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Biomedical subjects

J A Bryan

Publications and source records attributed to J A Bryan.

At least 55 records · Page 3Linked to original sources
PubMed1976

Viral hepatitis--a primer: 1. Epidem.iology.

Hepatitis A is most often transmitted by the fecal-oral route under conditions of crowding, poor hygiene, and prolonged exposure to infected persons. Direct spread of hepatitis B via person-to person contact has only recently been proved. Hepatitis B is usually transmitted indirectly proved. Hepatitis B is usually transmitted indirectly by percutaneous routes, and the increase in drug abuse has brought about a change in its epidemiologic pattern.

Adolescent↗
PubMed1976

Viral hepatitis--a primer. 2. Prevention and control.

The clinical differentiation of hepatitis A from hepatitis B is often impossible, and only a finding of hepatitis B surface antigen in blood allows the presence of hepatitis B to be definitely diagnosed. Heaptitis A is most easily contracted via the fecal-oral route, while hepatitis B is usually transmitted percutaneously, especially by inoculation with contaminated instruments. Because viral hepatitis has a long incubation period, controlling its spread is difficult. Prevention and control have traditionally depended on general public health measures, and for hepatitis A, passive immunization with immune serum globulin. Promising research is now being conducted to develop vaccines for both active and passive immunization against hepatitis B.

Disinfection↗
PubMed1976

Transmission of hepatitis B associated with hemodialysis: role of malfunction (blood leaks) in dialysis machines.

In the first 10 months of 1974, 26 of 60 susceptible patients in a commercial hemodialysis unit developed asymptomatic infection with hepatitis B virus; 17 (65%) of the 26 cases occurred in 14 weeks from July to October. In a case-control study, 15 of 16 cases for whom records were available were found to be associated with malfunctions of dialysis machines (primarily leaks or ruptures in dialysis membranes) that had occurred before patients converted to hepatitis B surface antigen (HBs Ag) positivity. In comparison, 17 of 34 controls were associated with machine malfunctions (P less than 0.01). In addition, the mean number of malfunctions in machines per patient was significantly greater for cases of infection (2.25 +/- 1.34) than for controls (1.06 +/- 1.39) (P less than 0.01). Furthermore, a direct correlation was demonstrated between an increase in blood leaks in machines used with susceptible patients and subsequent increases in cases of hepatitis for the various beds in the unit (r=0.994, P less than 0.0001). The mean period from the last blood leak to HBs Ag seroconversion was 67 days. Six of the 36 blood leaks associated with cases of infection occurred less than 6 hr after leaks in the contaminated area, whereas only one of 36 leaks associated with controls demonstrated this relationship (P less than 0.05). These data suggest that the conversion to HBs Ag positivity was linked to the occurrence of machine malfunctions (blood leaks) and that events which occurred during these episodes caused the spread of infection.

Hepatitis B↗
PubMed1976

An outbreak of type B hepatitis associated with transfusion of plasma protein fraction.

An outbreak of type B hepatitis followed transfusion with a single lot of plasma protein fraction (PPF) at a 1200-bed hospital in June and July 1973. Of 51 recipients of the product, 31 were available as a study population and 19 (61%) had an illness compatible with hepatitis. Epidemiologic and serologic investigations provided firm evidence that this material was the vehicle for transmission of disease to its recipients. Recipients of four other PPF lots from the same manufacturer were studied. Two of these lots were also associated with extremely high clinical hepatitis attack rates (45% and 55%). The other two lots, which had been prepared from donor plasma contributing to the composition of the initially-studied PPF lot, failed to produced clinical illness, although one of these lots was associated with a high prevalence of hepatitis B seropositivity in recipients. Thus, a broad spectrum of clinical and serologic responses was evident in PPF produced from similar donor plasma and pasteurized in the same bulk container. This study is the first to incriminate heat-treated PPF in transmission of type B hepatitis and suggests the need for further studies of the effect of pasteurization cycles on inactivation of hepatitis B virus.

Antibodies, Viral↗
PubMed1976

Hemodialysis-associated hepatitis: report of an epidemic with further evidence on mechanisms of transmission.

