Israel Medical Association Journal

Background: Pertussis is the only vaccine-preventable disease that has re-emerged in Israel. The reported crude incidence of the disease increased 16-fold since 1998.

Objectives: To describe the epidemiology of pertussis and to explain the substantial increase in reported pertussis incidence in Israel in recent years.

Methods: Crude and specific pertussis incidence by age, patient immunization status, hospitalization rate and national immunization coverage rate were calculated from information provided by the public health offices of the Ministry of Health.

Results: The reported crude incidence of pertussis increased from 1–2/100,000 in 1994–98 to 23/100,000 in 2004. The trend was observed in all age groups, being most prominent in infants under age 1 year and in children aged 5–14. The incidence of pertussis was substantially higher in unvaccinated and partly vaccinated compared to fully vaccinated persons. Fifteen percent of notified cases were hospitalized, but in infants under age 1 year the hospitalization rate was 50%. National pertussis immunization coverage by age 2 years was stable during the last 10 years.

Conclusions: There are several possible explanations for the re-emergence of pertussis in Israel. The most plausible reason seems to be the waning of vaccine-induced immunity in face of infrequent natural exposure to the infectious agent and lack of a pertussis vaccine booster dose after age 1.
 

Because of its high case-fatality rate, its very high transmission potential, and the worldwide shortage of effective vaccine, smallpox tops international lists of over a dozen possible bioterror and biologic warfare agents. In a scenario involving aerosol variola virus release, tens to hundreds of first-generation cases would ensue, as would hundreds to thousands of subsequent cases resulting from person-to-person transmission. A smallpox outbreak in Israel must not be regarded as a doomsday event: the methods of smallpox outbreak control are known and will be implemented. The rapidity with which organized outbreak control measures are competently executed will determine how many generations of cases occur before the outbreak is brought under control. Planning, vaccine stockpiling, laboratory expansion, professional training and public education, all carried out well in advance of an epidemic, will minimize the number of casualties. The reinstitution of routine smallpox vaccination in Israel, as in other countries, must be given serious consideration, since it has the potential for eliminating the threat of smallpox as a bioterror agent.

Background: The large number of cases of West Nile fever diagnosed in Israel in 2000 once again brought into focus the confusion that frequently accompanies the use of the term “epidemic”.

Objective: To examine the different definitions of the term “epidemic” and to propose ways in which it can be used to both improve communication among professionals and provide the public with a better sense of the associated risks.

Methods: The literature wes reviewed for the various definitions of the terms “epidemic” and “outbreak”. Sources included popular and medical dictionaries, ancient documents, epidemiology texts, legal texts, and the medical literature.

Result: The term epidemic is variously defined. The broad definition given by epidemiologists - namely, more disease the is anticipated by previous experience - is less meaningful to the general public. In some ways it conflicts with the definitions found in the popular literature, which generally imply danger to the public and a very large number of victims.

Conclusions: The interpretation of the term epidemic may vary according to the context in which it is used. For risk communication, we suggest that every effort be made to add descriptive terms that characterize the epidemic.

Background: Spinal dural arteriovenous fistulae comprise the majority of spinal vascular malformations. The most common clinical presentation is that of progressive myelor­adicuiopathy, probably related to venous hypertension, which may lead to permanent disability and even death.

Objective: To report our clinical experience with spinal dural arteriovenous fistulae.

Methods: Nine patients with spinal dural AVF were managed at our center during a one year period (1998-1999). The patients, eight men and one woman ranging in age from 46 to 75 years, presented with initially fluctuating and eventually permanent and progressive paraparesis, sensory disturbances and sphincter dysfunction. The neurological signs generally began symmetrically and progressed from the distal to proximal limb regions. The duration of symptoms before diagnosis ranged from 6 to 36 months during which the patients underwent an extensive but fruitless work-up and even unnecessary operations due to misdiagnosis. All patients finally underwent magnetic resonance imaging and spinal angiography, which demonstrated the pathological vascular fistula. Interruption of the AVF was achieved by embolization or by surgical resection.

Results: Following treatment, six patients experienced improvement of gait and sphincter control, and the severe neurological deficits stabilized in the other three patients with long duration of illness. There was no further deterioration in any of the treated patients.

Conclusions: The history, neurological findings and radiological changes on MRI scan should alert clinicians to the possibility of spinal dural AVF, leading to diagnostic spinal angiography. Early diagnosis and treatment may significantly improve outcome and prevent permanent disability and even mortality.

Background: Between 1970 and 1979, there was an increase in the incidence of viral hepatitis in Israel with a shift of peak incidence to an older age in the Jewish population, followed by a declining trend during the early 1980s. In July 1999 universal immunization of infants against hepatitis A was introduced.

Objective: To evaluate the chan-ges in the epidemiology of viral hepatitis A in Israel during the past decade.

Methods: Viral hepatitis is a notifiable disease in Israel and cases are reported to the regional health offices, which in turn provide summary reports to the Ministry of Health's Department of Epidemiology. The data in this study were derived from the summary reports and from results of seroprevalence studies.

Results: Following the increase in the incidence of reported viral hepatitis (mainly due to type A) between 1970 and 1979, the rates then stabilized and around 1984 began to decline until 1992. Since then there has been a slight increase. Whereas until 1987 the rates were consistently higher in the Jewish population. since then they are higher in the Arab population. The shift in the peak age-specific incidence from the 1-4 to the 5-9 year age group observed in the Jewish population around 1970 occurred 20 years later in the Arab population. The previously described seasonality is no longer evident. Recent seroprevalence studies indicate that by age 18 years only about 30-40% of the Jewish population have anti-hepatitis A antibodies.

Conclusions: The decline in the incidence of hepatitis probably reflects the changing socioeconomic condition occurring at different times in the two major population groups. Since hepatitis A accounts for almost all the acute viral hepatitis in Israel, the universal vaccination of infants introduced in 1999 should substantially lower the morbidity within the next few years.