Alex Leventhal

Regional Infectious Disease Surveillance Networks and their Potential to Facilitate the Implementation of the International Health Regulations

The International Health Regulations (IHR) 2005 present a challenge and opportunity for global surveillance and control of infectious diseases. This article examines the opportunity for regional networks to address this challenge. Two regional infectious disease surveillance networks, established in the Mekong Basin and the Middle East, are presented as case studies. The public-private partnerships in the networks have led to an upgrade in infectious disease surveillance systems in capacity building, purchasing technology equipment, sharing of information, and development of preparedness plans in combating avian influenza. These regional networks have become an appropriate infrastructure for the implementation of the IHR 2005.

Elimination of hepatitis a infection outbreaks in day care and school settings in southern Israel after introduction of the national universal toddler hepatitis a immunization program.

Background: In 1999, Israel became the first country to begin universal toddler immunization against hepatitis A infection with a 2-dose schedule at 18 and 24 months. The effect of the Israeli program on outbreaks of Hepatitis A in day care and school settings was studied. Methods: The records of all hepatitis A illness outbreaks in day care and school settings reported to the Ministry of Health in Southern Israel during 1993 through 2005 were reviewed. The number of exposed contacts for whom postexposure prophylaxis was administered was retrieved from records of epidemiologic investigations. Rates of immunization coverage were extracted from records of Maternal and Child Health Clinics. Results: Three hundred nineteen cases of hepatitis A illness during the years 1993 through 2005 were associated with 113 outbreaks in day care and school settings of which 92% occurred before the institution of universal toddler immunization. Since 2000, no hepatitis A infection outbreaks have been reported in any day care and school settings in the region. An average of 732 children received immunoglobulin prophylaxis yearly because of exposure to an outbreak in an educational setting during the preimmunization period, 106 in 2000 and zero in the 5 years since 2001. The data showed marked herd immunity since school-aged children born before 1999 were not immunized, but elimination of outbreaks occurred equally in that age group. Immunization coverage was 86.4% for one dose of hepatitis A vaccine by age 3 years and 77.3% for 2 doses among the birth cohort of 2000. Conclusions: Universal hepatitis A immunization of toddlers was associated with disappearance of outbreaks in educational settings. This included cohorts of nonimmunized children representing marked herd immunity.

Relative prevalence of malformations at birth among different religious communities in Israel.

The aim of this research was to determine the relative prevalence at birth of major malformations among the different religious communities in Israel as a way to better understand their causes. We collected data on malformations present among liveborn infants in a 10‐year period from the national registry of birth defects according to the religious affiliation. In a total of 1,203,763 liveborn infants, the prevalence of major malformations was in a similar range among Jews and Christians and much higher among Muslim and Druze. These observations may be explained by differences between these communities, in particular, the rates of consanguinity and of therapeutic abortions. The Muslim and Druze communities in Israel are those with the highest consanguinity rates and the lowest rates of termination of pregnancies when a malformation is diagnosed. Analysis of the differences in the rate of malformations at birth in different communities is important for Public Health planning. It may also help to delineate causes and serve as the basis for research.

The Israeli public health response to wild poliovirus importation

In 2013, a silent wild poliovirus type 1 importation and sustained transmission event occurred in southern Israel. With the aim of preventing clinical poliomyelitis and ensuring virus re-elimination, the public health response to the importation event included intensification of clinical and environmental surveillance activities, enhancement of vaccine coverage, and supplemental immunisation with a bivalent oral polio vaccine against wild poliovirus types 1 and 3. A national campaign launched in August, 2013, resulted in vaccination of 943,587 children younger than 10 years (79% of the eligible target population). Expanded environmental surveillance (roughly 80% population coverage) documented a gradual disappearance of wild poliovirus type 1 in the country from September, 2013, to April, 2014. No paralytic poliomyelitis case was detected. A prompt extensive and coordinated national public health response, implemented on the basis of evidence-based decision making, successfully contained this serious importation and sustained transmission event of wild poliovirus to Israel. On April 28, 2015, WHO officially declared Israel as a polio-free country.

