Household Willingness to Pay for Azithromycin Treatment for Trachoma Control in the United Republic of Tanzania. (Research)

Article excerpt

Voir page 106 le resume en francais. En la pagina 106 figura un resumen en espanol.

Introduction

Trachoma is an important cause of blindness worldwide, with estimates of 5-7 million blind and 300-500 million more affected (1). Children form the main reservoir of infection in endemic communities, although complications from blinding occur mainly in adults. Blinding trachoma is caused by repeated or prolonged infection with Chlamydia trachomatis, which results in scarring of the conjunctiva and inturning eyelashes which scratch the surface of the eye (trichiasis), causing corneal opacities. In hyperendemic areas such as the Kongwa district of central United Republic of Tanzania, the prevalence of active trachoma in preschool children is around 60%, and that of trichiasis in persons over 55 years of age is about 8% (2).

WHO recommends a four-pronged approach for trachoma control (referred to as SAFE) that includes community-wide treatment with antibiotics, health education, environmental changes, and trichiasis surgery (3, 4). Traditionally trachoma was treated using tetracycline, which is more readily available than azithromycin, but is more burdensome to administer. Pfizer, Inc., is continuing to make azithromycin donations in a growing consortium of countries. The combination of the promotion of a four-pronged approach, an antibiotic donation programme, and the formation of the Alliance for the Global Elimination of (blinding) Trachoma (GET2020), has spurred interest in trachoma control.

Successful trachoma control efforts require resources that are greater than the costs of antibiotics. Delivery of the antibiotics and provision of other aspects of the SAFE strategy are likely to be expensive. One study in Nigeria estimated the costs of distributing donated ivermectin to be equal to the entire annual government health expenditure (5). Even if, initially, philanthropy covers trachoma control programme expenses, the issue of cost recovery will likely arise as it takes years for control efforts to succeed. The components of the SAFE strategy most likely to be subject to cost-recovery efforts are surgery and antibiotics.

Cost-recovery programmes can have a negative impact on utilization of health services. Additionally, the need for repeated mass treatments for a disease that leads to blindness later in life may limit compliance. In the present study we tested for associations between willingness to pay for a follow-up treatment with azithromycin and measures of socioeconomic status, risk factors for active trachoma, and perceived impact of an initial treatment with azithromycin.

Several factors suggest that it is important to assess the willingness to use resources for future azithromycin treatment. First, while the SAFE strategy is integrated from a health planning perspective, the affected population does not necessarily perceive it as an integrated strategy. Second, azithromycin treatment is a key component of the Tanzanian national trachoma control programme. The willingness to pay for azithromycin treatment specifically can be analysed since at the time of the study the villages concerned had only had the antibiotic component of the SAFE strategy, although all have subsequently been enrolled in the national programme. During the study, individuals with trichiasis were referred for additional treatment.

Information about who is willing to use personal resources for follow-up treatment will help to target the promotion of mass treatment programmes for communities with endemic active trachoma, thus maximizing the response to such programmes.

Conceptual model

In the context of our study, willingness to pay measures the total value of azithromycin treatment for those affected (6). A household's willingness to pay is determined by the household decision-makers' preferences and constraints, which are in turn a function of resources and "prices" such as the value and amount of time required to obtain treatment (opportunity costs). …