Prevalence and Characteristics of Carriage of Neisseria meningitidis Among Young Israeli Adults.

Background: No updated data currently exist regarding Neisseria meningitidis carriage and genomic epidemiology among young Israeli adults. Methods: Oropharyngeal swabs were collected from 1801 military recruits on the day of recruitment during 2019. Neisseria meningitidis was detected and identified by culture and quantitative polymerase chain reaction (qPCR). Confirmed isolates were serotyped by qPCR, and encapsulated strains underwent whole-genome sequencing. Risk factors for carriage were determined by analyzing focused questionnaires using uni- and multivariate models. Genomic typing was performed by means of core genome multilocus sequence typing. Results: Carriage rates overall and of encapsulated strains were 20.1% and 6.7%, respectively. Genogroups B (49.2%) and Y (26.7%) were the most commonly encapsulated strains. Genogroups C, W, and X were scarce, and genogroup A was absent. The most notable clonal complexes (CCs) were CC23 (n = 30), CC32 (n = 16), and CC44/41 (n = 9). Carriage was significantly associated with smoking (odds ratio [OR], 1.82; 95% CI, 1.43-2.33) and boarding school attendance before recruitment (OR, 1.49; 95% CI, 1.14-1.96). Conclusions: The prevalence of meningococcal carriage among young Israeli adults is high, compared with similar studies in other developed countries. This might be due to sociocultural characteristics including smoking and boarding school attendance during and after high school. The dominant genogroups and CCs found were compatible with those implicated in invasive disease in Israel.

Population seroprotection against hepatitis a virus in Israel 18 years after introduction of inactivated vaccine into the routine childhood vaccination schedule.

Vaccine against Hepatitis A virus (HAV) is part of the routine vaccination schedule in Israel since 1999. As of 2016, new recruits to the Israel Defense Forces should have been vaccinated in their childhood. This sero-survey aimed to determine immunity against HAV 18 years after childhood vaccination, and to re-evaluate the need for HAV vaccination booster upon recruitment. Two populations were studied: soldiers who were recruited during 2011-2012, who belonged to birth cohorts before childhood vaccination (BCV) was introduced; and recruits from 2017, who belonged to birth cohorts after childhood vaccination (ACV) was introduced. Data on 339 BCV recruits and 295 ACV recruits were analyzed. Seropositivity was 35% in the BCV group and 68% in the ACV group (P < 0.0001). Seropositivity rates among ACV subjects enable evaluation of the vaccination program's impact on the population. Our findings do not support discontinuation of HAV vaccination of at risk groups until further evaluation.

Measles Outbreak in a Highly Vaccinated Population - Israel, July-August 2017.

On August 6, 2017, the Israeli Defense Force Public Heath Branch (IDFPHB) was notified of two suspected measles cases. IDFPHB conducted an epidemiologic investigation, which identified nine measles cases in a population with high measles vaccination coverage. All measles patients had signs and symptoms consistent with modified measles (i.e., less severe disease with milder rash, fever, or both, with or without other mild typical measles symptoms). A total of 1,392 contacts were identified, and 162 received postexposure prophylaxis (PEP) with measles-mumps-rubella (MMR) vaccine; the remaining contacts were followed for 21 days (one incubation period). No tertiary cases were identified.

An Outbreak of Microsporum canis infection at a military base associated with stray cat exposure and person-to-person transmission.

Tinea corporis caused by Microsporum canis is usually associated with exposure to animals, but outbreaks with anthropophilic transmission were described. A large outbreak in a military base was investigated. We investigated the outbreak's source and risk factors for infection in order to contain and eliminate it. All staff-members at the base were interviewed and examined. A case-control analysis of symptomatic patients was used to elucidate risk factors. Stray cats were captured and sampled. M. canis isolated from skin and fur specimens of patients and cats were genotyped by microsatellite sequencing. Fifty-three of 502 staff-members were symptomatic. Logistic regression showed risk associated with female gender, cat contact at base and performance of guarding duty. Multiple stray cats were found at the base. M. canis isolates from 4 cats and 4 patients had an identical genotype, while 2 patients had different genotypes. We describe the largest M. canis outbreak reported until now. Epidemiological and phylogenetic tools were used to investigate the source of the outbreak. Multiple exposures to stray cats caused infection of mainly young female soldiers performing guarding duty. Other persons were infected by person-to-person transmission. These findings aided in the termination of the outbreak.

Pertussis Outbreak Among Soldiers During Basic Training: The Need for Updated Protocols.

