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Biomedical subjects

J G Wells

Publications and source records attributed to J G Wells.

At least 91 records · Page 5Linked to original sources
PubMed1984

Sporadic cases of hemorrhagic colitis associated with Escherichia coli O157:H7.

After two outbreaks of hemorrhagic colitis associated with a previously unrecognized pathogen, Escherichia coli O157:H7, a surveillance system was established to identify and study sporadic cases of this distinct clinical illness in the United States. Between August 1982 and April 1984, we identified 28 persons from 11 states who met our case definition and whose stool specimens yielded E. coli O157:H7. Patients ranged in age from 1 to 80 years. Seventeen patients required hospitalization. All patients recovered, although one developed hemolytic-uremic syndrome 7 days after the onset of bloody diarrhea. Detection of E. coli O157:H7 in stools from persons with hemorrhagic colitis was highly associated with collection of stool specimens within the first 6 days after onset of illness. All E. coli O157:H7 isolates produced a Vero cytotoxin. Hemorrhagic colitis caused by E. coli O157:H7 is widely distributed in the United States as a sporadic illness; clinicians should be aware of its distinctive clinical presentation, and should collect specimens promptly when the diagnosis is suspected.

Adolescent↗
PubMed1984

Campylobacter enteritis on Hopi and Navajo Indian reservations. Clinical and epidemiologic features.

From June 22 through September 30, 1981, stool specimens from 522 Hopi and Navajo outpatients were cultured because of diarrheal illnesses at the Keams Canyon Indian Health Service Hospital, Arizona. Campylobacter jejuni was isolated from the specimens of 26 (5%) of the patients. This pathogen was found as frequently as Shigella in patients younger than 2 years or older than 20 years, but was significantly less common in the 2 to 20-year age group (P<.000001). Campylobacter enteritis was indistinguishable clinically from shigellosis in adult patients, but in children younger than 5 years, a rectal temperature higher than 38 degrees C (100.5 degrees F) was significantly more common with Shigella than with Campylobacter infection (P=.003). In a field study of 20 families, we found that households with a case of Campylobacter enteritis were more likely than age- and community-matched controls to own farm animals (P=.05), but were not more likely to own household pets. C jejuni is less common than Shigella as a cause of summer seasonal diarrhea and dysentery among the Hopi and Navajos; the striking differences in the age-specific rates of these two infections suggest different routes of transmission.

Adolescent↗
PubMed1983

Hemorrhagic colitis associated with a rare Escherichia coli serotype.

We investigated two outbreaks of an unusual gastrointestinal illness that affected at least 47 people in Oregon and Michigan in February through March and May through June 1982. The illness was characterized by severe crampy abdominal pain, initially watery diarrhea followed by grossly bloody diarrhea, and little or no fever. It was associated with eating at restaurants belonging to the same fast-food restaurant chain in Oregon (P less than 0.005) and Michigan (P = 0.0005) and with eating any of three sandwiches containing three ingredients in common (beef patty, rehydrated onions, and pickles). Stool cultures did not yield previously recognized pathogens. However, a rare Escherichia coli serotype, O157:H7, that was not invasive or toxigenic by standard tests was isolated from 9 of 12 stools collected within four days of onset of illness in both outbreaks combined, and from a beef patty from a suspected lot of meat in Michigan. The only known previous isolation of this serotype was from a sporadic case of hemorrhagic colitis in 1975. This report describes a clinically distinctive gastrointestinal illness associated with E. coli O157:H7, apparently transmitted by undercooked meat.

Adolescent↗
PubMed1983

Human Campylobacter infection associated with certified raw milk.

Between May 27 and June 18, 1981, 50 individuals in 30 households in suburban Atlanta, Georgia, had a gastrointestinal illness caused by Campylobacter jejuni. Epidemiologic evidence strongly associated consumption of unpasteurized milk with illness. A culture survey confirmed fecal carriage of C. jejuni by cows in the implicated dairy and in a control dairy, but failed to document presence of the organism in the milk. The standard plate counts and leukocyte counts (two indicators of microbiologic quality of milk), facilities, and operating procedures at the implicated dairy were all within accepted levels for production of Grade A raw milk in Georgia. Inasmuch as the parameters used by regulatory officials to determine the wholesomeness of milk were not violated at the implicated dairy, the only means available to ensure the public's health would be proper pasteurization before consumption.

Adult↗
PubMed1983

Laboratory investigation of hemorrhagic colitis outbreaks associated with a rare Escherichia coli serotype.