Immune response to an intercalated enhanced inactivated polio vaccine/oral polio vaccine programme in Israel: impact on the control of poliomyelitis

A combined enhanced inactivated polio vaccine (EIPV) and oral polio vaccine (OPV) programme was introduced in Israel in 1990, with the purpose of providing a solution to the persistent polio morbidity in spite of a 30 year long OPV programme. The schedule comprised two doses of EIPV administered at the age of 2 and 4 months, intercalated with two doses of OPV at 4 and 6 months, followed by a reinforcing dose with the two vaccines simultaneously administered at 12 months. The 5-year evaluation of the programme included: the assessment of clinical suspicions of polio, early immune response in successive cohorts administered the new schedule, dynamics of the immune profile in a cohort followed up to the age of 5, and monitoring of wild poliovirus excretion in sewage specimens collected in 25 permanent sites throughout Israel as well as from the Palestinian Authority. No paralytic polio cases associated with a wild or vaccinal poliovirus strain were detected since the introduction of the programme. At the age of 4 months, one week after administration of the second EIPV and first OPV dose, 100% seropositivity and high geometric mean titres (GMTs) of neutralizing antibody (NA) to the three vaccinal and to the wild poliovirus type 1, responsible for the 1988 polio outbreak, were observed. No change in percent of seropositivity occurred between the age of 6 and 12 months. Thirty days after the IPV and OPV reinforcing doses, GMTs to each of the four poliovirus strains were > or = 3037. Up to the age of 5, the seropositivity was unchanged. After a 2.5-10-fold decline in the first year following the completion of the programme, GMTs to the three vaccinal and the wild poliovirus strain levelled off at rather high values, considered protective. Between 1990 and 1995, 16 wild poliovirus type 1 strains were isolated in three separate episodes in Gaza Strip sewage and once only in one Israeli site very close to Gaza City. The rapidly established, high and persistent NA titre to the vaccinal and wild poliovirus strains and the presence of immunological memory are indicative of high individual protection throughout the first 5 years of life. The only one-time introduction, without circulation, of a wild poliovirus strain in a single Israeli settlement suggests community protection. The intercalated programme offers a contribution to polio eradication by providing a solution to the primary and secondary failure associated with OPV, as well as to the control of vaccine-associated paralytic poliomyelitis.

Five decades of trends in anemia in Israeli infants: implications for food fortification policy

Objective: To describe the secular trends in the prevalence rates of iron-deficiency anemia (IDA) in infants in Israel, identify population group differences and assess the effectiveness of the 1985 Public Health directives on iron supplementation and avoidance of cow’s milk in the first year of life.Design: A systematic analysis of published and unpublished cross-sectional studies.Methods: IDA rates in 1-y-old infants between 1946 and 1997 were assessed from published papers and reports. Rates for Arab infants were available from 1984. Data on routine hemoglobin tests on 1-y-old infants for Arabs and Jews separately were obtained from four health districts for the period 1987 to 1997. Analyses were done for the periods prior to and following the Public Health directives.Results: The prevalence of IDA in Jewish infants declined from 68% in 1946 to 50% in 1985 at an average annual rate of −1.43%. Following the iron supplementation directives, the average annual rate of decline increased to −4.0% and reached a prevalence of about 11% in 1996. IDA rates in Arab infants declined by an annual average of −3.7%, and were consistently almost twice as high as for Jewish infants.Conclusions: Despite the contribution of the iron supplementation program to the reduction in IDA, the persistently high rates indicate inadequate iron content in the diet. This emphasizes the important role of a national food fortification program, using staple foods commonly consumed.European Journal of Clinical Nutrition (2001) 55, 82–87

Chest Radiography Validity in Screening Pulmonary Tuberculosis in Immigrants From a High-Burden Country

