Search PubMed⌕ Search

Biomedical subjects

R A Keenlyside

Publications and source records attributed to R A Keenlyside.

At least 19 recordsLinked to original sources
PubMed1989

Lead exposure among lead-acid battery workers in Jamaica.

To assess lead exposure in the Jamaican lead-acid battery industry, we surveyed three battery manufacturers (including 46 production workers) and 10 battery repair shops (including 23 battery repair workers). Engineering controls and respiratory protection were judged to be inadequate at battery manufacturers and battery repair shops. At manufacturers, 38 of 42 air samples for lead exceeded a work-shift time-weighted average concentration of 0.050 mg/m3 (range 0.030-5.3 mg/m3), and nine samples exceeded 0.50 mg/m3. Only one of seven air samples at repair shops exceeded 0.050 mg/m3 (range 0.003-0.066 mg/m3). Repair shop workers, however, had higher blood lead levels than manufacturing workers (65% vs. 28% with blood lead levels above 60 micrograms/dl, respectively). Manufacturing workers had a higher prevalence of safe hygienic practices and a recent interval of minimal production had occurred at one of the battery manufacturers. Workers with blood lead levels above 60 micrograms/dl tended to have higher prevalences of most symptoms of lead toxicity than did workers with lower blood lead levels, but this finding was not consistent or statistically significant. The relationship between zinc protoporphyrin concentrations and increasing blood lead concentrations was consistent with that described among workers in developed countries. The high risk of lead toxicity among Jamaican battery workers is consistent with studies of battery workers in other developing countries.

Adult↗
PubMed1989

Lead poisoning among household members exposed to lead-acid battery repair shops in Kingston, Jamaica.

To investigate the risk of lead poisoning among household members exposed to 'backyard' battery repair shops (BBRS) in Kingston, Jamaica, environmental and blood lead (PbB) were measured at 24 households (112 individuals) with a BBRS worker or located at a BBRS premises and at 18 neighbourhood control households (74 individuals). Elevated PbB (greater than or equal to 25 micrograms per decilitre [micrograms/dl]) was common among subjects of all ages living at BBRS premises, especially among children less than age 12, 43% of whom had PbB greater than 70 micrograms/dl. Potentially hazardous soil and house dust lead levels were also common at BBRS premises, where 84% of yards had soil lead levels above 500 parts per million (geometric mean 3388 parts per million [ppm] at BBRS premises households with a BBRS worker). Geometric mean blood and environmental lead levels were significantly lower at control households, where less than 10% of subjects in all age groups had elevated PbB (maximum 33 micrograms/dl). Sharing a premises with a BBRS was a stronger determinant of household blood lead and environmental contamination than was the presence of a BBRS worker in a household. Blood lead levels were associated with soil and house dust lead levels in all age groups. We conclude that small battery repair shops, which have also been described in other developing countries, create a high lead poisoning risk for nearby residents.

Adolescent↗
PubMed1988

A large outbreak of acupuncture-associated hepatitis B.

An epidemiologic investigation of an acupuncturist's practice in Rhode Island identified 35 patients who were infected with hepatitis B virus during 1984. Of 366 patients seen by the acupuncturist during 1984, 316 (86%) completed questionnaires and submitted serum for hepatitis B serology. Use of tests for immunoglobulin M antibody to hepatitis B core antigen (IgM anti-HBc) identified 17 case-patients who otherwise may have gone undetected. Thirty-four of the 35 case-patients were treated in only one of the two clinics run by the acupuncturist. Patients who received a greater number of acupuncture needles during their treatment course were more likely to have been infected; the attack rate for patients who received less than 150 needles was 9%, compared with 33% for patients who received greater than or equal to 450 needles (p less than 0.001). Attack rates were higher during a one-month period when the index case-patient was more likely to have been viremic than during any other period in 1984 (relative risk = 4.1, 95% confidence interval = 2.3-7.3). While observing the acupuncturist's technique, the investigators noted several potential mechanisms for needle contamination. This study highlights the potential for transmission of hepatitis B in situations of repeated needle use.

