Increased reports of Mycoplasma pneumoniae from laboratories in Scotland in 2010 and 2011 - impact of the epidemic in infants.

In common with reports from other European countries, we describe a substantial increase in the number of laboratory reports of Mycoplasma pneumoniae in Scotland in 2010 and 2011. The highest number of reports came from those aged one year and younger. However, reports from young children were more likely to come from PCR testing than serological testing.

Population exposure to a novel influenza A virus over three waves of infection.

BACKGROUND: The influenza A(H1N1)2009 virus has been spreading throughout the world since April 2009. Since then, several studies have been undertaken to measure the frequency of antibodies that react against the virus. Microneutralisation assays have regularly been used for these analyses, and titres of ≥40 have conventionally been taken to represent significant levels of antibodies (this significance is derived from it being four times the minimum level of antibodies that the assay can detect rather an established correlate of protection). However a microneutralisation titre that correlates with protection against influenza A(H1N1)2009 has not been established. OBJECTIVES: Analysing influenza A(H1N1)2009 antibody seroprevalence in Scotland at multiple timepoints, and in different age groups and geographical locations, and comprehensively describing the spread of the virus in Scotland (taken alongside previously published data). This study presents for the first time the effects of a novel influenza virus on a naïve population that has been followed from the initial outbreak to a time when the majority of the population have reactive antibodies. STUDY DESIGN: A microneutralisation titre ≥10 represents the minimum level of antibodies detectable by the assay. Blood samples (taken in April 2009 and April 2010 in Edinburgh (n=400 each year), and in February 2011 in Aberdeen, Edinburgh, Glasgow, and Inverness (n=1600)) were tested for the presence of influenza A(H1N1)2009 antibodies at this titre. This represents an effective indicator of the proportion of a population who have been exposed to the virus. RESULTS: Following the 2010/2011 influenza season, there is evidence of exposure to influenza A(H1N1)2009 in approximately four fifths of the Scottish population. CONCLUSIONS: This study provides impetus to the call for further research in establishing robust correlates of susceptibility to influenza infection and the development of clinical illness, provides useful information for future outbreaks, and is relevant to public health policy in planning for future influenza seasons.

Influenza A(H1N1)2009 antibody seroprevalence in Scotland following the 2010/11 influenza season.

Following the 2010/11 influenza season, we determined the age- and location-specific seroprevalence of antibodies against the influenza A(H1N1)2009 virus in Scotland. Samples were analysed by microneutralisation assay. Age/seropositivity profiles varied significantly between cities. The increases in seroprevalence relative to the previous influenza season (2009/10) were similar across age groups and geographic locations. However, the increased seropositivity in older adults appeared to be driven by exposure to vaccination, indicating significantly lower levels of infection than in younger age groups.

2009 pandemic influenza A(H1N1) virus in Scotland: geographically variable immunity in Spring 2010, following the winter outbreak.

We determined the age- and location-specific seroprevalence of antibodies against 2009 pandemic influenza A(H1N1) virus in Scotland following the first two waves of infection. Serum samples collected following the winter outbreak were analysed by microneutralisation assay. The proportion of positive sera varied significantly between cities and, in the case of Inverness, between age groups (with younger adults more likely to be positive than older individuals). This study demonstrates that older people are no longer more likely to have antibodies against the virus than younger adults.

Use of genomic analysis of varicella-zoster virus to investigate suspected varicella-zoster transmission within a renal unit.

BACKGROUND: The source of hospital-acquired chickenpox infection may be presumed from a known exposure, but has not been previously proven using genomic analysis. OBJECTIVE: Investigation of suspected VZV transmission was done using single nucleotide polymorphism genomic analysis. STUDY DESIGN: Comparison was made of viral isolates from two patients with chickenpox on the same ward who were not known to have had direct contact. RESULTS: An identical genotype in the variable R1 region of the VZV was isolated from the two patients. CONCLUSION: Inapparent hospital-acquired transmission was the most likely route of infection.

Increasing incidence of acute hepatitis B virus infection referrals to the Aberdeen Infection Unit: a matter for concern.

OBJECTIVES: To assess the epidemiology and clinical outcomes of acute hepatitis B virus (HBV) infections presenting to a regional Infection Unit over a ten year period--with reference to the issues of injection drug use and strategies aimed at reducing transmission, notably needle exchange and immunisation programmes. METHODS: A retrospective casenote review of all patients with acute HBV managed at the Infection Unit in Aberdeen between 1991-2000. RESULTS: One hundred and nineteen (119) patients with acute HBV infection were managed during the period of review. The annual number of patients increased from a mean of 3.3/year during the years 1991-96 to 46 in 2000. The risk factors associated with HBV infection were being an injection drug user (IDU) in 57 (47.9%), heterosexual sex in 22 (18.5%), sex with an IDU in 4 (3.4%), men who had sex with men in 10 (8.4%), tattooing in 1 (0.8%), a needle stick injury in 1 (0.8%), trauma 1 (0.8%) and unknown in 23 (19.3%). Many of these patients had "dabbled" in drug use. Thirty-one (54.4%) of the IDU patients had previously been hospitalised with drug-related medical problems. Eighteen (31.6%) of the IDUs were receiving methadone at the time of presentation. CONCLUSIONS: There is an epidemic of HBV infection in the Grampian region of Scotland currently. Forty-six (65.7%) of the 70 infected patients diagnosed during 2000 were seen at the Infection Unit. The remainder had mild or asymptomatic disease and were managed in the community. This epidemic has occurred despite extensive use of local needle exchange facilities and might reflect missed opportunities to immunise IDUs against HBV infection. A co-ordinated approach is now in place to immunise IDUs and other high-risk groups, but the use of universal immunisation demands consideration.