BACKGROUND: Chest x-ray (CXR) is widely used for diagnosing and screening pulmonary tuberculosis (PTB), yet its validity is debatable and its costs are relatively high. This study aimed to determine the validity of CXR screening in detecting radiological findings compatible with active PTB or with old healed tuberculosis (OHTB). METHODS: All Ethiopian immigrants to Israel between 2001 and 2005 were radiographed before emigration. Immigrants whose CXR demonstrated PTB or OHTB were evaluated, treated, and followed for one year after arrival. The end point of this historical cohort study was a diagnosis of active pulmonary disease within the study period. RESULTS: CXR was performed on 13,379 immigrants. Changes suggesting PTB were identified in 150 (1.1%) of those, and 46 were diagnosed with active PTB. Sensitivity, specificity, and positive predictive value of a CXR suggesting PTB were 80.1%, 99.2%, and 31%, respectively. As PTB prevalence in this cohort is 0.4%, post-test odds for CXR suggestive of PTB were 75.5. Changes suggesting OHTB were identified in 257 (1.9%) immigrants. Of those, 15 (5.8%) developed active PTB within one year following arrival. Sensitivity, specificity, and positive predictive value of CXR suggestive of OHTB were 17.2%, 98.2%, and 5.8%, respectively, when active PTB during the first year was the end point. In this study, 291 CXR were required to detect one active PTB patient, costing

A tap water turbidity crisis in Tel Aviv, Israel, due to technical failure: Toxicological and risk management issues

5,802. CONCLUSIONS: CXR is a valid and cost-saving tool for screening active PTB in immigrants originating in high-burden countries, and is beneficial in detecting OHTB in immigrants who are at a higher risk for developing active PTB.

The control of mumps in Israel

Herein, we report on the actual events linked to an ammonia spillage into the main waterline of the Tel-Aviv metropolitan area and its surrounding municipalities. Based upon a large magnitude increase of unknown origin in the turbidity and ammonia levels of the main drinking water supply, area residents were warned of possible serious contamination and advised to refrain from drinking tap water until further notice. Turbidity was later linked only to CaCO3, which was precipitated from the water due to the rise in pH caused by the excessive ammonia levels. The source of the ammonia (a malfunction of the measurement buoy in the ammonia tank) was not identified until several days after the warning was issued. The toxicological implications of the turbidity and ammonia elevations are considered and reconciled with the management strategies that followed. Of consequence to the management of this crisis was the approach of Ministry of Health officials to regard the ammonia, from the onset, as an indicator of several possible sources of origin rather than as a contaminant. Decision-making policies were hampered by ineffective communication between the national water supplier and government health officials. An outcome of this crisis was a heightened awareness of the potential of a water crisis occurring during peace time and not only in association with terrorist activities, to which Israeli citizens are highly sensitized. Finally, the present paper may serve to guide municipal environmental and health officials more appropriately in the event of similar drinking water crises in Israel or elsewhere.

BMI May Overestimate the Prevalence of Obesity Among Women of Lower Socioeconomic Status

Background: Measles–mumps–rubella (MMR) vaccine replaced monovalent measles vaccine in the routine childhood vaccination schedule in Israel in December 1988, primarily to achieve the elimination of the congenital rubella syndrome. In this observational study, we report on changes in reported mumps incidence in Israel from the time of the introduction of MMR vaccine until the end of 1998. Methods: The report is based upon passive national surveillance of mumps incidence, which has been notifiable in Israel since 1977. Results: Reported mumps incidence in Israel is now less than 2% the pre-vaccine incidence. Conclusions: In the decade since the introduction of routine mumps vaccination in 1-year-olds in Israel, mumps control has been achieved. Although small outbreaks occur and may continue to occur in future years, because of undervaccination of children, primary vaccine failure and waning immunity, it can tentatively be said that mumps is no longer a public health problem in Israel.