Assessment of the Public Health Risks and Impact of a Tornado in Funing, China, 23 June 2016: A Retrospective Analysis.

(1) Background: Tornadoes are one of the deadliest disasters but their health impacts in China are poorly investigated. This study aimed to assess the public health risks and impact of an EF-4 tornado outbreak in Funing, China; (2) Methods: A retrospective analysis on the characteristics of tornado-related deaths and injuries was conducted based on the database from the Funing's Center for Disease Control and Prevention (CDC) and Funing People's Hospital. A change-point time-series analysis of weekly incidence for the period January 2010 to September 2016 was used to identify sensitive infectious diseases to the tornado; (3) Results: The 75 to 84 years old group was at the highest risk of both death (RR = 82.16; 95% CIs = 19.66, 343.33) and injury (RR = 31.80; 95% CI = 17.26, 58.61), and females were at 53% higher risk of death than males (RR = 1.53; 95% CIs = 1.02, 2.29). Of the 337 injuries, 274 injuries (81%) were minor. Most deaths occurred indoors (87%) and the head (74%) was the most frequent site of trauma during the tornado. Five diseases showed downward change-points; (4) Conclusions: The experience of the Funing tornado underscores the relative danger of being indoors during a tornado and is successful in avoiding epidemics post-tornado. Current international safety guidelines need modification when generalized to China.

Comparing risk factors for primary multidrug-resistant tuberculosis and primary drug-susceptible tuberculosis in Jiangsu province, China: a matched-pairs case-control study.

To find out the reason why some people get infected directly with multidrug-resistant tuberculosis (MDR-TB), whereas some get infected with drug-susceptible tuberculosis (DS-TB), a 1:1:1 matched-pairs case-control study was conducted to identify predictors associated with primary MDR-TB and primary DS-TB against the control in Jiangsu Province, China. All three groups were geographically matched (by neighborhood) and matched on sex and age (±5 years). In total, 110 participants were enrolled in each of three matched groups. Conditional logistic regression analysis showed that predictors independently associated with primary MDR-TB were illiteracy or primary school education, annual per capita income ≤ US$2,000, per capita living space < 40 m(2), and interval ≥ 7 days of eating fruits; predictors with primary DS-TB were body mass index ≤ 20 and feeling higher life pressure. This indicates that there are different predictors impacting the transmission range of primary MDR-TB and primary DS-TB in the general population.

[Influenza-associated-excess-hospitalization in children, Wuxi city, Jiangsu province, 2005-2010].

OBJECTIVE: To estimate the rates due to influenza-associated-excess-hospitalization in children aged 0-14 years in Wuxi city,Jiangsu province in 2005-2010. METHODS: We collected data on hospitalization due to influenza, pneumonia and other respiratory diseases from fourteen 2nd level or above hospitals in Wuxi, as well as data on influenza virological surveillance in southern China to fit the negative binomial regression models, to estimate the rate on influenza-associated-excess hospitalization. RESULTS: During 2005-2010, an average annual hospitalization rate appeared as 91.6‰ (79.2‰ -99.3‰). Among the total hospitalization eases, respiratory diseases accounted for 54.2%, while both influenza and pneumonia accounted for 38.1%. The average annual influenza- associated-excess-hospitalization rates due to influenza and pneumonia appeared as 1.28‰ (95% CI:0.29‰ -4.84‰), while 2.18‰ (95% CI:0.61‰ -6.79‰) due to respiratory diseases. In 2009, A (H1N1) pdm induced influenza pandemic caused 993 excess hospitalizations due to influenza/pneumonia and 1 042 excess hospitalizations due to respiratory diseases, with rates as 1.14‰ and 1.20‰ respectively. CONCLUSION: Both seasonal and pandemic A(H1N1)pdm influenza caused considerable burden on hospitalization in children aged 0-14 years inWuxi.

Virological and serological study of human infection with swine influenza A H1N1 virus in China.

BACKGROUND: Pigs are considered to be "mixing vessels" for the emergence of influenza viruses with pandemic potential. 2009 Pandemic Influenza H1N1 further proved this hypothesis, and raised the needs for risk assessment of human cases caused by swine influenza virus. METHODS: A field investigation was conducted after a case identified with infection of European avian-like swine influenza H1N1 virus. The diagnosis was confirmed by real-time PCR, virus isolation, whole genome sequencing and serological assays. Samples from local pigs and close contacts were tested to identify the source of infection and route of transmission. RESULTS: The virus from the index case was similar to viruses circulating in the local pigs. The case's grandfather was asymptomatic with sero-conversion. A total of 42.8% of swine sera were positive for European avian-like swine H1N1. CONCLUSIONS: This study highlighted the importance of performing surveillance on swine influenza to monitor new virus emergence in humans.

