Prolonged viral shedding in pandemic influenza A(H1N1): clinical significance and viral load analysis in hospitalized patients

The clinical significance of prolonged viral shedding (PVS) and viral load (VL) dynamics has not been sufficiently assessed in hospitalized patients with pandemic 2009 influenza A(H1N1). We performed a prospective study of adults with confirmed influenza A(H1N1) virus infection admitted to our hospital from 20 September 2009 to 31 December 2009. Consecutive nasopharyngeal swabs were collected every 2 days during the first week after diagnosis, and then every week or until viral detection was negative. Relative VL was measured on the basis of haemagglutinin and RNaseP gene analysis. PVS was defined as positive detection of influenza A(H1N1) virus by real-time RT-PCR at day 7 after diagnosis. We studied 64 patients: 16 (25%) presented PVS. The factors associated with PVS were admission to the intensive-care unit (69% vs. 33%, p 0.02), purulent expectoration (75% vs. 44%, p 0.04), higher dosage of oseltamivir (62.5% vs. 27%, p 0.016), corticosteroid treatment (50% vs. 21%, p 0.05), mechanical ventilation (MV) (50% vs. 12.5%, p 0.004), and longer stay (34 vs. 7 median days, p 0.003). Multivariate analysis revealed the factors independently associated with PVS to be immunosuppression (OR 5.15; 95% CI 1.2–22.2; p 0.03) and the need for MV (OR 11.7; 95% CI 2.5–54.4; p 0.002). VL at diagnosis correlated negatively with age and septic shock. VL dynamics of patients with acute respiratory distress syndrome and/or mortality were very different from those of other patients. PVS was detected in 25% of hospitalized patients with pandemic 2009 influenza A(H1N1) and was strongly associated with immunosuppression and the need for MV. Diagnostic VL and viral clearance varied with the clinical course.     

Low seroprevalence and zero incidence rate of hepatitis E in men who have sex with men during a hepatitis A outbreak

Hepatitis E virus (HEV) and hepatitis A virus (HAV) are both secreted in feces. Despite HEV transmission in Europe is mainly zoonotic, person-to-person transmission has not been completely excluded. Men who have sex with men (MSM) constitute a high-risk group for HAV mostly due to oral sex. We investigated the potential transmission of HEV during an acute hepatitis A (AHA) outbreak mainly affecting MSM. One hundred and two patients were diagnosed with AHA. Sixty-nine (68%) self-reported to be MSM, 75% of whom had high-risk sexual behaviors and 46% had suffered previous sexually transmitted diseases. We collected serum from 85 (83%) patients during AHA. HEV-IgG seroprevalence was not different among MSM (7%) compared with non-MSM (8%) patients. Two patients had positive anti-HEV-IgM, but all samples tested negative for HEV-RNA. These results suggest that HEV does not spread by sexual contact or person-to-person in our area.     

Occult hepatitis B infection in patients infected with HIV: Report of two cases of hepatitis B reactivation and prevalence in a hospital cohort

Patients co‐infected with human immunodeficiency virus (HIV) and hepatitis B virus (HBV) are particularly at risk of hepatitis B reactivation. Two cases of patients infected with HIV with isolated anti‐HBc antibodies who had experienced an HBV reactivation are described. In the two cases HBV reactivation occurred after withdrawal of anti‐retroviral treatment with anti‐HBV activity from the patients' highly active antiretroviral therapy (HAART), in accordance with HIV genotypic resistance profiles. Consequently, plasma samples from 383 patients infected with HIV were tested to assess the prevalence of occult HBV infection in the Infectious Diseases Department Unit of Nancy Hospital by investigating serological patterns and HBV replication. Forty‐five percent (172/383) of patients had had previous contact with HBV. Isolated anti‐HBc antibodies were observed in 48 patients (48/383, 12%) and, among these, 2 were HBV‐DNA positive. Since 75% (288/383) of the patients were treated with HAART, including at least one drug active against HBV, occult HBV infection was perhaps unrecognized. In cases of HIV infection, all patients should be screened for HBV infection and the knowledge of HBV status as well as the monitoring of HBV viral load are essential in preventing HBV reactivation. Consideration should be given to the continuation of drugs with anti‐HBV activity in co‐infected patients receiving HAART, as cessation of therapy is associated with a risk of HBV reactivation. At least, close monitoring of the HBV viral load is warranted in such situations. J. Med. Virol. 82:206–212, 2010. © 2009 Wiley‐Liss, Inc.     

