Trials have provided conflicting estimates of the risk of gastrointestinal illness attributable to tap water. To estimate this risk in an Iowa community with a well-run water utility with microbiologically challenged source water, the authors of this 2000–2002 study randomly assigned blinded volunteers to use externally identical devices (active device: 227 households with 646 persons; sham device: 229 households with 650 persons) for 6 months (cycle A). Each group then switched to the opposite device for 6 months (cycle B). The active device contained a 1-µm absolute ceramic filter and used ultraviolet light. Episodes of "highly credible gastrointestinal illness," a published measure of diarrhea, nausea, vomiting, and abdominal cramps, were recorded. Water usage was recorded with personal diaries and an electronic totalizer. The numbers of episodes in cycle A among the active and sham device groups were 707 and 672, respectively; in cycle B, the numbers of episodes were 516 and 476, respectively. In a log-linear generalized estimating equations model using intention-to-treat analysis, the relative rate of highly credible gastrointestinal illness (sham vs. active) for the entire trial was 0.98 (95% confidence interval: 0.86, 1.10). No reduction in gastrointestinal illness was detected after in-home use of a device designed to be highly effective in removing microorganisms from water.
Given the increased risk of Guillain-Barré Syndrome (GBS) found with the 1976 swine influenza vaccine, both active surveillance and end-of-season analyses on chart-confirmed cases were performed across multiple US vaccine safety monitoring systems, including the Medicare system, to evaluate the association of GBS after 2009 monovalent H1N1 influenza vaccination. Medically reviewed cases consisted of H1N1-vaccinated Medicare beneficiaries who were hospitalized for GBS. These cases were then classified by using Brighton Collaboration diagnostic criteria. Thirty-one persons had Brighton level 1, 2, or 3 GBS or Fisher Syndrome, with symptom onset 1-119 days after vaccination. Self-controlled risk interval analyses estimated GBS risk within the 6-week period immediately following H1N1 vaccination compared with a later control period, with additional adjustment for seasonality. Our results showed an elevated risk of GBS with 2009 monovalent H1N1 vaccination (incidence rate ratio = 2.41, 95% confidence interval: 1.14, 5.11; attributable risk = 2.84 per million doses administered, 95% confidence interval: 0.21, 5.48). This observed risk was slightly higher than that seen with previous seasonal influenza vaccines; however, additional results that used a stricter case definition (Brighton level 1 or 2) were not statistically significant, and our ability to account for preceding respiratory/gastrointestinal illness was limited. Furthermore, the observed risk was substantially lower than that seen with the 1976 swine influenza vaccine.
Abstract Purpose Immediate‐release forms of generic mixed amphetamine salts (MAS) have been the subject of passive surveillance reports signaling lack of effectiveness. We examined switching patterns that might suggest whether long‐term users of specific MAS are more likely to switch away or switch back after use of the MAS of interest in the FDA's Sentinel Distributed Database. Methods We required at least 60‐day continuous supply of selected MAS grouped by Abbreviated New Drug Application (ANDA) to describe patterns of switching away from and to generics approved under the ANDAs of interest among individuals ages 15–64 years with attention deficit hyperactivity disorder or narcolepsy during 2013–2019. Results We observed the greatest number of treatment episodes for ANDA 040422 ( n = 525 771), followed by ANDA 202424 ( n = 181 693), ANDA 040439 ( n = 62 363), ANDA 040440 ( n = 21 143), and ANDA 040480 ( n = 8792). Of those with switches away from their original ANDA, episodes initiated on generic products under ANDA 040422 (48.6%) and ANDA 202424 (43.0%) were most likely to switch back, while those initiated on generic product under ANDA 040480 were least likely (24.1%). Of those episodes with switches to a generic under an ANDA of interest, about one‐third (range 27.1% to 37.0%) switched back to the same product. These switches back had a median time to switch of about 30 days. Conclusions These descriptive analyses, although subject to limitations, did not suggest increased switching away or switching back after use of the generics of interest. Continued post‐marketing surveillance is warranted.
ISEE-548 Abstract: The correlation between indicator organisms and health in recreational water in a cohort of beachgoers at Mission Bay, California during the summer of 2003. Background: There is uncertainty about how best to study associations between recreational water contamination and human health. Choices must be made about how to obtain water samples for exposure assessment, how to analyze data from non-swimmers in such studies, and which indicator organisms best correlate with health. Decisions about closing potentially contaminated beaches carry enormous implications (potential illness burdens, health care costs, impacts on local businesses, liability issues). Methods: We conducted a cohort study of the relationship between several health outcomes and traditional as well as novel candidate indicators (including rapid detection and viral methods) at Mission Bay (San Diego), CA. At this site there is no point source of fecal contamination. We enrolled beachgoers, interviewed them about health conditions on the day of exposure and 14 days later, and collected water quality samples frequently at their swimming sites. The principal health outcome (highly credible gastrointestinal illness, HCGI) has been used in prior studies of recreational water and health. Logistic models were used to analyze the data. Results: A total of 12,458 participants were enrolled, and 8,790 (71%) completed the entire study. 45% were male and 55% female (among enrollees and those completing). There were 5,398 swimmers and 3,740 non-swimmers. Swimmers were 61.4% Latino and 23.8% White; Non-swimmers were 43.2% Latino and 34.9% White. The mean time at the beach was 270 minutes for swimmers and 240 minutes for non-swimmers. At enrollment, 1.7% of swimmers and 3.5% of non-swimmers reported a current gastrointestinal complaint. We found an increased risk of HCGI illness: 1) among swimmers compared to non-swimmers (OR 1.32, p<26>0.03); and 2) among those with longer exposure to the water (OR 1.14 per additional 100 min exposure, p=0.03). We also found significant associations (p<0.05) among swimmers (compared to non-swimmers) with respect to diarrhea, nasal congestion, rash, fever, and eye irritation. No significant associations (p>0.05) were seen with respect to nausea, vomiting, cough, sore throat, or ear discharge. The relationship between increasing exposure to enterococcus and HCGI was also measured (OR 1.31, 95% CI 0.97-1.76 per 100 cfu/ml increase). (When non-swimmers were excluded from this model the estimated OR=1.27 (95% CI 0.94-1.73)). Conclusions: Measurable associations between increased exposure to recreational water and several health outcomes were detected when water quality samples drawn in close proximity to swimmer locations. Results from our use of viral and rapidly measured bacterial indicators will be presented at the symposium.
