Duration of viral shedding and factors associated with prolonged shedding among inpatients with influenza treated with oseltamivir: a prospective cohort study.

The purpose of this study was to determine the rate of decline in the diagnostic yield of influenza PCR assay after oseltamivir administration, and to identify risk factors for prolonged shedding. This was a prospective observational study. We included adult inpatients with clinical signs of influenza during the influenza seasons 2015 and 2016, who had positive influenza PCR tests and who were treated with oseltamivir. Clinical follow-up and repeat PCR testing were performed on days 2, 4 and 6 after the first positive test. We defined prolonged shedders as patients who still required hospitalization and had a positive PCR assay on day 4. Risk factors for prolonged shedding were assessed in univariate and multivariate analyses. A total of 215 patients were included in our study. The median age was 64 years and 49.3% were men. The main influenza type was H1N1 (50.1%). Rates of PCR positivity among evaluable patients on days 2, 4 and 6 were 142/215 (66%), 50/78 (64.1%) and 20/30 (66.6%), respectively. Independent risk factors for prolonged shedding (50 patients) included hypoxemia [odds ratio (OR) 2.55, 95% confidence interval (1.3-5.1)] and lower diastolic blood pressure [OR 0.94, 95% CI (0.92-0.97)] on admission. Negative PCR tests taken more than 48 h after initiation of treatment had low diagnostic yield. More severe disease, manifested by hypoxemia and lower blood pressure, is associated with prolonged shedding on oseltamivir treatment.

Parvovirus B19V infection in Israel: prevalence and occurrence of acute infection between 2008 and 2013.

Differences in the seroprevalence and unique pattern of parvovirus B19 (B19V) acute infections have been documented around the world. This study was conducted to estimate the seroprevalence of anti-parvovirus B19V IgG antibodies in the Israeli population and to assess the pattern of acute infection based on data from two laboratories in Israel. The overall IgG prevalence in the 1008 representative sera samples was 61·4% and the age-adjusted prevalence rate was 58·2%. Seropositivity was significantly associated with age, ranging from 25·7% in children aged 20 years. While no significant differences in seropositivity were detected between sexes and population groups, significantly lower seroprevalence was observed in older Jews born in Africa or Asia. Acute infection rates of 4·1% (234 cases) were found based on the positive IgM results identified in samples from 5663 individuals collected between 2008 and 2013. Annual peaks of infection were observed in 2008 and 2011-2012 and major seasonal peak of B19V IgM positivity was identified in June each year. The number of requests for B19V serology was significantly higher for women aged 20-39 years while the majority IgM-positive cases were identified in young children. With more than 30% of the adult population being susceptible to B19V infection, monitoring B19V status should be considered in specific risk groups such as pregnant women.

Genetic variants associated with susceptibility of Ashkenazi Jews to West Nile virus infection.

The epidemiology of West Nile virus (WNV) in Israel is different from other neighbouring countries in the Middle East where disease burden has been minimal. We analysed a cohort of Ashkenazi Jewish patients with symptomatic WNV infection (n = 39), and WNV-negative controls (n = 61), for nine genetic variants that has been suggested to be associated with susceptibility to WNV. Two single nucleotide polymorphisms were significantly more frequent in WNV-infected than non-infected individuals, rs7280422 (MX1) [odds ratio (OR) 4·05, 95% confidence interval (CI) 2·04-8·03, P < 0·001] and rs3213545 (OASL) (OR 1·85, 95% CI 1·03-3·3, P = 0·03). Genetic polymorphism may play a significant role in susceptibility to WNV infection in Ashkenazi Jews.

Extinction of expression of immunoglobulin genes in myeloma X fibroblast somatic cell hybrids.

Adherent hybrids between immunoglobulin-producing mouse myeloma cells and fibroblasts do not produce immunoglobulin polypeptide chains. These hybrids retained the actively rearranged immunoglobulin genes of the myeloma parental cells but lacked immunoglobulin heavy- and light-chain RNA transcripts. We conclude that the shutoff of immunoglobulin production in these hybrids occurs at the transcription or early processing level.

Drug-resistant HIV infection among drug-naive patients in Israel.

