Serotyping and PFGE Type of Salmonella Isolates in Yunnan Province / 昆明医科大学学报

Objective To study the serotypes and molecular characteristics of foodborne Salmonella in Yunnan Province using pulsed field gel electrophoresis (PFGE) and to establish PFGE fingerprint database. Methods This study was carried out on the basis of the Serological typing of 322 strains of foodborne Salmonella which was isolated from Yunnan national foodborne disease surveillance from 2013 to 2016. The clustering analysis was conducted on 148 strains of Salmonella DNA restriction enzyme map by using the software of BioNumerics. Fingerprint database was established through the comparison of clustering analysis correlation on bacterial strain. Results The serotype of 322 strains of Salmonella mainly included A, B, C, D, E, F, G and other 7 groups,among which Salmonella typhimurium was the major type, accounting for 11.4% (37/322) . Cluster analysis was applied using BioNumerics software in 148 strains of Salmonella DNA restriction enzyme map. According to the different number and the different positions, electrophoresis strips were divided into 102 different PFGE patterns (Figure 1) , which was categorized into 39 clusters if 90% of the strips was similar. Conclusion Foodborne salmonella molecular classification is complex. Salmonella typhimurium is the major type. PFGE belt type presents diversity.

Main Pathogenic Bacteria and Their Influencing Factors about Food-borne Diarrhea in Yunnan Province from 2012 to 2016 / 昆明医科大学学报

Objective To investigate the incidence and its main pathogenic bacteria infection status of food-borne diarrhea and analyze their influencing factors in Yunnan province from 2012 to 2016. Me thods 1743 cases of food-borne diarrhea were collected, which were supervised from 11 hospitals covering from 2012 to 2016 years in Yunnan province.We gathered and tested the biological samples. Meanwhile, we analyzed the main pathogenic bacteria and their influencing factors. Re s ults 65 positive strains samples were checked out in 1743 cases of food-borne diarrhea positive samples, the positive rate was 3.73％ (65/1743). Salmonella and Shigella strains were the main pathogenic bacteria, the main suspect food was meat and its products, as well as fruits and their products. In this study, Professions, methods of processing and clinical diagnosis were considered as the main factors of main pathogenic microbe detectable rates of food-borne diarrhea cases in Yunnan province. Conclus ion We should carry out public health education widespreadly in nursery, scattered children, farmers and migrant workers, students and other special crowds, provide intervention measures, attach great importance to food processing, reduce the possible contamination of food during processing, improve the level of clinical diagnosis and treatment and the recognization ability of food-borne diseases, and propose targeted prevention and control measures.Thus, food-borne disease can be prevented and controlled effectively.

The first confirmed human case of avian influenza A (H5N1) in mainland, China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To ascertain the causation of a family cluster involving two undefined pneumonia cases, a 12-year-old girl and her brother, reported October, 2005 in Xiangtan county, Hunan province.</p><p><b>METHODS</b>Information on epidemiology and clinical manifestation of the cases was collected from interviewing the keyman and referring to related medical records. The environment exposure of the cases to their households and the timeline of the illness were reproduced, using this information. Medical check-up was undergone among the close contacts of the cases and on sick/dead poultry. Throat swab of the cases were collected and tested by both RT-PCR and real-time PCR to detect viral nucleic acids of A/H5N1, and were then inoculated into special pathogen free (SPF) embryonated hens' eggs. Serum of the cases including acute and convalescent phases were also collected and tested by microneutralization and haemagglutination-inhibition (HI) assays to detect H5-specific antibodies.</p><p><b>RESULTS</b>Both the girl and her brother developed fever 2 and 4 days after sudden deaths of chickens being raised in the same house. Both of them had developed pneumonia and the girl died from acute respiratory distress syndrome (ARDS) complicated with multi-organ failure. The boy survived and subsequently discharged from hospital. An eighth-day serum from the girl tested H5 antibody negative, while 4-fold and greater increased in antibody titers were detected in serum from the boy using microneutralization and HI assays in sequential acute and convalescent sera. Of 192 cases, only one doctor who cared for the girl during hospitalization had upper respiratory symptoms but tested negative for H5N1 by microneutralization assay.</p><p><b>CONCLUSION</b>The boy was the first confirmed human case of avian influenza A (H5N1) in the mainland of China and his sister was diagnosed clinically. The most probable explanation of these two cases was that the transmission of H5N1 virus from infected poultry within the same household environment. No evidence of human-to-human transmission was noted in the family cluster.</p>

Study on a fatal pregnant woman died from by avian influenza (H5N1) / 中华流行病学杂志

<p><b>OBJECTIVE</b>To ascertain the causation of a pregnant woman with undefined pneumonia reported from the People's Hospital of Tongling city in Anhui province on November 2005.</p><p><b>METHODS</b>Epidemiological and clinical information of the case was collected from the keypersons close to the case and referring to the medical record. A medical observation was carried out on the close contacts of the case and sick or dead poultry. Tracheal aspirates being collected were tested by both RT-PCR and real-time PCR to detect viral nucleic acids of A/H5N1, and were inoculated into special pathogen free (SPF) embryonated hens' eggs.</p><p><b>RESULTS</b>The pregnant woman was found to have been contacted with the sick/dead poultry directly on the 4th day before onset of illness. All the 122 close contacts were healthy after a 10-day medical observation. The major clinical features of the case were viral pneumonia with rapidly developed leukopenia and lymphopenia. The progress to acute respiratory distress syndrome and multiple organ dysfunction syndromes was found at clinical presentation. HA and NA gene of A/H5N1 virus were positive. The 8 gene fragments of A/Anhui/1/2005 (H5N1) isolated from the tracheal aspirates had not carried genes from a human virus through reassortment, and the receptor-binding site of the hemagglutinin was polybasic cleavage site.</p><p><b>CONCLUSION</b>This was the first documented case of H5N1 infection in pregnant woman. The immunotolerant state of pregnancy might have predisposed to the fatal outcome of the patient.</p>