multibacillary (MB), and 36 (26.7 percent) were under 15 years of age; there were no cases with disability.

During the second round, 15 new patients were detected, yielding a new-case detection rate of 51 per 100,000; among them were three MB patients, It patients with single lesions, and seven children under 15 years of age. Compared to the first round of screening, both the number of new patients and the detection rate were reduced by 84 percent.