Lack of homologous protection against Campylobacter jejuni CG8421 in a human challenge model.

BACKGROUND: Campylobacter jejuni is a common cause of diarrhea and is associated with serious postinfectious sequelae. Although symptomatic and asymptomatic infections are recognized, protective immunity is not well understood. Previous data suggests that interferon γ (IFN-γ) may be associated with protection. To better define the clinical and immunologic development of protective immunity to C. jejuni, we assessed the ability of an initial infection to prevent clinical illness after a second experimental infection. METHODS: Subjects with no clinical or immunologic evidence of prior infection with C. jejuni received an initial challenge with C. jejuni CG8421 with rechallenge 3 months later. The primary endpoint was campylobacteriosis, as defined by diarrhea and/or systemic signs. Close inpatient monitoring was performed. Serum immunoglobulin A (IgA) and immunoglobulin G (IgG), fecal IgA, IgA antibody-secreting cells (ASCs), and IFN-γ production were evaluated. All subjects were treated with antibiotics and were clinically well at discharge. RESULTS: Fifteen subjects underwent a primary infection with C. jejuni CG8421; 14 (93.3%) experienced campylobacteriosis. Eight subjects received the second challenge, and all experienced campylobacteriosis with similar severity. Immune responses after primary infection included serum IgA, IgG, ASC, and IFN-γ production. Responses were less robust after secondary infection. CONCLUSIONS: In naive healthy adults, a single infection with CG8421 did not protect against campylobacteriosis. Although protection has been demonstrated with other strains and after continuous environmental exposure, our work highlights the importance of prior immunity, repeated exposures, and strain differences in protective immunity to C. jejuni. CLINICAL TRIALS REGISTRATION: NCT01048112.

In a randomized, double-blinded, placebo-controlled trial, the single oral dose typhoid vaccine, M01ZH09, is safe and immunogenic at doses up to 1.7 x 10(10) colony-forming units.

M01ZH09, S. Typhi (Ty2 Delta aroC Delta ssaV) ZH9, is a single oral dose typhoid vaccine with independently attenuating deletions. A phase II randomized, double-blind, placebo-controlled, dose-escalating trial evaluated the safety and immunogenicity of M01ZH09 to 1.7 x 10(10) colony-forming units (CFU). 187 Healthy adults received vaccine or placebo in four cohorts. Serologic responses and IgA ELISPOT were measured. At all doses, the vaccine was well tolerated and without bacteremias. One subject had a transient low-grade fever. 62.2-86.1% of subjects seroconverted S. Typhi-specific LPS IgG and 83.3-97.4% IgA; 92.1% had a positive S. Typhi LPS ELISPOT. M01ZH09 is safe and immunogenic up to 1.7 x 10(10)CFU. Efficacy testing of this single-dose oral typhoid vaccine is needed.

Evaluation of risk assessment questions used to target blood lead screening in Illinois.

