[A case-control study on Guillain-Barre syndrome in children of North China].

OBJECTIVE: This study aimed at exploring the risk factors for Guillain-Barre syndrome (GBS). METHODS: A case-control study design was used with 51 cases of GBS, diagnosed based on their symptoms, signs and electrophysiological examinations and exclusion of poliomyelitis and other acute flaccid paralysis, and 51 controls matched on age, sex and resident village. Serum IgG antibodies specific for Campylobacter jejuni were determined for all the subjects by enzyme-linked immunosorbent assay (ELISA) with a preparation of surface antigen of C. jejuni C(1) strain isolated from the patients and prevalent in north China. Each case and control were interviewed with his/her parents or guardians by a trained interviewer using an ad hoc questionnaire, including his/her demographic information, socioeconomic status, onset of the illness, and potential risk factors in their environment and personal hygiene. Data were analyzed with SAS software release 6.04 in a microcomputer. RESULTS: GBS was associated with a few factors, such as residential areas (45 of the 51 cases living in the rural areas, accounting for 88.2% of the total), polio and hepatitis B vaccine immunization before onset of the illness (with ORs of 7.27 and 3.14, respectively), no hand washing after defecation and before meals (with an OR of 6.15) and getting cold and going to the river or lake site before onset of the illness (with ORs of 13.75 and 12.20, respectively). Infection with Campylobacter jejuni associated strongly with the illness (with an OR of 9.5, P < 0.001). Thirty-five of the 51 cases had precursor symptoms before onset of the illness (68.6%). CONCLUSION: It suggests that occurrence of GBS may correlate to infection with Campylobacter jejuni and poor personal hygiene in children.

A prospective clinical and electrophysiologic survey of acute flaccid paralysis in Chinese children.

We studied 29 children admitted to Beijing Children's Hospital (BCH) with acute flaccid paralysis between June 1991 and June 1993. Twenty-seven patients had Guillain-Barré syndrome--7 with acute inflammatory demyelinating polyneuropathy and 20 with acute motor axonal neuropathy (AMAN). Two had poliomyelitis. The most common cause of acute flaccid paralysis at BCH is the AMAN pattern of GBS.

Viral etiology of acute childhood encephalitis in Beijing diagnosed by analysis of single samples.

OBJECTIVE: To understand the viral etiology of acute childhood encephalitis in Beijing. METHODS: Ninety-seven Chinese children (between 7 months and 13 years of age) with acute encephalitis were retrospectively investigated. They were treated in Beijing Children's Hospital between June, 1991, and October, 1994. Different serologic methods (immunofluorescence assay, enzyme-linked immunosorbent assay, solid phase reverse immunosorbent test) were used for detection of IgM antibody to enteroviruses, herpesviruses, mumps, measles, rubella and Japanese encephalitis virus. The viral DNA of six herpesviruses was detected by polymerase chain reaction. RESULTS: Viral etiology was identified in 35 of 97 (36.0%) cases. The most frequently identified pathogens were enteroviruses (15; 15.4%), followed by mumps (7; 7.2%), rubella (6; 6.1%), Japanese encephalitis virus (5; 5.1%), human herpesvirus 6 (2; 2.0%), herpes simplex virus (2; 2.0%) and Epstein-Barr virus (1; 1.0%). IgM antibody in cerebrospinal fluid was detected for enterovirus, mumps and rubella viruses. CONCLUSIONS: Enteroviruses were the most frequent viral pathogens of acute childhood encephalitis in Beijing. Detection of IgM in cerebrospinal fluid may be useful for diagnosis in certain cases of viral encephalitis.

Detection of respiratory viruses in nasopharyngeal secretions with immunofluorescence technique for multiplex screening-an evaluation of the Chemicon assay.

