Salman Zarka

Control of Streptococcus pneumoniae serotype 5 epidemic of severe pneumonia among young army recruits by mass antibiotic treatment and vaccination.

Abstract During an outbreak of severe pneumonia among new army recruits, an epidemiological investigation combined with repeated nasopharyngeal/oropharyngeal cultures from sick and healthy contacts subjects was conducted. Fifteen pneumonia cases and 19 influenza-like illness cases occurred among 596 recruits over a 4-week period in December 2005. Pneumonia attack rates reached up to 5.5%. A single pneumococcus serotype 5 clone was isolated from blood or sputum cultures in 4 patients and 30/124 (24.1%) contacts. Immunization with 23-valent polysaccharide vaccine supplemented with a 2-dose azithromycin mass treatment rapidly terminated the outbreak. Carriage rates dropped to <1%, 24 and 45 days after intervention.

A Cluster of Ecthyma Outbreaks Caused by a Single Clone of Invasive and Highly Infective Streptococcus pyogenes

BACKGROUND Ecthyma is an invasive, ulcerated skin infection. Four ecthyma outbreaks occurred in different infantry units in the Israeli Defense Force from October 2004 through February 2005. Morbidity attack rates in the first 3 outbreaks were 89% (49 of 55 soldiers), 73% (32 of 44), and 82% (37 of 45). In the fourth outbreak, in which early intervention (antimicrobial treatment and improvement of hygiene) was applied, the attack rate was 25% (10 of 40 soldiers). In the first outbreak cluster, 4 soldiers experienced poststreptococcal glomerulonephritis, and 5 cases of systemic sequelae were recorded (1 case of severe septic shock, 3 cases of pneumonia, and 1 case of septic olecranon bursitis). METHODS Streptococcus pyogenes and Staphylococcus aureus were isolated from ecthyma sores, oropharynx, and anterior nares of affected and unaffected soldiers involved in all 4 outbreaks. RESULTS Although the S. aureus isolates had different genomic profiles, >90% of S. pyogenes isolates were identified as belonging to a single clone, emm type 81, T type 8. Epidemiological investigation revealed that the hygiene levels of the soldiers and their living conditions were probably the most important cause for the difference in attack rates, wound severity, and systemic sequelae found between and within the units. CONCLUSIONS Our study demonstrates the possible ramifications of the combination of a virulent and highly infective S. pyogenes strain and poor living conditions, and it emphasizes the importance of early intervention in such conditions.

The functional profile of young adults with suspected Developmental Coordination Disorder (DCD)

We assessed the non-academic and academic functioning of young adults with DCD, and investigated the emotional influences and the role of strategy use within this population. A random sample of 2379 adolescents and young adults aged 19-25 (1081 males [45.4%]; mean age=20.68, SD=3.42) was used to develop the instruments. From this sample, three study groups were identified (n=429) based on the Adolescents & Adults Coordination Questionnaire: probable DCD (n=135; 67.2% males), suspected borderline DCD (n=149; 51.4% males) and control (145; 70.5% males). Participants completed the Daily Life Functions Questionnaire (assessing non-academic and academic functioning), the Recent Emotional State Test (assessing feelings resulting from task performance), the Internal Factors Attributed to Success Questionnaire and the Problem Solving Questionnaire to assess strategy and executive strategy use. A MANOVA revealed statistically significant differences between-groups (F[7,422]=16.19; p<.001; η=.197); post hoc analyses revealed differences for all measures (except the Problem Solving Questionnaire), with the probable DCD and suspected borderline DCD groups performing worse than controls. Severity of motor deficits was correlated with all outcomes except strategy use. Logistic regression revealed that non-academic functioning was the most significant predictor of group placement (B=-1.32; p<.001); academic functioning/handwriting was the second most significant predictor (B=0.44; p=.047). Deficits in motor coordination continue into adulthood and have an effect on academic and non-academic function, as well as on the emotional state of the individual.

Cognitive test scores in male adolescent cigarette smokers compared to non-smokers: a population-based study

