Richard M. Vezina

Diarrhea in American infants and young children in the community setting: incidence, clinical presentation and microbiology.

Objective: The characteristics and microbiology of the full spectrum of pediatric diarrhea occurring in the U.S. community setting are not well-understood. Methods: Six-month prospective cohort study of 604 healthy 6- to 36-month-old children recruited by the Slone Center Office-based Research Network. Results: The incidence of parent-defined diarrhea was 2.2 episodes per person-year. The median duration of diarrhea was 2 days with a median of 6 stools per episode. Outpatient visits and hospitalization were prompted by 9.7 and 0.3% of episodes, respectively. The most common microorganisms identified in healthy baseline stools were atypical enteropathogenic Escherichia coli (12.2%), enteroaggregative Escherichia coli (3.7%), Clostridium difficile (3.5%) and Clostridium perfringens (2.9%), and each of these was no more common in diarrhea stools. In contrast, all of the viruses analyzed were more prevalent in diarrhea specimens than in baseline specimens: enteric adenovirus (5.7% diarrhea versus 1.4% baseline), rotavirus (5.2% versus 1.4%), astrovirus (3.5% versus 1.4%), Sapporo-like virus (3.0% versus 0.8%) and norovirus (1.9% versus 0.8%). A likely pathogen was detected in 20.6% of diarrhea specimens. Vomiting and ≥16 stools in an episode were predictive of isolating a pathogen from the stool, each with a relative risk of ∼2. Conclusions: Healthy young children in this study experienced more than 2 cases of diarrhea per person-year, but most were brief and do not require medical attention. Although most diarrhea-associated pathogens were viruses, no likely pathogen was found in almost 80% of cases; possible etiologies for these cases include currently unknown gastrointestinal infections, nongastrointestinal illnesses and dietary/environmental factors.

Frequency of bed sharing and its relationship to breastfeeding

ABSTRACT. Bed sharing has been promoted as facilitating breastfeeding but also may increase risks for sudden, unexpected infant deaths. This prospective cohort study was performed to determine the prevalence of adult and infant bed sharing and its association with maternal and infant characteristics. Demographic data were collected from 10,355 infant-mother pairs at birth hospitals in Eastern Massachusetts and Northwest Ohio, and follow-up data were collected at 1, 3, and 6 months by questionnaire. Associations with bed sharing were estimated using odds ratios and 95% confidence intervals from multiple logistic regression models while adjusting for confounding variables. At 1, 3, and 6 months, 22%, 14%, and 13% of infant-mother pairs shared a bed, respectively. On multivariate analysis, race/ethnicity and breastfeeding seemed to have the strongest association with bed sharing. These factors need to be considered in any comprehensive risk to benefit analysis of bed sharing.

Cancer Risk and Tetrachloroethylene-contaminated Drinking Water in Massachusetts

Abstract A population-based case-control study was used to evaluate the relationship between cases of bladder cancer (n = 61), kidney cancer (n = 35), and leukemia (n = 34) and exposure to tetrachloroethylene from public drinking water. Subjects were exposed to tetrachloroethylene when it leached from the plastic lining of drinking water distribution pipes. Relative delivered dose of tetrachloroethylene was estimated, using an algorithm that accounted for (1) residential history and duration, (2) whether lined pipe served the neighborhood, (3) distribution system flow characteristics, and (4) pipe age and dimensions. Whether or not latency was considered, an elevated relative risk of leukemia was observed among ever exposed subjects (adjusted OR = 1.96, 95% CI = 0.71–5.37, with latency; adjusted OR = 2.13, 95% CI = 0.88–5.19, without latency) that increased further among subjects whose exposure level was over the 90th percentile (adjusted OR = 5.84, 95% CI = 1.37–24.91, with latency; adjusted OR = 8.33, 9...

Cancer risk and residential proximity to cranberry cultivation in Massachusetts.