OBJECTIVE: Beginning in 1995, Illinois law permitted targeted-as opposed to universal-blood lead screening in low-risk areas, which were defined by ZIP code characteristics. State guidelines recommended specific lead risk assessment questions to use when targeting screening. This study was designed to evaluate the sensitivity and specificity of Illinois lead risk assessment questions. DESIGN: Parents bringing their 9- or 10- or 12-month and 24-month-old children for health supervision visits at 13 pediatric practices and parents of children (aged 6 through 25 months and who needed a blood lead test) receiving care at 5 local health departments completed a lead risk assessment questionnaire concerning their child. Children had venous or capillary blood lead testing. Venous confirmation results of children with a capillary level >/=10 micrograms/dL were used in analyses. CHILDREN: There were 460 children with both blood and questionnaire data recruited at the pediatric practices (58% of eligible) and 285 children (51% of eligible) recruited at local health departments. Of the 745 children studied, 738 provided a ZIP code that allowed their residence to be categorized as in a low-risk (n = 456) or high-risk (n = 282) area. RESULTS: Sixteen children (3.5%) living in low-risk areas versus 34 children (12.1%) living in high-risk areas had a venous blood lead level (BLL) >/=10 micrograms/dL; 1.8% and 5.3%, respectively, had a venous BLL >/=15 micrograms/dL. For children living in low-risk areas, Illinois mandated risk assessment questions (concerning ever resided in home built before 1960, exposure to renovation, and exposure to adult with a job or hobby involving lead) had a combined sensitivity of.75 for levels >/=10 micrograms/dL and.88 for levels >/=15 micrograms/dL; specificity was.39 and.39, respectively. The sensitivity of these questions was similar among children from high-risk areas; specificity decreased to.27 and.28, for BLLs >/=10 micrograms/dL and >/=15 micrograms/dL, respectively. The combination of items requiring respondents to list house age (built before 1950 considered high risk) and indicate exposure to renovation had a sensitivity among children from low-risk areas of.62 for BLLs >/=10 micrograms/dL with specificity of.57; sensitivity and specificity among high-risk area children were.82 and.36, respectively. For this strategy, similar sensitivities and specificities for low and high-risk areas were found for BLLs >/=15 micrograms/dL. CONCLUSIONS: The Illinois lead risk assessment questions identified most children with an elevated BLL. Using these questions, the majority of Illinois children in low-risk areas will continue to need a blood lead test. This first example of a statewide screening strategy using ZIP code risk designation and risk assessment questions will need further refinement to limit numbers of children tested. In the interim, this strategy is a logical next step after universal screening.

Tuberculosis screening and prevention for foreign-born students: eight years experience at Ohio University.

In the mid-1980s, international students enrolled at Ohio University were identified as a high-risk group for tuberculosis (TB), contributing an estimated 30%-50% of all active TB cases in the sparsely populated county where the university is located. While the student health center routinely screened all newly enrolled international students with PPD Mantoux tests, no provision for Isoniazid (INH) chemoprophylaxis was available until the Preventive Medicine/Public Health Section of Ohio University College of Osteopathic Medicine initiated a program in September 1985. In 1993, cases of active TB among international students had declined significantly from a pre-1986 rate of 97.5/100,000 student-years to 19.4/100,000 after 1986 (P < .01), while case rates among other groups in the county increased. Positive PPD reaction rates have remained high (53.6%), but less than 15% of international students who should have taken INH chemoprophylaxis by Centers for Disease Control (CDC) criteria did so. This finding suggests that other factors may have contributed to the observed decline in active cases. We examined the influence of five variables (age, gender, geographic origin, BCG vaccination status, and year of enrollment) on PPD status. In this international student population, geographic origin and BCG vaccination status were the most important contributors to positive PPD testing. We suggest that PPD status alone may no longer be sufficient to distinguish those at higher risk of developing active TB in similar populations. A changing mix in international students' geographic origin and BCG vaccination status may help explain the decrease in active case rates in the face of continued high positive PPD rates.

Work-related injuries in Athens County 1982 to 1986. A comparison of emergency department and workers' compensation data.

In 1987, the Panel on Occupational Safety and Health Statistics issued a report concluding that the existing national surveillance system for occupation injuries might result in substantial underreporting of occupational injuries. In this study, we examined two sources of data on occupational injuries, the National Electronic Injury Surveillance System (NEISS) and lost-work time claims to the Bureau of Workers' Compensation (BWC), available in one community, Athens County, Ohio. Based on comparison of the NEISS and BWC data sets, we conclude that neither data set alone gives a complete nor an accurate picture of occupational injuries in Athens County. The two may provide a more complete representation of occupational injuries when examined together. Using the NEISS and BWC data sets in combination results in a total number of injuries higher than that predicted by national norms.

Patient problems encountered at a student health service.

Descriptions of the health problems of our student populations can be valuable in many ways, including facility planning, staff and student education, quality assurance programs, and research. Planning for national programs requires a description of student health practices nationwide. I encourage ACHA or other organizations to support the collection and analysis of data required to do this.