BACKGROUND: Antigen detection with immunofluorescence is an efficient method for diagnosis of respiratory tract infections, but has previously not allowed for simple screening of many respiratory viruses. Pools of monoclonal antibodies against various respiratory viruses are now available, and are potentially important tools for improvement of antigen detection in nasopharyngeal samples. OBJECTIVE: To evaluate the commercially available Chemicon immunofluorescence assay (IFA; respiratory viruses panel and identification kit), an indirect IFA containing a pool of monoclonal antibodies for screening for influenza A, B, respiratory syncytial virus (RSV), parainfluenza 1, 2, 3 and adenovirus, and the respective individual antibodies. STUDY DESIGN: Ninety-six frozen preparations from nasopharyngeal secretions or bronchoalveolar lavages were retrospectively examined with the assay, and the results compared with other IFAs for antigen detection and cell culture isolation obtained in the everyday routine. Nasopharyngeal preparations from 300 children with lower respiratory tract infections at Beijing Children's Hospital during the 1994-1995 winter season were also examined. RESULTS: The sensitivity of the Chemicon assay compared to the combined results of routine IFA and isolation was 89% and specificity 92%. If five identifications of RSV made with the Chemicon assay alone were regarded to be truly positive, the specificity was 100%. A viral etiology was identified in 105/280 (38%) evaluable samples drawn from the Chinese children (influenza A 20%, RSV 14%, adenovirus 3% and parainfluenza 1, 2 or 3, 7%). CONCLUSION: One problem with the Chemicon assay was that for around 4-13% of samples there was a non-specific staining in the screening assay, necessitating stainings for verification. Despite this, the assay is an excellent tool for identification of viral respiratory tract infections, giving an increased sensitivity compared to direct immunofluorescence assays.

Detection of group C rotavirus in infants with extrahepatic biliary atresia.

The purpose of this retrospective study was to examine liver tissue from patients with cholestatic disease for the presence of group C rotavirus RNA. The reverse transcriptase-polymerase chain reaction (PCR) for genes 5 and 6 was used, and the PCR products were subjected to liquid hybridization with a 32P-labeled probe. A second amplification with nested primers was also used. Samples from 32 subjects (20 with biliary atresia or choledochal cyst and 12 controls) were tested. Ten of 20 biliary atresia patients were positive for group C rotavirus RNA; no controls were positive (P < .003). Three of the positive patients were positive for both genes 5 and 6. Six of the 10 had > 1 sample that was positive. These data suggest a possible relationship between group C rotavirus and extrahepatic biliary atresia in the 10 patients in whom virus RNA was detected.

Detection of cytomegalovirus DNA in paraffin-embedded lung tissue specimens using in situ polymerase chain reaction.

OBJECTIVE: To develop a possible alternative laboratory diagnostic method, an in situ polymerase chain reaction (ISPCR) for definitive diagnosis of human cytomegalovirus (HCMV) pneumonia in infants. METHODS: The material involved in this study was formalin-fixed paraffin-embedded lung tissue specimens from 6 infants died of histopathologically diagnosed cytomegalic inclusion body pneumonia (CMIBP) and from 4 infants died of other diseases. When DNA extracts from the specimens of these 10 infants were tested by using a previously applied conventional PCR, the specimens from the 6 infants with CMIBP were positive for HCMV DNA, while those from the other 4 infants were negative. In the ISPCR, biotin-11-dUTP was used for labeling the amplified products and streptavidin, biotin-alkaline phosphatase for in situ color development. RESULTS: The results of the study showed specific staining for HCMV DNA in the lung tissue slices from the 6 cases with CMIBP, while no staining was found in the specimens from the 4 infants who died of other diseases. The control ISPCR tests on the HCMV DNA positive specimens without adding either biotin-11-dUTP or Taq DNA polymerase or the primers for HCMV DNA showed negative results. The specific staining for HCMV DNA was seen in bronchial and alveolar epithelial cells, small vascular endothelial cells and leukocytes in the lumens of small blood vessels. CONCLUSIONS: The results suggested that the ISPCR was able to demonstrate both presence of HCMV DNA in the lung tissues and active HCMV infection; therefore the ISPCR may be applicable in definitive diagnosis of HCMV pneumonia when proper specimens such as lung biopsy material or bronchoalveolar lavage is available for the test.

Acute motor axonal neuropathy: a frequent cause of acute flaccid paralysis in China.