Antigenic and genetic characterization of a European avian-like H1N1 swine influenza virus from a boy in China in 2011.

Cross-species transmission of influenza A viruses from swine to human occurs occasionally. In 2011, an influenza A H1N1 virus, A/Jiangsu/ALS1/2011 (JS/ALS1/2011), was isolated from a boy who suffered from severe pneumonia in China. The virus is closely related antigenically and genetically to avian-like swine H1N1 viruses that have recently been circulating in pigs in China and that were initially detected in European pig populations in 1979. The isolation of JS/ALS1/2011 provides additional evidence that swine influenza viruses can occasionally infect humans and emphasizes the importance of reinforcing influenza virus surveillance in both pigs and humans.

Author Response: Human infections with avian influenza A(H7N9): preliminary assessments of the age and sex distribution

We thank Dr Viroj Wiwanitkit for his comments on our preliminary assessment of the age and sex distribution of the human cases with avian influenza A(H7N9) virus infection. To clarify, we posed three scenarios which could possibly explain the preponderance of cases among elderly men reported through China’s surveillance system: (1) differential exposure due to gender-associated practices and norms, e.g. more high-risk behaviours among elderly men; (2) differential clinical course post-exposure/infection, e.g. given similar exposures, elderly men have a more severe outcome relative to other age–gender groups; and (3) differential health care-seeking/access behaviour favouring selection of elderly men, e.g. elderly men accessing health care more than other age-gender groups.

Surveillance of 16 respiratory viruses in patients with influenza-like illness in Nanjing, China.

Much less is known about the etiology of influenza-like illness in China. A continuous surveillance of 16 respiratory viruses was conducted from November 2010 to October 2011 of outpatients with influenza-like illness in Nanjing, China. The two largest general hospitals and a provincial virus laboratory in Nanjing participated in this study. Throat swabs were collected from outpatients during medical visits for influenza-like illness and were tested for 16 respiratory viruses using PCR. Three hundred seventeen viruses were detected in samples from 246 (50.6%) patients with influenza-like illness. The viruses found mostly commonly were influenza, rhinovirus, hCoV HKU1, and adenovirus. The identification rates of respiratory viruses differed significantly among different sampling seasons (P = 0.0002). The rates of influenza A and hCoV HKU1 were much higher during the influenza-like illness winter peak than during the influenza-like illness summer peak and other months. Co-infections were detected in 57 (11.7%) patients and were found most commonly in adults older than 60 years. RSV was detected in 5.9% and 2.6% of patients who were 0-5 and 6-15 years old, respectively, but was not detected in other age groups. This study confirmed that multiple respiratory viruses may circulate concurrently in the population and account for a large proportion of influenza-like illness. In addition to influenza virus, hCoV HKU1 may be associated with the influenza-like illness winter peak in Nanjing, China.

Molecular characterization of avian-like H1N1 swine influenza a viruses isolated in Eastern China, 2011.

Currently, three predominant subtypes of influenza virus are prevalent in pig populations worldwide: H1N1, H3N2, and H1N2. European avian-like H1N1 viruses, which were initially detected in European pig populations in 1979, have been circulating in pigs in eastern China since 2007. In this study, six influenza A viruses were isolated from 60 swine lung samples collected from January to April 2011 in eastern China. Based on whole genome sequencing, molecular characteristics of two isolates were determined. Phylogenetic analysis showed the eight genes of the two isolates were closely related to those of the avian-like H1N1 viruses circulating in pig populations, especially similar to those found in China. Four potential glycosylation sites were observed at positions 13, 26, 198, 277 in the HA1 proteins of the two isolates. Due to the presence of a stop codon at codon 12, the isolates contained truncated PB1-F2 proteins. In this study, the isolates contained 591Q, 627E and 701N in the polymerase subunit PB2, which had been shown to be determinants of virulence and host adaptation. The isolates also had a D rather than E at position 92 of the NS1, a marker of mammalian adaptation. Both isolates contained the GPKV motif at the PDZ ligand domain of the 3' end of the NS1, a characteristic marker of the European avian-like swine viruses since about 1999, which is distinct from those of avian, human and classical swine viruses. The M2 proteins of the isolates have the mutation (S31N), a characteristic marker of the European avian-like swine viruses since about 1987, which may confer resistance to amantadine and rimantadine antivirals. Our findings further emphasize the importance of surveillance on the genetic diversity of influenza A viruses in pigs, and raise more concerns about the occurrence of cross-species transmission events.