Acupuncture Therapy↗
PubMed1983

Nasal cancer in a worker exposed to formaldehyde.

Formaldehyde has not been established as a human carcinogen. Toxicological studies have, however, demonstrated that formaldehyde causes squamous cell carcinoma of the nasal cavity in rats. A case of squamous cell carcinoma of the nasal cavity occurred in a 57-year-old man who had 25 years of occupational exposure to low concentrations of formaldehyde in the textile-finishing industry.

Carcinoma, Squamous Cell↗
PubMed1983

Keratoconjunctivitis associated with adenovirus type 37: an extended outbreak in an ophthalmologist's office.

An outbreak of epidemic keratoconjunctivitis occurred in three clusters among patients of an ophthalmologist during 1977-1978. Cases in the third cluster and possibly one case in the first were caused by infection with adenovirus type 37. Among 83 infected patients, the mean interval between a visit to the ophthalmologist's office and the onset of symptoms was 11 days. Conjunctival specimens from 64 (77%) of the patients yielded adenovirus type 37, and adenovirus hexon antigen was identified by counterimmunoelectrophoresis in pooled specimens from the office environment. Infected patients were older and had more glaucoma, and were therefore tested more frequently by tonometry, than noninfected control patients. The association of this outbreak with adenovirus type 37 was made in 1981, the year in which this new serotype was fully described and reference reagents were produced. This is the first report of infection due to adenovirus type 37 in the United States.

Adenoviridae Infections↗
PubMed1983

Case-control study of Mastomys natalensis and humans in Lassa virus-infected households in Sierra Leone.

Lassa virus infection and antibodies were studied in households where Lassa fever cases occurred, and compared to those in nearest neighbor houses and "far" houses located across the village from case houses. Seventy-nine percent of all rodents caught in the houses were Mastomys, the natural reservoir of Lassa virus. Rodent infection was not randomly distributed, but rather focal. Thirty-nine percent of the Mastomys in case houses were viremic, compared to 3.7% in control houses. Human antibody prevalence in case houses was 30%, compared to 20% in non-case houses (P less than 0.05, chi-square test, df = 2). Neither seroconversions nor antibody prevalence rates were associated with household size or number of persons per room. Trapping of rodents in half of the case and control houses resulted in a Mastomys reduction ranging from 2.2- to 3.3-fold. This reduction failed to significantly reduce the seroconversion rate to Lassa virus in the people of trapped houses compared to those in untrapped ones. More complete trapping will be needed in order to better evaluate this procedure as a means of interruption of Lassa virus transmission in endemic villages.

Animals↗
PubMed1981

Nosocomial herpetic infections in a pediatric intensive care unit.

A series of acute herpetic infections occurred among nurses and patients in a pediatric intensive care unit (PICU). Epidemiologic study revealed two separate time clusters of infections, one in early summer and another six weeks later. Restriction endonuclease analysis of DNA extracted from virus isolates showed that each time cluster was associated with a different genetic strain of herpes simplex virus (HSV) type 1 and provided evidence of cross infection between patients and nurses. Three nurses had herpetic whitlow; the husband of one had acute gingivostomatitis; a fourth nurse had acute pharyngitis. They had no previous history of HSV infection and sequential antibody testing of affected nurses showed 19S antibody in all initially positive serums, confirming primary infection. The data provide clear evidence that PICU personnel risk acquiring serious herpetic infections from patients and vice versa unless specific precautions are taken. Restriction endonuclease analysis of HSV DNA was useful in the epidemiologic study of the infections.

Adult↗
PubMed1980

An outbreak of adenovirus type 3 disease at a private recreation center swimming pool.

In the period June 6--July 24, 1977, and outbreak of illness due to adenovirus type 3 (AV3) occurred in residents of a suburban community (Community A), Dekalb County, Georgia. Based on surveys, at least 105 cases occurred. The illness was primarily characterized by sore throat, fever, headache, and anorexia. Conjunctivitis affected only 34 of 105 (32%) of the individuals in two surveys. Frequent use of a private swimming pool was associated with illness in Community A residents. The outbreak coincided with a temporary defect in the pool filtration system which probably prevented maintenance of proper chlorine levels in the pool water, and suggested that the infection was spread by pool water. However, the predominant mode of transmission could not be shown conclusively to be waterborn rather than person-to-person.

