IgG Serum Antibodies to Shigella sonnei Lipopolysaccharide Are Inversely Associated with the Incidence of Culture-Proven S. sonnei Shigellosis in Israeli Children and Adolescents.

BACKGROUND: Shigella is a leading cause of moderate-to-severe diarrhea globally, with young children most affected. The burden of shigellosis drops increasingly with age, inferring the acquisition of natural immunity. We tested the hypothesis that IgG antibodies elicited against Shigella O-specific polysaccharide (O-SP) are correlates of age-acquired immunity. OBJECTIVES: We examined levels and determinants of serum IgG to S. sonnei LPS and the association with the incidence of S. sonnei shigellosis in Israeli children and adolescents. METHODS: We analyzed 1096 serum samples from 0- to 19-year-olds collected in 2008-2015 for IgG anti-S. sonnei LPS levels by ELISA. Corresponding age-specific incidences of culture-proven S. sonnei shigellosis from 2008 to 2015 were obtained. We compared ecologically IgG levels, prevalence above a proposed protective threshold, and S. sonnei shigellosis incidence. RESULTS: In a multivariable analysis model, children aged 1-4, 5-14, and 15-19 years were 6.71, 27.68, and 48.62 times more likely to have IgG anti-S. sonnei LPS above the threshold than those aged < 1 year, respectively (p < 0.001). Infants 0-3 months old had relatively high IgG anti-S. sonnei LPS levels of maternal origin that dropped thereafter. Children of low socioeconomic status had a 2.73 times higher likelihood of having IgG anti-S. sonnei LPS above the threshold (p < 0.001). A significant inverse correlation between age-specific IgG anti-S. sonnei LPS levels and S. sonnei shigellosis incidence was observed (Spearman rho= -0.76, p = 0.028). CONCLUSIONS: The study results support anti-S. sonnei LPS antibodies as correlates of protection that can inform Shigella vaccine development.

Serologic Response and Safety after a Third Dose of the COVID-19 BNT162b2 Vaccine in Patients with Inflammatory Bowel Diseases.

Vaccines are pivotal for control of the coronavirus disease (COVID-19) pandemic. Patients with inflammatory bowel diseases (IBDs) treated with antitumor necrosis factor (TNF)-α have lower serologic response after two COVID-19 vaccine doses. Data regarding a third vaccine dose are scarce. An Israeli multicenter prospective observational study recruited 319 subjects: 220 with IBD (79 treated with anti-TNFα) and 99 healthy control (HC) participants. All patients received two mRNA-BNT162b2 vaccines (Pfizer/BioNTech), 80% of whom received a third vaccine dose. Evaluation included disease activity, anti-spike (S) and nucleocapsid (N) antibody levels, anti-TNFα drug levels, and adverse events (AEs). All participants showed significant serologic response one month after receiving a third dose. However, three months later, the anti-S levels decreased significantly in patients treated with anti-TNFα compared with the non-anti-TNFα and HC groups. A correlation between serologic response to the third vaccine dose and anti-TNF drug levels was not found. No significant AE or IBD exacerbation was observed. Importantly, lower serologic response after the third vaccine dose predicted infection. A third dose of BNT162b2 is effective and safe in patients with IBD. Lower serologic response predicted infection, even in seropositive subjects. Lower serologic responses and their rapid decline suggest a fourth vaccine dose in this patient population.

Predictors of reinfection with pre-Omicron and Omicron variants of concern among individuals who recovered from COVID-19 in the first year of the pandemic.

OBJECTIVES: The predictors of SARS-CoV-2 reinfection are unclear. We examined predictors of reinfection with pre-Omicron and Omicron variants among COVID-19-recovered individuals. METHODS: Randomly selected COVID-19-recovered patients (N = 1004) who donated convalescent plasma during 2020 were interviewed between August 2021 and March 2022 regarding COVID-19 vaccination and laboratory-proven reinfection. The sera from 224 (22.3%) participants were tested for antispike (anti-S) immunoglobulin G and neutralizing antibodies. RESULTS: The participants' median age was 31.1 years (78.6% males). The overall reinfection incidence rate was 12.8%; 2.7% versus 21.6% for the pre-Omicron (mostly Delta) versus Omicron variants. Negative associations were found between fever during the first illness and pre-Omicron reinfection: relative risk 0.29 (95% confidence interval 0.09-0.94), high anti-N level at first illness and Omicron reinfection: 0.53 (0.33-0.85), and overall reinfection: 0.56 (0.37-0.84), as well as between subsequent COVID-19 vaccination with the BNT162b2 vaccine and pre-Omicron 0.15 (0.07-0.32), Omicron 0.48 (0.25-0.45), and overall reinfections 0.38 (0.25-0.58). These variables significantly correlated with immunoglobulin G anti-S follow-up levels. High pre-existing anti-S binding and neutralizing antibody levels against the SARS-CoV-2 Wuhan and Alpha strains predicted protection against Omicron reinfections. CONCLUSION: Strong immune responses after the first COVID-19 infection and subsequent vaccination with the BNT162b2 vaccine provided cross-protection against reinfections with the Delta and Omicron variants.

