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P Morgan-Capner

Publications and source records attributed to P Morgan-Capner.

At least 55 records · Page 3Linked to original sources
PubMed1995

Predicting the impact of measles vaccination in England and Wales: model validation and analysis of policy options.

Measles incidence in England and Wales has fallen to an all-time low. Attention is now focused on preventing local outbreaks, and, in the long run, on the elimination of indigenous measles. A realistic age-structured (RAS) mathematical model of measles transmission is used to reconstruct the impact of measles vaccination in England and Wales from 1968 to the present and to evaluate the merits of future policy options. In general, the predictions of the model show good agreement with long-term age stratified case reports and seroprevalence surveys. The model underestimates the proportion of cases that are notified in 0-2-year-old children. However, recent work suggests a high degree of misdiagnosis in this age group. Projections on the basis of the existing vaccination strategy in the UK suggest that the present level of measles vaccine coverage will be insufficient to eliminate small seasonal outbreaks of measles. This result is, however, sensitive to the assumed level of vaccine efficacy. Explorations of a variety of changes to current vaccination strategy favour a 2-dose schedule with the second dose administered at age 4 years irrespective of vaccination history. A vaccination campaign in school-age children, to reduce deficits in herd immunity, would accelerate progress towards measles elimination.

Adolescent↗
PubMed1995

Interpretation of serological surveillance data for measles using mathematical models: implications for vaccine strategy.

Serological surveillance of measles immunity has been carried out in England since 1986/7. Results from sera collected in 1989-91 revealed that the proportion of school age children who were susceptible to measles was increasing, following the introduction of the measles, mumps and rubella vaccination programme in October 1988. Mathematical models are used to interpret these data and determine whether this increasing susceptibility is sufficient to allow a resurgence of disease from the low levels achieved by 1993. The models summarize serological profiles by a single parameter, the reproduction number R, which quantifies the level of herd immunity in the population. Results showed that there was cause for concern over the levels of susceptibility to measles, with an epidemic of over 100,000 cases likely in 1995/6. These predictions are consistent with trends in the incidence and age distribution of measles and have enabled the planning of a major vaccination campaign.

Adolescent↗
PubMed1995

The risk of acquiring Q fever on farms: a seroepidemiological study.

OBJECTIVES: To determine the occupational risk of Q fever. DESIGN: Cohort study. SETTING: Community: five English local authority districts. SUBJECTS AND METHODS: Prevalence and incidence of immunoglobulin G (IgG) specific antibody to Coxiella burnetii phase II antigen was measured in a representative (study) cohort of farm workers in the United Kingdom, and detailed exposure data were collected. Also seroprevalence of Q fever in a (control) cohort of police and emergency service personnel was measured. RESULTS: Prevalence was significantly (P < 0.01) higher in the study cohort (105/385 v 43/395). During the first 12 month period after enrollment no seroconversions were found (upper 95% confidence limit: 1318/100,000/year). During the second 12 month period after enrollment two seroconversions were found, equalling an incidence of 813/100,000/year (95% confidence interval (95% CI) 98-2937/100,000/year). No association was found between seroprevalence and age. In the study cohort, extent of total contact with farm animals seemed more important than exposure to any specific animal: full time employees were more than four times more likely to be antibody positive than part time employees (P < 0.05). Exposure to cattle, but not sheep, goats, cats, raw milk, and hay (all reported sources of Q fever) was associated with being positive to Coxiella burnetii IgG by univariate analysis but this association was not independent of total farm animal contact. CONCLUSIONS: The risk of Q fever on livestock farms is related to contact with the farm environment rather than any specific animal exposure. The absence of an increasing prevalence with age suggests that exposure may occur as clusters in space and time (outbreaks).

Adolescent↗
PubMed1994

The epidemiology of measles in England and Wales: rationale for the 1994 national vaccination campaign.

An epidemic of between 100,000 and 200,000 cases of measles during 1995 has been predicted in England and Wales. This prediction was based on epidemiological evidence from several sources. Notifications of measles to the Office of Population Censuses and Surveys have risen in 1994, with a high proportion of cases in children aged over 10 years. An increase in the incidence of measles was seen in data from other sources, including laboratory reports of confirmed infections and consultations with general practitioners for new episodes of measles. Antibody tests were performed on saliva and serum from notified cases in several districts. Over three quarters of the notified cases in 1994 that were confirmed occurred in children of school age. The proportion of children aged 7 to 14 years who were susceptible to measles, obtained from studies of the age specific prevalence of antibody, rose from 6.0% (146/2453) in 1986 and 1987 to 9.2% (144/1565) in 1991. Mathematical modelling has predicted that the level of susceptibility anticipated in the school age population in 1995 would have been sufficient to allow a resurgence of measles. Over half of the cases in the resulting epidemic would have occurred in people aged at least 10 years and, because mortality is higher in this older age group, between 30 and 60 deaths would have occurred. A mass campaign to immunise all children of school age is expected to cause an immediate reduction in disease transmission and prevent a substantial toll of morbidity and mortality.

