Objective To detect Chlamydia trachomatis phage Vp1 gene in clinical swab specimens and anti-Vp1 antibodies in serum specimens.MethodsCervical and urethral swab as well as serum specimens were collected from attendees to the sexually transmitted disease(STD) clinic in the Tianjin Institute of STD,during March 2008 to March 2011.PCR was conducted to detect chlamydial phage Vp1 gene in swab samples,enzyme linked immunosorbent assay(ELISA) and Western blot to detect anti-Vp1 antibody in sera.The swab specimens positive for Vp1 gene were subjected to cell culture followed by the detection of Vp1 protein with an immunofluorescence-based method.ResultsTotally,36 out of 1542 swab specimens turned out to be positive for Vp1 gene,and 23 out of 453 serum specimens for anti-Vp1 antibody.No positive results were obtained in the Vp1 gene-positive swab specimens by cell culture and immunofluorescence-based assay.ConclusionThe Vp1 gene of Chlamydial trachomatis phage and anti-Vp1 antibody are successfully detected from clinical swab and serum specimens respectively.

Objective:To investigate the prognosis of severe hyperbilirubinemia in full-term infants who met the exchange transfusion criteria and were treated by blood exchange transfusion and phototherapy.Methods:A total of 168 full-term infants with severe hyperbilirubinemia who met the criteria for exchange transfusion and were hospitalized in the Neonatology Department of seven tertiary hospitals in Hebei Province from June 2017 to December 2018 were retrospectively included. According to the treatment protocol, they were divided into two groups: exchange transfusion group (38 cases) and phototherapy group (130 cases). Two independent sample t-test and Chi-square test were used to compare the clinical manifestations and follow-up results between the two groups. Multivariate logistic regression was used to analyze the risk factors for poor prognosis. Results:Neonatal severe hyperbilirubinemia in the exchange transfusion and phototherapy group were both mainly caused by hemolytic disease [42.1%(16/38) and 29.2%(38/130)], sepsis [28.9%(11/38) and 11.5%(15/130)] and early-onset breastfeeding jaundice [15.8%(6/38) and 11.5%(15/130)]. Total serum bilirubin level on admission in the exchange transfusion group was significantly higher than that in the phototherapy group [(531.7±141.3) vs (440.0±67.4) μmol/L, t=3.870, P<0.001]. Moreover, the percentage of patients with mild, moderate and severe acute bilirubin encephalopathy in the exchange transfusion group were higher than those in the phototherapy group [15.8%(6/38) vs 3.8%(5/130), 7.9%(3/38) vs 0.8%(1/130), 13.2%(5/38) vs 0.0%(0/130); χ2=29.119, P<0.001]. Among the 168 patients, 135 were followed up to 18-36 months of age and 12 showed poor prognosis (developmental retardation or hearing impairment) with four in the exchange transfusion group (12.9%, 4/31) and eight in the phototherapy group (7.7%, 8/104). Multivariate logistic regression analysis showed that for full-term infants with severe hyperbilirubinemia who met the exchange transfusion criteria, phototherapy alone without blood exchange transfusion as well as severe ABE were risk factors for poor prognosis ( OR=14.407, 95% CI: 1.101-88.528, P=0.042; OR=16.561, 95% CI: 4.042-67.850, P<0.001). Conclusions:Full-term infants who have severe hyperbilirubinemia and meet the exchange transfusion criteria should be actively treated with blood exchange transfusion, especially for those with severe ABE, so as to improve the prognosis.