Enzyme linked immunosorbent assay for detecting adenoviruses in stool specimens: comparison with electron microscopy and isolation.

A commercial enzyme linked immunosorbent assay (ELISA) for detection of adenoviruses in stool samples was compared with the use of electron microscopy and isolation in Graham 293 cells. Although specific, the ELISA was less sensitive than both electron microscopy and isolation. The ELISA had an overall sensitivity of 78% and a specificity of 100%. The sensitivity was related to the amount of virus particles present in the stool sample, increasing to 90% with about 10(7) viral particles/ml of stool. The ELISA was easy to perform, requiring no instrumentation, and is a useful first line test for detection of adenoviruses in stool samples, especially in laboratories without access to an electron microscope. Wider use of ELISAs should help in evaluating the role of adenoviruses in viral gastroenteritis.

Diagnosis of cytomegalovirus infection in heart transplant recipients.

In a prospective study eight (47%) heart transplant recipients had recurrent cytomegalovirus (CMV) infection. Of these, five had received hearts from seropositive donors. Neither serology nor virus isolation from urine was reliably associated with clinical CMV infection, but a high CMV IgM index correlated with CMV infection.

Changes in age related seroprevalence of antibody to varicella zoster virus: impact on vaccine strategy.

AIM: To study changes in the seroprevalence of varicella zoster virus (VZV) antibody over the past 25 years with a view to determining the target age group for any future vaccination strategy. METHODS: Stored sera collected from different age groups over a period of 25 years were tested by a commercial VZV IgG enzyme immunoassay at a four year time interval. Data were analysed by logistic regression to investigate the evidence for changes in incidence and hence seroprevalence over that period. RESULTS: There was a significant rise in VZV antibody prevalence in the 1-4 year age group during the study period. CONCLUSIONS: A universal childhood VZV vaccination strategy will need to take account of the increase in incidence of VZV infection in children under the age of 4 years; hence, the suggested target age would be between 12 and 18 months---soon after the disappearance of maternal antibody.

Comparison of cell culture with an amplified enzyme immunoassay for diagnosing genital herpes simplex infection.

An amplified enzyme immunoassay (EIA) for herpes simplex virus (Novo Nordisk) was compared with cell culture in 853 genital specimens from a genito-urinary medicine clinic. The sensitivity of the EIA was 86% and its specificity 99.6%. The sensitivity increased to 94% for lesion swabs but decreased to 68% for cervical swabs. Sensitivity for urethral and vulval swabs was 83% and 82%, respectively. It is concluded that the EIA is specific and quick and easy to perform. It will be suitable for testing for genital herpes simplex infections in laboratories without access to local cell culture facilities.

Comparison of ultracentrifugation and polyethylene glycol precipitation for concentration of hepatitis B virus (HBV) DNA for molecular hybridisation tests and the relationship of HBV-DNA to HBe antigen and anti-HBe status.

A 32P-labelled DNA probe was used to examine 50 hepatitis B surface antigen (HBsAg)-positive sera for the presence of hepatitis B virus (HBV) DNA. HBV-DNA was detected in all 21 HBeAg-positive samples, in one out of 21 anti-HBe-positive samples and in three out of eight HBeAg- and anti-HBe-negative samples. The results of this DNA hybridisation test correlated well with HBeAg status and could be used to determine infectivity in HBeAg- and anti-HBe-negative samples. Ultracentrifugation was marginally superior to polyethylene glycol precipitation for concentrating HBV-DNA from serum.

Failure to find an association between hepatitis C virus and thyroid autoimmunity.

A high frequency of hepatitis C antibodies has been reported from France in patients with autoimmune thyroiditis. Two cases of Hashimoto's thyroiditis in association with chronic active hepatitis and hepatitis C infection have also been reported. We have examined this potential association in 46 patients with autoimmune hypothyroidism and found that 16 apparently had hepatitis C antibodies in one of the two commercially available enzyme-linked immunosorbent assays (ELISA), but all patients were negative in a confirmatory commercially available recombinant immunoblot assay (RIBA-3) indicating that none of the patients were truly positive for hepatitis C antibodies. We also tested sera from 111 patients with proven hepatitis C infection and found no increased prevalence of thyroid autoantibodies. These results suggest that hepatitis C infection is not a risk factor for the development of thyroid autoimmunity in the United Kingdom.

False-positive legionella titres in routine clinical serology testing detected by absorption with campylobacter: implications for the serological diagnosis of legionnaires' disease.