Epidemiology and outcome of HIV infection in North-East Scotland (1985-1997).

OBJECTIVE: to assess the epidemiology of HIV infection in North-East Scotland. METHODS: retrospective casenote review of all HIV-infected patients who have had contact with the Infection Unit in Aberdeen. RESULTS: one hundred and forty-two HIV-infected patients were treated between April 1985 and December 1997. The risk behaviour related to the acquisition of the HIV infection was: 56 (39%) homosexually infected, 45 (32%) heterosexually-infected, 34 (24%) injecting drug users (IDUs), and seven (5%) blood products or not known. Sixteen of the 45 (36%) heterosexually-infected patients were native to Africa and 16 of the 34 (31%) IDUs were prisoners in Peterhead prison at the time of referral. Fifty-two (37%) of the cohort continue to attend the Infection Unit, 41 (29%) have relocated, 40 (28%) have died and nine (6%) have been lost to follow-up. The ratio of heterosexual:homosexual men:IDUs changed significantly between the first 7 years (12:21:25) and the second 6 years (33:35:9) of the review, with significantly more patients being infected through heterosexual contact and fewer infected by IDU in the second period-P<0.001. The median AIDS survival was 17 months. Survival was significantly longer in those patients who took anti-retroviral therapy (median = 20 months) than in the patients who opted not to take anti-retroviral therapy (median = 11 months)-P<0.01. CONCLUSIONS: Although homosexual contact represents the commonest risk group for HIV infection in this region, the number of heterosexually-infected patients has increased significantly in the last 5 years. Temporary residents account for one-third of the HIV-infected population cared for in NE Scotland. Almost half of those lost to follow-up have returned to Africa or been released from prison. The introduction of anti-retroviral therapy has resulted in a dramatic improvement in AIDS survival in our cohort as it has done elsewhere.

Parenteral ganciclovir treatment of acute CMV infection in the immunocompetent host.

The treatment with ganciclovir of two non-compromised patients who required hospitalisation with acute cytomegalovirus (CMV) infection is described. Ganciclovir has rarely been used in such circumstances but, in four previously reported patients and in the patients described here, a rapid response to therapy was seen. In contrast to previous reports, relatively short courses of treatment (3-5 days) were given to our patients. The drug was well tolerated in each case and may have a role to play in the treatment of severe acute CMV infection in the normal host.

Respiratory viruses in a hospitalized paediatric population in Edinburgh 1985-1994.

We describe the incidence of respiratory viruses identified in children admitted to an Edinburgh hospital between October 1985 and July 1994. Respiratory syncytial (RS) virus, influenza viruses and parainfluenza viruses showed seasonal activity whereas adenoviruses and rhinoviruses did not. Parainfluenza viruses were the most changeable in their epidemiological behaviour and RS virus the least.

Human immunity to rotavirus.

Rotaviruses are the most important cause of severe gastro-enteritis in infants and young children. However, the determinants of protective immunity are poorly understood. Human immunity to rotavirus can be acquired passively or actively. It may be humoral or cell-mediated, protective or non-protective, homotypic or heterotypic and mucosal or systemic, or any combination of these. Mucosal immunity is protective against rotavirus illness, but not against infection, whereas systemic immunity reflects exposure, but probably has little if any role in protection. Both local and cell-mediated immunity are likely to be important in protection. However, there is no agreement as to a reliable surrogate marker of small intestinal protective immunity, and little is known about small intestinal cell-mediated immunity in man, especially infants. Passive mucosal immunity, but not systemic immunity, may contribute to protection in breast-fed infants, and in those at increased risk of serious illness who have been given oral immunoglobulin, either as prophylaxis or therapeutically. Animal and adult studies may have only limited relevance to those who are at greatest risk of serious illness. However, it is probably from such studies that hypotheses about small intestinal cell-mediated immunity in the protection of infants against rotavirus infection in man remain unclear, and this continues to hinder vaccine research.

Dot-blot hybridisation assay for detection of parvovirus B19 infections using synthetic oligonucleotides.

Pools of 10 synthetic oligonucleotides with sequences derived from the genome of parvovirus B19 and of 30 bases in length were made and labelled at the time of synthesis with digoxigenin (DIG) or dinitrophenyl (DNP) at the 5' end. They were used in a dot-blot hybridisation assay to detect parvovirus B19 DNA in sera submitted for routine virological diagnosis where parvovirus infection was suspected. Detection down to 10-100 fg DNA (equivalent to 10(3)-10(4) copies of parvovirus B19 genome) was obtained with both probe cocktails and colorimetric or chemiluminescent detection systems. Of 141 clinical samples examined from 126 patients presenting with rash and/or joint pains, 107 were clearly negative with both probes, 20 were clearly positive and the remaining 14 samples gave discrepant results. Of these 34 samples, 33 contained parvovirus B19 specific IgM. The parvovirus oligonucleotide probe cocktail produced and labelled with either DIG or DNP provided a useful diagnostic reagent for the detection of specific DNA in clinical specimens using a simple and sensitive dot-blot assay.

Measles, mumps and rubella immunisation in children at risk of infection with human immunodeficiency virus.

A retrospective serological study of 81 children at risk of HIV (II HIV-infected, 70 HIV-negative) was performed to assess susceptibility to measles, mumps and rubella and response to measles, mumps and rubella (MMR) immunisation. There was no difference in the initial serological response between the HIV-infected and HIV-negative children. Repeat serology should be performed on HIV-infected children as during follow-up antibodies may be lost. Reimmunisation should be considered for the seronegative.