A Shigella flexneri 2a synthetic glycan-based vaccine induces a long-lasting immune response in adults.

Shigella is a leading cause of moderate to severe diarrhea worldwide and of diarrhea-associated deaths in children under 5 years of age in low-and middle-income countries. A vaccine against shigellosis is in high demand. SF2a-TT15, a synthetic carbohydrate-based conjugate vaccine candidate against Shigella flexneri 2a (SF2a) was found safe and strongly immunogenic in adult volunteers. Here, SF2a-TT15 at 10 µg oligosaccharide (OS) vaccine dose is shown to induce a sustained immune response in magnitude and functionality in the majority of volunteers followed up 2 and 3 years post-vaccination. High levels of either one of the humoral parameters as well as the number of specific-IgG memory B-cells determined 3 months after vaccination were good predictors of the durability of the immune response. This study is the first to examine the long-term durability of antibody functionality and memory B-cell response induced by a Shigella vaccine candidate.

Threshold protective levels of serum IgG to Shigella lipopolysaccharide: re-analysis of Shigella vaccine trials data.

OBJECTIVES: Establishing a correlate of protection is essential for the development and licensure of Shigella vaccines. We examined potential threshold levels of serum IgG to Shigella lipopolysaccharide (LPS) that could predict protection against shigellosis. METHODS: We performed new analyses of serologic and vaccine efficacy (VE) data from two randomized vaccine-controlled trials of the Shigella sonnei-Pseudomonas aeruginosa recombinant exoprotein A (rEPA) conjugate conducted in young adults and children aged 1-4 years in Israel. Adults received either S. sonnei-rEPA (n = 183) or control vaccines (n = 277). Children received the S. sonnei-rEPA conjugate (n = 1384) or S. flexneri 2a-rEPA conjugate (n = 1315). VE against culture-proven shigellosis was determined. Sera were tested for IgG anti-S. sonnei LPS antibodies. We assessed the association of various levels of IgG anti-S. sonnei LPS antibodies with S. sonnei shigellosis risk using logistic regression models and the reverse cumulative distribution of IgG levels. RESULTS: Among adults, four vaccinees and 23 controls developed S. sonnei shigellosis; the VE was 74% (95% CI, 28-100%). A threshold of ≥1:1600 IgG anti-S. sonnei LPS titre was associated with a reduced risk of S. sonnei shigellosis and a predicted VE of 73.6% (95% CI, 65-80%). The IgG anti-S. sonnei LPS correlated with serum bactericidal titres. In children, a population-based level of 4.5 ELISA Units (EU) corresponding to 1:1072 titre, predicted VE of 63%, versus 71% observed VE in children aged 3-4 years. The predicted VE in children aged 2-4 years was 49%, consistent with the 52% observed VE. CONCLUSION: Serum IgG anti-S. sonnei LPS threshold levels can predict the degree of VE and can be used for the evaluation of new vaccine candidates.

SARS-CoV-2 IgG Antibody Levels in Women with IBD Vaccinated during Pregnancy.

