Motivation, recruitment, and screening of volunteers for a phase I/II HIV preventive vaccine trial in Thailand.

Data from recruitment and screening for a phase I/II preventive HIV-1 vaccine trial in Thailand were evaluated with respect to correlates of participation at each phase. Correlates included demographic variables, motivation for interest in the trial, and factors related to communication and contact. Participants were recruited at two sites through varied methods. The majority of prescreenees reported altruistic motives for interest in the trial and blood donors emerged as a group that may have been particularly altruistic. Findings indicated site differences in attrition during recruitment and screening, but not in enrollment into the vaccine trial. Blood donation and willingness to be contacted by phone at home were significantly related to making and keeping screening appointments.

PIP: The issue of recruitment of volunteers for trials of an HIV preventive vaccine has raised concerns, especially in developing countries, about motivation, the potential for coercion, informed consent, unblinding, and the social consequences of vaccine-induced seropositivity. The present study evaluated factors related to the recruitment and retention of volunteers for a double-blind, placebo-controlled phase I/II preventive HIV vaccine trial conducted at two medical centers in Thailand (Bangkok and Chiang Mai). 217 men and women responded to calls for volunteers, 124 scheduled a screening appointment, and 104 appeared for the appointment; 54 actually enrolled. 56.2% of prescreenees expressed altruistic motives (desire to benefit Thai society or contribute to stopping the AIDS epidemic) for their interest in the study. Multivariate analysis indicated that willingness to schedule an appointment was significantly associated with a history of blood donation and a willingness to be contacted by the project at home by phone. Actual attendance at the appointment was significantly associated only with blood donation history. None of the factors examined--motives, willingness to be contacted by phone or mail, site, demographics, and blood donation history--was related to whether screened volunteers were deemed eligible and enrolled. Only 2 volunteers dropped out of the study, both at an early point. The presence of multiple stages of recruitment allows potential volunteers an opportunity to reevaluate their willingness to participate and seems to ensure a high level of commitment.

Nursing frequency and the energy intake from breast milk and supplementary food in a rural Thai population: a longitudinal study.

A group of 60 infants representative of a rural Thai population were studied longitudinally over the first year of life. Their breast milk intake, supplementary food intake and nursing patterns were measured for 2 consecutive days at about 15, 45, 90, 180, 270 and 360 days of age. For the sample as a whole, the estimated peak value for energy intake from breast milk was 529 kcal (2213 kJ) and occurred at 34 days post-partum. Thereafter milk intake declined, with 40% of infants fully weaned by the end of the first year. Supplements were introduced early, with 15% of infants supplemented by 2 weeks and 68% by 6 weeks. Higher levels of supplementation were associated with lower breast milk intake. In addition there was an independent positive effect of nursing patterns (number of breast feeds per day). Interaction terms show that both supplementary feeding and number of feeds have quantitatively different effects at different ages: breast milk intake varies more with level of supplementation in younger infants than in older infants, and varies more with number of feeds in older infants than in younger infants. Higher peak levels of breast milk intake were followed by a steeper decline, and infants who took more breast milk at 15 days were more likely to be fully weaned by their first birthday.

The bacterial content of infant weaning foods and water in rural northern Thailand.

Samples of weaning food and supplementary water were collected for analysis of bacterial content from among a random sample of 65 infants under the age of 1 year living in a rural area of northern Thailand. Using geometric means, mean total bacterial count of infant's drinking water was 351 organisms/ml (95 per cent CIs 170-770), and the most probable number (MPN) of faecal coliforms/ml was 47 (95 per cent CIs 19-78). Mean total bacterial count of weaning foods was 38,000 (95 per cent CIs 25,000-59,000) organisms/g with 10 per cent recording counts greater than 1,000,000 organisms/g. Bacterial counts were similar to those reported in weaning food and water in other developing countries, and were above internationally recommended 'safe' levels. The bacterial count of water was not affected by boiling, due to poor cleaning and frequent re-use of utensils. Weaning foods were contaminated during preparation, in part through premastication and also via mode of cleaning of utensils.