Pertussis is a highly contagious, vaccine preventable upper respiratory disease. The incidence of the disease has been rising in the past few decades. During the winter of 2015, an upper respiratory outbreak occurred in one of Israel Defense Forces basic training bases in northern Israel. Following the detection of the first primary cases, a suspected outbreak investigation was initiated in conjunction with more rigorous clinical and laboratory testing efforts to include specific antibody enzyme-linked immunosorbent assay assays and polymerase chain reaction to diagnose pertussis. Initially, 1,596 soldiers were surveyed clinically using a questionnaire and physicians' interviews for upper respiratory disease symptoms. A total of 158 soldiers were further evaluated and 38.6% (61) of those were diagnosed as having pertussis (with laboratory evidence). Based on the protocol that we developed during the course of this outbreak, a postexposure prophylaxis was given to every soldier for whom there was a high level of suspicion for infection and met the inclusion criteria for the postexposure prophylaxis protocol. The effects of the postvaccination waning immunity among a vaccinated population were demonstrated, thus the need of maintaining a high index of suspicion of Brodetella pertussis as a causative agent during respiratory diseases outbreaks in young soldiers.

Seroprevalence of anti-HBs antibodies at young adulthood, before and after a booster vaccine dose, among medical personnel vaccinated in infancy.

BACKGROUND: Questions remain regarding the long-term protection provided by childhood HBV vaccination. The goals of this study were to assess HBV seroprevalence among medical personnel purportedly vaccinated in infancy; to investigate the immune response after a booster dose given in young adulthood; and to identify predictors of non-responders. METHODS: Between 2011 and 2013 we studied Israeli male military recruits purportedly vaccinated in infancy. All subjects were born after January 1st 1992 and were undergoing medic training. We collected personal data and blood samples at baseline, and administered a dose of HBV vaccine. Subjects were retested one month later and received a second dose. A third blood draw was conducted one month after the second dose. Data collected at baseline were used as predictor variables of seropositivity (anti-HBs≥10mIU/ml). RESULTS: 617 subjects were available for baseline analysis and 539 for paired observations at one month. Baseline seropositivity was 33.7%. Subjects who received post-infancy vaccine doses had a seropositivity rate double that of those denying additional doses (RR 2.22, 95% CI 1.55-3.18). One month after the first booster dose, the overall cumulative population seropositivity reached 87.7%. One month after the second vaccine dose, population seropositivity was 97.9%. Heavy smokers were 5 times less likely to demonstrate detectable antibodies after a single booster dose (OR 0.196, 95% CI 0.060-0.641, P=0.007). CONCLUSIONS: This population-based study is important for informing public health vaccination policy. Our results strongly indicate that among cohorts vaccinated in infancy, two doses in adulthood will provide maximal protective antibody levels, while one dose will provide sufficient population protection.

Neglect of skin wounds and the risk of becoming a Staphylococcus aureus nasal carrier: a cohort study.

BACKGROUND: Nasal carriers of Staphylococcus aureus have an increased risk of acquiring skin and soft tissue infections, which could manifest as outbreaks, especially in crowded settings. Current prevention programs are ineffective, antibiotic resistance is rising and risk factors for becoming a carrier are incompletely understood. We aimed to examine whether a behavior, the neglect of skin wounds, is a risk factor for becoming a Staphylococcus aureus carrier during training. METHODS: We conducted a field-based cohort study among male infantry trainees in three seasons in Israel during 2011-12. Participants underwent anterior nares cultures and answered structured questionnaires on potential risk factors on two occasions: before and 3 weeks after start of training (N = 542). Attitudes and practices toward neglect of skin wounds were defined as perseverance in training at all costs, despite having a wound. Samples were processed within 18 hours for identification of Staphylococcus aureus. Univariable and multivariable logistic regression analyses were performed to assess risk factors for becoming a carrier. RESULTS: Carriage prevalence increased by 43.3% during training, from 33.2% to 47.6% (p < 0.01). One-fourth (25.4%) of those with a negative culture before training became carriers. None of the socio-demographic characteristics was a risk factor for becoming a carrier while the risk was lower in the winter (Odds ratio [OR] = 0.42; 95% confidence interval [CI]: 0.23-0.78, p < 0.01) and spring (OR = 0.46; 0.26-0.81, p < 0.01) seasons compared to the summer season. Neglect of skin wounds in practice and attitude was a risk factor for becoming a carrier (OR = 2.40; 1.13-5.12, p = 0.02), as well as neglect in practice or attitude (OR = 1.86; 1.04-3.34, p = 0.04) compared to no neglect when controlled for season. The preventable fraction in the population attributed to neglect of skin wounds was 33%. CONCLUSIONS: Neglect of skin wounds is an independent, common and strong risk factor for becoming a Staphylococcus aureus carrier during training. This preventable behavior should not be ignored and should be addressed in public health programs during training and in other settings. Further research on behavioral determinants of Staphylococcus aureus carriage and infection is warranted.