[Epidemiology and etiology of hand-foot-and-mouth disease seen in Jiangsu province from 2008 to 2010].

OBJECTIVE: To analyze the etiological and epidemiological characteristics of hand-foot-and-mouth disease (HFMD) seen in Jiangsu province from 2008 to 2010, and provide evidence for its prevention and control. METHODS: Based on the requirement of supervision program of HFMD, surveillance and report were done according to National Disease Supervision Information Management System. Descriptive epidemiological method, performed between 2008 and 2010, was used to analyze the time, region and population distribution and results of etiologic analysis of HFMD. Nucleic acid of enterovirus (EV) genome was detected by real-time RT-PCR. RESULTS: The average incidence rate of HFMD was 86.70 per million between 2008 and 2010, the peak incidence occurred in April to July. There were significant differences among the incidence in different districts (P<0.05), and the highest incidence was seen in the densely inhabited southern areas of Jiangsu province. Most of the cases were infants and children aged less than 5 years. The number of male cases (2008: 17,008, 2009: 48 768, 2010: 50,231) was much larger than that of the female cases 2008: 9662, 2009: 29 151, 2010: 30,655. The HFMD cases with mild symptoms were caused mainly by enterovirus 71 (EV71) and coxsackievirus A16 (Cox A16) and there was difference among different years. The severe HFMD cases and deaths were mainly caused by EV71 infection. CONCLUSIONS: The epidemiologic characteristics of HFMD in Jiangsu province from 2008 to 2010 had close relationship with season, population and region. The mild cases of HFMD were mainly infected with EV71 and Cox A16. However, EV71 illness seemed to be more severe and had significantly greater frequency of serious complications and fatality than the illness caused by Cox A16.

Seroprevalence of avian influenza A (H5N1) virus among poultry workers in Jiangsu Province, China: an observational study.

BACKGROUND: Since 2003 to 06 Jan 2012, the number of laboratory confirmed human cases of infection with avian influenza in China was 41 and 27 were fatal. However, the official estimate of the H5N1 case-fatality rate has been described by some as an over estimation since there may be numerous undetected asymptomatic/mild cases of H5N1 infection. This study was conducted to better understand the real infection rate and evaluate the potential risk factors for the zoonotic spread of H5N1 viruses to humans. METHODS: A seroepidemiological survey was conducted in poultry workers, a group expected to have the highest level of exposure to H5N1-infected birds, from 3 counties with habitat lakes of wildfowl in Jiangsu province, China. Serum specimens were collected from 306 participants for H5N1 serological test. All participants were interviewed to collect information about poultry exposures. RESULTS: The overall seropositive rate was 2.61% for H5N1 antibodies. The poultry number was found associated with a 2.39-fold significantly increased subclinical infection risk after adjusted with age and gender. CONCLUSIONS: Avian-to -human transmission of avian H5N1 virus remained low. Workers associated with raising larger poultry flocks have a higher risk on seroconversion.

[A viral meningitis outbreak associated with Echo30 in drinking water].

OBJECTIVE: To study the source of infection, the scope of epidemic and control measures in an outbreak involving students having symptoms as fever, dizziness, headache, vomiting and nausea. METHODS: The suspected-case was defined as fever (armpit temperature ≥ 37°C) and with one or more of the following symptoms: dizziness, headache, vomiting and nausea, among students and teachers at school from Mar 1, 2012. Confirmed-case was among suspected case accompanied by both throat and rectal swabs enterovirus positive by RT-PCR. All the cases were collected through checking the medical records from 4 hospitals as well as through the absence records of students and teachers, from Mar 1, 2012. We conducted a case-control study with ratio of 1:2 and data on the exposures to water among students and teachers was collected prior to the illness. 27 cases' throat and rectal swabs were collected and analyzed by RT-PCR and PCR sequence methods. 2 warm-water samples were collected for testing the counts on total bacteria and E. coli. RESULTS: 103 students' cases were identified in school L, with the attack rate as 4.6% (103/2255). Students from Grade three had the high attack rate as 18.1% (72/397) and 77.7% (80/103) of the cases located in the building with 'multiple-functions'. Epidemic curve of the outbreak showed a pattern with continuous common source of infection. It seemed that the exposure to warm-water appeared to be the major risk factor (OR = 18.3, 95%CI: 2.0 - 169.5) together with the intake of un-boiled water (OR = 15.5, 95%CI: 1.7 - 141.8). Specimens from 27 students (81.5%, 22/27) were identified enterovirus positive by RT-PCR, and 7 of the 9 students were confirmed carrying Echo 30. Bacteria and coli were negative from the 2 warm-water samples. CONCLUSION: This viral meningitis-outbreak was caused by Echo 30, with drinking water as the major risk factor.

