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BACKGROUND: Nine COVID-19 (Corona Virus Disease, 2019) cases were observed in one community in Guangzhou. All the cases lived in three vertically aligned units of one building sharing the same piping system, which provided one unique opportunity to examine the transmission mode of SARS-CoV-2. METHODS: We interviewed the cases on the history of travelling and close contact with the index patients. Respiratory samples from all the cases were collected for viral phylogenetic analyses. A simulation experiment in the building and a parallel control experiment in a similar building were then conducted to investigate the possibility of transmission through air. RESULTS: Index patients living in Apartment 15-b had a travelling history in Wuhan, and four cases who lived in Apartment 25-b and 27-b were subsequently diagnosed. Phylogenetic analyses showed that virus of all the patients were from the same strain of the virus. No close contacts between the index cases and other families indicated that the transmission might not occur through droplet and close contacts. Airflow detection and simulation experiment revealed that flushing the toilets could increase the speed of airflow in the pipes and transmitted the airflow from Apartment 15-b to 25-b and 27-b. Reduced exhaust flow rates in the infected building might have contributed to the outbreak. CONCLUSIONS: The outbreak of COVID-19 in this community could be largely explained by the transmission through air, and future efforts to prevent the infection should take the possibility of transmission through air into consideration. A disconnected drain pipe and exhaust pipe for toilet should be considered in the architectural design to help prevent possible virus spreading through the air.
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Club drugs and alcohol abuse are prevalent among methadone maintenance treatment (MMT) patients. However, little is known about the association between these abuse and treatment outcomes among MMT patients. The aim of this study was to examine the prevalence of club drugs and alcohol abuse among MMT patients and to investigate the associations between these abuse and treatment outcomes - dropout and poor adherence. In this one-year cohort study conducting in Guangzhou, China, data including background characteristics, club drugs use in the last six months, alcohol use history and treatment-related information was collected. Cox regression analyses and log-binomial regression analyses were applied to identify the associations between these abuse and dropout and poor adherence, respectively. Thirty-seven participants (9.2%) admitted to the use of at least one type of club drugs in the last six months and 88 (21.9%) were identified as alcohol abusers. Of all participants, 21.0% had dropped out of treatment and 27.7% exhibited poor adherence during the study period. Adjusting for significant background variables, use of at least one type of club drugs [hazards ratio (HR) = 1.90, 95% confidence interval (CI) = 1.01-3.56] and use of methamphetamine in the last six months (HR = 2.26, 95% CI = 1.15-4.43) significantly predicted dropout. Frequency of having six or more drinks on one drinking occasion when drinking [relative risk (RR) = 1.87, 95% CI = 1.16-2.95] significantly predicted poor adherence. Our findings indicated that club drugs and alcohol abuse predicted dropout and poor adherence among MMT patients. Early identification and intervention for the abuse should be taken into consideration when developing interventions tailored to improve treatment outcomes among MMT patients.
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Alcoholismo/epidemiología , Drogas de Diseño , Cumplimiento de la Medicación/estadística & datos numéricos , Metadona/uso terapéutico , Narcóticos/uso terapéutico , Pacientes Desistentes del Tratamiento/estadística & datos numéricos , Adulto , Consumo de Bebidas Alcohólicas/epidemiología , China/epidemiología , Estudios de Cohortes , Femenino , Humanos , Masculino , Tratamiento de Sustitución de Opiáceos , Trastornos Relacionados con Opioides/tratamiento farmacológicoRESUMEN
A considerable proportion of methadone maintenance treatment (MMT) clients have experienced mental health problems (e.g., depression and anxiety), and poor mental health status is associated with HIV-related risk behaviors and treatment drop-out. Resilience is known to be a protective factor for mental health problems but is not studied among MMT clients in China. This study aimed to explore the relationship between resilience and mental health problems (depression, anxiety and stress) among clients of community-based MMT clinics in China. A total of 208 MMT clients completed the face-to-face interview conducted at 4 of 11 MMT clinics in Guangzhou. The Chinese short version of Depression Anxiety Stress Scale (DASS-21) was used to assess the presence of depressive, anxiety and stress symptoms, and the Connor-Davidson Resilience Scale (CD-RISC) was used to measure resilience. Logistic regression models were fit in data analyses. Of all participants, 12.8%, 19.5% and 8.3% had depression, anxiety and stress, respectively. The mean resilience score was 57.6 (SD = 15.9). In the univariate analyses, resilience was negatively associated with two studied mental health problems (depression and anxiety, ORu = 0.96 and 0.96, p < .01). In multivariate models adjusting for both background and other psycho-social factors, resilience was independently associated with probable depression (ORa = 0.97, 95% CI: 0.93-0.99) and anxiety (ORa = 0.96, 95% CI: 0.94-0.99). Resilience was independently associated with depression and anxiety. As resilience is changeable, interventions targeting mental health problems of MMT users should consider resilience as an important part in the designing of such interventions.
