Sharps discarded in inner city parks and playgrounds--risk of bloodborne virus exposure.

The objectives of this study were to determine the number of discarded syringes found in four parks in Southwark, South London, over a specific time period and to test their contents for the presence of hepatitis B virus (HBV) and hepatitis C virus (HCV). Of 106 syringes collected over a four-month period, evidence of HBV was detected in 4.7% (5/106) and HCV in 4.7% (5/106). Urban children, park users and workers are at risk of contact with sharps which may be contaminated with both viruses. Park users need more information on what to do in the event of an injury, and park workers should be immunised against HBV and educated on safe disposal of sharps.

Acute hepatitis C viral infection during pregnancy: failure of mother to infant transmission.

A pregnant woman developed an acute hepatitis C virus (HCV) type 3a infection during the second trimester of pregnancy. The clinical virological features are presented, including HCV RNA quantification of maternal serum samples collected during pregnancy. These findings are discussed in light of the child's remaining uninfected after 5 years of follow-up.

Hepatitis B nucleotide sequence analysis: linking an outbreak of acute hepatitis B to contamination of a cryopreservation tank.

An epidemiological investigation indicated that six patients treated in a haematology unit who developed acute hepatitis B may have been infected as a result of contamination of a liquid nitrogen bone marrow storage tank. The clinical details are described elsewhere (Tedder et al., 1995); we describe the virological methods used to support the findings. HBV DNA was amplified from sera using a nested PCR with primers for the surface gene, and a region encompassing precore, the 3' end of X, and the 5' end of core. HBV DNA was also extracted from the frozen detritus in the liquid nitrogen storage tank. After equilibration, the aqueous material was filtered, co-precipitated with albumin and polyethylene glycol and the HBV DNA extracted by phenol-chloroform and ethanol precipitation. Direct nucleotide sequence analysis indicated that four patients were infected with HBsAg subtype adw viruses which carried novel amino acid substitutions at codons 145 and 146 of the X gene. HBV DNA extracted from the storage tank detritus contained identical sequences. The samples from two other patients, subtype ayw, did not contain the novel sequence changes in X and had other sequence differences. These findings linked conclusively the four patients as a cluster and the rescue of HBV-DNA sequences from the contaminated storage tank by the method described confirmed this as the common source of infection. Two other HBsAg-positive patients were excluded from the cluster by sequence analysis. Demonstration of infection by this route has implications for the safe storage of bone marrow and other related biological materials.

Detection of herpesvirus DNA by nested polymerase chain reaction in cerebrospinal fluid of human immunodeficiency virus-infected persons with neurologic disease: a prospective evaluation.

A nested polymerase chain reaction-based method was used prospectively to detect herpesvirus DNA in cerebrospinal fluid (CSF) from 111 patients with AIDS, 39 of whom had a suspected diagnosis of cytomegalovirus (CMV)-associated neurologic disease (patients with encephalopathy, polyradiculopathy, or peripheral neuropathy) and 72 who had alternative diagnoses. CSF from 24 (62%) of the patients with suspected CMV-associated disease had detectable CMV DNA compared with only 8 (11%) of the patients with other diagnoses. Varicella-zoster virus DNA was detected in CSF from 3 patients (2 with myelitis and 1 with encephalitis), all of whom had recent cutaneous zoster. No CSF specimen contained detectable herpes simplex virus type 1 DNA, and none of the patients with myelitis had detectable herpes simplex virus type 2 DNA in CSF. This study demonstrates a significant association between detectable CMV DNA in CSF and suspected CMV-associated neurologic disease in patients with AIDS.

Investigation of hepatitis B virus transmission in a health care setting: application of direct sequence analysis.

An epidemiologically linked cluster of hepatitis B virus (HBV) infections was investigated using HBV DNA amplification by a nested polymerase chain reaction with primers complementary to the region around the immunodominant a determinant of the surface gene, part of the X and core genes, and precore region and direct nucleotide sequence analysis. The cluster, in which 2 persons died of fulminant hepatitis, comprised 1 blood donor, 2 patients, and 2 health care workers. The Kimura two-parameter method was used to compare variance among the cluster with that in the control samples, which were collected from 7 patients infected with the same HBV subtype. Significantly less variation occurred within the cluster than in the control group (unpaired t test, P < .05). In an unrooted phylogenetic tree analysis, the 5 study samples formed a cluster distinct from the controls. This direct molecular approach of analyzing conserved regions of the HBV genome differentiated between viruses involved in HBV transmission events.

Hepatitis B transmission from contaminated cryopreservation tank.

Over a 25-month period, six multiply transfused patients undergoing cytotoxic treatment for haematological or other malignant disorders developed icteric acute hepatitis B virus (HBV) infection. Bone marrow or peripheral-blood stem cells had been harvested from all six patients and stored in the same cryopreservation tank for possible future transplantation. Human DNA, HBsAg, and HBV DNA with sequences identical to those from four patients with related infections were subsequently found in the liquid nitrogen. Leakage of the cryopreservation bags used to store bone marrow harvested from the first patient when acutely infected with HBV led to contamination of the tank and its contents with HBV and subsequent transmission to patients after transplantation. This incident emphasises the continuing need to screen donors of tissue to be cryopreserved for bloodborne virus infections. It also reinforces the requirement for primary containers used to cryopreserve human tissue to be sealed in a way which prevents exchange of material between the specimen and the liquid nitrogen.

