Molecular Epidemiology On HIV In Hainan Province

To investigate the genetic background of HIV-1 strains in Hainan Province of South China we performed an HIV serological study and molecular epidemiological study based on blood samples of volunteers collected in March,2007.Of 96 volunteers, accounting for 18%of total Hainan samples,88 were confirmed to be infected with HIV-1.The peripheral blood CD4 T cell counts(mean±SD,3034±230 cells/μl) have inverse correlation to the plasma viral loads(geometric mean±SE,37,810±40,958 RNA copies/ml,P＜0.001).61%and 69%of total 88 persons were infected with HBV or HCV respectively.83 pol and env sequences were successfully amplified respectively. Phylogenetic analysis was conducted for each new sequenceindividually.The result is asfollow:1.Low prevalence of HIV was detected in Haina Province.But high morbidity was detected in special crowd in some area.2.As many as 64%of HIV-1-infected persons were injecting drug users(IDUs).Most of them live in west and south littoral. All IDUs with AIDS are infected with subtype CRF01_AE HIV.33%(29/88) of HIV-1-infected cases acquired the virus by heterosexual transmission.Subtype CRF01_AE,B,B',C,CRF₀8BC was infected by heterosexual transmission.3.The most important subtype is CRF01_AE.Transmission of CRF01_AE by both heterosexual contacts and IDU formed a huge transmission cluster.We also identified other subtype including B'(9.6%),C(2.4%),B(1.2%),CRF08_BC(1.2%) and a new recombination of CRF01_AE/B'.4.The existence of transmission clusters was determined using the statistical robustness of the ML topologies assessed by high bootstrap values(＞98%) with 1000 resamplings and short branch lengths(genetic distances＜0.015%) of HIV-1 pol gene sequences.Of the 83 pol sequences analysis,66(80%) segregated into 4 clusters having sequence similarity based on the established criteria.Cluster 1 has 59 persons forming a big one.To understand the prevalence and distribution of HIV-1 drug resistant genotypes,we conducted a study on the 83 persons infected with HIV.Although primary protease resistance mutations were not found in all 83 persons,secondary mutations are found in each person.The frequencies of protease secondary mutations were found to be significantly different between subtype B and CRF01_AE strains:M36I(0%vs 100%, p＜0.01 ),L63P(100%vs 23%,p＜0.01),A71T(44%vs 1%,p＜0.01),V77I(89%vs I%,p＜0.01 ).Of the 83 persons,10(12%) have already received antiretroviral therapy (ART).As for the reverse transcriptase,20%(2/10) of 10 person with ART have primary resistance mutations,i.e.D67N,K70N,F116Y,Q151M,M184V,K101E/H/N/Q,V106L, Y181C,G190A.Taken together,our finding shows that injecting drug transmission is becoming a major risk for current HIV outbreaks in Hainan province.Given that nearly 80%of people with HIV-1 infection are undiagnosed in China,the very large number of undiagnosed persons with advanced(high viremia) HIV-1 infection may represent a major source leading to new nationwide HIV outbreaks.Multisectoral responses are needed and more needs to be done to increase understanding and support from revevant agencies.An enhanced HIV/AIDS education is urgently needed to reduce the stigma.Our findings demonstrated that some drug resistant HIV-1 strains have been emerging overtime since the initiation of antiretroviral therapy.And the resistance strains might have transmitted in a group of people.Since there are only limited drug regimens available to patients in China,the antiretroviral therapy management should be strengthened.