OBJECTIVES This study evaluated the relationship between cancer risk and residential proximity to cranberry cultivation. METHODS A population-based case-control study was conducted. Cases, diagnosed during 1983 through 1986 among residents of the Upper Cape Cod area of Massachusetts, involved incident cancers of the lung (n = 252), breast (n = 265), colon-rectum (n = 326), bladder (n = 63), kidney (n = 35), pancreas (n = 37), and brain (n = 37), along with leukemia (n = 35). Control subjects were randomly selected from among telephone subscribers (n = 184), Medicare beneficiaries (n = 464), and deceased individuals (n = 723). RESULTS No meaningful increases in risk were seen for any of the cancer sites except for the brain. When latency was considered, subjects who had ever lived within 2600 ft (780 m) of a cranberry bog had a twofold increased risk of brain cancer overall (95% confidence interval [CI] = 0.8, 4.9) and a 6.7-fold increased risk of astrocytoma (95% CI = 1.6, 27.8). CONCLUSIONS Residential proximity to cranberry bog cultivation was not associated with seven of the eight cancers investigated; however, an association was observed with brain cancer, particularly astrocytoma. Larger, more detailed studies are necessary to elucidate this relationship.

Validity of Parental Reporting of Recent Episodes of Acute Otitis Media: A Slone Center Office-based Research (SCOR) Network Study

Background: The validity of parental reporting of children’s health outcomes is an important methodological issue in community-based pediatric research. We assessed the validity of parents’ reports of their children’s acute otitis media (AOM) history over the previous month in a pilot study of xylitol for AOM prevention. Methods: Parents of children participating in a study conducted in the Slone Center Office-Based Research (SCOR) Network were interviewed monthly for 3 months and asked whether their child had been diagnosed with AOM in the previous month. A blinded physician reviewed medical records. Results from parental interviews and medical records were compared by correlation analysis. Results: Medical records were obtained for 102 of 120 children (85.0%); 272 monthly interviews were completed. κ for the agreement between parental reports and medical records was 0.88 [95% confidence intervals (CI): 0.76 to 0.94]. The positive predictive value of a parental report of an AOM episode within the previous month was 85.0%, and the negative predictive value was 99.1%. Conclusions: The results of this study suggest that parental reporting of children’s recent AOM history correlates well with medical records. Parental interview is a reasonable approach to collecting data on recent AOM outcomes, particularly in large-scale community-based studies where obtaining medical records is often impractical.

Vasectomy and prostate cancer.

PURPOSE Vasectomy has been associated with an increased risk of prostate cancer in some previous studies but not in others. We evaluated the association in a population based, case control study in Massachusetts. MATERIALS AND METHODS Included in our study were 1,216 patients younger than 70 years with newly diagnosed prostate cancer and 1,400 controls with no history of prostate cancer who were matched to patients by age and town of residence. Data on vasectomy and potential confounding factors were obtained by telephone interview, and confounding was controlled by conditional logistic regression analysis. RESULTS Overall 16% of patients and 15% of controls had undergone vasectomy. Compared with no vasectomy the odds ratio for ever having undergone vasectomy was 1.0 (95% confidence interval [CI] 0.8 to 1.3), which did not vary significantly by age at or interval since vasectomy. In men who reported urological symptoms and those without symptoms the odds ratio was 0.9 (95% CI 0.7 to 1.2) and 1.4 (1.0 to 1.9), respectively. In men younger than 55 years and those 55 years old or older at diagnosis of prostate cancer the odds ratio was 1.9 (95% CI 1.2 to 3.2) and 1.0 (0.8 to 1.3), respectively [corrected]. In the younger men with stages A or B and C or D disease the odds ratio was 2.3 (95% CI 1.2 to 4.3) and 1.3 (0.5 to 3.5), respectively. CONCLUSIONS Our findings do not support the hypothesis that vasectomy increases the risk of prostate cancer in men older than 55 years. Further study is needed to determine whether the observed association between vasectomy and prostate cancer in men younger than 55 years is due to chance, detection bias or a causal effect.

