Drug coverage surveys for neglected tropical diseases: 10 years of field experience

Abstract

Mass drug administration is one of the public health strategies recommended by the World Health Organization for the control and elimination of seven neglected tropical diseases (NTDs). Because adequate coverage is vital to achieve program goals, periodically conducting surveys to validate reported coverage to guide NTD programs is recommended. Over the past decade, the Centers for Disease Control and Prevention (CDC) and collaborators conducted more than 30 two-stage cluster household surveys across three continents. The questionnaires gathered coverage data and information relevant to improving NTD programs including NTD-related attitudes and practices. From the 37 coverage survey estimates obtained in those surveys, 73.3% indicated an over reporting of coverage, including all three that assessed school-based distributions. It took an average of 1 week to conduct a survey. Our experiences led us to conclude that coverage surveys are useful and feasible tools to ensure NTD elimination and control goals are reached.

Figure 1.

Improved random walk method. Step 1: Spin a bottle in the village center to determine the direction of travel. Count all houses following a straight line until the village boundary. *In this example, 12 houses are counted. Step 2: Randomly choose a number between 1 and the total number of houses counted. This number corresponds to the first house to be surveyed. *In this example, the random number is 3, so the 3rd house is the first house to survey. Step 3: Select the subsequent houses by continuing away from the village center. Include all houses on the left side of the road. Turn left each time a road is encountered on the left. Continue until 10 houses are surveyed.

Figure 2.

Map of surveyed countries.