桂北地区HIV-1感染者HIV-1病毒亚型分布观察

目的观察桂北地区HIV感染者HIV-1病毒亚型分布。方法采集桂北地区80例HIV-1感染者的静脉血,提取其中单个核细胞的DNA,用巢氏PCR扩增病毒膜蛋白env基因的C2-V3区,对PCR纯化产物进行测序,并应用GCG软件等对序列进行分析。结果通过PCR扩增得到env基因序列55份,分属4个亚型,分别为B型1份,CRF07-BC型19份,CRF08-BC型23份,CRF01-AE型8份,C型4份。感染途径为静脉吸毒者16例,性34例,非法献血2例,不详3例。16例吸毒感染者中CRF08-BC型12例,CRF07-BC型4例。34例性行为感染者中CRF07-BC型19例,CRF08-BC型11例,CRF01-AE型4例。结论桂北地区HIV感染者存在HIV-1亚型多样。静脉吸毒感染者以CRF08-BC型为主。性行为感染者以CRF07-BC型和CRF08-BC型为主。     

Evidence of a high frequency of HIV-1 subtype F infections in a heterosexual population in Buenos Aires, Argentina

We analyzed HIV-1 genetic variability, phylogenetic relationships, and association with transmission modes among 58 HIV-1-infected patients from Buenos Aires City, Argentina. The 58 strains were classified as env(gp41) HIV-1 group M subtype B (n = 34) and subgroup F1 of subtype F (n = 24). Potential recombinants combining parts of viral regions from different subtypes, B(prot)/F(env) and F(prot)/B(env), were found in two patients, and a dual infection with HIV-1 prot subtypes B and F was identified in one individual. Epidemiologic analysis of behavioral risks revealed that the frequency of infection with subtype F viruses was significantly higher (p < 0.0001) among heterosexual patients (71%) compared with homosexual patients (11%). The spread of non-B subtypes into heterosexual populations may be more common than previously thought. Our findings provide important information for monitoring the transmission of HIV-1 strains among different risk groups in Argentina as well as for vaccine development.     

Identification of mixed HIV-1/HIV-2 infections in Brazil by polymerase chain reaction.

Analysis of sera from hospitalized Brazilian patients by whole-virus lysate-based enzyme immunoassay and Western blot indicated that 0.4% were reactive to HIV-2 alone while 4% were reactive to both HIV-1 and HIV-2. When these sera were tested for HIV antibody by type-specific peptide enzyme immunoassays, dual seropositivity was confirmed in only 0.4% of patients. To define genetically the HIV strains within the population, we analyzed peripheral blood mononuclear cells from selected seropositive patients for the presence of HIV-1 and HIV-2 proviral DNA using the polymerase chain reaction (PCR). Independent primers/probes sets were used for the amplification and detection of viral sequences from the long terminal repeat (LTR), gag, and protease (prt) gene regions. Our findings confirmed the serologic evidence of HIV-2 in Brazil and determined the extent of mixed HIV-1 and HIV-2 infections. Detailed evaluation of the amplified viral protease sequences by endonuclease restriction analysis and DNA sequencing independently confirmed mixed HIV-1 and HIV-2 infections in the two patients seropositive for HIV-1 and HIV-2. The data further indicated that these isolates are distinct from the HIV laboratory standards. We interpret the combination of culture and PCR findings to demonstrate the presence of both HIV-1 and HIV-2 in Brazil.     

Epidemiological study of phylogenetic transmission clusters in a local HIV-1 epidemic reveals distinct differences between subtype B and non-B infections

Background  

The number of HIV-1 infected individuals in the Western world continues to rise. More in-depth understanding of regional HIV-1 epidemics is necessary for the optimal design and adequate use of future prevention strategies. The use of a combination of phylogenetic analysis of HIV sequences, with data on patients' demographics, infection route, clinical information and laboratory results, will allow a better characterization of individuals responsible for local transmission.     

HIV-1 subtype diversity in Minnesota

BACKGROUND: Genetic variation in human immunodeficiency virus (HIV)-1 poses significant public-health and clinical challenges. In North America, subtype B is most prevalent. HIV-1 subtyping is not integrated into routine HIV/acquired immunodeficiency syndrome surveillance in the United States. In 2003, the Minnesota Department of Health piloted HIV-1 subtyping with routine surveillance to describe the existence and variety of non-subtype B strains. METHODS: Targeted HIV-1 subtype surveillance was conducted on 98 African-born HIV-infected patients. Sentinel subtype surveillance was conducted in a Minneapolis sexually transmitted disease clinic on 28 newly diagnosed non-African HIV-positive patients. Subtype determination was based on a partial sequence of the gp41 region of the HIV-1 env gene. RESULTS: Subtyping was successful for 87 of 98 samples from African-born HIV-infected patients; 95% were non-B subtypes. The 7 subtypes observed were consistent with strains endemic in patients' birth regions. Subtyping was also completed for samples from 25 of 28 non-African-born patients; all were subtype B. CONCLUSIONS: Multiple HIV-1 subtypes are present in Minnesota. Our data suggest that most of the HIV cases in Minnesota among African-born patients are non-B subtypes. Population-based surveillance inclusive of groups at high risk for variant strains is needed to monitor the prevalence and variety of HIV subtypes in the United States.     

