Nancy Hargrett-Bean

Symptoms and risk factors of Helicobacter pylori infection in a cohort of epidemiologists

To identify symptoms and risk factors associated with Helicobacter pylori infection, a cohort of 341 epidemiologists was studied. All subjects had one banked serum (collected between 1969 and 1987) and one recent serum sample (collected in 1988) evaluated for H. pylori immunoglobulin G by enzyme-linked immunosorbent assay; subjects provided information on gastrointestinal symptoms and risk factors for gastritis and peptic ulcer disease. Prevalence of infection decreased from the early 1970s to the present. Eleven subjects (3% of the total cohort) seroconverted during the interval between serum samples, giving a crude conversion rate of 0.49% per person-year (95% confidence interval, 0.3-0.9). Nonreactors on the 1988 serum sample described similar symptoms to reactors. However, subjects who seroconverted in the interval between the two serum samples were more likely than either persistent nonreactors [relative risk (RR), 4.1] or persistent reactors (RR, 3.7) to have experienced upper gastrointestinal symptoms in the interval years. Consumption of caffeinated beverages (RR, 4.6) and residence in the northeastern United States (RR, 5.3) seemed to increase risk for infection. Because pain was similarly common in H. pylori-positive and -negative patients, H. pylori cannot be summarily accepted as the cause of dyspeptic symptoms even when infection is confirmed.

Chronic Diarrhea Associated with Drinking Untreated Water

PURPOSE To determine the cause of an outbreak of chronic diarrhea and to define the clinical profile of the illness. DESIGN A case series of patients with chronic diarrhea and case-control and cohort studies to determine the vehicle and cause of the illness. SETTING Rural Henderson County, Illinois. PATIENTS Seventy-two patients who had onset of chronic diarrheal illness between May and August 1987. Controls were local residents and eating companions who did not have diarrheal illness. A cohort study included 80 truck drivers from a local firm. METHODS AND MEASUREMENTS Nonbloody diarrhea was characterized by extreme frequency (median, 12 stools/d), marked urgency, fecal incontinence, and weight loss (mean, 4.5 kg). The median incubation period was 10 days. Nine patients were hospitalized; none died. Diarrhea persisted in 87% of patients after 6 months. Antimicrobial therapy produced no clinical improvement. No bacterial, mycobacterial, viral, or parasitic agents known to be enteropathogenic were detected in stools or implicated water. Three of five small-bowel biopsies showed mild inflammatory changes. Mild inflammation was also seen in two of nine colonic biopsies. Case-control studies implicated a local restaurant (P = 0.0001, odds ratio = 19) and subsequently the untreated well water served in the restaurant (P = 0.04, odds ratio = 9.3) as the vehicle of transmission. CONCLUSIONS This is the first outbreak of chronic diarrhea linked to drinking untreated water. The causative agent and pathophysiologic mechanism of the illness remain elusive.