A simple absorption step using blocking fluid prepared from a selected campylobacter strain was introduced in parallel with routine legionella serology tests. Over 12 months, 2716 patients were tested for legionella antibodies by the Indirect Fluorescent Antibody Test of whom 58 (2.1%) had a positive titre (> or = 16) in one or more sera. Campylobacter blocking fluid significantly reduced the legionella titres in 17 of these patients (29%) including four patients with diagnostic serology results (two of whom had pneumonia) and 13 patients with non-diagnostic titres. Absorption with campylobacter however had no effect on the legionella titres in 10 patients with positive serology, in whom legionnaires' disease had been confirmed by culture of Legionella pneumophila from sputum or detection of legionella urinary antigen by ELISA. These results indicate that the serological cross-reaction between legionella and campylobacter is encountered in routine legionella serology tests. The important implications for the diagnosis of legionnaires' disease are discussed.

Coxiella burnetii serology in granulomatous hepatitis.

Granulomatous hepatitis as the sole manifestation of acute Q fever has been reported only rarely, although minimal hepatic dysfunction may be common in the acute disease. In this paper we report two patients with acute Q fever who presented with hepatitis; one of whom had granulomatous hepatitis on liver biopsy. We discuss the serological diagnosis of acute and chronic Q fever particularly in relation to hepatitis.

Clinical rubella reinfection--a case of arthropathy.

We describe a case of arthropathy due to rubella reinfection. Clinical rubella reinfection with rash and lymphadenopathy has been reported but as far as we are aware this is the first report of a case with arthropathy as the sole presentation. Rubella IgG subclass and avidity tests confirmed the reinfection.

Prolonged cryptosporidiosis during primary HIV infection.

Primary infection with the human immunodeficiency virus causes profound immunosuppression with a decrease in lymphocyte numbers and function. However, this immunosuppression is transient and most individuals regain normal immune function. Infection with opportunist pathogens during the period of immunosuppression is rare. We report a case of severe prolonged cryptosporidiosis complicating primary HIV infection. This has not previously been described. A review of other cases of opportunist infections in primary HIV infection suggests that various pathogens may take advantage of the transient immunosuppression. This has important implications for the diagnosis and management of acute HIV infection, and for the diagnostic criteria currently used for AIDS.

A Scottish case of nephropathy due to Hantaan virus infection.

An illness characterised by acute renal failure, fever, conjunctivitis and a macular erythematous centrifugal rash is described in a Scot who had not recently travelled abroad. There was serological evidence that the illness was due to Hantaan or a closely related virus.

Is VZV reactivation a common cause of unexplained unilateral pain? Results of a prospective study of 57 patients.

OBJECTIVE: Pain is a common reason for patients to present to a doctor. Many patients with zoster have seen their doctor with pain during the days before the rash and zoster sine herpete is well described. If early varicella zoster virus (VZV) reactivation could be identified confidently, it could provide an opportunity for early antiviral intervention. This prospective study was performed to assess how often patients presenting to their general practitioner with unilateral pain of no obvious clinical cause proved to have evidence of VZV reactivation. METHODS: Fifty-seven patients were recruited and followed for 28 days; laboratory testing included VZV polymerase chain reaction (PCR) from peripheral blood mononuclear cells, VZV IgG, IgA and IgM. The control group consisted of 81 blood donors. RESULTS: Only two study patients developed the rash of zoster. There was no significant difference in PCR or serological responses between the study group and control group. Clinical characteristics did not enable identification of patients presenting to their doctor with unilateral pain who had prodromal zoster. CONCLUSION: There was no evidence on clinical or laboratory tests used in this study to support the view that reactivation of VZV is a common cause of unexplained unilateral pain.

Incidence of herpes simplex virus type-1 and type-2 from patients with primary (first-attack) genital herpes in Sheffield.

In a study to determine the herpes simplex virus (HSV) type isolated from patients with primary (first-attack) genital herpes and to identify any clinical or epidemiological features that might influence the reported incidence of any particular viral type, there was almost an equal incidence of HSV-1 and HSV-2 isolated from women (48% versus 52%). In the case of women, the initial clinical diagnosis was correct in 97% with HSV-1 and 95% with HSV-2 infection. Amongst men, HSV-2 was isolated more frequently than HSV-1 (71% versus 29%). However, the initial clinical diagnosis in men was correct in only 53% with HSV-1 and 83% with HSV-2 infection. These results suggest that in primary genital herpes the incidence of HSV-1 and HSV-2 is probably equal, while in men the reported incidence of HSV-1 may be affected by underdiagnosis giving a falsely high incidence of HSV-2 infection.

Effect of glycerol on intracellular virus survival: implications for the clinical use of glycerol-preserved cadaver skin.