Neutralizing antibody responses in recent seroconverters with HIV-1 subtype C infections in India

The longitudinal heterologous neutralization response against two HIV-1 subtype C isolates was studied in 33 ART-naive individuals recently infected with HIV-1 subtype C from India. Seven of 33 (21%) seroconverters demonstrated a consistent response against both isolates (65-100% neutralization), whereas the remaining 26 (79%) were nonresponders. Four of the seven responders demonstrated a neutralization response (>75% neutralization) within 2-3 months of infection and in the remaining three, the response was demonstrated between 22 and 38 months after infection. In the past, HIV vaccines targeted the V3 region for the development of neutralizing antibodies. However, recent studies have shown that anti-V3 antibodies are generated after HIV-1 infection, but are not effective in neutralizing virus. In this study, the V3 sequences of HIV-1 from seven responders were analyzed and compared with those from nonresponders. The V3 region sequences from early and late responders did show certain mutations that were not found in the nonresponders; however none of these mutations could explain the neutralization responses. This suggested that HIV-1 envelope regions other than the V3 domain may be involved in generating a neutralization response. This is the first report that describes the pattern of emergence and persistence of the heterologous neutralization response in recently HIV-1 subtype C-infected individuals from India and studies its association with sequence variation in the V3 region.     

78例未经抗病毒治疗的HIV-1 B亚型感染者耐药结果分析

目的分析未经抗病毒治疗的HIV-1 B亚型感染者的耐药情况及主要耐药位点与血清病毒载量的关系,明确我国中原地区HIV-1天然耐药的耐药谱,为今后确定高效抗逆转录病毒治疗方案提供参考。方法检测78例未经抗病毒治疗感染者血清HIV基因耐药情况及病毒载量情况,进行描述性统计及多元统计分析。结果78例感染者耐药以HIV蛋白酶基因次要位点L93P、V77I及I93L为最多见,三者对病毒载量均无明显影响;主要耐药位点出现率较国外偏低,主要为K103N,另有Q151M。逐步回归分析病毒载量可能与I93IL等少见突变有一定关系。结论我国中原地区未经治疗的HIV-1 B亚型感染者中天然耐药的发生率较低,且常见HIV基因位点和病毒载量变化无直接相关性;而少见的主要位点突变因影响抗病毒药物选择,应引起足够重视。     

Preferential in-utero transmission of HIV-1 subtype C as compared to HIV-1 subtype A or D

OBJECTIVE: To determine whether different HIV-1 genotypes present in a single cohort, in Dar es Salaam, Tanzania, showed differences in timing for transmission from mothers to their infants. METHODS: We determined the maternal viral load, transmission time, and the HIV-1 envelope (env) subtype of 253 HIV-1-infected infants enrolled in a randomized double-blind placebo-controlled trial to examine the efficacy of vitamins in decreasing mother-to-child transmission in Tanzania. Classification of HIV-1 positivity in utero was based on PCR results at birth. Infants were classified as intrapartum infected if they scored negative for the sample collected at birth and positive for the sample collected at 6 weeks of age. RESULTS: We found significant differences in the distribution of transmission time according to subtype. A higher proportion of HIV-1 with subtype C env (C-env) was transmitted in utero than HIV-1 with subtype A env (A-env), subtype D env (D-env), or both combined. CONCLUSIONS: The identification of patterns of mother-to-child transmission times among HIV-1 genotypes may be useful in the selection of drug regimens for chemoprophylaxis. Based on our results, the efficacy of regimens administered only at labor may not protect as large a fraction of infants born in geographical regions with subtype C-env epidemics as compared to epidemics in regions where subtypes A-env and D-env predominate in the population.     

HIV-1 subtype J recombinant viruses in Spain

Genetic characterization of HIV-1 was carried out in two women who originated in Cameroon and Equatorial Guinea, respectively, and who were diagnosed more recently as HIV-1 seropositive in Madrid, Spain. Phylogenetic studies showed that the protease-encoding gene from both individuals clustered with subtype J sequences with a high bootstrap. However, env sequences clustered with subtypes A and C, respectively. This work represents the first characterization of HIV-1 containing subtype J-like genomic regions in Spain.     

中国首例HIV-1 J亚型毒株的鉴定

目的通过对1例来自刚果的人类免疫缺陷病毒Ⅰ型（HIV-1）感染者样品进行序列分析，鉴定其亚型种类。方法从该感染者血浆样品中提取RNA，经逆转录后采用套式PCR扩增HIV env、gag及pol基因的部分区段，PCR产物直接测序，将所获序列与参考序列进行比对分析，计算基因距离及构建系统进化树。结果该感染毒株样品序列与HIV-1J亚型国际参考株J．SE．93及J．SE．94聚在一起，与两参考株序列在env基因区距离均为8．2％，pol基因区距离分别为6．4％和6．3％，gag基因区距离分别为8．9％和8．0％，证实其为HIV-1J亚型。这是国内首次报道检出HIV-1J亚型。结论HIV-1J亚型毒株已随国际旅行者传人我国，加强对国际旅行人员中HIV毒株亚型的监测具有重要意义。     

Prevalence and risk factors for Hepatitis C and HIV-1 infections among pregnant women in Central Brazil

Background  

Hepatitis C (HCV) and human immunodeficiency virus (HIV) infections are a major burden to public health worldwide. Routine antenatal HIV-1 screening to prevent maternal-infant transmission is universally recommended. Our objectives were to evaluate the prevalence of and potential risk factors for HCV and HIV infection among pregnant women who attended prenatal care under the coverage of public health in Central Brazil.