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Ansiedad/psicología , Depresión/psicología , Salud Mental , Trastornos Relacionados con Opioides/psicología , Resiliencia Psicológica , Adulto , Ansiedad/diagnóstico , China , Depresión/diagnóstico , Femenino , Humanos , Masculino , Metadona/uso terapéutico , Persona de Mediana Edad , Tratamiento de Sustitución de Opiáceos , Trastornos Relacionados con Opioides/tratamiento farmacológico , Escalas de Valoración Psiquiátrica , Estrés Psicológico/diagnóstico , Estrés Psicológico/psicologíaRESUMEN
Mental health problems are prevalent among drug users. Methadone maintenance treatment (MMT) is an evidence-based effective treatment for drug addiction; however, there are few studies investigating depression, suicidal ideation, and their related factors among MMT users. In this cross-sectional study, 648 MMT users were recruited from six MMT clinics in Guangzhou, China. Data were collected through face-to-face interviews by trained interviewers. Of all participants, 270 (42.7%) exhibited probable depression (Depression Subscale of the Chinese short version of Depression, Anxiety, and Stress Scale (DASS-D), score ≥ 10) and 99 (15.3%) reported having suicidal ideation in the last six months. After adjusting for significant socio-demographic characteristics, all studied variables, including drug use history, social support, family support for MMT use, and satisfaction toward MMT services were significantly associated with both probable depression and suicidal ideation in the last six months. Furthermore, depression fully mediated the associations between drug use history, satisfaction toward MMT services, and suicidal ideation. In the final multivariate models, probable depression was associated with social support (OR = 0.88, 95% CI = 0.83-0.93) and satisfaction toward MMT services provided by doctors (OR = 0.59, 95% CI = 0.40-0.86), while for suicidal ideation, social support (OR = 0.85, 95% CI = 0.78-0.92) and probable depression (OR = 5.94, 95% CI = 3.39-10.42) were significant. The findings suggest that there are unmet mental health needs among MMT users. For countries with limited resources of psychological services, mental health care toward MMT users should be implanted into current health care settings and incorporate components such as social support, family's understanding of MMT, and service satisfaction.
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Depresión , Metadona/uso terapéutico , Tratamiento de Sustitución de Opiáceos , Trastornos Relacionados con Sustancias , Ideación Suicida , Adulto , China/epidemiología , Estudios Transversales , Depresión/diagnóstico , Depresión/psicología , Consumidores de Drogas/psicología , Femenino , Humanos , Entrevista Psicológica/métodos , Masculino , Narcóticos/uso terapéutico , Tratamiento de Sustitución de Opiáceos/métodos , Tratamiento de Sustitución de Opiáceos/psicología , Tratamiento de Sustitución de Opiáceos/estadística & datos numéricos , Satisfacción del Paciente , Escalas de Valoración Psiquiátrica , Apoyo Social , Trastornos Relacionados con Sustancias/epidemiología , Trastornos Relacionados con Sustancias/psicología , Trastornos Relacionados con Sustancias/terapiaRESUMEN
BACKGROUND: China experiencing an increasing HIV epidemic among men who have sex with men (MSM), and unprotected anal intercourse (UAI) has played a key role in this process. The aims of this study were to examine the trend of UAI and to explore the factors correlated with UAI among MSM in Guangzhou, China. METHODS: Data from 2008 to 2013 were retrieved from the annual serological and behavioral surveys system. We collected information on demographic, HIV related sexual behavior with men and women, access to HIV prevention services, and symptoms of sexually transmitted infections. Chi-square test was used to examine the similarity of the participants during the study period. Univariate and multivariate logistic regression were conducted to test the factors associated with UAI. Trend test was used to check the change of UAI in different characteristic stratums during the study period. RESULTS: In total, 58.4% (range from 54.5% to 62.0%) of the participants reported that they engaged in UAI in the past six months. Participants who aged less than 20 [Adjusted Odds Ratio (AOR): 2.22, 95% Confidential Interval (CI): 1.07-4.61], only attended elementary school (or less) (AOR: 1.41, 95% CI: 1.04-1.90), cohabiting with male partner (AOR: 2.15, 95% CI: 1.66-2.79), divorced or widowed (AOR: 2.80, 95% CI: 1.54-5.07), did not test for HIV in the past year (AOR: 1.36, 95% CI: 1.12-1.65), and had 10 or more partners in the past six months (AOR: 1.85, 95% CI: 1.18-2.91) had higher odds of UAI. However, the proportions of UAI were stable in different stratums during the study period. CONCLUSIONS: The proportion of MSM engaged in UAI was consistently high during the study period. Effective intervention strategies, which include but not limit to risk reduction counseling and testing services, are urgently needed to bring down the risk behaviors of the MSM in Guangzhou, in order to control HIV/STIs epidemic in this specific population.
