Relationship of human herpes virus 6 and multiple sclerosis: A systematic review and meta-analysis.

Infection with human herpes viruses has been suggested to contribute to multiple sclerosis (MS), while interaction between human herpes 6 (HHV6) and MS remain unclear yet. Here, we conducted a meta-analysis on the relationship of HHV6 infection and MS. All related studies were collected from major databases. The analyses were performed by STATA 14 and Comprehensive Meta-Analysis V2.0 softwares. Pooled odds ratios (ORs) and 95%CIs were calculated from the raw data of the including studies by the random effects models when I2 > 50% and fix model when I2 < 50%. Thirty nine studies were included in the meta-analysis that 34 studies used molecular assays and 7 studies used serological assays for diagnosis of HHV6 infected cases. The relationship of HHV6 and MS was significant in healthy control group by yielding a summary OR of (2.23 [1.5-3.3], p = 0.06). A significant HHV6 association with MS were in the studies with >6 score that used serum/blood sample with OR of (6.7 [95%CI 4.8-8.6], p < 0.00001) and in serological studies, IgM positive titer in other neurological diseases (OND) control group was significant with OR of (8.3 [95%CI 3-24.07], p < 0.00001). This study has been showed that there were significant relationship between MS and HHV6 infection.

Sensitivity and specificity of the World Health Organization pertussis clinical case definition.

OBJECTIVES: Bordetella pertussis continues to circulate even in countries with good childhood vaccination coverage. This study was undertaken to define the relationship between documented disease and the clinical criteria proposed by the World Health Organization (WHO). METHODS: Nasopharyngeal swab samples were collected from previously healthy 6-14-year-old school children in Tehran, presenting with persistent cough of at least 2- week duration. Specimens were examined for Bordetella pertussis and Bordetella parapertussis by culture and polymerase chain reaction (PCR). RESULTS: Out of 6601 students, 328 (5.0%) had been coughing for at least 2 weeks. Of these children with cough, 182 (55.5%) experienced whooping, 194 (59.1%) suffered a paroxysmal cough, and 73 (22.3%) had post-tussive vomiting. Twenty-one (6.4%) samples tested positive for B. pertussis and six (1.8%) for B. parapertussis by PCR. Culture of four (1.2%) specimens was positive for B. pertussis. In comparison to PCR, the sensitivity and the specificity of the WHO clinical criteria (year 2000) were 95.2% and 15.0%, respectively. CONCLUSIONS: Pertussis remains one of the etiologies of prolonged cough, even in communities with high immunization in children. The specificity of the WHO criteria is low in diagnosing pertussis compared with PCR.