Secular trends in 1,192 diarrheal outbreaks in the Israel Defence Forces between 1988-2011.

BACKGROUND: In the military, outbreaks of infectious diarrhea pose a significant health problem. In this descriptive analysis of data collected by the IDF on all infectious diarrhea outbreaks between 1988-2011, we analysed temporal, seasonal, and unit-type trends in 1,192 diarrheal outbreaks in the Israel Defence Forces (IDF) over a 24-year period, and described the long-term trends in seasonality and the effects of strategic preventive measures on outbreak frequency among populations at risk. RESULTS: We found two distinct phases in annual outbreak occurrence. The mean annual number of outbreaks during the period 1988-1996 was 75.8 (±14.50) but dropped to 34.0 (±8.13) during the period 1997-2011 (P < 0.0001). Overall, a downward trend continued through the 1990's, while from 2000 onwards outbreak counts fluctuated annually. A significantly higher number of outbreaks occurred during the summer season, throughout the study period. The greatest number of outbreaks occurred in deployed units, although the proportion of outbreaks in this unit type decreased over time. Accordingly, the proportion of outbreaks in training units more than doubled during the study window. When we looked at outbreak size, summer outbreaks increased in magnitude over time, and during all periods outbreaks were larger, on average, in training units than in deployed units. CONCLUSIONS: The changing patterns in diarrheal outbreaks in the Israel Defence Forces require maintenance of a higher level of vigilance than ever before. Lack of a clear peak period require the use of all available preventive measures throughout the year. This is especially true in training units, where the increased number of outbreaks coincides with increased trainee volume, regardless of season.

Airway control in case of a mass toxicological event: superiority of second-generation supraglottic airway devices.

INTRODUCTION: Early respiratory support and airway (AW) control with endotracheal intubation (ETI) are crucial in mass toxicology events and must be performed while wearing chemical personal protective equipment (C-PPE). AIM: The aim of this study is to evaluate the efficiency of AW control by using second-generation supraglottic AW devices (SADs) as compared with ETI and first-generation SAD while wearing C-PPE. METHODS: This is a randomized crossover trial involving 117 medical practitioners. Four AW management devices were examined: endotracheal tube, the first-generation SAD, laryngeal mask AW unique and 2 second-generation SAD, the laryngeal tube suction disposable, and supreme laryngeal mask AW (SLMA). Primary end point measured were success or failure, number of attempts, and time needed to achieve successful device insertion. Secondary end point was a subjective appraisal of the AW devices by study population. RESULTS: More attempts were required to achieve AW control with endotracheal tube, with and without C-PPE (P<.001). Time to achieve AW control with ETI was, on average, 88% longer than required with other devices and improved with practice. The mean times to achieve an AW were longer when operators were equipped with C-PPE as compared with standard clothing. Subjectively, difficulty levels were significantly higher for ETI than for all other devices (P<.0001). CONCLUSIONS: When compared with ETI, the use of SADs significantly shortened the time for AW control while wearing C-PPE. Second-generation SAD were superior to laryngeal mask AW unique. These finding suggest that SADs may be used in a mass toxicology event as a bridge, until definite AW control is achieved.

Secular trends of chickenpox among military population in Israel in relation to introduction of varicella zoster vaccine 1979-2010.

Chickenpox is a contagious disease caused by the varicella zoster virus. There is scarce data on long-term trends of chickenpox and its relation to vaccinations practices. We aimed to evaluate trends of chickenpox in a military population during the period 1979-2010 and to assess temporal associations in relation with the introduction of varicella zoster vaccine to the civilian population in Israel in 2000. The archives of the Epidemiology Section of the Israel Defense Forces, where chickenpox is a notifiable disease, were reviewed for all cases of chickenpox from January 1, 1979-December 31, 2010. Annual and monthly incidence rates were calculated and analyzed in relation to vaccine introduction. Between 1979-2000, incidence rates fluctuated around 10 cases per 10,000 soldiers without a clear trend. Since 2000 there has been a dramatic 10-fold decline in incidence, especially notable since 2008, from eight per 10,000 soldiers in 2000 to the lowest rate ever recorded, in 2009, of 0.57 cases per 10,000 soldiers. A seasonal sinusoidal pattern was clearly demonstrated, with rising incidence from November to May followed by a gradual decline to October. The results of this long-term study suggest that the rates of chickenpox in the military population have significantly declined since the introduction of the vaccine to the civilian population in Israel and almost disappeared completely since 2008 as the vaccine was included in the state-funded routine childhood immunization schedule. These findings underscore the need for a strong surveillance system and will aid in determing vaccination policies.