Long-term hepatitis E viral load kinetics in an immunocompromised patient treated with ribavirin

Hepatitis E virus (HEV) can cause chronic infections in immunocompromised hosts. Viral kinetics in plasma and stools are poorly understood, particularly during antiviral treatment. Prolonged faecal shedding may be a concern for transmission. We describe HEV kinetics in an immunocompromised patient with prolonged faecal shedding despite undetectable viraemia on ribavirin treatment.     

Lack of complement-dependent cytolytic antibodies in hepatitis A virus infection

Sera collected from patients with acute hepatitis A virus (HAV) infection and convalescent sera were examined for cytolytic activity against HAV-infected human-embryo lung fibroblasts (HAV carrier fibroblasts). Using the 51chromium release assay, no complement dependent antibody mediated cytolytic activity against HAV carrier cells could be detected. In control experiments with identical cell strains, anti-herpes simplex virus (HSV) positive sera and complement caused specific lysis of HSV type 1 infected target cells. The data presented here do not support the hypothesis that in the possible immunopathogenesis of HAV infection, complement-dependent cytolytic antibodies play an essential role.     

Incidence of hepatitis A virus (HAV) infection in rural Liberia

To provide background for future hepatitis A vaccine trials, sera were collected from 0- to 4-year-old Liberian infants and their mothers on two occasions an average of 14.75 months apart and tested for antibody to hepatitis A virus (anti-HAV). The prevalence of anti-HAV rose from 2.5% in infants 0-6 months of age to 70% in children 3-4 years of age and did not differ between male and female infants. The annual incidence of new infections was slightly lower in the first year of life (35%) than in the subsequent 3 years, when it averaged 45%. The presence of HBV infection did not affect the incidence of HAV seroconversion. No clinical hepatitis was recognized in the subjects who seroconverted. Dual hepatitis A and B virus infection were observed; these were all clinically inapparent. The extraordinary incidence of HAV infection documented in the present study offers an opportunity for vaccine efficacy trials requiring minimal numbers of subjects.     

Concurrent hepatitis C virus and hepatitis delta virus superinfection in patients with chronic hepatitis B virus infection.

Since hepatitis C virus (HCV) and hepatitis delta virus (HDV) are transmitted by the same routes as hepatitis B virus (HBV), simultaneous or concurrent HCV and HDV infection in patients with chronic HBV infection may occur. To test this hypothesis and to examine the clinicohistological and immunopathological presentations of such multiple hepatitis virus infections, acute and/or convalescent serum specimens from 86 patients with acute HDV superinfection were tested by enzyme immunoassay for antibodies to HCV. Of the 86 patients, 18 (20.9%) were associated with HCV infection. Although patients with early mortality cannot be evaluated by the HCV markers used in this study, the results showed that the clinical and histologic features were similar except that patients with HCV infection were older than those without HCV infection (P less than 0.01). Immunopathological studies carried out within 2 months after the onset of acute HDV superinfection demonstrated that hepatitis B core antigen (HBcAg) was not detected in any patient and HDV antigen was detected in 18.2% of the patients with HCV infection whereas HBcAg and HDAg were found in 7% and 65.1%, respectively, of those without HCV coinfection (P less than 0.02). It is concluded that concurrent HCV and HDV superinfections can and do occur in patients with chronic HBV infection. In these triple viral infections, HCV may even transiently suppress HDV and HBV.     

Semiquantitative detection of JCV-DNA in peripheral blood leukocytes from HIV-1-infected patients with or without progressive multifocal leukoencephalopathy.