INTRODUCTION: Regulatory agencies supported vaccination of pregnant women with SARS-CoV-2 mRNA vaccines, including patients with IBD. No data exist regarding these vaccines in IBD during pregnancy. AIM: To assess the serologic response to two doses of the mRNA SARS-CoV-2 BNT162b2 vaccine in pregnant women with IBD vaccinated during pregnancy, compared to that of pregnant women without IBD, and non-pregnant women with IBD. METHODS: Anti-spike antibody levels were assessed in all women and in cord blood of consenting women. RESULTS: From December 2020 to December 2021, 139 women were assessed: pregnant with IBD-36, pregnant without IBD-61, and not pregnant with IBD-42. Antibodies were assessed in cords of two and nine newborns of women with and without IBD, respectively. Mean gestational ages at administration of the second vaccine doses were 22.0 weeks in IBD and 23.2 weeks in non-IBD, respectively. Mean (SD) duration from the second vaccine dose to serology analysis in pregnant women with IBD, without IBD, and in non-pregnant women with IBD was 10.6 (4.9), 16.4 (6.3), and 4.3 (1.0) weeks, respectively. All women mounted a serologic response. In multivariable analysis, no correlation was found between the specific group and antibody levels. In both pregnancy groups, an inverse correlation between antibody levels and the interval from the second vaccine dose was demonstrated. Cord blood antibody levels exceeded maternal levels in women with and without IBD. CONCLUSION: All patients with IBD mounted a serologic response. The interval between vaccine administration to serology assessment was the most important factor determining antibody levels. A third vaccine dose should be considered in pregnant women with IBD vaccinated at early stages of pregnancy.

Pentraxin 3 and Shigella LPS and IpaB Antibodies Interplay to Defeat Shigellosis.

Shigella causes moderate to severe diarrhea or dysentery after invading the colon mucosa. Long Pentraxin 3 (PTX3) is recognized as the humoral component of the innate immune response to bacterial pathogens. We examined the interplay between levels of PTX3 and levels of anti-Shigella lipopolysaccharide (LPS) and anti-Shigella type 3 secretion system protein-IpaB antibodies in children during acute shigellosis and after recovery. PTX3 concentrations in serum and stool extracts were determined by sandwich ELISA using commercial anti-PTX3 antibodies. Serum IgG, IgM, and IgA anti-S. sonnei LPS or anti-S. sonnei IpaB were measured using in house ELISA. Children with acute shigellosis (n = 60) had elevated PTX3 levels in serum and stools as compared with recovered subjects (9.6 ng/mL versus 4.7 ng/mL, p < 0.009 in serum and 16.3 ng/g versus 1.1 ng/g in stool, p = 0.011). Very low levels of PTX3 were detected in stools of healthy children (0.3 ng/g). Increased serum levels of PTX3 correlated with high fever accompanied by bloody or numerous diarrheal stools characteristic of more severe shigellosis while short pentraxin; C-Reactive Protein (CRP) did not show such a correlation. PTX3 decreased in convalescence while anti-Shigella antibodies increased, switching the response from innate to adaptive toward the eradication of the invasive organism. These data can inform the development of Shigella vaccines and treatment options.

Anti-TNFα Treatment Impairs Long-Term Immune Responses to COVID-19 mRNA Vaccine in Patients with Inflammatory Bowel Diseases.

Patients with inflammatory bowel disease (IBD) treated with anti-tumor-necrosis factor-alpha (TNFα) exhibited lower serologic responses one-month following the second dose of the COVID-19 BNT162b2 vaccine compared to those not treated with anti-TNFα (non-anti-TNFα) or to healthy controls (HCs). We comprehensively analyzed long-term humoral responses, including anti-spike (S) antibodies, serum inhibition, neutralization, cross-reactivity and circulating B cell six months post BNT162b2, in patients with IBD stratified by therapy compared to HCs. Subjects enrolled in a prospective, controlled, multi-center Israeli study received two BNT162b2 doses. Anti-S levels, functional activity, specific B cells, antigen cross-reactivity, anti-nucleocapsid levels, adverse events and IBD disease score were detected longitudinally. In total, 240 subjects, 151 with IBD (94 not treated with anti-TNFα and 57 treated with anti-TNFα) and 89 HCs participated. Six months after vaccination, patients with IBD treated with anti-TNFα had significantly impaired BNT162b2 responses, specifically, more seronegativity, decreased specific circulating B cells and cross-reactivity compared to patients untreated with anti-TNFα. Importantly, all seronegative subjects were patients with IBD; of those, >90% were treated with anti-TNFα. Finally, IBD activity was unaffected by BNT162b2. Altogether these data support the earlier booster dose administration in these patients.

Lower Serologic Response to COVID-19 mRNA Vaccine in Patients With Inflammatory Bowel Diseases Treated With Anti-TNFα.