In northern China, annual epidemics of acute-onset flaccid paralysis diagnosed clinically as Guillain-Barré syndrome have been recognized for at least 20 years. On the basis of an historical analysis of more than 3,200 patients, distinctive features include most cases occurring during the summer months among children and young adults, most of whom reside in rural areas. Of 90 patients with acute flaccid paralysis, 88 had a distinctive pattern that shares clinical and cerebrospinal fluid findings with demyelinating Guillain-Barré syndrome, but that differs from Guillain-Barré syndrome physiologically and pathologically. The clinical course is marked by rapidly progressive ascending tetraparesis, often with respiratory failure, but without fever, systemic illness, or sensory involvement. Cerebrospinal fluid is acellular, and elevations of protein content occur in the second or third week of illness. Electrodiagnostic studies show normal motor distal latencies and limb conduction velocities, but reduced compound muscle action potential amplitudes. Sensory nerve action potentials and, when elicitable, F waves are within the range of normal. Recovery is usually good. Autopsy studies have shown Wallerian-like degeneration of motor fibers. These studies establish that this is a distinctive syndrome, distinguishable from poliomyelitis and demyelinating Guillain-Barré syndrome.

Detection of rotavirus antigen in tracheal aspirates of infants and children with pneumonia.

Clinical manifestations of respiratory tract infection often precede or coincide with rotavirus gastroenteritis in infants and children. To investigate the possible association between respiratory tract manifestations and rotavirus infection, the authors determined human rotavirus (HRV) antigen and respiratory syncytial virus (RSV) antigen in tracheal aspirates of 58 children with clinically diagnosed pneumonia by enzyme-linked immunosorbent assay (ELISA) and immunofluorescent antibody techniques. HRV antigen was detected in 16 out of the 58 cases (27.6%) and RSV antigen was found positive in 27 cases (46.5%). In four cases both HRV and RSV antigens were detected. The results of our study suggest that rotavirus may occasionally by one of the etiologic agents of acute lower respiratory infections of infants and children and that rotavirus infection may be transmitted via respiratory route. However, further extensive studies are needed for confirmation of the association between rotavirus and respiratory tract infection.

Nasopharyngeal secretory antibody response to poliovirus type 3 virion proteins exhibit different specificities after immunization with live or inactivated poliovirus vaccines.

By using immunoblotting, neutralization, and ELISA, the development of secretory antibody responses to poliovirus type 3 virion proteins (VP1, VP2, VP3) and to intact or trypsin-treated poliovirus type 3 was studied in the nasopharyngeal secretions in groups of infants after immunization with live attenuated poliovirus vaccine (OPV), enhanced potency inactivated poliovirus vaccine (IPV-EP), or after combined vaccination with IPV-EP followed by OPV. After three doses of vaccine, infants in all vaccine groups developed similar secretory IgA response to VP1 and VP2. The antibody response to VP3 was observed in 76.5% of subjects immunized with OPV alone and approximately 60% of those immunized with IPV-EP followed by OPV. However, only 13% of those immunized with IPV-EP alone exhibited VP3-specific antibody response. Significant differences in poliovirus type 3 specific antibody activity were observed between OPV and IPV-EP immunized subjects when trypsin-treated poliovirus was used as the antigen for neutralization or for ELISA in vitro. The neutralizing antibody activity against cleaved virus was significantly higher than against whole virus in the OPV vaccinated subjects. Both neutralizing and ELISA antibody activity against cleaved virus was significantly lower than against the whole virus in IPV-EP immunized subjects.

Characteristics of the immune response to poliovirus virion polypeptides after immunization with live or inactivated polio vaccines.

Groups of infants were immunized with high-potency, inactivated polio vaccine (IPV) or live, attenuated oral polio vaccine (OPV) and studied for antibody responses to whole virus and polypeptides VP1, VP2, and VP3. Both vaccines induced neutralizing and enzyme-linked immunosorbent assay (ELISA) IgG to the whole virus, IgG antibody to VP1 and VP3, and similar secretory IgA to VP1 and VP2 in the nasopharyngeal secretions (NPS) without any VP3 response. Virus-specific neutralizing activity in NPS was observed in 70% of subjects receiving OPV and in only 26.7% of subjects receiving IPV. ELISA antibody also appeared to be lower in IPV than in OPV subjects. These observations suggest that specific ELISA antibody to poliovirus virion proteins can be frequently induced in the secretory sites, by OPV as well as by IPV. Neutralizing antibody response in the NPS appeared, however, to be more effectively induced by OPV than by the high-potency IPV.