Progressive Multifocal Leukoencephalopathy (PML) is a severe and fatal demyelinating disease that occurs especially in HIV-infected patients. It has been suggested that JC virus (JCV) migrates in peripheral blood leukocytes from the kidney to the central nervous system where it initiates demyelination. To investigate the physiopathological role of the peripheral blood virus in the development of PML, the prevalence of JCV infection and the levels of JCV DNA load were evaluated in peripheral blood leukocytes or mononuclear cells of 10 AIDS patients at the time of onset of PML symptoms, and in 150 non-PML HIV-1-infected patients using a semiquantitative PCR and ELISA-hybridization assay. In PML-AIDS patients, 60% (6/10) were positive for JCV-DNA detection in peripheral blood cells compared with 26% (13/50) and 18% (18/100) positive for non-PML HIV-infected control patients with CD4+ T lymphocyte counts below and above 200.10(6) /l, respectively (60 vs. 26%, P = 0.06; 60 vs. 18%; P = 0.007). The prevalence of JCV infection in the peripheral blood cells taken from controls appeared to be independent of the CDC stage of infection and CD4+ T lymphocyte counts. The predictive positive value of a positive JCV DNA PCR in peripheral blood cells for the diagnosis of PML in an HIV-infected patient was 16% whereas the predictive negative value was 96%. The levels of circulating JCV DNA load, ranging from 1.69 to 2.53 log of copies per 10(6) cells, did not differ between patients at time of PML symptoms onset and controls, and appeared to be independent of the clinical and the biological status in control patients. The findings do not indicate any significant JCV genomic replication activity in peripheral blood cells at the onset of PML disease, and suggest that JCV replication markers in the systemic compartment would not be valuable for predicting the development of PML in AIDS patients.     

Non-A, non-B hepatitis in chimpanzees: interference with acute hepatitis A virus and chronic hepatitis B virus infections

Two chimpanzees with persistent non-A, non-B (NANB) hepatitis were superinfected with marmoset-passaged MS-1 HAV. Two control chimpanzees were also infected with marmoset-passaged HAV. Neither animal with persistent NANB hepatitis developed elevated alanine aminotransferase (ALT) activity, whereas both control chimpanzees exhibited ALT elevations within 3 weeks after inoculation. In addition, both NANB-infected chimpanzees demonstrated a delayed anti-HAV antibody response in which one animal failed to produce detectable IgM anti-HAV. With the exception of one stool, all serial liver biopsy specimens and daily stool suspensions from the superinfected chimpanzees were negative for HAV antigen. One chimpanzee with a chronic HBV infection was superinfected with non-A, non-B hepatitis and was shown to develop elevated ALT activity and hepatocyte ultrastructural alterations accompanied by a marked reduction in the titer of serum HBsAg. Our combined findings indicate that acute and persistent non-A, non-B hepatitis infections are capable of interferring with two distinctly different hepatotropic viruses. These results also suggest that in vitro detection of non-A, non-B hepatitis infection or virus(es) may be achieved by antibody-independent methodologies that employ the basic principle of viral interference.     

Detection of hepatitis A virus RNA in serum from patients with acute hepatitis

Hepatitis A virus (HAV) RNA was extracted from the sera of patients with acute hepatitis and then detected by molecular hybridization using cloned HAV complementary DNA (cDNA). HAV RNA was detected in 20 of 85 patients with acute HAV infection, mainly during the prodromal stage, or early during the icteric phase of the disease; it was detected as long as 21 days after its initial detection. Patients with HAV RNA in the serum had a significantly higher titer of anti-HAV IgM.     

Immunological and virological consequences of patient-directed antiretroviral therapy interruption during chronic HIV-1 infection

