Israel Medical Association Journal

Background: The epidemiology of human brucellosis (HB) continues to evolve.

Objectives: To describe the current epidemiology of HB in Israel in general and in the population at risk.

Methods: We calculated the incidence of HB in Israel for the period 2009–2015, overall and for the Arab population. Data are based on mandatory reporting of HB in Israel, defined clinically with either laboratory confirmation or epidemiological linkage to a laboratory-confirmed case. We mapped the geographic distribution of HB throughout the study period according to localities. We specified localities with high incidence (≥ 10 per 100,000 population) and mapped the distribution of dense localities with time.

Results: The incidence of HB in the general population in Israel increased sharply from 1.9 per 100,000 in 2009 to a peak of 7.3 per 100,000 in 2014. Each year, 95–100% of cases occurred among Arabs, thus the incidence in the Arab population increased from 10 per 100,000 in 2009 to 33.5 per 100,000 in 2014. Throughout this period 133 different localities reported at least one case of HB, and of these 20 were high-incidence localities during one year at least. During the period 2009–2013 the number of affected localities ranged from 35 to 44 per year and the disease was local, while in 2014 there were 82 localities distributed across the country.

Conclusions: We demonstrate the importance of analyzing incidence in the population at risk for a disease. HB is an urgent public health issue in the Arab population in Israel, mandating an immediate and long-term eradication and control program.

Background: During 2013–2014 Israel experienced a continuous circulation of wild poliovirus type 1 (WPV1) but with no clinical cases. WPV1 circulation was gradually terminated following a national vaccination campaign of bivalent oral poliovirus vaccine (bOPV) for 943,587 children < 10 years. Four cases of children with neurological manifestations that appeared following bOPV vaccinations were reported during the campaign: three of Guillain-Barré syndrome (GBS) and one of acute disseminated encephalomyelitis (ADEM). 

Objectives: To present an analysis of these cases, the rapid response and the transparent publication of the results of this analysis. 

Methods: The clinical, laboratory and epidemiological data of these four patients were available during the analysis. In addition, data regarding the incidence of GBS and ADEM during previous years, and reported cases of acute flaccid paralysis (AFP) and the incidence of Campylobacter jejuni enteritis were collected from the Epidemiology Department of the Israel Ministry of Health.

Results: The incidence of GBS among bOPV-vaccinated children was not higher than among bOPV-unvaccinated children. For all the cases reviewed the "incubation period" from vaccination to the event was longer than expected and other more plausible causes for the neurologic manifestations were found. There is no evidence in the literature of a causal relationship between bOPV and ADEM. 

Conclusions: There was no association between the bOPV vaccine and the reported neurological manifestations. We believe that our experience may assist other public health professionals when confronting a similar problem of alleged side effects during a mass medical intervention.

 

Background: The majority of human brucellosis cases in Israel are caused by the ingestion of unpasteurized dairy foods produced from unlicensed family-owned flocks whose products are sold door-to-door at low prices. Exposure to infected farm animals is another major cause of infection.

Objectives: To determine, by examining recent incidence data and brucellosis control programs, whether a reduction in the incidence of human brucellosis in Israel can be sustained.

Methods: Case information is reported to the Health Ministry and national data are compiled and analyzed by the Division of Epidemiology. The current study focuses on data from 1998 through 2009 and discusses several of the major prevention and health education programs that have been implemented.

Results: An incidence decline of almost 70% during the period 1998–2002 was followed by a return to previously existing levels, although the incidence has remained consistently lower than in past decades. The disease is mostly limited to certain sectors of the rural Arab population. In 2009 the incidence rate per 100,000 population was 7.0 among Arabs compared with 0.2 among Jews. Between 1998 and 2009, 63% of cases were from the Beer Sheva and Acre health districts, which together comprise 15.5% of the Israeli population. Control programs - including efforts to combat brucellosis in animals and to discourage the sale of unpasteurized homemade dairy products - have met with partial success.

Conclusions: Without routine vaccination of all family-owned flocks, more effective restraints on the market for unpasteurized dairy foods and improved regional cooperation, human brucellosis will continue to be a contained, but persistent, health problem in Israel due to cultural behavior, socioeconomic factors, and the regional political environment.
 

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.
 

Objectives: To characterize the demographic and clinical features of malaria acquired in Kenya, and to assess the adequacy of preventive measures.

Methods: Data were collected from investigation forms at the Ministry of Health. All persons who acquired malaria in Kenya during the years 1999–2001 were contacted by phone and questioned about use of chemoprophylaxis, attitudes towards malaria prevention, and disease course. Further information was extracted from hospital records.

Results: Kenya accounted for 30 of 169 (18%) cases of malaria imported to Israel, and was the leading source of malaria in the study period. Of 30 malaria cases imported from Kenya, 29 occurred after short (1–2 weeks) travel to holiday resorts in Mombassa. Average patient age was 43 ± 12 years, which is older than average for travelers to tropical countries. Only 10% of the patients were fully compliant with malaria chemoprophylaxis. The most common reason for non-compliance was the belief that short travel to a holiday resort carries a negligible risk of malaria. Only 3 of 13 patients (23%) who consulted their primary physician about post-travel fever were correctly diagnosed with malaria. Twenty percent of cases were severe enough to warrant admission to an intensive care unit; one case was fatal.

Conclusions: Measures aimed at preventing malaria and its severe sequelae among travelers should concentrate on increasing awareness of risks and compliance with malaria chemoprophylaxis.

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: 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.