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Homosexualidad Masculina/estadística & datos numéricos , Sexo Inseguro/estadística & datos numéricos , Adolescente , Adulto , Anciano , China , Estudios Transversales , Encuestas Epidemiológicas , Homosexualidad Masculina/psicología , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Factores de Riesgo , Sexo Inseguro/psicología , Adulto JovenRESUMEN
PURPOSE: This study investigated for the HIV-1 CRF59_01B epidemic's spatiotemporal dynamics and its transmission networks in China. METHODS: Between 2007 and 2020, a total of 250 partial pol gene sequences of HIV-1 CRF59_01B were collected from four regions (10 Chinese provinces). Phylogenetic tree construction and cluster identification were then performed. The Bayesian skyline and birth-death susceptible-infected-removed models were employed for the phylodynamic analyses of subtypes and large clusters, respectively. Phylogenetic analyses and trait diffusion of these sequences were performed using Bayesian phylogenetic methods (beast-classic package). Distance-based molecular network analyses were performed to identify putative relationships. RESULTS: Using a genetic distance threshold of 1.3 %, We identified 45 clusters that included 62.40 % (156/250) of the sequences. Three clusters (6.67 %, 3/45) had 10 or more sequences, and were considered "large clusters". Six clusters (13.33 %) included sequences from different regions (Southeast, Northeast, Southeast, and Central China). Thirteen clusters (28.89 %) included sequences of men who had sex with men only, three clusters (6.67 %) included sequences of heterosexuals only, and 12 clusters (26.67 %) included sequences of both groups. The substitution rate of CRF59_01B was 1.91 × 10-3 substitutions per site per year [95 % highest posterior density (HPD) interval: 1.39 × 10-3-2.49 × 10-3)], the time to the most recent common ancestor of CRF59_01B was to be 1992.83 (95 % HPD: 1977.97-2002.81). A Bayesian skyline plot revealed that the effective population size of CRF59_01B increased from 2000 to 2015 and remained stable after 2015. The large clusters showed continuous growth from 2013 to 2020. Phylogeographic analysis showed that CRF59_01B B most likely originated in Southeast China, with a posterior probability of 97.44 %, and then spread to other regions. CONCLUSIONS: Our study revealed the temporal and geographical origins of HIV-1 CRF59_01B as well as the process of transmission among various regions and risk groups in China, which can help develop targeted HIV prevention strategies.
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Although methadone maintenance treatment (MMT) is an important means of HIV control, MMT clinics commonly have high attrition rates. The randomized controlled trial investigated the relative efficacy of adding a psycho-social intervention to the standard-of-care MMT in reducing attrition and non-attendance among first-time newly admitted MMT users in China (n = 288). Social workers implemented this three-phase intervention that was based on a behavioral maintenance theory. It also involved participants' family members and rectified some MMT-related misconceptions. As compared to the control group, the intervention group showed significantly lower likelihood of attrition (HR = 0.55, 95% confidence interval 0.39-0.80), lower estimated probability of attrition at Month 12 (0.35 vs. 0.55), and higher median number of days of attendance (Month 6: 147 vs. 91 days, p < 0.001; end-date: 225 vs. 142 days, p < 0.001). Further psycho-social services and translational research are warranted.