BACKGROUND & AIM: Patients with inflammatory bowel diseases (IBD), specifically those treated with anti-tumor necrosis factor (TNF)α biologics, are at high risk for vaccine-preventable infections. Their ability to mount adequate vaccine responses is unclear. The aim of the study was to assess serologic responses to messenger RNA-Coronavirus Disease 2019 vaccine, and safety profile, in patients with IBD stratified according to therapy, compared with healthy controls (HCs). METHODS: Prospective, controlled, multicenter Israeli study. Subjects enrolled received 2 BNT162b2 (Pfizer/BioNTech) doses. Anti-spike antibody levels and functional activity, anti-TNFα levels and adverse events (AEs) were detected longitudinally. RESULTS: Overall, 258 subjects: 185 IBD (67 treated with anti-TNFα, 118 non-anti-TNFα), and 73 HCs. After the first vaccine dose, all HCs were seropositive, whereas ∼7% of patients with IBD, regardless of treatment, remained seronegative. After the second dose, all subjects were seropositive, however anti-spike levels were significantly lower in anti-TNFα treated compared with non-anti-TNFα treated patients, and HCs (both P < .001). Neutralizing and inhibitory functions were both lower in anti-TNFα treated compared with non-anti-TNFα treated patients, and HCs (P < .03; P < .0001, respectively). Anti-TNFα drug levels and vaccine responses did not affect anti-spike levels. Infection rate (∼2%) and AEs were comparable in all groups. IBD activity was unaffected by BNT162b2. CONCLUSIONS: In this prospective study in patients with IBD stratified according to treatment, all patients mounted serologic response to 2 doses of BNT162b2; however, its magnitude was significantly lower in patients treated with anti-TNFα, regardless of administration timing and drug levels. Vaccine was safe. As vaccine serologic response longevity in this group may be limited, vaccine booster dose should be considered.

Convulsions in children hospitalized for acute gastroenteritis.

The study aim was to examine possible correlates of convulsions in children hospitalized for acute gastroenteritis (AGE). Data collected in a prospective study of AGE hospitalizations in children aged 0-59 months in 3 hospitals in Israel during 2008-2015 were analyzed. Stool samples were tested for rotavirus using immunochromatography and stool culture was performed for the detection of Salmonella, Shigella and Campylobacter We compared clinical and demographic characteristics of children hospitalized for AGE who had convulsions (n = 68, cases) with children hospitalized for AGE without convulsions (n = 3505, controls). Age differed between children with and without convulsions (p = 0.005); the former were mostly toddlers aged 12-23 months (51%) compared to 30% of the control group. A higher percentage of cases tested positive for Shigella (11% vs. 4%, p = 0.002), the opposite was found for rotavirus (2% vs. 30% p < 0.001). A multivariable model showed that body temperature (OR 2.91 [95% CI 1.78-4.76], p < 0.001) and high blood glucose level (> 120 mg/dL) (OR 5.71 [95% CI 1.27-25.58] p = 0.023) were positively related to convulsions in children with AGE, while severe AGE (Vesikari score ≥ 11) was inversely related with convulsions (OR 0.09 [95% CI 0.03-0.24], p < 0.001). Conclusion: Elevated body temperature is associated with convulsions in children with AGE, but not severity of AGE, while hyperglycemia might reflect a neuroendocrine stress reaction to convulsions, AGE or both.

Sero-Prevalence and Sero-Incidence of Antibodies to SARS-CoV-2 in Health Care Workers in Israel, Prior to Mass COVID-19 Vaccination.

