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Since serogroup B meningococcal (MenB) vaccines became available in the United States, six serogroup B meningococcal disease cases have been reported in MenB-4C (n = 4) or MenB-FHbp (n = 2) recipients. Cases were identified and characterized through surveillance and health record review. All five available isolates were characterized using whole genome sequencing; four isolates (from MenB-4C recipients) were further characterized using flow cytometry, MenB-4C-induced serum bactericidal activity (SBA), and genetic Meningococcal Antigen Typing System (gMATS). Three patients were at increased meningococcal disease risk because of an outbreak or underlying medical conditions, and only four of the six patients had completed a full 2-dose MenB series. Isolates were available from 5 patients, and all contained sub-family A FHbp. The four isolates from MenB-4C recipients expressed NhbA but were mismatched for the other MenB-4C vaccine antigens. These four isolates were relatively resistant to MenB-4C-induced SBA, but predicted by gMATS to be covered. Overall, patient risk factors, incomplete vaccine series completion, waning immunity, and strain resistance to SBA likely contributed to disease in these six patients., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: DG reports financial support was provided by NIAID, NIH. DG reports relationships with Sanofi Pasteur, OneBiopharma LLC, and OMVax Inc that include consulting or advisory. DG has patents for GNA1870-based vesicle vaccines for broad spectrum protection against diseases caused by Neisseria meningitidis. U.S. patent number 10,046,043, Issued August 14, 2018. licensed to OMVax, and for Factor H binding proteins (FHBP) with altered properties and methods of use, U.S. patent number 9,439,95, issued September 13, 2016. licensed to Sanofi and OMVax. All other authors have no known competing interests to declare., (Published by Elsevier Ltd.)

Objective: A recent study from Italy reported a high prevalence of ulcer disease in asymptomatic Helicobacter pylori infection. Such results are at variance with previous endoscopy screening studies. Our study was performed to obtain data on ulcer prevalence in normal H. pylori-infected subjects in the United States., Methods: One hundred and ninety healthy individuals of either gender, over the age of 18, were studied. After completion of a detailed questionnaire and a urea breath test for H. pylori status, endoscopy was performed. Ulcer was defined as a mucosal ulceration > 5 mm in diameter and with apparent depth., Results: There were 108 (57%) women and 82 (43%) men. The mean (+/-SD) age was 38.9 (+/-10.7) yr, range 21-79 yr. Careful history obtained after enrollment revealed presence of dyspeptic symptoms in 35 subjects (18%); the remaining 155 individuals were completely symptom-free. Infection with H. pylori was present in 102 subjects (54%). The infection rate was highest in Hispanics (70%), followed by African-Americans (58%), Caucasians (38%), and Asians (17%). The prevalence increased with age. Only two (1%) of 190 subjects, both with H.pylori infection, had peptic ulcer. In the H. pylori-infected group, the prevalence of peptic ulcer was 2%., Conclusion: In the United States, significant unrecognized and asymptomatic gastroduodenal disease is uncommon in H. pylori-infected individuals. These findings do not support the need for a mass screening program for H. pylori infection or for the use of antimicrobial treatment of asymptomatic subjects with this infection.

Helicobacter pylori infection is twice as frequent in blacks as in whites. It has been postulated that the apparent increase in susceptibility to H. pylori infection in blacks might have a genetic basis. A case-control seroepidemiologic study of H. pylori prevalence was performed in 108 healthy Hispanic volunteers. Eighty-nine Hispanics were matched (1:1:1) with blacks and whites for age and socioeconomic status. There was an inverse correlation between H. pylori infection and educational level that remained after logistic regression analysis adjusting for age and sex. The adjusted prevalence of H. pylori infection was almost identical in Hispanics and blacks and significantly higher than in whites. Because Hispanics do not constitute a race, the increased prevalence of H. pylori in Hispanics and blacks is unlikely to be genetic. It is speculated that the unrecognized bias is a reflection of a generation cohort phenomenon related to the generational distance from very low socioeconomic status, i.e., the prevalence of H. pylori in Hispanics and blacks is currently lower than that of their parents but higher than that of the white population, which has experienced higher socioeconomic status for several generations.

A causative role is now accepted for Helicobacter (formerly Campylobacter) pylori in type B gastritis, and evidence is accumulating that H. pylori infection plays a major contributory role in duodenal ulcer, gastric ulcer, and epidemic gastric cancer. The prevalence of H. pylori in any population remains unknown. We compared the prevalence of H. pylori infection in the Riyadh region of Saudia Arabia, using a specific and sensitive ELISA for IgG antibody against the high molecular weight cell-associated antigen of H. pylori (urease). Subjects were interviewed, demographic data were collected, and a serum sample was obtained. Subjects completed a questionnaire that included questions about level of education, smoking, medications used, presence and frequency of symptoms referable to the upper gastrointestinal tract, and family history of ulcer disease. We studied 557 individuals (ranging in age from 5 to 91 yr). The prevalence of H. pylori infection increased rapidly with age: from 40% of those ages 5-10 yr, to more than 70% of those 20 or older. H. pylori infection occurred with significantly more frequency in adults with less than 12 yr of schooling, compared with adults who had attended college. The high rate of acquisition of H. pylori infection in Saudia Arabia emphasizes that studies of H. pylori-disease associations must consider the baseline prevalence of H. pylori infection in that population.