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Dependencia de Heroína/tratamiento farmacológico , Cumplimiento de la Medicación , Metadona/uso terapéutico , Narcóticos/uso terapéutico , Tratamiento de Sustitución de Opiáceos/métodos , Educación del Paciente como Asunto/métodos , Adulto , China , Femenino , Infecciones por VIH/prevención & control , Dependencia de Heroína/psicología , Humanos , Masculino , Resultado del TratamientoRESUMEN
BACKGROUND: With the number of newly diagnosed HIV-positive heterosexual women increasing yearly, it is urgent to understand HIV-1 transmission among heterosexual women in Guangzhou, China. METHODS: HIV-1 pol sequences were obtained from people living with HIV-1 during 2008 to 2017 in Guangzhou, China. A molecular network was constructed using HIV-1 TRAnsmission Cluster Engine with 1.5% genetic distance. Potential linkage and centrality metric were measured with Cytoscape. Transmission pathways between heterosexual women and men who have sex with men (MSM) were determined using Bayesian phylogenetic analysis. RESULTS: In the network, 1799 (62.6%) MSM, 692 (24.1%) heterosexual men and 141 (4.9%) heterosexual women formed 259 clusters. Molecular clusters including MSM and heterosexuals were more likely to form larger networks (P<0.001). Nearly half of the heterosexual women (45.4%) were linked to heterosexual men and 17.7% to MSM, but only 0.9% of MSM were linked to heterosexual women. Thirty-three (23.4%) heterosexual women linked to at least one MSM node and were in peripheral role. Compared to general heterosexual women, the proportion of heterosexual women linked to MSM infected with CRF55_01B (P<0.001) and CRF07_BC (P<0.001) was higher than that of other subtypes, and the proportion diagnosed between 2012 and 2017 (Pâ¯=â¯0.001) was higher than that in 2008-2012. In MCC trees, 63.6% (21/33) of the heterosexual women differentiated from the heterosexual evolutionary branch, while 36.4% (12/33) differentiated from the MSM evolutionary branch. CONCLUSION: Heterosexual women living with HIV-1 were mainly linked to heterosexual men and were in peripheral positions in the molecular network. The role of heterosexual women in HIV-1 transmission was limited, but the interaction between MSM and heterosexual women were complex. Awareness of the HIV-1 infection status of sexual partners and active HIV-1 detection are needed for women.
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Infecciones por VIH , VIH-1 , Minorías Sexuales y de Género , Masculino , Humanos , Femenino , Heterosexualidad , Homosexualidad Masculina , VIH-1/genética , Filogenia , Teorema de Bayes , China/epidemiologíaRESUMEN
OBJECTIVE: To investigate the effectiveness of psychosocial services provided by social workers in reducing dropout rate and increasing treatment dosage in methadone maintenance treatment (MMT) users. METHODS: From May in 2009 to April in 2010, 300 MMT users were recruited from three MMT clinics in Guangzhou, and were randomly allocated into the intervention group and the control groups. The control group (152 cases) received standard MMT services while the intervention group (148 cases) received additional services provided by social workers. Methadone dosage, dropout rate, perceptions toward MMT etc. were compared between the two groups. RESULTS: The 1-month dropout rate of the control and intervention groups were 19.7% (30/152) and 6.8% (10/148) (P < 0.05) respectively; the 6-month dropout rate of the control and intervention groups were 75.5% (115/152) and 50.7% (75/148) (P < 0.05) respectively. The intervention group had higher average treatment dosage than the control group ((56.0 ± 21.2) vs (64.4 ± 23.1) ml/d, (58.0 ± 24.0) vs (66.1 ± 26.6) ml/d, P < 0.05). At 1-month and 6-month, the intervention group had higher scores of MMT-related perception ((1.26 ± 0.68) vs (1.84 ± 0.95), (1.55 ± 0.83) vs (2.44 ± 1.23), P < 0.05), self-efficacy of maintenance ((3.68 ± 1.33) vs (4.20 ± 1.05), (3.80 ± 1.38) vs (4.43 ± 0.79), P < 0.05) and satisfaction toward MMT((4.08 ± 0.54) vs (4.15 ± 0.60), (4.01 ± 0.67) vs (4.31 ± 0.64), P < 0.05) as compared to the control group. The reverse was true for the score of negative experiences ((1.05 ± 0.86) vs (0.96 ± 0.92), (1.46 ± 0.87) vs (1.11 ± 1.07), P < 0.05). CONCLUSION: The psychosocial interventions provided by social workers were effective in reducing dropout rate, increasing treatment dosage and improving cognitions of MMT users.