Objectives: This study aims to examine the prevalence and risk factors of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sero-positivity in health care workers (HCWs), a main risk group, and assess the sero-incidence of SARS-CoV-2 infection between the first and second waves of coronavirus disease 2019 (COVID-19) in Israel. Methods: A longitudinal study was conducted among 874 HCWs from nine hospitals. Demographics, health information, and blood samples were obtained at baseline (first wave-April-May 2020) and at follow-up (n = 373) (second wave-September-November 2020). Sero-positivity was determined based on the detection of total antibodies to the nucleocapsid antigen of SARS-CoV-2, using electro-chemiluminescence immunoassay (Elecsys® Anti-SARS-CoV-2, Roche Diagnostics, Rotkreuz, Switzerland). Results: The sero-prevalence of SARS-CoV-2 antibodies was 1.1% [95% confidence intervals (CI) 0.6-2.1] at baseline and 8.3% (95% CI 5.9-11.6) at follow-up. The sero-conversion of SARS-CoV-2 serum antibody was 6.9% (95% CI 4.7-9.9) during the study period. The increase in SARS-CoV-2 sero-prevalence paralleled the rise in PCR-confirmed SARS-CoV-2 infections among the HCWs across the country. The likelihood of SARS-CoV-2 sero-prevalence was higher in males vs. females [odds ratio (OR) 2.52 (95% CI 1.05-6.06)] and in nurses vs. physicians [OR 4.26 (95% CI 1.08-16.77)] and was associated with being quarantined due to exposure to COVID-19 patients [OR 3.54 (95% CI 1.58-7.89)] and having a positive PCR result [OR 109.5 (95% CI 23.88-502.12)]. Conclusions: A significant increase in the risk of SARS-CoV-2 infection was found among HCWs between the first and second waves of COVID-19 in Israel. Nonetheless, the sero-prevalence of SARS-CoV-2 antibodies remains low, similar to the general population. Our findings reinforce the rigorous infection control policy, including quarantine, and utilization of personal protective equipment that should be continued together with COVID-19 immunization in HCWs and the general population.

A nationwide analysis of population group differences in the COVID-19 epidemic in Israel, February 2020-February 2021.

BACKGROUND: Social inequalities affect the COVID-19 burden and vaccine uptake. The aim of this study was to explore inequalities in the incidence and mortality rate of SARS-CoV-2 infection and vaccine uptake in various sociodemographic and population group strata in Israel. METHODS: We analysed nationwide publicly available, aggregated data on PCR-confirmed SARS-CoV-2 infections and COVID-19 deaths between March 2020 and February 2021, as well as the first three months of COVID-19 immunisation according to sociodemographics, including population group and residential socioeconomic status (SES). We computed incidence and mortality rates of COVID-19. Comparisons between towns with predominantly Arab, ultra-Orthodox Jewish (the minorities), general Jewish populations, and according to SES, were conducted using generalised linear models with negative binomial distribution. FINDINGS: Overall, 774,030 individuals had SARS-CoV-2 infection (cumulative incidence 84•5 per 1,000 persons) and 5687 COVID-19 patients had died (mortality rate 62•8 per 100,000 persons). The highest mortality rate was found amongst the elderly. Most (>75%) individuals aged 60 years or above have been vaccinated with BNT162b2 vaccine. The risk of SARS-CoV-2 infection was higher in towns with predominantly Arab and ultra-Orthodox Jewish populations than in the general Jewish population, and in low SES communities. COVID-19 mortality rate was highest amongst Arabs. Conversely, vaccine uptake was lower amongst Arab and ultra-Orthodox Jewish populations and low SES communities. INTERPRETATION: Ethnic and religious minorities and low SES communities experience substantial COVID-19 burden, and have lower vaccine uptake, even in a society with universal accessibility to healthcare. Quantifying these inequalities is fundamental towards reducing these gaps, which imposes a designated apportion of resources to adequately control the pandemic. FUNDING: No external funding was available for this study.

Differences in glycated hemoglobin levels and cholesterol levels in individuals with diabetes according to Helicobacter pylori infection.

This study examined differences in glycated hemoglobin (HbA1c), fasting plasma glucose and cholesterol levels between H. pylori infected and uninfected persons with diabetes. Anonymized data of Maccabi Healthcare Services in Israel were analyzed, of 12,207 individuals (50.0% H. pylori positive) aged 25-95 years who underwent the urea breath test. The data included HbA1c, fasting plasma glucose and cholesterol levels. The inverse probability of treatment weighting approach was used to account for confounders. Differences between individuals who were H. pylori positive and negative, in HbA1c (> or ≤ 7.0%) and in cholesterol levels were assessed using weighted generalized estimating equations. For men, but not women, the likelihood of having HbA1c > 7.0% was increased in those infected than uninfected with H. pylori: prevalence ratio 1.11 (95% CI 1.00, 1.24), P = 0.04. For both sexes, total cholesterol (P = 0.004) and low-density lipoprotein (LDL) levels (P = 0.006) were higher among those infected than uninfected with H. pylori. No significant differences were found in glucose and HDL levels according to H. pylori infection. The results were consistent in unweighted multivariable analyses. In conclusion, H. pylori infection might be related to worse glycemic control in men, and higher total cholesterol and LDL cholesterol levels in both sexes.

