Human Papillomavirus Genotypes and HPV16 E6/E7 Variants among Patients with Genital Cancers in Vietnam.

We previously reported human papillomavirus type 52 (HPV52) as the most prevalent high-risk genotype in non-cancer individuals in Vietnam. This study aimed to evaluate HPV genotypes and HPV16 E6 and E7 (E6/E7) gene variations in Vietnamese patients with genital cancers. Biopsy samples were collected from 124 Vietnamese patients with genital cancers (20 with vaginal, 50 with vulvar, and 54 with penile cancer). The HPV-DNA was amplified and genotyped, and HPV16 E6/E7 genes were compared with those previously reported for women with normal cervical cytology (N = 23). HPV-DNA was detected in 80.6% (100/124) of the cancer patients (80.0% of vaginal, 82.0% of vulvar, and 79.6% of penile), with HPV16/18 in 86.0% (86/100) and HPV52 in 7.0% (7/100) of the HPV-positive samples. The HPV-DNA prevalence and HPV genotype distribution did not significantly differ among the genital cancer patients (both P = 0.95). Significantly fewer instances of the HPV16 A4 sublineage (34.8% vs. 82.6%, P < 0.0001) and HPV16 E7 29S (36.4% vs. 87.0%, P = 0.0002) occurred in the cancer patients than in the women with normal cytology. Our results indicate that HPV16/18 accounts for more than 85% of genital cancers in Vietnam, and the HPV16 sublineage A4 containing E7 29S may be less oncogenic.

Discrepancies in prevalence trends for HIV, hepatitis B virus, and hepatitis C virus in Haiphong, Vietnam from 2007 to 2012.

We previously reported a significant reduction in the prevalence of human immunodeficiency virus type 1 (HIV) from 2007 to 2012 in people who inject drugs (PWID; 35.9% to 18.5%, p < 0.001) and female sex workers (FSW; 23.1% to 9.8%, p < 0.05), but not in blood donors (BD) or pregnant women, in Haiphong, Vietnam. Our aim in the present study was to assess trends in the prevalence of infection with hepatitis B and C viruses (HBV and HCV, respectively). We also investigated the coinfection rates of HBV and HCV with HIV in the same groups. Between 2007 and 2012, HBV prevalence was significantly decreased in BD (18.1% vs. 9.0%, p = 0.007) and slightly decreased in FSW (11.0% vs. 3.9%, p = 0.21), but not in PWID (10.7% vs. 11.1%, p = 0.84). HCV prevalence was significantly decreased in PWID (62.1% in 2007 vs. 42.7% in 2008, p < 0.0001), but it had rebounded to 58.4% in 2012 (2008 vs. 2012, p < 0.0001). HCV prevalence also increased in FSW: 28.6% in 2007 and 2009 vs. 35.3% in 2012; however, this difference was not significant (2007 vs. 2012, p = 0.41). Rates of coinfection with HBV and HCV among HIV-infected PWID and FSW did not change significantly during the study period. Our findings suggest that the current harm reduction programs designed to prevent HIV transmission in PWID and FSW may be insufficient to prevent the transmission of hepatitis viruses, particularly HCV, in Haiphong, Vietnam. New approaches, such as the introduction of catch-up HBV vaccination to vulnerable adult populations and the introduction of HCV treatment as prevention, should be considered to reduce morbidity and mortality due to HIV and hepatitis virus coinfection in Vietnam.

Change in the Prevalence of HIV-1 and the Rate of Transmitted Drug-Resistant HIV-1 in Haiphong, Northern Vietnam.