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Metadona/uso terapéutico , Tratamiento de Sustitución de Opiáceos , Servicio Social , Adulto , Femenino , Dependencia de Heroína/tratamiento farmacológico , Humanos , Masculino , Metadona/administración & dosificación , Cooperación del Paciente , Centros de Tratamiento de Abuso de Sustancias , Resultado del TratamientoRESUMEN
Methadone maintenance treatment (MMT) is an important approach to address opioid dependence. However, MMT clinics usually report high attrition rates. Our previous randomized controlled trial demonstrated additional psycho-social services delivered by social workers could reduce attrition rates compared to MMT alone. This study aimed to evaluate the effectiveness of psycho-social service in a real-world context. A quasi-experimental design and propensity score matching was adopted. 359 clients were recruited from five MMT clinics in Guangzhou from July 2013 to April 2015. One 20-minute counseling session was offered to the control group after enrolment. The intervention group received six sessions of psycho-social services. The baseline characteristics were unbalanced between two arms in the original sample. After propensity score matching, 248 participants remained in the analysis. At month six, the intervention group had a lower attrition rate [intervention (39.5%) versus control (52.4%), P = 0.041], higher monthly income [monthly income of 1000 CNY or higher: intervention (55.9%) versus control (39.0%), P = 0.028)], higher detoxification intention score [full intention score: intervention (51.6%) versus control (32.5%), P = 0.012)], higher family support in MMT participation [intervention (77.9%) versus control (61.4%), P = 0.049)]. This study demonstrated that psycho-social services delivered by social workers can reduce MMT clients' attrition and improve their well-being in real-world settings.
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Cumplimiento de la Medicación/psicología , Metadona/uso terapéutico , Tratamiento de Sustitución de Opiáceos/psicología , Trastornos Relacionados con Opioides/terapia , Servicio Social , China , Femenino , Humanos , Masculino , Persona de Mediana Edad , Trastornos Relacionados con Opioides/psicología , Puntaje de PropensiónRESUMEN
AIMS: To investigate the incidence of dropout and the prevalence of poor adherence among newly admitted first-time clients of methadone maintenance treatment (MMT) clinics, and the associations between MMT-related misconceptions and these two treatment outcomes. DESIGN: A cohort study (maximum follow-up period = 17.6 months) was conducted. SETTING: Three of the nine MMT clinics in Guangzhou, China participated in the study. PARTICIPANTS: The sample included 158 newly admitted first-time MMT clients. MEASUREMENTS: Information collected included background characteristics, history of drug use, MMT-related misconceptions, dropout during the entire study period and poor adherence within the first 6 months since admission to MMT. FINDINGS: Of all newly admitted MMT clients, 98.2% possessed at least one and 50.6% possessed all four types of MMT-related misconception; 51.3% had dropped out before the completion of the study [95% confidence interval (CI): 43.5-59.1%] and 62% exhibited poor adherence within the first 6 months since admission (95% CI: 54.2-69.6%). Adjusting for significant background variables, the number of misconceived responses predicted significantly both dropout [hazard ratio (HR) = 3.80 for two to three misconceived items, HR = 7.13 for four misconceived items, with zero to one misconceived item being the reference] and poor adherence within the first 6 months [relative risk (RR) = 4.13 for two to three misconceived items; RR = 4.40 for four misconceived items, with zero to one misconceived item being the reference. CONCLUSIONS: Among opiate addicts in China prescribed methadone maintenance therapy for the first time, misconceptions about this medication are prevalent and are associated with poor adherence to the medication regimen and a high a rate of dropout from the treatment programme.
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Cumplimiento de la Medicación/psicología , Metadona/uso terapéutico , Narcóticos/uso terapéutico , Tratamiento de Sustitución de Opiáceos/psicología , Trastornos Relacionados con Opioides/rehabilitación , Malentendido Terapéutico/psicología , Adulto , Anciano , Actitud Frente a la Salud , China/epidemiología , Femenino , Humanos , Masculino , Cumplimiento de la Medicación/estadística & datos numéricos , Persona de Mediana Edad , Trastornos Relacionados con Opioides/epidemiología , Pacientes Desistentes del Tratamiento/psicología , Pacientes Desistentes del Tratamiento/estadística & datos numéricos , Estudios ProspectivosRESUMEN
The methadone maintenance treatment (MMT) program is scaling up in China, but little is known about drug users' cognitions of MMT. To investigate the prevalence and associated factors of MMT-related misconceptions, a totally of 300 newly admitted MMT users were interviewed in three MMT clinics in Guangzhou. Four statements were used to assess MMT-related misconceptions. The results showed that the majority of participants misconceived that MMT is intended primarily for detoxification (92.3%), that one could be completely detoxified and quit using methadone after using it for 2-3months (64.2%), that MMT is not a long-term or even lifetime treatment (77.9%); and that one should attempt to reduce its treatment dosage as methadone is harmful to one's health (84.3%); 48.5% of the respondents possessed all four types of misconceptions. Prior experience of methadone use in voluntary drug detoxification centers (OR=1.82 to 2.55, p<0.05) was associated with some misconception items, whilst being introduced by some peer drug users or community members to use MMT (versus not being introduced by anyone; OR=0.38 to 0.50, p<0.05), having taken up HIV voluntary counseling and testing prior to admission (OR=0.52, p<0.05), and a higher HIV-related knowledge level (OR=0.38, p<0.05) were associated with lower likelihoods for possessing some of the misconceptions. The findings suggested that MMT-related misconceptions were very prevalent among newly recruited MMT users in China. Misconceptions are potential factors causing drop-outs. Interventions targeting such misconceptions are greatly warranted.