BACKGROUND: In Israel, <0.06% of the general population is infected with human immunodeficiency virus (HIV), with a much higher prevalence among specific groups. These groups are distinguished demographically by risk behavior category and by virus subtype. We investigated transmission of drug resistance within groups to assess the impact of these factors. METHODS: Plasma samples from >15% of all patients with new diagnoses of HIV infection were randomly collected between June 1999 and June 2003. Sequences from 176 drug-naive patients included 20 of subtype A, 20 of subtype AE, 2 of subtype AC, 29 of subtype B, 100 of subtype C, and 5 of subtype F. RESULTS: Major drug resistance mutations (protease: L90M; reverse transcriptase: M41L, K103N, V106M, M184V, Y181S, G190A, L210W, T215Y/F, and K219R) were detected in 1 subject with A subtype, 3 with subtype B, and 9 with subtype C. In addition, 1 subject with A subtypes, 2 with subtype B, and 10 with subtype C had secondary mutations (protease: M46I; reverse transcriptase: A98G, K101Q, and V108I). Only 1 patient had mutations associated with >1 class of drugs. Among subjects who contracted HIV infection in Israel, 16 of 56 (1 of 7 with subtypes A or AE, 4 of 17 with subtype B, and 11 of 32 with subtype C; P=.7-1.0) carried resistant virus--a significantly higher proportion (P<.001) than in subjects infected in other countries (10 of 120 infected). CONCLUSIONS: Drug-resistant virus was detected in 14.8% of patients with new diagnoses of HIV infection but in 28.6% of patients known to have been infected in Israel. The implications include a need for pretreatment resistance testing and for better programs aimed at prevention of transmission, directed particularly at patients. We did not find significant differences in transmission of resistant virus between those infected with subtypes B and C, despite the different demographic background. A conclusive analysis and interpretation should await a more extensive study.

JC polyomavirus reactivation is common following allogeneic stem cell transplantation and its preemptive detection may prevent lethal complications.

Extended application of allogeneic stem cell transplantation (alloSCT) is expected to increase the frequency of JC polyomavirus (JCPyV)-related progressive multifocal leukoencephalopathy (PML). The aim of this study was to assess frequency, risk factors and course of JCPyV reactivation in allografted hematology patients. This retrospective study included consecutive adult patients, treated with alloSCT between January 2008 and December 2011. Quantitative JCPyV-PCR analysis was performed on whole blood DNA samples, originally drawn for cytomegalovirus detection since transplant date. The study included 164 patients diagnosed with hematological malignancies. Patients received reduced-intensity conditioning (n=74) or myeloablative conditioning (n=90), followed by alloSCT. Twenty patients developed transient and 20 had persistent JCPyV reactivation. Two of the patients with persistent reactivation showed a gradual increase in JCPyV levels, preceding PML development by 96 and 127 days. Cessation of immunosuppression resulted in complete resolution of neurological symptoms in one patient, while the other died of PML. Seventy percent of the 'persistently reactivating' patients died. Multivariate analysis confirmed age to be the only significant predictive factor for JCPyV reactivation. In conclusion, JCPyV reactivation occurs in a quarter of allografted patients. Preemptive detection of JCPyV reactivation in high-risk subjects and early discontinuation of immunosuppressive therapy may prevent development of lethal PML.

Salivary detection of H1N1 virus: a clinical feasibility investigation.

The fast and efficient transportation among continents will continue to play a role in the spread of airborne pandemics. The objective of this study was to detect H1N1 virus in the saliva of individuals who visited the emergency department and were diagnosed as having H1N1 influenza. Nasopharyngeal swabs and saliva samples from those who presented to the emergency department with flu-like symptoms were sent to the laboratory. RNA was extracted from both samples. Real-time RT-PCR tests were performed, and the saliva and nasopharyngeal swab tests were compared. Samples were drawn from 26 individuals. A positive nasopharyngeal swab test and salivary test was found in 14 persons, and negative tests were found in 12 persons. Saliva sampling for H1N1 has excellent predictive value, is highly accurate and reliable, and is more convenient than the nasopharyngeal swab. Clinical trial with the Helsinki Committee at Rambam Health Care Campus, registration number 036309-RMB.