Adenoviridae Infections↗
PubMed1980

Fatal Guillain-Barré syndrome after the national influenza immunization program.

Fifty-eight fatal cases of Guillain-Barré syndrome (GBS) were reported during the 1976 to 1977 National Influenza Program: Thirty-two (58%) of these patients had received the A/New Jersey influenza vaccine. The mean interval from vaccination to onset was 3.9 weeks, and the incidence of preceding illness in vaccinated or unvaccinated patients was similar. Fifty-eight percent had at least one chronic disease before onset. The clinical features were similar in vaccinated and unvaccinated patients. Most deaths followed medical complications of respiratory paralysis: Fifteen had pneumonia, 29 (83%) died suddenly, 15 had sudden arrhythmias or hypotension, and 7 had myocardial infarction or pulmonary embolus.

Adolescent↗
PubMed1979

Pharyngoconjunctival fever caused by adenovirus type 4: report of a swimming pool-related outbreak with recovery of virus from pool water.

During the summer of 1977, an outbreak of pharyngoconjunctival fever (PCF) occurred at a private recreational facility in Georgia. A total of 72 cases of PCF was identified. Adenovirus type 4 (AV-4) was recovered from conjunctival or pharyngeal swab specimens from 20 of 26 persons in the group of cases tested. AV-4 was also recovered, for the first time reported in the literature, from two concentrated samples of water obtained from the swimming pool at the facility on different dates. All persons affected had had direct or indirect contact with the pool. A linear relation between the amount of time spent in the water and the attack rate was demonstrated (r = 0.929, P less than 0.01). Investigation showed that inadequate amounts of chlorine had been added to the pool water. Frequently, levels of free chlorine were below the recommended level of 0.4 mg/liter. Breakpoint chlorination and closing of the pool for the summer stopped the spread of PCF.

Adenoviridae Infections↗
PubMed1979

Guillain-Barre syndrome following vaccination in the National Influenza Immunization Program, United States, 1976--1977.

Because of an increase in the number of reports of Guillian-Barre syndrome (GBS) following A/New Jersey influenza vaccination, the National Influenza Immunization Program was suspended December 16, 1976 and nationwide surveillance for GBS was begun. This surveillance uncovered a total of 1098 patients with onset of GBS from October 1, 1976, to January 31, 1977, from all 50 states, District of Columbia, and Puerto Rico. A total of 532 patients had recently received an A/New Jersey influenza vaccination prior to their onset of GBS (vaccinated cases), and 15 patients received a vaccination after their onset of GBS. Five hundred forty-three patients had not been recently vaccinated with A/New Jersey influenza vaccine and the vaccination status for 8 was unknown. Epidemiologic evidence indicated that many cases of GBS were related to vaccination. When compared to the unvaccinated population, the vaccinated population had a significantly elevated attack rate in every adult age group. The estimated attributable risk of vaccine-related GBS in the adult population was just under one case per 100,000 vaccinations. The period of increased risk was concentrated primarily within the 5-week period after vaccination, although it lasted for approximately 9 or 10 weeks.

Adolescent↗
PubMed1977

The distribution and significance of hepatitis B surface antigen in a rural population in Kenya.

A rural population in Kenya was studied and a prevalence of HBsAg of 5-0% and an antibody prevalence of 50% in HBsAg in negative subjects has been found; 1-2% of the negative subjects converted to positive over a six-month period. A group of HBsAg positive subjects was compared with a matched group of HBsAg negative controls clinically in liver function tests and past medical history. No statistically significant differences were found between the two groups and neither group had experienced in the past significantly more skin scarification, injections or illness with jaundice. Both ad and ay subtypes occurred in the population. This is an unexpected and important finding, which gives scope for further detailed epidemiological studies in this population.

Adolescent↗