BACKGROUND Although previous studies indicate that people with lower intelligence quotient (IQ) scores are more likely to become cigarette smokers, IQ scores of siblings discordant for smoking and of adolescents who began smoking between ages 18-21 years have not been studied systematically. METHODS Each year a random sample of Israeli military recruits complete a smoking questionnaire. Cognitive functioning is assessed by the military using standardized tests equivalent to IQ. RESULTS Of 20 221 18-year-old males, 28.5% reported smoking at least one cigarette a day (smokers). An unadjusted comparison found that smokers scored 0.41 effect sizes (ES, P < 0.001) lower than non-smokers; adjusted analyses remained significant (adjusted ES = 0.27, P < 0.001). Adolescents smoking one to five, six to 10, 11-20 and 21+ cigarettes/day had cognitive test scores 0.14, 0.22, 0.33 and 0.5 adjusted ES poorer than those of non-smokers (P < 0.001). Adolescents who did not smoke by age 18, and then began to smoke between ages 18-21 had lower cognitive test scores compared to never-smokers (adjusted ES = 0.14, P < 0.001). An analysis of brothers discordant for smoking found that smoking brothers had lower cognitive scores than non-smoking brothers (adjusted ES = 0.27; P = 0.014). CONCLUSION Controlled analyses from this large population-based cohort of male adolescents indicate that IQ scores are lower in male adolescents who smoke compared to non-smokers and in brothers who smoke compared to their non-smoking brothers. The IQs of adolescents who began smoking between ages 18-21 are lower than those of non-smokers. Adolescents with poorer IQ scores might be targeted for programmes designed to prevent smoking.

Transmission of Streptococcus pneumoniae in adults may occur through saliva.

Of 742 army recruits tested for pneumococcal nasopharyngeal/oropharyngeal carriage, 6·6% were positive. Frequent sharing of a drinking glass/bottle was a common, strong and independent risk factor for pneumococcal carriage. Our findings strongly suggest, for the first time, that in young adults, transmission of pneumococci may occur via saliva and this should be considered when conducting an outbreak investigation and carriage studies.

Varicocoele among 1 300 000 Israeli adolescent males: time trends and association with body mass index

Scarce data are available on epidemiology of varicocoele, the most common surgically correctable cause of male infertility. The objectives of this study were to evaluate the association between body mass index (BMI) and varicocoele and to assess trends in prevalence over time. We conducted a nationwide population‐based long‐term (1967–2010) study among 1 323 061 Israeli adolescent males using data from mandatory medical examination. BMI was grouped into underweight, normal weight, overweight and obese categories by percentiles adjusted for age in months and by further classification to five categories within normal weight. Univariable and multivariable logistic regression models were constructed, adjusting for possible confounders. Varicocoele prevalence (N = 47 398) increased during the study period from 1.6% for the 1950–1954 birth cohort to 4.6% for the 1990–1993 birth cohort, with the steepest rise in the normal weight group. Varicocoele unadjusted rates were highest (4.1%) among underweight and lowest (1.6%) among obese. In a multivariable model, adjusted for birth cohort, height, age and socio‐demographic factors, we found a decreased risk for varicocoele in the overweight group [odds ratio (OR) = 0.51, 95% confidence interval (CI): 0.49, 0.54] and the obese group (OR = 0.34, 95% CI: 0.32, 0.37), compared with the normal weight group. Within the normal weight group, a monotonic inverse association between BMI percentile and varicocoele was observed, most notable among 75–84.9 percentile compared to 25–49.9 percentile (OR = 0.65, 95% CI: 0.63, 0.68). In conclusion, varicocoele is common among adolescents in Israel, and its prevalence had increased in recent decades, providing clues to direct further andrological research on the role of modern lifestyle and environment in the aetiology of varicocoele. BMI, across percentiles, was found to be monotonically inversely associated with varicocoele, thus directing research and clinical efforts.

Rubella seroprevalence in the first birth cohort reaching fertility age after 20 years of two dose universal vaccination policy in Israel

BACKGROUND A national program of a 2-dose universal childhood MMR vaccination policy has been in effect in Israel since 1988. As the 1988 birth cohort reached fertility age, questions regarding immunity against rubella were raised. OBJECTIVE To assess the seroprevalence of rubella IgG antibodies among young Israeli adults born after 1987 in comparison to previous birth cohorts, in order to determine evidence based policy for prevention of rubella and congenital rubella syndrome. METHODS We conducted a seroprevalence study of rubella IgG antibodies among 416 Israeli adults (42.5% females) born in 1988-1989, based on a representative sample of sera collected at age 18-19 upon recruitment to mandatory military service in 2007. RESULTS In total, 87.7% were seropositive (>15 IU/ml) as compared with 84.8% in the 1999 recruitment (P=0.26) and 93.4% in 1987 (P=0.004). Yet there was a difference by gender. The proportion of seropositives among female young adults (92.7%) was significantly lower as compared to those measured in the 1999 (99.2%, P=0.001) and 1987 (99.0%, P=0.006) recruitments. The proportion of seropositives among males (84.1%) was significantly higher as compared to those measured in 1999 (73.0%, P<0.001) but similar to those of 1987 (88.8%, P=0.13). Females born in the FSU were found to be high risk groups as 11.5% were seronegative. CONCLUSIONS Our findings indicate that despite a successful program of congenital rubella syndrome prevention in Israel, there is a decline in seroprevalence among female young adults, especially immigrants from the FSU. A proactive catch-up program for females, especially for those of higher risk for susceptibility should be considered in Israel and in other countries.

