ABSTRACT
<p><b>BACKGROUND</b>To determine the etiologic agent of an atypical pneumonia human case admitted to Xiangtan City hospital, Hunan Province in Oct. 2005.</p><p><b>METHODS</b>The patient's respiratory tract samples and serum were collected. Throat swabs were tested by microneutralization and hemagglutination-inhibition assays.</p><p><b>RESULTS</b>The results of nucleic acid detection of all respiratory samples were negative and virus isolation was also negative. The H5-specific antibodies of convalescence showed a 4-fold greater rise than acute phase.</p><p><b>CONCLUSION</b>The atypical pneumonias case was confirmed as the first human case of avian influenza A (H5N1) infection in the mainland of China.</p>
Subject(s)
Animals , Chick Embryo , Child , Humans , Male , Antibodies, Viral , Blood , Cell Line , China , Clinical Laboratory Techniques , Hemagglutination Inhibition Tests , Hemagglutinin Glycoproteins, Influenza Virus , Genetics , Allergy and Immunology , Influenza A Virus, H5N1 Subtype , Genetics , Allergy and Immunology , Influenza, Human , Diagnosis , Virology , Neutralization Tests , Pneumonia, Viral , Diagnosis , Virology , Reagent Kits, Diagnostic , Reverse Transcriptase Polymerase Chain Reaction , Sequence Analysis, DNAABSTRACT
<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>
Subject(s)
Animals , Child , Female , Humans , Male , Chickens , China , Fatal Outcome , Influenza A Virus, H5N1 Subtype , Allergy and Immunology , Influenza in Birds , Influenza, Human , Diagnosis , Pneumonia , Virology , Respiratory Distress Syndrome , VirologyABSTRACT
<p><b>OBJECTIVE</b>To provide methods and alert thresholds which are scientific, sensitive, specific and practical for Early Warning System in Public Health Surveillance.</p><p><b>METHODS</b>Alert data was based on historical infectious diseases reports. Control chart was used to detect outbreaks or epidemics. An epidemic was defined by consulting Specialists. After calculating sensitivity, specificity, positive predictive value and describing receiver-operating characteristic curve (ROC), the optimal model and thresholds were chosen.</p><p><b>RESULTS</b>At 80 percentile, the sensitivities and the specificities of epidemic haemorragia fever, hepatitis A, dysentery, epidemic cerebrospinal meningitis and malaria were over 90%, and there was a high efficacy of early warning. At 90 percentile, the sensitivities and the specificities of tuberculosis and measles were over 85%, and there was a high efficacy of early warning also.</p><p><b>CONCLUSION</b>Control chart based on five years was chose as a essential method in early warning system. The alert threshold for epidemic haemorragia fever, hepatitis A, dysentery, epidemic cerebrospinal meningitis and malaria was 80 percentile. The alert threshold for tuberculosis and measles was 90 percentile.</p>