Two outbreaks of hemorrhagic colitis, a newly recognized syndrome characterized by bloody diarrhea, severe abdominal pain, and little or no fever, occurred in 1982. No previously recognized pathogens were recovered from stool specimens from persons in either outbreak. However, a rare E. coli serotype, O157:H7, was isolated from 9 of 20 cases and from no controls. It was also recovered from a meat patty from the implicated lot eaten by persons in one outbreak. No recovery of this organism was made from stools collected 7 or more days after onset of illness; whereas 9 of 12 culture-positive stools had been collected within 4 days of onset of illness. The isolate was not invasive or toxigenic by standard tests, and all strains has a unique biotype. Plasmid profile analysis indicates that all outbreak-associated E. coli O157:H7 isolates are closely related. These results suggest that E. coli O157:H7 was the causative agent of illness in the two outbreaks.

Anti-Bacterial Agents↗
PubMed1983

Traveler's diarrhea at sea: two multi-pathogen outbreaks caused by food eaten on shore visits.

In 1976 and 1981, two outbreaks of gastrointestinal illness aboard cruise ships occurred within 24 hours following onshore visits to Haiti and Mexico, respectively. Three hundred eighty-six of 600 (64 per cent) and 98 of 260 (38 per cent) passengers became ill following luncheons in Port-au-Prince, Haiti, and Cozumel, Mexico. No increase in illness was observed among those passengers who did not attend the onshore luncheons. In both outbreaks, unrefrigerated seafood dishes served at outdoor buffets were epidemiologically incriminated as the vehicles of transmission. Several species of Vibrion, Salmonella, and toxigenic Escherichia coli were recovered from stool specimens of ill passengers in both outbreaks. In addition, invasive Escherichia coli and Shigella were isolated from stool specimens of ill passengers who ate at the Haitian buffet. Previous investigations of outbreaks of gastrointestinal illness aboard cruise ships have implicated exposures on board as the source and have involved only a single pathogen.

Diarrhea↗
PubMed1983

Persistence of cholera in the United States.

In 1973, 1978, and 1981, cases of cholera were acquired along the Gulf Coast of the United States. The isolates from all of the cases were toxigenic Vibrio cholerae O-group 1, biotype El Tor, serotype Inaba, hemolytic, and of the same phage sensitivity pattern, and all had the same restriction endonuclease pattern by molecular genetic analysis. The strain from one of the two 1981 cases differed from the others in having a small plasmid and a negative Voges-Proskauer reaction. Multiple importations, chronic carriers, and continuous occurrence of undetected cases are unlikely explanations for these findings, which suggest that toxigenic V. cholerae 01 can multiply and persist for years in some environments, making eradication of cholera a formidable task.

Adult↗
PubMed1983

Campylobacter enteritis in the United States. A multicenter study.

During a 15-month study, 8097 fecal specimens submitted to clinical microbiology laboratories at eight hospitals in different parts of the United States were examined. Campylobacter jejuni was isolated from 4.6%, Salmonella from 2.3%, and Shigella from 1.0%. Isolation rates for each pathogen were highest from stool specimens that were watery, bloody, or contained leukocytes. The peak isolation rate for C. jejuni was in persons ages 10 to 29 years; for Salmonella, in children younger than age 10 years; and for Shigella, in children ages 5 to 9 years. The clinical features of the three infections were nearly identical. In contrast, abdominal pain, bloody diarrhea, fever, tenesmus, and abnormal sigmoidoscopy findings were present significantly more often in patients infected with C. jejuni than in a control group of patients with diarrhea. Of patients with leukocytes in their stools and a history of fever, 45.9% were infected with one of the three pathogens. Use of laboratory and clinical findings defined groups with high or low risk of these three infections but could not accurately predict isolation. Fecal cultures had the highest yields when obtained from patients within 7 days from the onset of symptoms.

Adolescent↗
PubMed1983

Campylobacter enteritis from untreated water in the Rocky Mountains.

During the summers of 1980 and 1981 Campylobacter jejuni was isolated from 23% and Giardia lamblia was isolated from 8% of persons with diarrheal disease acquired in the area of Grand Teton National Park, Wyoming. Campylobacter enteritis occurred most frequently in young adults who had been hiking in wilderness areas and was significantly associated with drinking untreated surface water in the week before illness (p less than 0.02 in 1980; p less than 0.005 in 1981). Penner serotype 4 was the commonest serotype isolated from humans and the only serotype isolated from an implicated mountain stream. These studies show that backcountry surface water can be an important source of C. jejuni and that infection with Campylobacter, as well as G. lamblia, should be considered as a cause of diarrhea in those who have recently returned from wilderness areas.

Adult↗
PubMed1982

Trimethoprim activity in media selective for Campylobacter jejuni.

