Size Estimation of Groups at High Risk of HIV/AIDS using Network Scale Up in Kerman, Iran

Objective: to estimate the size of groups at high risk of hiv,network scale up (nsu), an indirect method, was used.methods: 500 kermanian male aged 18 to 45 were recruited. 8groups at high risk of hiv were defined: users of opium, unknowndrug, ecstasy, and alcohol; intra?venous drug users (idus; maleswho have extra?marital sex with females (msf); male who havesex with female sex workers (mfsw); and male who have sexwith other male (msms). we asked respondents whether theyknow anybody (probability method), and if yes, how many people(frequency method) in our target groups.results: estimates derived in the probability method were higherthan the frequency method. based on the probability method,13.7% (95% ci: 11.3%, 16.1%) of males used alcohol at least oncein last year; the corresponding percent for opium was 13.1% (95%ci: 10.9%, 15.3%). in addition, 12% has extra?marital sex in lastyear (95% ci: 10%, 14%); while 7% (95% ci: 5.8%, 8.2%) had sexwith a female sex worker.conclusion: we showed that drug use is more common amongyoung and mid?age males; although their sexual contacts werealso considerable. these percentages show that special preventiveprogram is needed to control an hiv transmission. estimatesderived from probability method were comparable with data fromexternal sources. the underestimation in frequency method mightbe due to the fact that respondents are not aware of sensitivecharacteristics of all those in their network and underreporting islikely to occur.