Safety and immunogenicity of a synthetic carbohydrate conjugate vaccine against Shigella flexneri 2a in healthy adult volunteers: a phase 1, dose-escalating, single-blind, randomised, placebo-controlled study.

BACKGROUND: Shigella remains in the top four pathogens responsible for moderate to severe diarrhoea in children below 5 years of age. The shigella O-specific polysaccharide (O-SP) is a promising vaccine target. We developed a conjugate vaccine prototype incorporating a unique well defined synthetic oligosaccharide hapten, chemically designed for optimal antigenic, conformational, structural, and functional mimicry of the O-SP from Shigella flexneri 2a (SF2a). We aimed to assess the safety, tolerability, and immunogenicity of this original synthetic oligosaccharide-based vaccine candidate, SF2a-TT15, conceived to drive the antibody response towards the key protective determinants of the native lipopolysaccharide antigen, in a first-in-human phase 1 study. METHODS: We did a first-in-human, dose-escalating, single-blind, observer-masked, randomised, placebo-controlled study at the Clinical Research Center of Tel Aviv Sourasky Medical Center (Israel). Participants were healthy adults aged 18-45 years with low titres of serum SF2a-specific IgG antibodies. 64 eligible participants were assigned to one of two cohorts. 32 participants in each of the two cohorts were randomly assigned via computer-generated algorithm in a stepwise manner to receive the 2 µg (cohort 1) and 10 µg oligosaccharide dose (cohort 2) of the SF2a-TT15 vaccine candidate non-adjuvanted or adjuvanted with aluminium hydroxide (alum) or matching placebos. The vaccine was administered as three single intramuscular injections into the arm, 28 days apart. The primary outcome was the incidence and severity of adverse events, which were assessed in the intention-to-treat safety population analysis including all participants who were randomly assigned and received at least one vaccine or placebo injection. The immunogenicity endpoints were secondary outcomes and were analysed in all participants who were randomly assigned, received all of the assigned injections before the time of the immunogenicity assessment, and provided blood samples for immunological follow-up (per-protocol immunogenicity analysis). The study is registered with ClinicalStudies.gov, NCT02797236 and is completed. FINDINGS: Of 203 volunteers initially screened, 64 participants were enrolled between Sept 20, 2016, and Sept 26, 2017. In each of the two cohorts, 12 participants received the adjuvanted vaccine, 12 received the non-adjuvanted vaccine and eight received the matching placebo (four each). The SF2a-TT15 glycoconjugate was well tolerated at both doses. No serious or severe adverse events occurred. Overall, seven (88%) of eight to 12 (100%) of 12 in each group of volunteers had one adverse event or more after receiving the study agents with the majority of adverse events, 300 (98%) of 307, considered mild in intensity. Of the seven adverse events defined as moderate in severity, one (nausea) was suspected to be related to the vaccine candidate. At all post-immunisation days and for both oligosaccharide doses, whether adjuvanted or not, SF2a-TT15 induced significantly higher serum IgG anti-SF2a lipopolysaccharide geometric mean titres (GMTs) as compared with baseline or with the corresponding GMTs in placebo recipients (p<0·01). After one injection, the non-adjuvanted 10 µg oligosaccharide dose induced a 27-times increase in IgG GMT (5080 vs 189) and the non-adjuvanted 2 µg oligosaccharide dose induced a five-times increase (1411 vs 283), compared with baseline. Alum enhanced the specific IgG response at 2 µg oligosaccharide dose after the third injection (GMTs 3200 vs 1176, p=0.045). INTERPRETATION: SF2a-TT15 was safe and well tolerated and induced high titres of anti-SF2a LPS IgG antibodies. These results support further evaluation of this original synthetic oligosaccharide-protein conjugate vaccine candidate for safety, immunogenicity, and protective efficacy in target populations. FUNDING: The European Union Seventh Framework Programme.

Enhanced Humoral Immune Responses against Toxin A and B of Clostridium difficile is Associated with a Milder Disease Manifestation.