We previously reported a significant decrease in HIV-1 prevalence, with no increase in drug-resistant HIV-1 among injecting drug users (IDU), female sex workers (FSW), and blood donors (BD), in Haiphong, Vietnam, from 2007 to 2009. In 2012, 388 IDU, 51 FSW, and 200 BD were recruited for further analysis. None had a history of antiretroviral treatment. From 2007 to 2012, HIV-1 prevalence was reduced from 35.9% to 18.6% (p<0.001), 23.1% to 9.8% (p<0.05), and 2.9% to 1% (p=0.29) in IDU, FSW, and BD, respectively. Of 79 anti-HIV-1 antibody-positive samples, 61 were successfully analyzed for the pol-reverse transcriptase (RT) region. All HIV-1 strains were CRF01_AE. Nonnucleoside RT inhibitor-resistant mutations, Y181C/I, were detected in three subjects; one had the nucleoside RT inhibitor-resistant mutations L74V and M184V and one had E138K. The prevalence of transmitted drug-resistant HIV-1 in Haiphong increased slightly from 1.8% in 2007 to 6.6% in 2012 (p=0.06).

Application of an M-cell-targeting ligand for oral vaccination induces efficient systemic and mucosal immune responses against a viral antigen.

Oral mucosal vaccination is an alternative method to overcome the pitfalls of current injection-based vaccines, such as pain and high cost of vaccination. It is a feasible and economic vaccine application, especially in developing countries. However, achieving effective antigen delivery into mucosal lymphoid organs and efficient immune stimulation are prerequisites to successful oral mucosal vaccination. One promising approach for oral mucosal vaccine development is exploring the potential of M cells via M-cell-targeting ligands that have the potential to deliver ligand-conjugated antigens into mucosal lymphoid organs and evoke conjugated-antigen-specific systemic and mucosal immune responses. Here, we investigated the M-cell-targeting ligand, Co1, in inducing specific immune responses against a pathogenic viral antigen, envelope domain III (EDIII) of dengue virus, to provide the foundation for oral mucosal vaccine development against the pathogen. After oral administration of Co1-conjugated EDIII antigens, we observed efficient antigen delivery into Peyer's patches. We also report the elicitation of EDIII-specific immunity in systemic and mucosal compartments by Co1 ligand (located in the C-terminus of EDIII). Furthermore, the antibodies induced by the ligand-conjugated EDIII antigen showed effective virus-neutralizing activity. The results of this study suggest that the M-cell-targeting strategy using Co1 ligand as a mucosal adjuvant may be applicable for developing oral vaccine candidates against pathogenic viral antigen.

Prevalence of HBV infection among different HIV-risk groups in Hai Phong, Vietnam.

Hepatitis B virus (HBV) infection in Hai Phong, northern Vietnam, was characterized by analyzing the prevalence and genotype distribution of HBV as well as co-infection with human immunodeficiency virus type 1 (HIV-1) among five different risk groups for HIV infection. Plasma samples were collected from intravenous drug users (n=760, anti-HIV-1 antibody positive rate: 35.9%), female sex workers (FSWs; n=91, 23.1%), seafarers (n=94, 0%), pregnant women (n=200, 0.5%), and blood donors (n=210, 2.9%) in 2007 [Ishizaki et al. (2009): AIDS Res Hum Retroviruses 25:175-182]. Samples were screened for the hepatitis B surface antigen (HBsAg) and anti-HBs antibody and analyzed genetically. The cumulative HBV incidence rate (HBsAg+anti-HBs) was 53.2% (10.7+42.5%) in intravenous drug users, 51.6% (11.0+40.6%) in FSWs, 54.3% (9.6+44.7%) in seafarers, 50.5% (12.5+38.0%) in pregnant women, and 51.0% (18.1+32.9%) in blood donors; there was no significant difference among these groups. Of 163 HBsAg-positive samples, 113 could be analyzed genetically. Phylogenetic analysis, based on the preS1 region, revealed genotype B4 was most prevalent (90/113; 79.6%), followed by C1 (17.7%), I1 (1.8%), and B2 (0.9%). There was no significant difference in HBV genotype distribution among different HIV infection-risk groups. The prevalence of HBsAg was 10.3% (31/301) in HIV-1-infected individuals and 12.5% (132/1,054) in non-HIV-1-infected individuals, which was not significant. In addition, no significant difference in HBV genotype distribution was observed between HBV/HIV-1 coinfected and HBV mono-infected groups. These results suggest that, although HBV and HIV-1 share modes of transmission, major transmission routes of HBV have been different from those of HIV-1 in Hai Phong, Vietnam.