Dynamics of pneumococcal acquisition and carriage in young adults during training in confined settings in Israel.

Background Outbreaks and sporadic cases of pneumococcal illness occur among young adults in confined settings. Our aim was to characterize pneumococcal acquisition and carriage among healthy young adults in Israel during military training in confined settings. Methods During the years 2007–2008, an observational longitudinal study was conducted in three cohorts of healthy soldiers, during a 7-month basic training period. Epidemiological data, oropharyngeal and nasopharyngeal cultures were sampled on 5 occasions: before and 3, 6, 12 and 24 weeks after start of training. Samples were processed within 2–18 hours. Relatedness of isolates was investigated by capsular typing of all isolates and pulsed-field gel electrophoresis to determine acquisition and transmission. Carriage and acquisition patterns were analyzed and multivariable logistic regression analysis was performed to assess the impact of time on acquisition after mixing, controlling for other covariates. Results Pneumococci were recovered on 202 of 1872 visits among 742 individuals, including 40 different serotypes. Mean carriage prevalence increased in all visits following training initiation. Acquisition during training was high, as 36.9% of individuals acquired pneumococci at least once during training, and for almost one fourth of the whole population this occurred during the first 6 weeks. Significant clustering was noted. Sharing drinking glass/bottle was found to be a significant and common risk factor for pneumococcal acquisition. Conclusions Pneumococcal acquisition is highly frequent when young adults live in close contact in confined settings, especially early after mixing.

Sub-optimal prevalence of mumps antibodies in a population based study of young adults in Israel after 20 years of two dose universal vaccination policy

BACKGROUND A recent mumps outbreak in Israel despite an ongoing national program of a 2-dose universal childhood vaccination policy since 1988, raised questions regarding population immunity among young adults. OBJECTIVE To assess the seroprevalence of mumps antibodies among young Israeli adults born after 1987 in order to determine evidence based vaccination policy. METHODS We conducted a seroprevalence study of mumps IgG antibodies among 441 Israeli adults born in 1988-9, based on a representative sample of sera collected upon recruitment to mandatory military service in 2007. RESULTS The overall seroprevalence of IgG antibody to mumps virus among 1988-9 born was 83.7%, 82.1% among males and 85.7% among females. Seroprevalence among 2007 recruits was similar to 1999 recruits (83.3%, P=0.89) and significantly lower than 1987 recruits (94.1%, P<0.0001). The absolute decrease between 2007 and 1987 for males was 13.1% (P<0.0001) and for females 7.0% (P=0.02). Seroprevalence was not significantly higher among native Israelis (84.9%) than among young adults born in the Commonwealth of Independent States (81.1%, P=0.46) and significantly higher compared to young adults born in Western Europe or North America (68.2%, P=0.045). CONCLUSIONS Our findings indicate sub-optimal population seroprevalence despite a 2-dose universal childhood vaccination policy. This study allows better understanding of current mumps outbreaks in Israel and elsewhere following periods of low circulation of wild virus. These findings support mumps vaccination, even for populations and individuals that received two doses during childhood, as means for outbreak containment among young adults, especially in crowded settings, and serve as a reminder to the need for dynamic vaccination policy, supported by health promotion activities.

Post exposure prophylaxis of tick-borne relapsing fever

Tick-borne relapsing fever (TBRF) is endemic to Israel. Since 2004, the Israel Defence Forces (IDF) has mandated the prophylaxis of tick-bitten subjects with a five-day doxycycline course. We examined the safety and effectiveness of this policy in preventing TBRF. We analyzed the records from January 2004 to January 2007, and identified all reported events of tick bites or TBRF cases. Data were available on 27 events in which 816 soldiers have undergone physical examination following exposure, and seven TBRF cases were recorded in this group—an attack rate of 0.86% compared with the expected rate of 5.34% from previous army data (relative risk [RR] = 0.16). Of those screened, 128 (15.7%) had tick-bite and were intended for prophylaxis, of which four TBRF cases occurred—3.13% attack rate compared with an expected rate of 38.4% in these bitten individuals without prophylaxis (RR = 0.08, number needed to treat = 3). In all cases in which screening and prophylaxis were provided within 48 h of tick bite, complete prevention of TBRF was achieved. No cases of Jarisch–Herxheimer reaction (JHR) was recorded. Tick-bite screening and prophylactic treatment with doxycycline in endemic areas is a practical, safe, and highly effective policy for preventing TBRF.