Attempted early detection of influenza A (H1N1) pandemic with surveillance data of influenza-like illness and unexplained pneumonia.

BACKGROUND: To collect disease information and provide data for early detection of epidemics, two surveillance systems were established for influenza-like illness (ILI) and unexplained pneumonia (UP) in Wuxi, People's Republic of China. OBJECTIVES: The current study aims to describe the performance of these surveillance systems during 2004-2009 and to evaluate the value of surveillance data in detection of influenza epidemics. METHODS: Two national ILI sentinel hospitals and three UP sentinel hospitals provided data to the surveillance systems. The surveillance data from hospital-based outpatient clinics and emergency rooms were compared by year. The ILI data of 2009 were further modeled based on previous data using both a control chart method and a moving average regression method. Alarms of potential epidemics would be raised when the input surveillance data surpassed a threshold. RESULTS: In 2009, the proportions of ILI and respiratory illness with fever (one surveillance syndrome of the UP system) to total patient visits (3·40% and 11·76%, respectively) were higher than the previous years. The surveillance data of both systems also showed developing trends similar to the influenza A (H1N1) pandemic in 2009. When the surveillance data of 2009 were fitted in the two detection models, alarms were produced on the occurrence of the first local case of influenza A (H1N1), outbreaks in schools and in general populations. CONCLUSIONS: The results indicated the potential for using ILI and UP surveillance data as syndromic indicators to detect and provide an early warning for influenza epidemics.

Seroprevalence of pandemic (H1N1) 2009 in pregnant women in China: an observational study.

BACKGROUND: We investigated the seropositive rates and persistence of antibody against pandemic (H1N1) 2009 virus (pH1N1) in pregnant women and voluntary blood donors after the second wave of the pandemic in Nanjing, China. METHODOLOGY/PRINCIPAL FINDINGS: Serum samples of unvaccinated pregnant women (n = 720) and voluntary blood donors (n = 320) were collected after the second wave of 2009 pandemic in Nanjing. All samples were tested against pH1N1 strain (A/California/7/2009) with hemagglutination inhibition assay. A significant decline in seropositive rates, from above 50% to about 20%, was observed in pregnant women and voluntary blood donors fifteen weeks after the second wave of the pandemic. A quarter of the samples were tested against a seasonal H1N1 strain (A/Brisbane/59/2007). The antibody titers against pH1N1 strain were found to correlate positively with those against seasonal H1N1 strain. The correlation was modest but statistically significant. CONCLUSIONS AND SIGNIFICANCE: The high seropositive rates in both pregnant women and voluntary blood donors suggested that the pH1N1 virus had widely spread in these two populations. Immunity derived from natural infection seemed not to be persistent well.

[The application of time series analysis in predicting the influenza incidence and early warning].

OBJECTIVE: This research aimed to explore the application of ARIMA model of time series analysis in predicting influenza incidence and early warning in Jiangsu province and to provide scientific evidence for the prevention and control of influenza epidemic. METHODS: The database was created based on the data collected from monitoring sites in Jiangsu province from October 2005 to February 2010. The ARIMA model was constructed based on the number of weekly influenza-like illness (ILI) cases. Then the achieved ARIMA model was used to predict the number of influenza-like illness cases of March and April in 2010. RESULTS: The ARIMA model of the influenza-like illness cases was (1 + 0.785B(2))(1-B) ln X(t) = (1 + 0.622B(2))ε(t). Here B stands for back shift operator, t stands for time, X(t) stands for the number of weekly ILI cases and ε(t) stands for random error. The residual error with 16 lags was white noise and the Ljung-Box test statistic for the model was 5.087, giving a P-value of 0.995. The model fitted the data well. True values of influenza-like illness cases from March 2010 to April 2010 were within 95%CI of predicted values obtained from present model. CONCLUSION: The ARIMA model fits the trend of influenza-like illness in Jiangsu province.

