Kayoko KatoTeiichiro ShiinoShigeru KusagawaHironori SatoKyoko NohtomiKayo ShibamuraNguyen Tran HienPham Kim ChiTruong Xuan LienMai Hoang AnhHoang Thuy LongGaysorn BunyaraksyotinYoshiko FukushimaMitsuo HondaChantapong WasiShudo YamazakiYoshiyuki NagaiYutaka TakebeNational Institute of Infectious DiseasesNational Institute of Hygiene and Epidemiology HanoiPasteur Institute in Ho Chi Minh CityPreventive Medicine CenterRegional Medical Science CenterMahidol University2018-09-072018-09-071999-09-01AIDS Research and Human Retroviruses. Vol.15, No.13 (1999), 1157-1168088922292-s2.0-0033200064https://repository.li.mahidol.ac.th/handle/123456789/25431To investigate the molecular epidemiology of a recent HIV-1 outbreak in northern Vietnam and its relation to the epidemic in surrounding areas, we analyzed 17 HIV-positive blood specimens from 3 heterosexuals, 2 sexually transmitted disease patients, and 12 injecting drug users (IDUs), collected in 4 provinces near Hanoi in 1998. These were compared with the specimens from Ho Chi Minh City (n = 10) and An Giang Province (n = 10) in southern Vietnam and with published sequences from neighboring countries. Genetic subtyping based on the env C2/V3 sequences revealed that HIV-1 subtype E predominated throughout Vietnam in all risk populations; the exception was one typical United States-European-type HIV-1 subtype B detected in a patient in He Chi Minh City, the first case of HIV infection identified in Vietnam in 1990. The HIV-1 subtype E sequences identified in 9 of the 12 IDUs from northern provinces were closely related phylogenetically to those in IDUs in nearby Guangxi Province of China, and also shared a common amine acid signature downstream of the env V3 loop region. The low interperson nucleotide diversity among IDUs in northern Vietnam supports the view that HIV-1 subtype E was introduced recently among IDUs in northern Vietnam. These data indicate a linkage between HIV-1 circulating among IDUs in northern Vietnam and southern China, and suggest recent transborder introductions as the likely source of HIV-1 subtype E in northern Vietnam.Mahidol UniversityImmunology and MicrobiologyArticleSCOPUS10.1089/088922299310250