Respiratory infections positive for human respiratory syncytial virus (RSV) subtype A were characterised in children admitted to hospitals in Rome and Ancona (Italy) over the last three epidemic seasons. Different strains of the novel RSV-A genotype ON1, first identified in Ontario (Canada) in December 2010, were detected for the first time in Italy in the following 2011/12 epidemic season. They bear an insertion of 24 amino acids in the G glycoprotein as well as amino acid changes likely to change antigenicity. By early 2013, ON1 strains had spread so efficiently that they had nearly replaced other RSV-A strains. Notably, the RSV peak in the 2012/13 epidemic season occurred earlier and, compared with the previous two seasons, influenza-like illnesses diagnoses were more frequent in younger children; bronchiolitis cases had a less severe clinical course. Nonetheless, the ON1-associated intensive care unit admission rate was similar, if not greater, than that attributable to other RSV-A strains. Improving RSV surveillance would allow timely understanding of the epidemiological and clinicopathological features of the novel RSV-A genotype.
BackgroundA good correlation between HCV core antigen (HCVAg) and different HCV-RNA assays has been described, but little data are available in HCV/HIV co-infection. We aimed to evaluate HCVAg in comparison with HCV-RNA and to determine their kinetics during antiviral treatment in selected HCV/HIV co-infected patients.Methods355 samples from 286 HCV/HIV co-infected subjects for whom HCV-RNA (Abbott RealTime) was requested were analysed also for HCVAg (Abbott ARCHITECT) in order to evaluate the correlation between the two parameters both in patients treated or untreated for chronic hepatitis C and according to different HCV genotypes. The differences between percentages were evaluated by chi square or Fisher’s exact test, while mean and median values were compared by Student’s t test or the Mann–Whitney test, respectively. All differences were considered significant for a p value <0.05.ResultsHCVAg was detectable on 288/315 sera (91.4%) positive for HCV-RNA and in 5 out of40 (12.5%) sera with undetectable HCV-RNA for a total concordance of 90.1%. The correlation was fair both in untreated (r = 0.742) and in treated (r = 0.881) patients and stronger for genotypes 1 and 4 than for genotype 3. Both HCV-RNA and HCVAg levels were significantly higher (p = 0.028 and p = 0.0098, respectively) in patients infected by genotype 1 than by genotype 3. The mean ratio of Log values between HCV-RNA (IU/mL) and HCVAg (fmol/liter) was 2.27 ± 1.09 in untreated and 2.20 ± 0.82 in treated patients (p = n.s.),consistent with a sensitivity of HCVAg corresponding to about 1,000 IU/mL of HCV-RNA, and ranged from 2.21 to 2.32 among HCV genotypes with no significant differences; five samples (1.4%; 2 genotype 1a or 1c, 3 genotype 3a) showed highly divergent values. The analysis of 18 monitoring profiles from patients treated with PEG-IFN and Ribavirin showed similar trends, except in one case in which relapse could be predicted by HCVAg and not by HCV-RNA.ConclusionThese results suggest that HCVAg represents an adequate tool for determining an ongoing HCV infection also in HIV co-infected patients, with lower costs and faster turnaround time than HCV-RNA.
BackgroundOccult hepatitis B virus (HBV) infection (OBI) is characterized by HBV DNA persistence even though the pattern of serological markers indicates an otherwise resolved HBV infection. Although OBI is usually clinically silent, immunocompromised patients may experience reactivation of the liver disease.Case presentationWe report the case of an individual with human immunodeficiency virus (HIV) infection and anti-HBV core antibody positivity, who experienced severe HBV reactivation after discontinuation of lamivudine-including antiretroviral therapy (ART). HBV sequencing analysis showed a hepatitis B surface antigen escape mutant whose presence in an earlier sample excluded reinfection. Molecular sequencing showed some differences between two isolates collected at a 9-year interval, indicating HBV evolution. Resumption of ART containing an emtricitabine/tenofovir combination allowed control of plasma HBV DNA, which fell to undetectable levels.ConclusionThis case stresses the ability of HBV to evolve continuously, even during occult infection, and the effectiveness of ART in controlling OBI reactivation in HIV-infected individuals.
To evaluate the performance of different commercial assays for the detection of recent cytomegalovirus (CMV) in pregnancy, the sensitivity and specificity of assays for CMV-specific IgM antibodies were compared. Routine specimens from pregnant women were screened for CMV IgM using the Abbott AxSYM assay. Sera that were reactive according to AxSYM were further tested for IgM by other commercial assays. In selected IgM positive samples a CMV IgG avidity assay (Radim) and virus isolation from urine (shell vial) were also performed. The positivity rate for IgM anti-CMV by AxSYM was relatively high (140 out of 492, combining reactive and grayzone results). Only 26 of the 140 samples were positive for IgM according to Radim. The IgG avidity was low in 16 of the 43 samples tested, and the Radim and DiaSorin IgM assays were negative in 5 of them; 2 of the latter cases were also positive for viral isolation according to a shell vial method. There are differences in the sensitivity of the commercially available tests for CMV antibodies. CMV screening in pregnancy is performed as a first step by immunoassays and the choice of highly sensitive IgM test associated with further serological and virological methods could help to identify early primary infections.
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