Calcium channel blocker use and the risk of prostate cancer

A recent study suggested that the risk of all cancers, including prostate cancer, is increased by the use of calcium channel blockers. The objective of this study was to determine whether prostate cancer is associated with calcium channel blocker use. A case-control study was conducted in Massachusetts using cases diagnosed from December 1992 through February 1995. Cases were men identified by tumor registrars who were less than 70 years old with newly diagnosed prostate cancer. Controls were men with no history of prostate cancer or symptoms of undiagnosed prostate cancer, and were matched to the cases on precinct of residence and half-decade of age. A total of 1217 cases of prostate cancer and 1400 community controls are included in this analysis. Data were collected by telephone interview. Multiple logistic regression was used to estimate relative risks for calcium channel blockers use while controlling for confounding. The relative risk for prostate cancer for any use of calcium channel blockers relative to nonuse was 1.2 (95% confidence interval [CI], 0.9-1.5). There was no evidence of a trend according to duration of use. When the analysis was confined to symptomatic men, the relative risk estimate was 1.1 (0.8-1.4) overall and 1.2 (0.8-1.7) among those aged 65 to 69 years. Relative risk estimates for the use of other classes of antihypertensive drugs among symptomatic men were close to 1.0; the corresponding estimates among asymptomatic men were generally further from 1.0. These findings suggest that calcium channel blockers do not increase the risk of prostate cancer. The differences in the relative risk estimates between symptomatic and asymptomatic men are compatible with detection bias. Because of the widespread use of Prostate-Specific Antigen testing for early detection of prostate cancer, potential detection bias needs to be considered in future studies of prostate cancer.

Vasoactive Neurochemicals Identified in Omentum: A preliminary report

There has been increasing interest in biologic, immunologic, and chemical activity originating from omental tissue. Since clinical improvement has been observed in some patients very shortly after surgically transposing their omentum to the spinal cord or brain, the question arose as to whether neurochemicals might be present in omental tissue; a possible explanation for some of these neurological changes. This paper reports the presence of vasoactive neurochemicals in canine omental tissue. It remains unclear, however, whether the omentum produces or simply concentrates these and other neurochemicals.

Characteristics of persistent diarrhea in a community-based cohort of young US children.

Objective: The objective of the study was to define the characteristics and microbiology of persistent diarrhea (PD) in US children. Methods: Six-month prospective cohort study of a convenience sample of 604 healthy 6- to 36-month-old children recruited by the Slone Center Office-based Research Network. Results: Of 611 diarrhea episodes, 50 (8.2%) lasted ≤ 14 days. The incidence of PD was 0.18 episodes per person-year, and the median duration of episodes was 22.0 days (range, 14-64 days). PD episodes were more likely than acute episodes to result in a medical visit (28.0% vs 8.2%; P = 0.0001). The most commonly used treatments were oral rehydration solution (12.0% of episodes) and antibiotics (6.0%). No bacterial or parasitic pathogens were associated with PD; but norovirus, rotavirus and sapovirus were each significantly more prevalent in PD stools compared with baseline stools, with relative risks of 12.4, 6.9 and 6.2, respectively. Fifty-nine per cent of the PD specimens tested were negative for all studied pathogens. Conclusions: PD occurs with a frequency of approximately 1 case per 5 person-years in US infants and young children. It seems to be a generally benign illness, with only 28% of cases presenting to medical care. Although viral pathogens seem to cause a minority of PD episodes in this population, most are not due to currently known infectious agents.

Xylitol Syrup for the Prevention of Acute Otitis Media

BACKGROUND: Acute otitis media (AOM) is a common childhood illness and the leading indication for antibiotic prescriptions for US children. Xylitol, a naturally occurring sugar alcohol, can reduce AOM when given 5 times per day as a gum or syrup, but a more convenient dosing regimen is needed for widespread adoption. METHODS: We designed a pragmatic practice-based randomized controlled trial to determine if viscous xylitol solution at a dose of 5 g 3 times per day could reduce the occurrence of clinically diagnosed AOM among otitis-prone children 6 months through 5 years of age. RESULTS: A total of 326 subjects were enrolled, with 160 allocated to xylitol and 166 to placebo. In the primary analysis of time to first clinically diagnosed AOM episode, the hazard ratio for xylitol versus placebo recipients was 0.88 (95% confidence interval [CI] 0.61 to 1.3). In secondary analyses, the incidence of AOM was 0.53 episodes per 90 days in the xylitol group versus 0.59 in the placebo group (difference 0.06; 95% CI –0.25 to 0.13); total antibiotic use was 6.8 days per 90 days in the xylitol group versus 6.4 in the placebo group (difference 0.4; 95% CI –1.8 to 2.7). The lack of effectiveness was not explained by nonadherence to treatment, as the hazard ratio for those taking nearly all assigned xylitol compared with those taking none was 0.93 (95% CI 0.56 to 1.57). CONCLUSIONS: Viscous xylitol solution in a dose of 5 g 3 times per day was ineffective in reducing clinically diagnosed AOM among otitis-prone children.