The European Sero-Epidemiology Network 2: standardization of assay results for hepatitis B virus.

The aim of the European Sero-Epidemiology Network 2 was to coordinate and standardize the serological surveillance of vaccine-preventable diseases in Europe. In this study, the standardization of hepatitis B virus (HBV) results is described. The 15 participating national laboratories tested a unique panel of 172 sera established by the Greek reference centre for HBV surface antigen (HBsAg), antibodies to HBsAg (anti-HBs) and/or to the HBV core antigen (anti-HBc) by assay methods of their choice. Country-specific quantitative measurements for anti-HBs and anti-HBc were transformed into common units using standardization equations derived by regressing each country's panel results against the reference centre's results, thus adjusting for interassay and interlaboratory variability. For HBsAg, a qualitative analysis (positive/negative) showed at least 99% agreement with the reference laboratory for all countries. By combining these standardized and qualitative results for the markers mentioned earlier, it was possible to achieve comparable estimates of the proportion of the population susceptible to HBV, vaccinated against HBV, with a past HBV infection, and with a current infection or chronic carrier state. Standardization is a very important tool that allows for international serological comparisons to assess the current vaccination policies and the progress of HBV control in Europe.

Antibody to poliovirus in older children and young adults in Israel and the use of poliovaccines for the immunization of the seronegatives.

This report represents preliminary results of a more extensive study which is presently being carried out in Israel. The main aims of this study were twofold: (1) to carry out a survey of the state of immunity of children of various ages and of teenagers to the three poliovirus types and (2) to compare the antibody response of the seronegatives to the two kinds of presently available poliovaccines, the oral poliovaccine (O. P. V., Savin Vaccine) and the inactivated poliovaccine (I. P. V., Salk Vaccine).

Inhibitor(s) of natural anti-cardiolipin autoantibodies.

IgG fractions were purified on Sepharose anti-human IgG column from eight sera of healthy donors, having no anti-cardiolipin (aCL) activity as measured by anti-cardiolipin ELISA assay (aCL-ELISA). All the IgG fractions, after elution with 4.9 M MgCl2, reacted with CL. The antigen-binding characteristics of the IgG fractions purified from normal human serum (NHS) were similar to those of IgG fractions purified from sera of four patients with the anti-phospholipid syndrome (APLS). Competition assay confirmed the specificity of the binding of the purified IgG fractions to CL. The same results have been achieved with IgG fractions purified on Sepharose Protein-A column. The binding to CL was completely inhibited by either whole NHS and sera from various animal species, or by beta 2-glycoprotein I (beta 2-GPI). Our results support the notion of the existence of both natural anti-CL antibodies and serum inhibitor(s) in sera of healthy individuals. It is conceivable that in part the pathogenesis of APLS entails defects in the natural inhibitors of aCL antibodies.

Involvement of different S4 parts in the voltage dependency of Na channel gating.

Three synthetic peptides corresponding to parts of S4 of the first repeat of eel electroplax sodium channel were synthesized. The basic peptide was C1+ which corresponds to amino acids 210-223 (eel channel numbering) and two subfractions: an external fraction, C1+ex (amino acid 210-217); and an internal part, C1+in (amino acid 218-221). Peptide C1+ includes four of the charged amino acids of this domain; peptide C1+ex includes three of the charged amino acids and is closer to the external membrane surface (according to channel models) than peptide C1+in which includes the fourth charged amino acid alone. Antibodies generated in rabbits against these peptides were shown to be site specific. Using the whole-cell patch-clamp technique, we found that in rat dorsal root ganglion (DRG) cells, the antibodies against C1+in but not against C1+ex had an effect on the gating parameters. They shifted the Na-channel inactivation curve towards hyperpolarization and decreased the slope of the Na-channel activation curve. These results demonstrate that during the conformational changes associated with channel gating, the fourth charged amino acid of S4 must be accessible to antibodies given to the external solution. Furthermore, they indicate a specific involvement of S4 in the voltage dependency of the gating processes.