Increasing numbers of patients are choosing to interrupt highly active antiretroviral therapy (HAART). We describe the effect of patient-directed treatment interruption (PDTI) on plasma viral loads (pVL), proviral DNA (pDNA), lymphocyte subsets and immune responses in 24 chronically HIV-1 infected individuals. Patients were divided into group A with pVL > 50 copies/ml and group B with pVL < 50 copies/ml, prior to the PDTI. pVL rose significantly in group B during the first month off HAART and was associated with a significant decrease in CD4 T-cell count. At baseline there was a significant difference in HIV-1 pDNA levels between groups A and B, however, levels significantly increased in group B, but not in group A during PDTI becoming equivalent after 1 month PDTI. We have previously shown no increase in pDNA over the time of substitution in patients switching HAART regimens despite a small rebound in pVL. These observations indicate that to protect low pDNA levels PDTI should be discouraged and that changing regimen at the first sign of failure should be advised where possible. Only transient, no longer than 4 week, HIV-1-specific responses were observed during PDTI in 5/24 patients, 2 from group A and 3 from group B. The low numbers of responders and the transient nature of the anti-HIV-1 immune responses do not favour the auto-vaccination hypothesis.     

Optimized virus disruption improves detection of HIV-1 p24 in particles and uncovers a p24 reactivity in patients with undetectable HIV-1 RNA under long-term HAART

HIV-1 p24 antigen (p24) measurement by signal amplification-boosted ELISA of heat-denatured plasma is being evaluated as an alternative to HIV-1 RNA quantitation in resource-poor settings. Some observations suggested that virion-associated p24 is suboptimally detected using Triton X-100-based virus dissociation buffer (kit buffer). A new reagent (SNCR buffer) containing both denaturing and non-denaturing detergents was therefore developed and evaluated. The SNCR buffer increased the measured p24 concentration about 1.5- to 3-fold in HIV-negative plasma reconstituted with purified HIV-1 particles, while not increasing the background. Among 127 samples of HIV-1-positive patients with moderate to high concentrations of HIV-1 RNA the increase was about threefold across the entire concentration range (P < 0.0001). Specificity before neutralization among prospectively tested clinical samples ruled HIV-negative was 828 of 845 (98.0%) for the SNCR buffer and 464 of 479 (96.9%) for kit buffer. Specificity after confirmatory neutralization of reactive samples or a follow-up test was 100% with either buffer. Surprisingly, the SNCR buffer revealed a p24 reactivity in 115 of 187 samples (61.5%) from adult patients exhibiting undetectable HIV-1 RNA below 5 copies/ml for a duration of 6-30 months under HAART (3.7% with kit buffer). The rate of p24 reactivity in these patients did not decrease with duration of HAART. In conclusion, the SNCR buffer improves the detection of particle-associated HIV-1 p24, thereby increasing the measured p24 concentration in samples with medium to high HIV-1 RNA. It also uncovers the presence of a p24 reactivity, whose identity remains to be determined, in a significant fraction of samples with undetectable HIV-1 RNA under long-term HAART.     

Regulatory T cells and chronic immune activation in human immunodeficiency virus 1 (HIV-1)-infected children

The function of CD4⁺ T cells with regulatory activity (T_regs) is the down-regulation of immune responses. This suppressive activity may limit the magnitude of effector responses, resulting in failure to control human immunodeficiency virus 1 (HIV-1) infection, but may also suppress chronic immune activation, a characteristic feature of HIV-1 disease. We evaluated the correlation between viral load, immune activation and T_regs in HIV-1-infected children. Eighty-nine HIV-1-infected children (aged 6–14 years) were included in the study and analysed for HIV-1 plasmaviraemia, HIV-1 DNA load, CD4 and CD8 cell subsets. T_reg cells [CD4⁺ CD25^highCD127^lowforkhead box P3 (FoxP3^high)] and CD8-activated T cells (CD8⁺CD38⁺) were determined by flow cytometry. Results showed that the number of activated CD8⁺CD38⁺ T cells increased in relation to HIV-1 RNA plasmaviraemia (r = 0·403, P < 0·0001). The proportion of T_regs also correlated positively with HIV-1 plasmaviraemia (r = 0·323, P = 0·002), but correlated inversely with CD4⁺ cells (r = −0·312, P = 0·004), thus suggesting a selective expansion along with increased viraemia and CD4⁺ depletion. Interestingly, a positive correlation was found between the levels of T_regs and CD8⁺CD38⁺ T cells (r = 0·305, P = 0·005), and the percentage of T_regs tended to correlate with HIV-1 DNA load (r = 0·224, P = 0·062). Overall, these findings suggest that immune activation contributes to the expansion of T_reg cells. In turn, the suppressive activity of T_regs may impair effector responses against HIV-1, but appears to be ineffective in limiting immune activation.     

