OBJECTIVETo study the distribution of human immunodeficiency virus-1 (HIV-1) strains subtypes in Shandong province and to study their source in order to predict the epidemic trend.

METHODSEpidemiological investigation was made and 93 DNA fragments of HIV-1 env, gag, tat gene were amplified by nested polymerase chain reaction from people infected with HIV-1, in 2002 - 2003. Their C2-V3, P17/P24, 1st exon of tat and adjacent region were sequenced.

RESULTSSequence analysis showed that there were 7 HIV-1 strains or circulating recombinant forms (CRFs), B' (n = 71), CRF01-AE (n = 9), CRF07-BC (n = 3), CRF08-BC (n = 3), B (n = 2), C (n = 2), CRF02-AG (n = 2). B' strains was the predominant which, covered 10 cities and 4 kinds of population including blood donors, blood receivers, spouses of the infected people and clients of the sex workers. CRF07-BC, CRF08-BC strains were identified in 5 cities, mainly from injecting drug users. CRF01-AE and other strains were found distributed in developed cities, among sex workers.

CONCLUSIONThere were many kinds of subtypes and CRFs of HIV and their genomes which generated obvious variation in Shandong province, suggesting that they might facilitate the spread of the disease in Shandong province.