[Serologic survey on pandemic influenza A (H1N1) virus among aged ≥ 3 years population from Jiangsu province in 2009, China].

OBJECTIVE: To understand the antibody levels against pandemic influenza A (H1N1) virus (2009 H1N1) among aged ≥ 3 years population in 2009, from Jiangsu province, and to describe the distribution of 2009 H1N1. METHODS: Serum specimens were collected from natural populations at four different periods in Jiangsu, and tested with hemagglutination-inhibition (HI) assays. Rates of protective antibody against 2009 H1N1 and Geometric mean titers (GMTs) were estimated. RESULTS: The rates of protective antibody against 2009 H1N1 rose with the progress of epidemics in Jiangsu, which were 3.46%, 7.59%, 16.94%, respectively in July, August and November, 2009. There were no significant differences on the rates of protective antibody between males and females at four different cross-sectional periods (P > 0.05), and no significant differences on GMTs were observed at different periods except for November 2009. Significant differences on rates of protective antibody and GMTs among various age groups were observed at four different periods (P < 0.05), and similar results were observed among different periods in various age groups (P < 0.05). There were significant differences on rates of protective antibody and GMTs among different areas (P < 0.05). CONCLUSION: The 2009 H1N1 strain had been widely spread out in Jiangsu province since July 2009. People aged 12 - 17 years became the major victims after August. As of November 2009, the rate of protective antibody against 2009 H1N1 was still low, predicting that the epidemic might continue to exist for a certain period of time.

[The feasibility of outpatient data used for respiratory syndromic surveillance in general hospital].

OBJECTIVE: To find out the data sources of respiratory syndromes and their components from the outpatients of general hospitals and to describe the time distribution and mutual relations of different respiratory syndromes. Feasibility of respiratory syndromes used for early warning surveillance on respiratory infectious disease was also under research. METHODS: Retrospective investigation on Hospital Information System (HIS) was implemented in a general hospital in Guangzhou, 2005, and data of outpatients was collected and classified into different syndromes. The respiratory syndromes with its time distribution similar to influenza like illness (ILI), were selected, and cross-correlation analyses were conducted to investigate the feasibility of respiratory syndromes for early warning surveillance on respiratory infection diseases (influenza as an example). RESULTS: Primary sub-classification of respiratory syndromes in outpatient department would include upper respiratory infection (URI) (51.20%), trachitis/bronchitis (18.80%), asthma (17.52%), etc. Pulmonary infection accounted for only 2.26%. Time distributions of URI, trachitis/bronchitis, pulmonary infection, cough and asthma in outpatient department, X-ray tests and pneumonia/acute respiratory distress syndromes (ARDSs) in outpatient X-ray room were similar, with two peaks observed. Cross-correlation functions were calculated with the data sets of 1(st) - 28(th) week. The most significant correlation was detected between the time series of outpatient pulmonary infections and ILIs moved 4 weeks backward (r = 0.739, P < 0.01), and that was detected between URIs and ILIs moved 5 weeks backward (r = 0.714, P < 0.01). Correlation between X-ray tests, pneumonia/ARDSs in outpatient X-ray room and ILIs was the strongest when ILIs time series moved 1 week backward (r = 0.858, P < 0.001;r = 0.821, P < 0.001). CONCLUSION: Outpatient data from HIS system in general hospital could be applied to syndromic surveillance on respiratory diseases. For early warning epidemics or outbreaks of influenza or other respiratory infectious diseases, data of outpatient pulmonary infection appeared to be the most feasible for its specificity and timeliness, followed by URI and cough. X-ray tests and pneumonia/ARDSs in outpatient X-ray findings were important supplementary to verify the respiratory disease epidemics or outbreaks for its good specificity, but with no advantage for early warning.

[Molecular characterization of the early phase of the novel influenza A H1N1 (2009) viruses].

