[Clinical research of Bordetella pertussis infection in infants with prolonged cough].

OBJECTIVE: To explore the prevalence of Bordetella pertussis (B. pertussis) infection in unvaccinated or incomplete vaccinated infants with cough for a prolonged duration. METHODS: The serum samples and nasopharyngeal secretions were collected from 176 patients with cough for a prolonged duration ( ≥ 2 weeks) from 2011 to 2012 at Children's Hospital Affiliated to Capital Institute of Pediatrics. Multiplex PCR of nasopharyngeal secretion was employed to identify B.pertussis. And enzyme-linked immunosorbent assay(ELISA) was used to detect antibody to pertussis toxin(PT-IgG). Total bacterial DNA was enacted from nasopharyngeal secretion and two-target IS481/PT of B.pertussis was detected by PCR. The sera and nasopharyngeal secretions were also collected from household contacts with cough for a prolonged duration. Their clinical characteristic and epidemiological profiles were collected and analyzed. RESULTS: B.Pertussis infection was demonstrated in 51 cases (29.0%). The patients ages were from 23 days to 4 years. Among them, 46 cases (90.2%) were aged under 12 months and 5 cases (9.8%) over 12 months. And 40 cases were unvaccinated (31 cases <3 months old, 4 cases 3-12 months old, 5 cases >5 years old) and 11 cases incompletely vaccinated. There were 31 males and 20 females. More patients were found in spring and summer than those in autumn and winter. Nine infant cases had 12 household contacts. Among 12 household contacts, 3 were PCR positive and 12 PT-IgG positive. Pertussis was remarkably critical in infants. Serious complications included failure to thrive, pneumonia, respiratory failure and seizures. CONCLUSIONS: B.pertussis infection is an important cause in unvaccinated or incomplete vaccinated infants with prolonged cough. Peak seasons of pertussis are spring and summer. Undiagnosed adolescents and adults with pertussis may be a significant source for transmission of B.pertussis to other susceptible children. Infants aged under 1 year are at risk for severe pertussis and life-threatening complications. As a rapid and sensitive method of detecting B.pertussis, PCR may be used in early phase.

[Survey of pertussis infection in infants aged under 3 months with persistent cough].

OBJECTIVE: To explore the prevalence of pertussis in hospitalized infants aged under 3 months with persistent cough. METHODS: The nasopharyngeal secretions and serum samples were collected from hospitalized infants aged under 3 months with cough for over 2 weeks from January 2011 to January 2012. The samples of nasopharyngeal secretion were suctioned and collected. Multiplex PCR assay was employed to identify Bordetella pertussis (B. pertussis) and enzyme-linked immunosorbent assay used to detect antibody to pertussis toxin (PT-IgG). Total bacterial DNA was exacted from nasopharyngeal secretion and two-target IS481/PT of B. pertussis was detected by PCR. RESULTS: Fifty-nine infants (32 boys and 27 girls) were enrolled. None of them was pre-immunized with diphtheria-pertussis-tetanus vaccine. Seventeen infants (28.8%) were B. Pertussis positive. Among 17 cases, 3 infants under 1 month, 4 infants 1 -2 months, and 10 infants 2 - 3 months. Three infants had household contacts with persistent cough and their serum antibodies to pertussis toxin were positive. Sixteen infants with pertussis had the paroxysms of frequent and rapid coughs while another 5 with pertussis had long inspiratory effort accompanied by a high-pitched "whoop" at the end of paroxysms. Seven infants with pertussis had conjunctiva bleeding, a special sign of pertussis. Ten infants had lymphocytosis with a predominant elevation of lymphocytes. CONCLUSIONS: B. pertussis is an important pathogen for the infants under 3 months with persistent cough. Multiplex PCR may be used to identify B. pertussis with a high sensitivity. The unrecognized close family members of the infants with pertussis are probably an important source of infection.

[NEMO Delta 4-10 deletion of NEMO gene in Chinese incontinentia pigmenti cases].

OBJECTIVE: Incontinentia pigmenti (IP) is a rare X-linked dominant disorder that affects ectodermal tissues. In IP, mutations in NEMO lead to the complete loss of NF-kB activation creating a susceptibility to cellular apoptosis in response to TNF-alpha. Recently, a second nonfunctional copy of the gene, Delta NEMO was identified, opposite in direction to NEMO. Almost 90% of IP whose gene mutation type had been recognized have a recurrent genomic deletion of exons 4-10 of the NEMO (IKK gamma) gene, called NEMO Delta 4-10, which is necessary to activate the NF-kB pathway. Therefore, PCR-based detection of the NEMO deletion is a diagnostic measurement for IP. This study sought to analyze the NEMO Delta 4-10 deletion in NEMO gene of Chinese IP cases. METHODS: Seven IP cases and part of their families totally 15 persons were enrolled in this study. The 7 IP cases were aged 41 days to 8 years. Among them 1 was male and 6 were female. Four cases had family history of IP, the other 3 were sporadic cases. Fifty healthy children without any congenital diseases were taken as normal control group. According to the gene characteristics of IP, by PCR measurement NEMO Delta 4-10 deletion in NEMO gene was tested with specific primers In2/JF3R, and NEMO Delta 4-10 deletion in pseudogene Delta NEMO was checked out by primers Rev-2/JF3R. RESULTS: Five out of the 7 tested cases (case 1, 2, 3, 4, and 6) showed NEMO Delta 4-10 deletion in NEMO gene. The mothers of case 1 and case 6, 1a and 6a, also suffered from this disease, and their results were just the same as their daughters. For pseudogene Delta NEMO only case 2 and case 4 were proved having NEMO Delta 4-10 deletion, while other cases and families had negative results. For normal control group, NEMO Delta 4-10 deletion was not found either in NEMO gene or in their pseudogene Delta NEMO. CONCLUSION: Incontinentia pigmenti in most cases were caused by NEMO Delta 4-10 deletion in NEMO gene.