Social development and declining incidence of some common epidemic diseases in children. A study of the incidence in different age groups in Stockholm

Multiple sclerosis incidence in the era of measles-mumps-rubella mass vaccinations

BACKGROUND

Viral childhood infections may be involved in the multiple sclerosis (MS) pathogenesis. Following national Swedish vaccination programs, measles sharply declined in the 1970s, and measles, mumps, and rubella were virtually eliminated in cohorts born from 1981.

OBJECTIVES

To examine whether the vaccination induced reduction in these infections influences the MS incidence. In addition, the public health aspect justified an early evaluation of beneficial as well as harmful effects of mass vaccinations.

MATERIALS AND METHODS

From an incidence material of 534 MS patients, born 1959-1990, we selected one unvaccinated cohort and four cohorts, each corresponding to a vaccination program (MS patients = 251).

RESULTS

With the ability to detect a decrease by 30-35%, and an increase by 37-48% in the MS incidence in the first three cohorts, we found no vaccination related MS incidence changes. The background MS incidence showed a significant gradual age dependent increase.

CONCLUSIONS

While the present follow-up provided limited power in the last cohort, there is no evidence as yet that the radical decline in three viral infections influenced the MS incidence. However, the increasing background MS incidence of unknown cause may have concealed a reduction in MS risk associated with mass vaccinations.

Epidemiology of Epstein-Barr virus infection in pre-adolescent children: application of a new salivary method in Edinburgh, Scotland

STUDY OBJECTIVE

To describe the epidemiology of Epstein-Barr virus (EBV) among primary school children by testing saliva with a new EBV capsid antigen "G" antibody capture radioimmunoassay (GACRIA).

DESIGN

A population based sample of 7 year old schoolchildren were followed up at age 11.

SETTING

30 randomly chosen primary schools in Edinburgh, Scotland.

PARTICIPANTS

552 schoolchildren.

MEASUREMENTS

Data on risk factors for infection were collected by questionnaire at ages 7 and 11. Saliva samples collected at age 11 were examined by GACRIA for evidence of previous infection with EBV. For 102 subjects, a second salivary specimen collected approximately one month after the first sample was available for testing as a measure of the repeatability of the method.

MAIN RESULTS

Unequivocal results were found in 91% of samples and the repeatability of the test was good (kappa = 0.71). Fifty six per cent of children had antibodies to EBV. In a logistic regression analysis, independent risk factors for infection were sharing a room (odds ratio 1.78, 1.14, 2.79), head of household's social class IV/V compared with I (odds ratio 2.87, 1.08, 7.34), and schools serving predominantly rented housing estates (odds ratio 2.3, 1.09, 4.84).

CONCLUSION

This study is the first application of EBV viral capsid GACRIA to salivary samples. The method was successfully used to describe the epidemiology of EBV. In this study, characteristics of the home seemed to be more important than those of the school in determining the likelihood of infection with EBV.

Bordetella pertussis whole cell vaccines--efficacy and toxicity

The literature concerning efficacy and side effects of pertussis vaccines is reviewed. With few exceptions, most vaccines induce a protective immunity lasting for 2 to 5 years. The large-scale use of pertussis vaccines has markedly contributed to the decrease in pertussis morbidity in small children but in some countries the incidence has increased in older children. Not even countries with immunisation rates of 90-95% have managed to eradicate pertussis or prevent disease in infants below the age of immunisation. The pertussis-associated mortality is currently very low in the industrialised countries and no differences can be discerned when countries with high, low and zero immunisation rates are compared. Local and benign systemic reactions are commonly seen after immunisation. The vaccines also sometimes cause convulsions, a shock-like state and, rarely, serious neurological reactions.