Respondent Driven Sampling: An Effective Methodology to Estimate Vulnerability to HIV Transmission in Sex Workers of Santos, Brazil

Maria Graciela Gonzalez Morell
Neide Silva, Universidade de São Paulo
Regina Maria Lacerda, Universidade Federal de São Paulo (UNIFESP)

Some population groups of difficult access, as the sex workers (SW), present high vulnerability to HIV infection. The methodology Respondent Driven Sampling (RDS) begins with the identification of the first participants, named "seeds", that initiate the selection of others participants. RDS assumes that social nets are long enough for guarantee a representative final sample of the group to be studied. The RDS methodology applied in 175 sex workers of Santos, Brazil, showed that they did not communicate, forming two different nets, nightclubs workers and streets/hotels workers. Their vulnerability to the HIV was similar to the estimated at the beginning of epidemics in 1986. Despite of the similarity of exposition, the poorest women present a higher prevalence to the HIV. The change in the standard of drugs suggests revision of prevention actions that should be continuous and organized from the nets. The RDS constitutes an important strategy for access the TS.