The role of the humoral immune response to Clostridium difficile in modulating the severity of C. difficile infection (CDI) is unclear. We compared the levels of serum immunoglobulin G (IgG) and immunoglobulin A (IgA) against toxin A (TcdA) and toxin B (TcdB) of C. difficile between CDI and control patients and according to disease severity. The levels of IgG and IgA antibodies against TcdA and TcdB were measured in sera from patients with CDI (n = 50; 19 had severe CDI) and control patients (n = 52), using ELISA. Patients with CDI had higher levels of IgG antibodies against TcdA and TcdB than controls (p = 0.001 and p = 0.04, respectively). Higher IgG levels against TcdA and TcdB were found in patients with mild vs. severe CDI 7-14 days after the diagnosis (p = 0.004 and 0.036, respectively). A factor analysis included both IgA and IgG levels against both toxins into one composite variable, which was of higher values in patients with mild vs. severe CDI (p = 0.026). In conclusion, the systemic humoral immune responses against TcdA and TcdB might modulate the severity of CDI. These preliminary findings provide a basis for future large-scale studies and support the development and evaluation of active and passive immunotherapies for CDI management.

Correlates of gastroenterology health-services utilization among patients with gastroesophageal reflux disease: a large database analysis.

BACKGROUND: Gastroesophageal reflux disease (GERD) is associated with high utilization of health care services. Diagnostic tests usually are not required to establish GERD diagnosis, but endoscopy is recommended for patients with alarm symptoms such as dysphagia and unintentional weight loss, and those whose symptoms are not relieved by proton pump inhibitors (PPIs) therapy. Evidence on the correlates of utilization of gastroenterology health services among GERD patients is limited. The study aim was to examine associations of patient and physician's characteristics with high utilization of gastroenterology services. METHODS: In a cross-sectional study using the database of the second largest integrated care organization in Israel, data of all adult GERD patients (N = 75,219) in 2012-2015 were analyzed. High utilization of services was assessed using two dependent variables analyzed separately: undergoing two or more gastroscopies or having six or more visits to a gastroenterology consultant during the study-period. RESULTS: Overall, 11,261 (15.0%) patients had two or more gastroscopies and 23,703 (31.5%) had six or more visits to a gastroenterology consultant. The likelihood of high utilization of gastroscopy increased with age; in immigrants from the Former Soviet Union versus patients who were born in Israel; residents of Jerusalem, the south, the north and Haifa districts versus the center district; in patients with high PPI purchases, and in patients who belonged to clinics in which the physician-manger had no board certification. The correlates were similar for visits to a gastroenterology consultant. CONCLUSIONS: Patient and physician's characteristics were related to high utilization of gastroenterology services among GERD patients. The associations with age and country of birth might reflect more severe disease. The regional differences warrant further research and interventions at the district level. Training in gastroenterology of primary care physicians without a board certification is warranted.

Serum IgG antibodies to Shigella lipopolysaccharide antigens - a correlate of protection against shigellosis.

Shigella is a leading cause of diarrhea among children globally and of diarrheal deaths among children under 5 years of age in low- and middle-income countries. To date, no licensed Shigella vaccine exists. We review evidence that serum IgG antibodies to Shigella LPS represent a good correlate of protection against shigellosis; this could support the process of development and evaluation of Shigella vaccine candidates. Case-control and cohort studies conducted among Israeli soldiers serving under field conditions showed significant serotype-specific inverse associations between pre-exposure serum IgG antibodies to Shigella LPS and shigellosis incidence. The same serum IgG fraction showed a dose-response relationship with the protective efficacy attained by vaccine candidates tested in phase III trials of young adults and children aged 1-4 years and in Controlled Human Infection Model studies and exhibited mechanistic protective capabilities. Identifying a threshold level of these antibodies associated with protection can promote the development of an efficacious vaccine for infants and young children.

No evidence of an increase in the incidence of norovirus gastroenteritis hospitalizations in young children after the introduction of universal rotavirus immunization in Israel.