The activity of trimethoprim (TMP) in two selective media used for isolation of Campylobacter jejuni was evaluated. The two selective media, Campy-BAP and Skirrow medium, contain TMP in addition to other antimicrobial agents. The minimal inhibitory concentrations of TMP in blood agar base (basal agar for Skirrow medium) or brucella agar (basal agar for Campy-BAP) for three sensitive control organisms were compared with those in Mueller-Hinton agar, which contains low levels of thymidine. TMP was inactive in both blood agar base and brucella agar, even when lysed horse blood or thymidine phosphorylase was added. TMP had activity when used in combination with the other antimicrobial agents normally included in Skirrow medium and Campy-BAP, probably indicating synergism between TMP and one or more of the other antimicrobial agents. Sheep blood could be substituted for lysed horse blood in Skirrow medium without compromising the activity of TMP.

Campylobacter↗
PubMed1982

Patterns of Shigella infection in families in rural Bangladesh.

To assess the mode of transmission of Shigella infection in rural Bangladesh, questionnaire and culture surveys were conducted in baris (neighborhoods) where persons with diarrhea associated with Shigella infection and index controls with non-Shigella diarrhea lived. Nineteen percent of persons in Shigella baris and 7% of persons in control baris were infected during the survey periods (P less than 0.001). The prevalence of Shigella infection was highest for children 1-9 years of age and for females than 39 years and was not related to socioeconomic status, family size or household crowding. Use of surface water for drinking was not a risk factor for Shigella infection; in fact, use of river water was more frequent in control baris. Both household and bari contacts of Shigella index cases frequently excreted different serotypes from that excreted by the person with the index case. In Shigella baris, families with infection were significantly more likely than uninfected families to have a history of an overnight stay away from home by a family member during the previous week. These observations suggest there were multiple introductions of Shigella into some families and that the epidemiology of Shigella infection for families in rural Bangladesh differs from that observed for families living in more industrialized countries.

Adolescent↗
PubMed1981

Handwashing to prevent diarrhea in day-care centers.

Diarrhea has been recognized as a frequent health problem among children enrolled in day-care centers. Thus, we evaluated the effect of a handwashing program in two day-care centers (HWC) on the incidence of diarrhea among children when compared to children in two control centers (CC). After the program was begun, the incidence of diarrhea at the HWC began to fall and after the second month of the study was consistently lower than that at the CC. The incidence of diarrhea in the HWC was approximately half that of the CC for the entire 35-week study period. Adenoviruses, rotavirus, Giardia lamblia, and enteropathogenic Escherichia coli were found in the stools of a small number of ill children, but not pathogen was identified in the stools of most children with diarrhea. These results suggest that a handwashing program will probably prevent at least some of the diarrhea in day-care centers.

Adenoviruses, Human↗
PubMed1981

An outbreak of salmonellosis involving multiple vehicles.

A biphasic outbreaks of salmonellosis affected customers and employees of a restaurant in Maine, in October and November, 1979. Salmonella typhimurium was isolated from 27 customers and nine employees. Ten other individuals were ill but did not have specimens taken for culture, and there were four secondary cases including one affecting a laboratory technician. Fourteen individuals (28%) were hospitalized for up to 45 days, and a total of 416 days of work were lost as a result of the outbreak. Two different food items served at the restaurant at separate times were identified as vehicles. In the first part of the outbreak, 37 persons who consumed either egg-based foods (p = 0.003) or salad (p = 0.006) became ill. In the second phase of the outbreak, in late October and November, nine cases were associated with consumption of inadequately refrigerated salad (p = 0.008), but not with egg-based foods. An infected symptomatic food handler prepared the incriminated salad for some members of this latter group. Use of antacids was also associated with illness (p = 0.03). The occurrence of illness over a seven-week period, the implication of several vehicles, and the demonstration of secondary cases suggest that "sporadic" cases of salmonellosis in the community may be linked.

Adolescent↗
PubMed1981

Isolation of Legionella spp. from environmental water samples by low-pH treatment and use of a selective medium.

A selective medium was developed and used successfully to isolate Legionella pneumophila and Legionella-like organisms from environmental specimens previously positive by animal inoculation methods. This medium consists of charcoal-yeast extract agar to which have been added cephalothin (4 micrograms/ml), colistin (16 micrograms/ml), vancomycin (0.5 microgram/ml), and cycloheximide (80 micrograms/ml). Pretreating of the environmental water samples with an acid buffer (pH 2.2), followed by plating on the selective medium, improved the rate of recovery of both Legionella and Legionella-like organisms relative to that with direct plating on selective media.

Cephalothin↗
PubMed1981

Evaluation of transport methods for isolating Shigella spp.

Recovery of Shigella spp. from fecal specimens transported in buffered glycerol saline and Cary-Blair media held at frozen, refrigerated, or room temperature was compared with recovery by direct plating of fecal specimens. Buffered glycerol saline was the better transport medium for the recovery of Shigella spp. Refrigerated or frozen transport temperatures were superior to room temperature for recovery from either medium.

Animals↗