Adolescent↗
PubMed1994

Rubella surveillance to June 1994: third joint report from the PHLS and the National Congenital Rubella Surveillance Programme.

A downward trend in the incidence of acquired rubella in England and Wales was reversed in 1993 when there were local outbreaks. These affected young adult males in particular, especially those living in college residences. Some spread to local antenatal populations occurred. Twenty-five confirmed infections were reported in pregnant women, most of whom were young and in their first pregnancy; this compares with totals of 12 and two in 1991 and 1992, respectively. Reports of congenital rubella have not risen since the 1993 outbreaks. Diagnosis lags behind birth, however, and further evaluation may be needed. Notifications of 14 infants, including one set of triplets, born with congenital infection since the beginning of 1991 have been received. Nine of the 12 mothers were immigrants, and three of these acquired their infection abroad. Data on antibody prevalence have revealed a large pool of susceptible males aged 10 to 25 years, which indicates that outbreaks in males would continue for some years if no action were taken. The national measles and rubella vaccination campaign in schools this month should abolish the difference in susceptibility between boys and girls up to 16 years of age and hasten progress towards the interruption of rubella transmission in the United Kingdom. Susceptibility in girls aged 13 to 14 years rose to 5.8% in 1993 from an average of 3.6% between 1986 and 1992. This suggests that the vaccination of schoolgirls has recently declined, but this component of the selective rubella vaccination programme will be discontinued after the measles and rubella campaign.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Age specific antibody prevalence to parvovirus B19: how many women are infected in pregnancy?

Infection with parvovirus B19 is an important cause of late fetal mortality in the second trimester, and many infections in pregnancy remain undiagnosed. A serological survey stratified by age has been used to estimate the incidence of maternal infection with parvovirus B19 in pregnancy. Serum remaining from specimens submitted for diagnosis from 6864 people of all ages to seven public health laboratories in England was tested for antibody to parvovirus B19. The antibody prevalence rose with age to 45% at 10 years and 60% to 70% in adults. The age specific force of infection was highest in children aged less than 10 years and lowest in adults. Maternal infection with parvovirus B19 is estimated to occur in approximately one pregnancy in 400. It has been estimated that fetal death occurs in 9% of these cases, which suggests that parvovirus B19 may cause more than 150 fetal deaths in England and Wales each year. Testing for evidence of recent infection with parvovirus B19 should be considered for unexplained cases of fetal hydrops in the second trimester, especially in years of parvovirus B19 epidemics.

Adolescent↗
PubMed1994

The PHLS response to a pandemic of influenza. An action plan. PHLS Influenza Subcommittee.

This document sets out the Public Health Laboratory Service (PHLS) action plan for responding to an influenza pandemic. The plan entails, in phase 0, interpandemic surveillance by the Communicable Disease Surveillance Centre (CDSC) and the Enteric & Respiratory Virus Laboratory (ERVL) of the Central Public Health Laboratory (CPHL), as well as maintenance by Area & Regional (A & R) Public Health Laboratories of updated diagnostic techniques for influenza. In phase 1 (the emergence of a 'shifted' influenza virus strain) a Pandemic Working Group will be convened to consider what action by PHLS is necessary. In phase 2 (pandemic influenza outside UK) the pre-defined roles for PHLS laboratories and CDSC will be adopted. When a pandemic is imminent in the United Kingdom (phase 3) the Working Group will coordinate PHLS activities and the Director of the Service will assess what special studies should be implemented. In phase 4, when the pandemic has reached the UK, the action plan sets out comprehensive measures that will be taken by CDSC, ERVL and A & R Laboratories to gather and collate information, provide DoH with weekly surveillance data and develop recommendations for prophylaxis, clinical management and treatment. When influenza activity has returned to background levels (phase 5) a report will be drafted by the Working Group prior to it being stood down by the Director of the Service. The response is summarised in tabular form in Table 1.

Communication↗
PubMed1994

Age-specific antibody prevalence to hepatitis A in England: implications for disease control.

