Molecular epidemiologic characteristics and transmission clusters of HIV-1 CRF01_AE in Zhejiang, China

Abstract

Background HIV-1 CRF01_AE is becoming the predominant HIV-1 subtype among patients in China.The distribution and molecular epidemiologic characteristics of transmission clusters of HIV-1 CRF01_AE in Zhejiang,China remains unclear.This study analyzed the molecular epidemiologic characteristics and transmission clusters of HIV-1 CRF01_AE in Zhejiang. Methods Plasma samples obtained from 152 patients with HIV-1 CRF01_AE infection not undergoing ART were used to amplify HIV-1 pol and env. CRF01_AE drug resistance mutations (DRM) prevalence was analysed using Stanford University’s HIV Drug Resistance Database. A phylogenetic tree was constructed using FastTree (version 2.1.11) based on the GTR nucleotide substitution model and visualized using Figtree (version 1.4.4) and The Interactive Tree of Life; the Chinese HIV Gene Sequence Data Platform was used to construct genetic transmission networks. Result Most samples could be grouped into CRF01_AE transmission Clusters 1 (11.18%), 4 (64.5%), and 5 (7.24%). The CD4 + T-cell counts associated with Clusters 1, 4a, 4b, and 5 were 15, 38, 30, and 248 cells/mm3, respectively ( P < 0.05). DRM rates in Clusters 4a and 4b were 25.45% and 17.65%, respectively (P < 0.05), whereas they were 17.65% and 18.18% in Clusters 1 and 5, respectively. The high X4 tropism rates were 13.2%, 11.8%, 20%, and 0% in Clusters 1, 4a, 4b, and 5, respectively. In total, 24 transmission genetic networks, comprising 72 sequences and 61 links, were discovered; of them, 61.2%, 11.7%, and 18.2% were from Clusters 4, 1, and 5, respectively (P < 0.05). Conclusions In Zhejiang, different CRF01_AE clusters exhibited disease progression and outcome differences. The surveillance of molecular epidemiology of HIV-1 should be enhanced to improve prognosis of the disease and minimize its transmission.