Following the introduction of universal immunization against rotavirus, concerns were raised regarding pathogen-replacement of rotavirus by norovirus. The study aim was to examine the incidence and characteristics and norovirus gastroenteritis before and after the introduction of universal rotavirus immunization in Israel. We studied 1179 stool samples collected between November 2007 and December 2014 for a prospective hospital-based surveillance study of children aged 0-59 months hospitalized for gastroenteritis. A real-time RT-PCR assay was used to identify genogroup II (GII) norovirus in extracted fecal RNA samples. Overall, the weighted percentage of norovirus positive patients was 10.9%. Norovirus positivity was similar in the pre-universal rotavirus immunisation years (2008-2010) and the universal years (2011-2014), the respective average annual incidence of norovirus gastroenteritis was 1.6 (95% CI 0.6-2.3) per 1000 and 1.1 (95% CI 0.8-1.4) per 1000 children. Rotavirus was detected in 36.8% and 19.6% of the patients in the pre-vaccine years and the universal vaccine years, with an estimated incidence of 5.5 (95% CI 3.4-7.6) per 1000 and 2.1 (95% CI 1.6-2.7) per 1000 children, respectively. Most patients (59.1%) with norovirus gastroenteritis were infants aged 0-11 months. Norovirus was detected all year round with a significant 3-month peak from September through November. In conclusion, norovirus continues to be a leading cause of acute gastroenteritis associated with hospitalizations in young children. Future norovirus vaccines should target young infants. There was no evidence of pathogen-replacement by norovirus following the introduction of universal rotavirus immunization in Israel.

Burden and risk factors of Shigella sonnei shigellosis among children aged 0-59 months in hyperendemic communities in Israel.

OBJECTIVES: Ultraorthodox Jewish populations living in towns with good sanitary infrastructure but with conditions of crowding have been the epicenter of Shigella sonnei shigellosis outbreaks. In this study, the incidence and risk factors of S. sonnei shigellosis in children living in an ultraorthodox community were determined. METHODS: Data for the years 2000-2013 for all reported culture-proven S. sonnei shigellosis cases in children aged 0-59 months in the city of Elad were compared with data for the rest of the sub-district. Environmental factors obtained through parental interviews were evaluated for 78 incident cases of S. sonnei shigellosis and 141 community controls, matched by age, sex, and neighborhood. Conditional logistic regression models were performed. RESULTS: Cyclic epidemics of S. sonnei shigellosis occurred every 2 years. The mean annual incidence was 10.0 per 1000 children in Elad (95% confidence interval 7.9-12.6) vs. 3.8 per 1000 children (95% confidence interval 3.3-4.4) in the sub-district (p<0.001). Concurrent diarrheal disease in family members, having the same person in the daycare center responsible for food handling and changing diapers, and more rooms and sinks in the center, were positively associated with S. sonnei shigellosis, while children's hand-washing before meals was inversely associated. CONCLUSIONS: The burden of S. sonnei shigellosis in ultraorthodox communities is high. Enhanced hygiene interventions are required for epidemic control.

The effect of age at immigration on cervical cancer incidence: a population-based cohort study of 1 486 438 Israeli women.

OBJECTIVE: To clarify the effect of mass migration from a high-risk area (former Soviet Union) to a low-risk area (Israel) on cervical cancer incidence and mortality in Israel and the modifying effect of age at immigration. METHODS: All women who immigrated to Israel from the former Soviet Union between January 1, 1990 and December 31, 2000 (N=345 202) and all Jewish Israeli-born women who were 0-80 years old on January 1, 1990 (N=1 141 236) were included. Follow-up ended at December 31, 2010 or date of death or date of cervical cancer diagnosis, whatever occurred earlier. Crossing data from the computerized population registry of the Ministry of Interior, the Israel National Cancer Registry and the Central Bureau of Statistics, cervical cancer incidence and mortality and adjusted hazard ratios (aHR) with 95% confidence intervals (95% CI) were calculated. RESULTS: 1595 new cases (crude incidence rate 29.71: 100 000 person years) of cervical cancer were diagnosed in immigrants as compared with 6159 cases (crude incidence rate 27.21: 100 000 person years) diagnosed in Israel-born Jewish women. Immigration at an age older than 12 years was hazardous (aHR 1.27, 95% CI 1.19 to 1.35; P<0.001) while immigration at a younger age was protective (aHR 0.62, 95% CI 0.51 to 0.75; P<0.001) for cervical cancer incidence compared with native Israeli women. Cervical cancer mortality was also significantly higher in immigrants compared with Israel-born women with incidence density rates of 1.15 and 0.35 per 100 person years, respectively (P<0.0001). CONCLUSIONS: Factors related to the acquired causes of the disease at the country of origin are probably at the root of the low incidence of cervical cancer in Israel. Adult immigrants from the former Soviet Union should be managed as a high-risk group.