The efficacy of a daily dosage regimen of subsalicylate bismuth in preventing or reducing the severity of diarrhea among young healthy adults was evaluated in a double-blind, randomized, placebo-controlled trial. Diarrhea developed in 14 (23%) of 62 students receiving subsalicylate bismuth compared with 40 (61%) of 66 students taking a placebo. The protective effect of subsalicylate bismuth was apparent within a day or two of the study onset and became more obvious as the number of days at risk increased. The students treated with subsalicylate bismuth experienced fewer intestinal complaints and were less likely to pass soft or watery stools of any number. Once diarrhea occurred, enteropathogens were less commonly identified in stools of students receiving subsalicylate bismuth (33%) compared with placebo (71%). Subsalicylate bismuth was well tolerated by students during the 21-day trial.

A proper perspective of the association of Campylobacter pylori with various diseases can be achieved only when the incidence of C. pylori infection in the normal population is known. We used the 13C urea breath test (a simple, specific, noninvasive, safe, and reproducible method to assess the presence of active C. pylori infection) to compare the frequency of C. pylori infection in healthy young adults from three areas of the world. We studied 26 women and 32 men (ages 20 to 29): 29 from the United States, 10 from China, 6 from Mexico, and 13 from India. All foreign nationals had been in the United States 5 years or less. The frequency of C. pylori infection was 21%, 67%, 33% and 46%, for those from the U.S., China, Mexico and India, respectively. Although, we found no difference in the frequency of C. pylori infection among ethnic groups from North America (U.S. citizens compared with citizens of Mexico), all individuals studied were of middle to upper class socioeconomic status. Subsequent studies will investigate whether the prevalence of C. pylori infection is different in economically disadvantaged populations. Our results suggest that there may be major differences in the age-related frequency of C. pylori infection in individuals from different parts of the world.

One hundred forty-seven students from the United States were given trimethoprim-sulfamethoxazole (TMP-SMZ; 160 mg of TMP and 800 mg of SMZ) twice daily for 21 days after their arrival in Mexico. They were watched for the development of diarrhea during the 21 days and for an additional eight days after the termination of TMP-SMZ therapy. Diarrheal illness occurred in 11 (16%) of 67 students taking TMP-SMZ and in 44 (55%) of 80 students receiving a placebo; the differences were significant (P less than 0.001). Milder symptoms not quite satisfying the criteria for illness were also less common in the group receiving the active drug: 23% vs. 69% (P less than 0.001). The drug appeared to prevent infection by fully virulent enterotoxigenic Escherichia coli (strains producing heat-stable toxin and those producing heat-labile toxin) and perhaps by shigella strains. During the eight days of follow-up after drug administration, 14 students (26%) who had taken TMP-SMZ and two (2.5%) who had taken the placebo experienced diarrhea (P less than 0.05). Twelve subjects (14%) in the TMP-SMZ group and one subject (1%) in the placebo group developed a generalized rash that necessitated discontinuance of the drug. The eruption occurred after 9-16 days of drug administration (mean, 10 days). This study shows that TMP-SMZ taken twice daily can prevent travelers' diarrhea for up to three weeks. Diarrhea will develop, however, if the drug is stopped while the risk remains.

In a group of 133 United States students studied for 18 days after arriving in Mexico, diarrhea developed in 38 (29 per cent). Diarrhea rarely began before the fourth day, and the mean onset was 13 days after arrival. Symptoms lasted an average of 3.4 days but persisted in 21 per cent of sick students. Heat-labile enterotoxin-producing Escheria coli was found in the stools of 72 per cent of sick and 15 per cent of healthy students. None had heat-labile Esch. coli when they entered Mexico. The incubation period was short, generally 24 to 48 hours, and the carrier state was five days or less in 82 per cent of students surveyed. Entamoeba histolytica was found in 6 per cent of cases of diarrhea, but not salmonella, shigella or penetrating Esch. coli. These studies suggest that approximately 70 per cent of travelers' diarrhea in Mexico is associated with heat-labile toxigenic strains of Esch. coli.

Acute- and convalescent-phase sera from 132 students attending a university in rural Mexico were assayed for antibody against the heat-labile enterotoxin (LT) of Escherichia coli by neutralization of LT activity in the Y-1 adrenal cell assay and by passive immune hemolysis of LT-sensitized sheep erythrocytes. The two titration methods produced comparable results with respect to antitoxin responses detected. An inverse relationship was found between acute geometric mean antitoxin titer and the occurrence of diarrhea associated with LT-producing E. coli, especially in newly arrived students from the U.S.A. A significant correlation (P less than 0.00 5) was found between a rise in antitoxin titer detectable by the passive immune hemolysis technique and diarrhea with LT-producing E. coli isolated. Thus, humoral antitoxin titers appear to be a useful indicator of immune status with respect to enterotoxigenic (LT) E. coli diarrhea.