An early humoral immune response in peripheral blood following parenteral inactivated influenza vaccination.

The enzyme-linked immunospot assay was used to examine the humoral immune response in 15 healthy volunteers immunized with either split or subunit inactivated trivalent influenza vaccine containing A/Beijing/353/89 (H3N2), A/Taiwan/1/86 (H1N1) and B/Yamagata/16/88. The rapidity of the individual B-cell and serum antibody response was examined in lymphocyte and serum samples collected at various time intervals after vaccination. A rapid serological response was detected with increases in antibody titre detected in the majority of volunteers by 7-8 days postvaccination. Influenza-specific plasma cells were detected as early as 4 days postvaccination, higher numbers of IgA and IgG antibody-secreting cells (ASC) were observed which peaked at 7-8 days postvaccination. The number of ASCs then declined, with low numbers of cells detected at 11 days postvaccination. Influenza-specific IgA ASCs were predominantly of the IgA1 subclass. This rapid immune response may have a bearing on future vaccination policies of unimmunized 'at risk groups' in times of high influenza activity.

Attenuation of virulence in influenza B viral infection of volunteers.

A study was performed with volunteers in order to determine whether the virulence of an influenza B viral infection could be attenuated. Of a total of 62 persons, 26 received intranasal inoculations of an unpassaged influenza B virus isolate [virus U], while 26 received the same virus isolated passaged in cell culture and then in special pathogen-free embryonated hens' eggs [virus P]. The remaining 10 persons received uninoculated cell culture medium. Daily nasal wash samples were collected post-infection and scores for illness in the volunteers were evaluated. Viruses were isolated in cell culture and in eggs. Isolates were analysed by means of monoclonal antibodies (MAbs) raised against the influenza B viral haemagglutinin (HA) glycoprotein. One-step and nested polymerase chain reactions as well as direct nucleotide sequence analysis of part of the HA gene of the unpassaged specimens, together with the influenza B viruses isolated from those specimens, were performed. Nine of 26 volunteers who received the unpassaged virus became ill (illness scores from 13-84/100) whereas 7/26 of the volunteers who received the passaged virus had very mild illness (illness scores from 3-7/100). All the other volunteers remained well. Results of analysing the clinical specimens collected from the two groups of volunteers were compared. A difference in MAb reactivity, together with an aspartate for asparagine amino acid substitution at position 196 in a 432 base pair region of the viral HA gene, was observed. The loss of a potential glycosylation site at amino acid position 196-198 in the viral HA was associated with attenuation of virulence. This finding may have implications for the formulation of influenza vaccines.

Direct sequence determination of the influenza B HA-1 gene after PCR amplification of clinical specimens from an infected volunteer.

When clinical isolates of influenza A and B viruses are propagated in embryonated hens' eggs or tissue culture cells, different selective pressures in vitro result in specific amino acid substitutions in the haemagglutinin (HA) gene. A proportion of such viruses which lose a potential glycosylation site near the receptor binding region of the HA at amino acid positions 196-198 appear to have reduced virulence. Direct polymerase chain reaction (PCR) amplifications of cDNA and subsequent nucleotide sequence analysis of part of the HA-1 gene of the original infecting influenza B strain and the nasal wash material from an infected volunteer were performed. The nucleotide sequences of the viral HA-1 from the nasopharynx of the infected volunteer were the same as that of the original infecting strain. Antigenic analysis of both the original infecting virus and the viruses isolated from sequential samples collected from the volunteer, all of which were cultivated on Madin-Darby Canine Kidney (MDCK) cells and in embryonated hens' eggs, revealed variation in the HA of viruses only after egg adaptation. In particular, we describe the use of direct nucleotide sequencing techniques without the use of cloning strategies in order to determine the sequence of the HA-1 gene after direct PCR amplification of clinical nasal wash material.

Fatal case of echovirus type 9 encephalitis.

Enteroviruses are rare causes of acute focal encephalitis. A fatal case of echovirus type 9 infection is reported in a 9 month old boy who presented with a fever and a macular rash followed by two focal seizures. Echovirus type 9 was isolated from lung tissue after seven days.

Serological responses in volunteers to inactivated trivalent subunit influenza vaccine: antibody reactivity with epidemic influenza A and B strains and evidence of a rapid immune response.

A study of the immunogenicity of the inactivated trivalent subunit influenza vaccine for the 1989/90 season was performed in what proved to be an influenza epidemic year. One hundred student volunteers at The London Hospital Medical College participated in the study and the findings indicated that there was an excellent serological match between the epidemic strain of influenza A (H3N2) and the vaccine strain. Before vaccination, the geometric mean titre (GMT) to A/England/308/89, a representative H3N2 epidemic strain in the United Kingdom from the 1989/90 season, was 46. Post-vaccination the antibody levels rose and 99% of vaccinees had HI titres of greater than or equal to 40, the GMT being 131. The serological responses were also investigated against other circulating influenza A (H3N2 and H1N1) and B strains. Preliminary results of an evaluation of the rapidity of the immune response showed that in three of six subjects rises in HI antibody appeared within two days of vaccination.

Lead encephalopathy from an imported Toby mug.

Encephalopathy is an unusual manifestation of lead poisoning in an adult, the more common presentation being abdominal colic, anaemia and limb palsy. We report a case of adult lead encephalopathy and describe the use of a simple screening test for lead poisoning together with the increasing number of cases associated with imported ceramics.