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Objective To detect the positive rates of antibodies against avian influenza virus (AIV) subtypes H5, H6, H7 and H9 among people in poultry occupations in Guangdong province and to analyze the transmission of various subtypes of AIV from poultry to human contacts for the prevention and control of novel AIV infection in human beings.Methods Serum specimens were collected from 1066 peo-ple in poultry occupations ( occupational group) and 205 people not in poultry occupations ( non-occupational group) in 10 cities of Guangdong province.The inactivated AIV strains, isolated from poultry or environment of Guangdong province, were used as antigens to detect antibodies against AIV subtypes H5, H6, H7 and H9 by using the hemagglutination inhibition ( HI) assay.Results The positive rates of antibodies against AIV subtypes H5, H6, H7 and H9 carried by people from the occupational group were respectively 0.44%, 0%, 0.30%and 0.30%in 2013 and 1.08%, 0.0%, 0.0%and 0.27%in 2014.Only the anti-H9 anti-bodies were detected in serum samples collected form people in the non-occupational group in 2013 with a positive rate of 0.95%.No significant differences with the positive rates of anti-AIV antibodies were found between the occupational group and the non-occupational group.However, the geometric mean titer ( GMT) of anti-AVI antibodies in people from the occupational group was higher than that of the non-occupational group.Conclusion Although a grand spread of AIV from avian to human is not likely to happen yet, con-tacting with poultry is the risk factor for AIV infection in Guangdong population.A long-term surveillance of anti-AIV antibodies in serum should be strengthened among people in poultry occupations for the timely pre-vention and control of novel AIV outbreak.
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Objective To understand the enterovirus infection in family close contacts of patients with hand,foot and mouth disease (HFMD) and the contamination of environment.Methods Forty-one HFMD cases confirmed by laboratory from web-based surveillance system during July to August 2010 in Guangdong Province were selected.All members of the cases′ family were investigated by collecting their information on demography,habit of domestic hygiene and hygiene status in household.The stool samples of all members and the smear samples from the surface of family belongings from 16 families were collected and the enterovirus was detected by real time quantitative polymerase chain reaction.The data were analyzed by chi square teat and t test.ResultsForty-one HFMD cases′ families and 135 close contacts were included in this survey.The infection rate of the enterovirus was 39.2％ (53/135) in all close contacts.Of all the investigated families,the infectionrate was 58.5％ (24/41) in family with one or more close contacts and 9.8％ (4/41) in family with all close contacts.The differences of infection rates of enterovirus among the members of parents (32.5％,25/77),grandparents/aunts/ uncles (43.3％,13/30) and cousins (53.6％,15/28) didn′t show statistical significance (χ2 =4.07,P=0.131).The infection rate of enterovirus in close contacts from family with more than 5 members was higher than that from family with 4 or less members (OR=1.4,95％CI 1.1-1.9).Among 135 close contacts,27.4％ (37/135) were infected with the same types of entervirus as that of HFMD case in the family and 11.9％ (16/135) were infected with the different virus types.In 33 family belongings samples from 16 families,the positive rate of enterovirus detection was 6.1％ (2/33).Between 17 families with enterovirus testing negative and 23 families with enterovirus testing positive in close contacts,there were no statistical differences of the family hygiene status,hand-washing of babysitter,disinfection of tableware and drinking,sharing towels,airing bedding articles and toy cleaning (P＞0.05).ConclusionsThe infection rate of enterovirus in close contacts of HFMD cases is high and the enterovirus contamination exists in case family environment.Management of close contacts of HFMD cases and disinfection of the family environment are important in HFMD controls.
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Objective To study the effects of purified rabies vaccine for human use (RV) on specific Th1/Th2 cytokines in human. Methods Twenty cases were injected intramuscularly with 5 full doses of RV. PBMCs were isolated from the blood sample collected at day 0, 14, 45 after the RV inoculation. Neutralizing antibody was determined by ELISA, and the proliferation of lymphocyte by in vitro test. The levels of RV specific IFN-γ, TNF, IL-2,IL-4, IL-5, IL-10 in the culture supernatants were detected by cytometric bead array (CBA). Results The neutralizing antibody was tested positive in 19 cases 45 days after inoculation and 1 case after 60 days, with the positive rate reaching 100%. After stimulation with RV, the lymphocyte transformation index at day 14, 45 in cases were significantly higher than those day of 0 (P< 0.05), and similar results were confirmed with IFN-γ, IL-2, IL-4, IL-5 tested by CBA (P<0.05). Condusion The RV could induce humoral and antigen-specific cellular immune responses in human, tested by showing good protective effect on rabies virus.
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Objective To provide scientific evidence to identify and confirm severe acute respiratory syndrome (SARS) by laboratory detection.Methods Multiple clinical specimens were collected serially and systematically from the 4 suspected SARS patients, which occurred between Dec.2003 to Jan.2004 in Guangdong Province. The samples were tested by serologic and molecular methods.Results IgM or IgG antibodies against SARS-CoV were detectable after 6—8 days of the onset in four patients. The four-fold or greater rising in antibodies was clearly detected in three of the four patients, while the fourth patient’s seroconversion was from negative to positive. The results analysed by enzyme-linked immunosorbent assay( ELISA), immunoflourescence assay (IFA), and neutralization test were highly correlated. SARS-CoV RNA was just detected in 3 throat swab specimens from case 1 by real-time PCR. M, N and S genes were amplified by reverse transcriptase polymerase chain reaction (RT-PCR) from the positive samples. Sequencing results showed that they were SARS-CoV gene segments, and most closely matched SARS-CoV gene sequences were isolated from civet cats in Guangdong Province. Nevertheless, SARS-CoV was not isolated from any samples of the 4 patients.Conclusion Based on these results, the 4 reported cases were laboratorily confirmed as SARS cases.