Coxsackievirus A16 induced neurological disorders in young gerbils which could serve as a new animal model for vaccine evaluation.

Coxsackievirus A16 (CA16) is one of the major pathogens associated with human hand, foot, and mouth disease (HFMD) in the Asia-pacific region. Although CA16 infections are generally mild, severe neurological manifestations or even death has been reported. Studies on CA16 pathogenesis and vaccine development are severely hampered because the small animal models that are currently available show major limitations. In this study, gerbils (Meriones unguiculatus) were investigated for their suitability as an animal model to study CA16 pathogenesis and vaccine development. Our results showed that gerbils up to the age of 21 days were fully susceptible to CA16 and all died within five days post-infection. CA16 showed a tropism towards the skeletal muscle, spinal cord and brainstem of gerbils, and severe lesions, including necrosis, were observed. In addition, an inactivated CA16 whole-virus vaccine administrated to gerbils was able to provide full protection to the gerbils against lethal doses of CA16 strains. These results demonstrate that gerbils are a suitable animal model to study CA16 infection and vaccine development.

[Risk behavioral networks of newly reported HIV infections in Taizhou prefecture, Zhejiang province].

OBJECTIVE: To understand the risk behavioral networks of newly reported HIV infections in Taizhou prefecture, Zhejiang province. METHODS: Newly reported HIV infections from May 2008 through March 2010 in Taizhou prefecture were invited to participate in a cross-sectional survey which requested numbers and contact information of individuals with whom they had had high risk contacts as well as risk behavioral acts with them. Persons having had risky contacts with HIV-infected cases were thereof approached to participate in this survey and to receive HIV testing. Those who tested positive for HIV were subject to further round of the surveys. RESULTS: A total of 267 HIV cases were newly reported during this study period. Among them, 191 participated in the survey and served as 'index cases', including 158 cases identified from routine HIV surveillance programs and 33 cases identified from the present survey. Heterosexual transmission was the primary transmission route (74.9%, or 143/191), followed by homosexual transmission (19.4%, or 37/191) and injection drug use (5.8%, or 11/191). These 191 HIV cases reported a total of 1152 individuals with whom they had had risky contacts. They were able to provide contact information of 461 risk contacts. Of them, 129 received HIV testing and 61 (47.3%) tested positive for HIV. HIV prevalence was the highest among spouses or long-term sex partners of HIV cases (45.6%, or 47/103) and male sex partners of HIV-infected men having sex with men (MSM) (60.0%, or 12/20). Condom use was very low among them, with only 33.9% consistently using condoms for sex. CONCLUSION: Newly reported HIV infections in Taizhou prefecture reported a large and complicated risk behavioral networks and low condom use, suggesting a potential risk of HIV among these connected people, especially among MSM. Much efforts are needed to intervene these high risk subgroups and high risk behavioral networks.

[Human immunodeficiency virus/sexually transmitted infection, risk behavior and sexual networks among men who have sex with men in Taizhou city, Zhejiang province].

OBJECTIVE: To study the prevalence of human immunodeficiency virus (HIV), sexually transmitted infection (STI), risk behavior and the sexual networks among men who have sex with men (MSM) in Taizhou city, Zhejiang province. METHODS: A cross-sectional study was applied with venue-based sampling in 2 MSM gathering sites in Taizhou. 'Informed Consent' principle was applied and MSM were studied through a structured questionnaire. Blood samples were collected from those who accepted free and confidential HIV/STI counseling and then tested for HIV, syphilis, HCV and HSV-2 antibodies with ELISA. HIV positive sera were certified with western blot. RESULTS: 106 MSM were investigated and 97 qualified questionnaires were collected. 25.0% (23/92) of these MSM have ever had 1 female sex partner while 47.8% (44/92) had 2 or more. 14.3% (13/91) of them reported having had 1 male partner who had engaged in anal sex and 80.2% (73/91) had 2 or more. 22.1% (19/86) of them had participated in group sex but 62.5% (55/88) of them did not always use condom when having anal intercourse. 15.1% (14/93) of them had 1 oral sex partner while 75.3% (70/93) having 2 or more. 38.9% (37/95) of them had sex with female sex worker, and 35.5% (33/93) had sex with male-to-male sex worker. 15.3% (13/85) of them had once been male-to-male sex worker themselves. 3.9% (3/77) of them were found HIV positive in blood tests, with 24.7% (18/73) positive of syphilis, 15.1% (11/73) positive of HSV-2 but HCV appeared to be negative. 46 cases reported their egocentric recognition networks, with mean degree of 5.91 (ranging 0 - 10), and mean density of 0.548 (ranging 0.000 - 1.000). 43 sexual networks were identified, with mean degree of 2.70 (ranging 0 - 10), and mean density of 0.246 (ranging 0.000 - 1.000). CONCLUSION: Risk behaviors, such as multiple sex partners, low proportion of condom use and commercial sex engagement, both with heterosexuals and homosexuals, were extensively existed among MSM in Taizhou, and the prevalence of HIV/STI was relatively high. Their sexual networks seemed complicated but there might be in place of some substantially isolated MSM groups with high risk of HIV/STI infection. More study should be applied to identify the relationship between sexual networks and HIV/STI transmission.