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Actitud Frente a la Salud , Dependencia de Heroína/rehabilitación , Metadona/uso terapéutico , Narcóticos/uso terapéutico , Adulto , Anciano , China , Consumidores de Drogas/psicología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Centros de Tratamiento de Abuso de Sustancias/estadística & datos numéricosRESUMEN
OBJECTIVE: To investigate the dynamic trend of specific antibody against severe acute respiratory syndrome (SARS)-CoV in serum collected at various periods among employees in Guangzhou Xinyuan animal market. METHODS: Volunteers from employees of the animal market were recruited and their serum specific antibody against SARS-CoV were determined by enzyme linked immunesorbent assay (ELISA) method. RESULTS: Positive SARS-CoV specific IgG antibody was found 25.61% (n = 328), 13.03% (n = 238), 12.59% (n = 135), 5.04% (n = 139) and 9.43% (n = 53) among volunteers, which were sampled in May 2003, Dec. 2003, Jan. 2004, July 2004 and June 2005 respectively. No specific IgM antibody was found in all of those samples. Among 129 samples which were tested twice or more, 97 were all negative, 18 all positive, 13 changed from positive to negative but only one sample from negative to positive. When the volunteers were divided by the duration of their working experiences as short-term or long-term, those who had worked at animal market for less than or more then 6 months when being tested, the positive rate for long-term employees were relatively constant, however, all of the persons employed after January 2004, when the palm civets and raccoon dogs were culled from the market, were tested negative. CONCLUSION: The prevalence of specific antibody against SARS-CoV in employees of the animal market were somehow related with the presence or absence of palm civet. No serum was tested positive for persons who were employed after palm civets and raccoon dogs were culled from market. This data indicated that the SARS-CoV might have been from the palm civets and raccoon dog, and the animal market seemed to serve as one of the sources of infection.
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Anticuerpos Antivirales/análisis , Exposición Profesional , Síndrome Respiratorio Agudo Grave , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/inmunología , Animales , Comercio , Ensayo de Inmunoadsorción Enzimática , Humanos , Perros Mapache/virología , Viverridae/virologíaRESUMEN
Massive numbers of palm civets were culled to remove sources for the reemergence of severe acute respiratory syndrome (SARS) in Guangdong Province, China, in January 2004, following SARS coronavirus detection in market animals. The virus was identified in all 91 palm civets and 15 raccoon dogs of animal market origin sampled prior to culling, but not in 1,107 palm civets later sampled at 25 farms, spread over 12 provinces, which were claimed to be the source of traded animals. Twenty-seven novel signature variation residues (SNVs) were identified on the spike gene and were analyzed for their phylogenetic relationships, based on 17 sequences obtained from animals in our study and from other published studies. Analysis indicated that the virus in palm civets at the live-animal market had evolved to infect humans. The evolutionary starting point was a prototype group consisting of three viral sequences of animal origin. Initially, seven SNV sites caused six amino acid changes, at positions 147, 228, 240, 479, 821, and 1080 of the spike protein, to generate low-pathogenicity viruses. One of these was linked to the first SARS patient in the 2003-2004 period. A further 14 SNVs caused 11 amino acid residue changes, at positions 360, 462, 472, 480, 487, 609, 613, 665, 743, 765, and 1163. The resulting high-pathogenicity groups were responsible for infections during the so-called early-phase epidemic of 2003. Finally, the remaining six SNVs caused four amino acid changes, at positions 227, 244, 344, and 778, which resulted in the group of viruses responsible for the global epidemic.