[Distribution of HIV-1 subtypes among foreign patients, in Guangzhou, between 2008 and 2010, and in 2015].

Objective: To understand the characteristic of subtype distribution among foreigners who were living with HIV-1, in Guangzhou. Methods: HIV-1 RNAs were extracted from 114 serum specimens in foreigners diagnosed with HIV-1 infections between 2008 and 2010, and in 2015. Partial pol gene of HIV-1 genome from these RNA samples were amplified by nested reverse transcription polymerase chain reaction (nested-PCR) with nucleotide sequenced. Subsequently, phylogenetic tree was reconstructed using the pol sequences of samples and references. Results: Among all the 114 samples, 57.9% were from males and 42.1% from females, with an average age as 35.21 years old and the standard deviation as 9.63 years. A total of 6.8% of the samples were from Africans. The top three subtypes were identified as CRF02_AG, subtype G and subtype C, accounted for 30.7%, 14.9% and 12.3% respectively. Compared with samples gathered from 2008 to 2010, the proportions of subtype A1 and CRF01_AE significantly increased, while the other subtypes significantly decreased in 2015 (χ(2)=37.570; P=0.013, 99% CI: 0.010-0.016). Proportions of CRF01_AE and subtype G among males outnumbered the females but the proportions of subtype A1, CRF02_AG and URF among females appeared the other way round (χ(2)=15.528; P=0.029, 99%CI: 0.024-0.033). Proportions of CRF02_AG and subtype G among HIV-1 positive Africans were larger than those from other Southeast Asian countries or areas, However, the proportion of CRF01_AE among HIV-1 positive patients from Southeast Asian countries was higher than those patients from other areas (χ(2)=39.399; P=0.009, 99% CI: 0.006-0.011). The rates of resistance to any drug of protease inhibitors (PIs), reverse transcriptase inhibitors (RTIs), as well as to PIs, NRTIs, and NNRTIs alone, were 21.9%, 12.3%, 6.1% and 7.0%, respectively. One of nine CRF01_AEs from the HIV-1 positive patients were found closely clustered in those phylogenetic tree (bootstrap=0.855) samples, collected from local patients in Guangzhou. Conclusions: Our findings showed that these foreign subtypes had been spread to the natives, more from the Africans than from the other areas, in Guangzhou. These types of viruses were different from the strains identified locally, suggesting that they might have been brought in by foreigners living with HIV-1, in Guangzhou. Programs related to care, support and behavioral intervention for HIV positive foreigners living in Guangzhou, should be strengthened.