Glycerol has long been used for the preservation of skin allografts. The antimicrobial activity of glycerol has not been fully documented. This paper reports the results of an investigation of a model studying the effect of glycerol on the inactivation of intracellular viruses. Two viruses--herpes simplex type I (HSV-1) and poliovirus--were cultured within human dermal fibroblasts. These intracellular viruses were incubated with 50 per cent, 85 per cent and 98 per cent glycerol at 4 degrees C and 20 degrees C for 4 weeks. Each week, the cultures in glycerol and controls in fibroblast maintenance medium were assayed for virus infectivity by examining the ability of harvested viruses to infect further fibroblasts. At 4 degrees C, 85 per cent glycerol could not fully inactivate intracellular HSV-I or poliovirus even after 4 weeks; 98 per cent glycerol inactivated intracellular HSV-I (after 3 weeks) but could not fully inactivate intracellular poliovirus after 4 weeks. At 20 degrees C, 85 per cent glycerol inactivated intracellular HSV-I (within 1 week) but could not fully inactivate intracellular poliovirus after 4 weeks; 98 per cent glycerol inactivated intracellular HSV-I (within 1 week) and inactivated intracellular poliovirus (after 2 weeks). It is suggested that, on the basis of this study, glycerol can reduce intracellular virus infectivity but that its effects are very dependent on concentration, time and temperature such that we would recommend that allograft skin be exposed to 98 per cent glycerol for a minimum of at least 4 weeks at a minimum temperature of 20 degrees C before clinical use.

Hepatitis A in Scotland--is it a continuing problem?

The prevalence of anti-HAV in blood donors in West Scotland and in children admitted to a Glasgow hospital was determined. By the age of five years, 16% of the children had antibody and at 15 years, 30%. In adults, prevalence continued to rise with age, with 78% of those over 40 years showing evidence of past infection. Cases of acute hepatitis A in West Scotland have declined since 1983. At present the peak age group for infection is 25-34 years whereas in the early 80s the peak group was five to 14 years.

Lessons from a large norovirus outbreak: impact of viral load, patient age and ward design on duration of symptoms and shedding and likelihood of transmission.

BACKGROUND: Hospital norovirus outbreaks cause significant financial and operational disruption which should be minimised by optimal handling of affected areas and use of isolation facilities. AIM: To identify factors associated with increased duration of symptoms and viral excretion and increased probability of transmission. METHODS: Retrospective observational study of a large norovirus outbreak at a UK teaching hospital in the winter of 2009-2010 where patients were diagnosed using a real-time polymerase chain reaction (PCR) assay. FINDINGS: Symptom duration was significantly associated with patient age (Spearman rank correlation coefficient: 0.197; P = 0.002) but not with PCR cycle threshold (C(T)) value. Duration of viral excretion was found to be longer in patients with higher viral loads. Transmission within a ward bay was not significantly associated either with age or with C(T) value but was more likely to occur in some ward blocks than others, which may relate to differences in ward design. Transfer of patients into isolation rooms or cohorted area within two days of symptom onset did not significantly influence probability of onward transmission (52% vs 47%; P = 0.67). CONCLUSIONS: The presented data suggest that C(T) value may guide timing of repeat sample collection if ongoing gastrointestinal symptoms may relate to other pathologies, and that patients developing symptoms of norovirus may remain in their current bay rather than being moved into isolation facilities. The bay or ward should be closed to new admissions but it should be anticipated that duration of symptoms and therefore closure will be longer when the outbreak involves elderly patients.

Contribution of bacteriology and virology in sudden unexpected death in infancy.

OBJECTIVE: To appraise the inter-agency protocol used in sudden unexpected death in infancy (SUDI) cases in South Yorkshire, UK. DESIGN: A retrospective audit of 121 postmortems carried out over a 3-year period was completed to assess adherence to local guidelines introduced in 2005 specifying the required microbiological specimen set to be collected at postmortem in cases of SUDI. Data on organisms isolated was also collated and assessed for significance. SETTING: Sheffield Children's Hospital Histopathology Department is the South Yorkshire referral centre for SUDI. Post-mortem samples were processed by Sheffield Teaching Hospital's microbiology and virology departments. PATIENTS: All postmortems of SUDI in children less than 2 years of age performed between January 2004 and December 2007. RESULTS: 116/121 cases had samples sent for microbiological and/or virological investigation: 90% of cases had a blood culture and 68% had a cerebrospinal fluid sample taken. Of the 116 cases, 49% had a potentially pathogenic organism isolated, 73% had post-mortem flora and 10% had no organisms isolated (32% had both post-mortem flora and a potential pathogen). 27% of cases were found to have middle ear exudate requiring sampling, from 48% of which a potentially pathogenic organism was isolated. CONCLUSIONS: Our finding of a potential pathogen in 57/116 (49%) of our cases, although not necessarily the cause of death, confirms the relevance of performing multisite and virology investigations in all cases of SUDI. Standardised protocols with agreed definitions are necessary for a consistent approach.