OBJECTIVE: Pathogens of the first influenza pandemic this century belong to influenza A H1N1 viruses, which are different from human seasonal H1N1 viruses in antigenic and genetic characterization. To better understand the genetic characteristics and evolution, timely detect variant strains with epidemiological importance, we analyzed in detail the molecular characterization of the early influenza A H1N1 (2009) virus. METHOD: Genomic sequences of reference influenza viruses were obtained from Influenza Resource Center of GenBank. Sequences were analyzed using the EditSeq and Megalign program with the Lasergene sequence analysis software package (DNAStar, Madison, WI, USA). A/California/07/2009 (H1N1) was selected as a representative strains of the novel influenza A H1N1 (2009) virus, and its molecular characteristics was determined. RESULTS: A/California/07/2009 do not contained the molecular characteristics of highly pathogenic influenza virus, and its 11 proteins retained most of the molecular characteristics of swine influenza virus, but also had some characteristics of avian and human influenza viruses. With a classical swine H1N1 and human H1N1 dual character, PB1-F2 protein of A/California/07/2009 terminates after 11aa, 57aa and 87aa, which is a unique molecular characteristics of influenza H1N1 (2009) virus. CONCLUSION: This is the first report for detailed analysis of Molecular characteristics of the novel influenza A H1N1 (2009) virus. As the virus further adapt and persist in human populations, its molecular characteristics will change accordingly. So we should pay special attention to the effect on virus transmission and pathogenesis.

Probable limited person-to-person transmission of highly pathogenic avian influenza A (H5N1) virus in China.

BACKGROUND: In December, 2007, a family cluster of two individuals infected with highly pathogenic avian influenza A (H5N1) virus was identified in Jiangsu Province, China. Field and laboratory investigations were implemented immediately by public-health authorities. METHODS: Epidemiological, clinical, and virological data were collected and analysed. Respiratory specimens from the patients were tested by reverse transcriptase (RT) PCR and by viral culture for the presence of H5N1 virus. Contacts of cases were monitored for symptoms of illness for 10 days. Any contacts who became ill had respiratory specimens collected for H5N1 testing by RT PCR. Sera were obtained from contacts for H5N1 serological testing by microneutralisation and horse red-blood-cell haemagglutinin inhibition assays. FINDINGS: The 24-year-old index case died, and the second case, his 52-year-old father, survived after receiving early antiviral treatment and post-vaccination plasma from a participant in an H5N1 vaccine trial. The index case's only plausible exposure to H5N1 virus was a poultry market visit 6 days before the onset of illness. The second case had substantial unprotected close exposure to his ill son. 91 contacts with close exposure to one or both cases without adequate protective equipment provided consent for serological investigation. Of these individuals, 78 (86%) received oseltamivir chemoprophylaxis and two had mild illness. Both ill contacts tested negative for H5N1 by RT PCR. All 91 close contacts tested negative for H5N1 antibodies. H5N1 viruses isolated from the two cases were genetically identical except for one non-synonymous nucleotide substitution. INTERPRETATION: Limited, non-sustained person-to-person transmission of H5N1 virus probably occurred in this family cluster.

[An outbreak of human Streptococcus suis serotype 2 infections presenting with toxic shock syndrome in Sichuan, China].

OBJECTIVE: In mid-July 2005, five patients presented with septic shock to a hospital in Ziyang city in Sichuan, China, to identify the etiology of the unknown reason disease, an epidemiological, clinical, and laboratory study were conducted. METHODS: An enhanced surveillance program were established in Sichuan, the following activities were introduced: active case finding in Sichuan of (a) laboratory diagnosed Streptococcus suis infection and (b) clinically diagnosed probable cases with exposure history; supplemented by (c) monitoring reports on meningococcal meningitis. Streptococcus suis serotype 2 infection was confirmed by culture and biochemical reactions, followed by sequencing for specific genes for serotype and virulence factors. RESULTS: From June 10 to August 21, 2005, 68 laboratory confirmed cases of human Streptococcus suis infections were reported. All were villagers who gave a history of direct exposure to deceased or sick pigs in their backyards where slaughtering was performed. Twenty six (38%) presented with toxic shock syndrome of which 15 (58%) died. Other presentations were septicaemia or meningitis. All isolates were tested positive for genes for tuf, species-specific 16S rRNA, cps2J, mrp, ef and sly. There were 136 clinically diagnosed probable cases with similar exposure history but incomplete laboratory investigations. CONCLUSION: An outbreak of human Streptococcus suis serotype 2 infections occurred in villagers after direct exposure to deceased or sick pigs in Sichuan. Prohibition of slaughtering in backyards brought the outbreak to a halt. A virulent strain of the bacteria is speculated to be in circulation, and is responsible for the unusual presentation of toxic shock syndrome with high case fatality.