Sera from an age-stratified sample of 7196 individuals, submitted for diagnostic purposes to four public health laboratories in England in 1986/7, were tested for hepatitis A antibody. The serological profiles, which showed marked regional differences, were consistent with declining incidence in the past. The decline in the incidence of hepatitis A has resulted in an increase in susceptibility in adults. This has three main consequences: an increase in the average age of infection may be leading to an increase in morbidity; normal immunoglobulin may become less protective against hepatitis A; the risk of transmission through blood products contaminated by viraemic blood donors may rise. Current average annual incidence in 5-14-year olds was estimated to vary between regions from 0.5-1.9%. This supports the view that, in the absence of a vaccination programme, hepatitis A will remain endemic unless there are further improvements in living conditions and standards of hygiene. A vaccine giving long-lasting protection could eliminate hepatitis A transmission with modest coverage at a young age. Targeting childhood vaccination on economically deprived areas or using vaccine to control outbreaks might be more effective policies.

Adolescent↗
PubMed1994

Zoonotic illness--determining risks and measuring effects: association between current animal exposure and a history of illness in a well characterised rural population in the UK.

STUDY OBJECTIVES: To recruit a representative sample of farmworkers, accurately quantify the range and extent of their animal exposures, and measure the associated risks of illness. DESIGN: Inception cohort. SETTING: The study was undertaken among farmworkers living in five local authority areas in the catchment of Hereford and Preston Public Health Laboratories, England. PARTICIPANTS: A quota sample of 404 people on 255 agricultural holdings took part. The holdings were selected at random from the Ministry of Agriculture, Fisheries and Food register. Altogether 58% of eligible subjects approached agreed to participate. MEASUREMENTS AND MAIN RESULTS: The sample had the same sex distribution as the 1991 census for those giving their occupation as agriculture. The mean age was significantly (p < 0.01) higher (44.6 years v 42.2 years) than that of those giving their occupation as agriculture, forestry or fishing in the census, although the modal range (45-59 years) was the same. At enrollment interviews, subjects individually reported contact with up to nine animal species (mode 4) out of 26 reported in all. Based on the numbers contacted and the frequency and intimacy of contact, scores on a ranked ordinal scale from 0-5 were constructed for each species and frequencies for each score were plotted. Subjects also reported past operations and serious illness. A history of pneumonia was significantly (p < 0.05) associated with a pigeon loft on the farm (relative risk (RR) 7.3) and attending farrowing pigs (RR 6.6), and one of leptospirosis with a rat problem on the farm (RR 28.1). Cattle contact was associated with a significantly lower likelihood (protective) of glandular fever (RR 0.19) and rheumatic or scarlet fever (RR 0.12). These effects were significantly related to rankings of the extent of exposure. CONCLUSIONS: It is possible to recruit a representative sample of farmworkers and measure their animal exposures in great detail. Among these exposures, associations with plausible risk factors for pneumonia and leptospirosis and apparently protective factors for glandular fever, scarlet fever, and rheumatic fever have been demonstrated, which further show a relationship between the extent of exposure and response. These findings can be tested further by examining the relationship of exposures to serological evidence of illness or by further prospective follow up of this and similarly well characterised cohorts, or both.

Adult↗
PubMed1993

Slow maturation of IgG1 avidity and persistence of specific IgM in congenital rubella: implications for diagnosis and immunopathology.

Without appropriately timed specimens, serological confirmation of congenital rubella infection may be a problem. We have compared the persistence of specific IgM and low avidity specific IgG1 in 141 sera from 120 cases of serologically confirmed congenital rubella infection with the known time scales for postnatal primary rubella. The results demonstrate that the maturation of the immune response to the rubella virus is abnormally slow in congenital rubella cases both in terms of the isotype switch and especially the development of high avidity specific IgG1. Thus avidity studies may permit serological confirmation of congenital rubella for longer than is possible with tests currently in use. The pathological implications of prolonged low avidity antibody production are discussed.

Aging↗
PubMed1993

Prevalence of antibodies to Norwalk virus in England: detection by enzyme-linked immunosorbent assay using baculovirus-expressed Norwalk virus capsid antigen.

A total of 3,250 serum specimens collected in England in 1991 and 1992 were tested by an indirect enzyme-linked immunosorbent assay for antibody to Norwalk virus using baculovirus-expressed capsid antigen, and 2,382 (73.3%) were positive. The prevalence of Norwalk virus antibody differed regionally. It was lowest (24.6%) in 6- to 11-month-old infants and increased to 89.7% in persons over 60 years old.

Adolescent↗
PubMed1993

Cowpox virus.

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Adolescent↗