Prevalence of hepatitis A virus,hepatitis B virus,hepatitis C virus,hepatitis D virus and hepatitis E virus as causes of acute viral hepatitis in North India: A hospital based study

Context: Acute viral hepatitis (AVH) is a major public health problem and is an important cause of morbidity and mortality. Aim: The aim of the present study is to determine the prevalence of hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV) and hepatitis E virus (HEV) as causes of AVH in a tertiary care hospital of North India. Settings and Design: Blood samples and clinical information was collected from cases of AVH referred to the Grade I viral diagnostic laboratory over a 1-year period. Subjects and Methods: Samples were tested for hepatitis B surface antigen, anti-HCV total antibodies, anti-HAV immunoglobulin M (IgM) and anti-HEV IgM by the enzyme-linked immunosorbent assay. PCR for nucleic acid detection of HBV and HCV was also carried out. Those positive for HBV infection were tested for anti-HDV antibodies. Statistical Analysis Used: Fisher’s exact test was used and a P < 0.05 was considered to be statistically significant. Results: Of the 267 viral hepatitis cases, 62 (23.22%) patients presented as acute hepatic failure. HAV (26.96%) was identified as the most common cause of acute hepatitis followed by HEV (17.97%), HBV (16.10%) and HCV (11.98%). Co-infections with more than one virus were present in 34 cases; HAV-HEV co-infection being the most common. HEV was the most important cause of acute hepatic failure followed by co-infection with HAV and HEV. An indication towards epidemiological shift of HAV infection from children to adults with a rise in HAV prevalence was seen. Conclusions: To the best of our knowledge, this is the first report indicating epidemiological shift of HAV in Uttar Pradesh.     

Diagnosing acute HIV infection: The performance of quantitative HIV-1 RNA testing (viral load) in the 2014 laboratory testing algorithm

New recommendations for laboratory diagnosis of HIV infection in the United States were published in 2014. The updated testing algorithm includes a qualitative HIV-1 RNA assay to resolve discordant immunoassay results and to identify acute HIV-1 infection (AHI). The qualitative HIV-1 RNA assay is not widely available; therefore, we evaluated the performance of a more widely available quantitative HIV-1 RNA assay, viral load, for diagnosing AHI. We determined that quantitative viral loads consistently distinguished AHI from a false-positive immunoassay result. Among 100 study participants with AHI and a viral load result, the estimated geometric mean viral load was 1,377,793 copies/mL.     

Presumed common source outbreaks of hepatitis A in an endemic area confirmed by limited sequencing within the VP1 region

Hepatitis A virus isolates from anti-HAV IgM positive sera of 70 hepatitis cases in two outbreaks and 216 other cases in Central America, 136 sporadic cases and 53 cases from an hyper-endemic region in Costa Rica, were compared by phylogenetic analyses within the VP1 region. The outbreaks in all 531 cases, in 1992 and 1999, respectively, were presumed water borne. In the first outbreak, HAV RNA could be detected in 70% of the cases sampled during 6 weeks after onset of jaundice. In the hyper-endemic region of San Ramón in Costa Rica, 1,932 cases were registered between 1972 and 1985. All isolates belonged to subtype 1A. Background isolates from Costa Rica and El Salvador tended to form separate subclusters in the phylogenetic tree construction and were mostly unrelated to subtype 1A strains from other parts of the world. Based on their amino acid sequences, four HAV strains, all related to CR326 sampled in Costa Rica in 1960, were found to have circulated in the area during the last three decades. However, on the basis of nucleotide variability the isolates from the outbreaks could be distinguished from the strains from sporadic cases and sequence analysis could confirm the epidemiological homogeneity of both outbreaks. In the hyper-endemic region, 16 different sequences were encountered forming one single subcluster. Thus, limited sequencing within the VP1 region proved useful to identify outbreaks of hepatitis A in a highly endemic area, where most strains were local and only one subtype was prevalent.