In the period January-September 1974, 50 cases of hepatitis B infection occurred among a nephrology center's hemodialysis patients and staff. The in-center patient population had an attack rate of 96%. Epidemiologic analysis of risk factors for patients revealed an association between the receipt of intravenous medication and the subsequent development of hepatitis, suggesting that parenteral inoculation was a mode of spread among patients (p equals .008). Nineteen per cent of the staff contracted hepatitis, and all of these personnel had had close contact with patients (p equals .005). The prevalence of hepatitis B infection in staff was related to the failure to use gloves (p less than .01), and accidental needle puncture was associated with the development of clinical hepatitis. These data suggested that disease was transmitted to staff by contact with contaminated blood or close personal contact with patients. Additional data showed that the presence of endogenous antibody protected both patients and staff from antigenemia (p equals .002). These data support the hypothesis that contact with blood is the primary mechanism of spread of hepatitis B in dialysis units, and suggest that, as preventive measures, gloves should be used and antibody-positive staff should dialyze antigen-positive patients.

Antibodies, Viral↗
PubMed1976

Nosocomial viral hepatitis B. A cluster among staff with subsequent transmission to patients.

In a 2-month period four cases of hepatitis B occurred in hospital staff. Three months later two patients, hospitalized for open-heart surgery when the staff members had been infected, developed acute hepatitis B. Sera from all six ill individuals were subtype ayw and e-determinant positive. Epidemiologic investigation showed that the four staff had been exposed 3 months earlier to an asymptomatic hepatitis B surface antigen-positive (HBsAg) patient who was also e positive. To determine transmission from staff to patients study of 17 open-heart surgery patients was undertaken. Four of 17 were either HBsAg or anti-HBs positive. No correlation between infection and contact with three of four ill staff members or receipt of blood products was noted; however, 22 (46%) of 48 arterial blood gas specimens had been obtained from infected patients by one staff member, an inhalation therapist; this compared with seven (4%) of 157 specimens she obtained from control subjects (P less than 0.001). Furthermore, she handled indwelling arterial cannulae 25 (76%) of 33 times in infected patients compared with three (3%) of 95 times in control subjects (P less than 0.001). Transmission may have occurred via the arterial cannulae from a severe exudative dermatitis on the therapist's hands.

Adult↗
PubMed1975

HBs-Ag-negative hepatitis in a hemodialysis unit: relation to Epstein-Barr virus.

Eleven of 40 patients in a hemodialysis unit had clinical or biochemical evidence of hepatitis during a five-week period. The clinical disease was mild, being limited solely to dialysis patients. Epidemiologic investigation indicated that the incubation period was between 17 and 35 days and that 10 of 11 patients had been exposed to a single venous-pressure monitor before onset. Dried blood and evidence of blood reflux up the venous-pressure gauge suggested that cross-contamination of the blood of successive patients probably resulted in transmission of disease. No association with the hepatitis B surface antigen or anti-hepatitis B antibody was demonstrated, but 10 of the 11 patients with elevated transaminase levels had evidence of recent exposure, to Epstein-Barr virus as manifested either by Ox-cell hemolysin titers or rises in titers to viral capsid antigen.

Adult↗
PubMed1975

Food-borne hepatitis A in a general hospital. Epidemiologic study of an outbreak attributed to sandwiches.

In November and December 1973, an outbreak of food-borne hepatitis A occurred in a busy general hospital. Epidemiologic investigation implicated cafeteria-made sandwiches. Eventually, 44 clinical and 22 subclinical cases of hepatitis were diagnosed among hospital employees. In addition, at least seven persons in the community became ill with hepatitis after eating in the hospital cafeteria; hospital patients were not, in general, affected. Two cafeteria workers were potentially implicated in the spread of hepatitis; both would have had subclinical hepatitis during the probable transmission period. It was recommended that food-handlers with icteric hepatitis remain out of work for at least two to three weeks after the onset of jaundice, while food-handlers with subclinical hepatitis remain out of work for at least two to three weeks after the peak of enzyme level elevation.

Alanine Transaminase↗
PubMed1975

Prevention of nosocomial viral hepatitis, type B (hepatitis B).

Nosocomial viral hepatitis, type B, is assuming increasing importance in the United States. The keystone to an effective hepatitis control program is surveillance of patients and personnel, especially in high-risk areas, namely dialysis units, hematology-oncology units, and laboratories. Measures to control infection are outlined for specific areas of the hospital. Data currently available suggest that employees who have persisting hepatitis B surface antigen (HBSAg) need not be removed from their positions unless they have been proved to disseminate infection. Future investigations should include methods to study: [a] the mechanisms of nonpercutaneous spread of hepatitis B virus, [b] the role of the individual with persisting HBSAg in the dissemination of hepatitis B virus, [c] the efficacy of hepatitis B immune globulin in high-risk areas, and [d] the effectiveness of various chemical and physical procedures in use for inactivation of hepatitis B virus using animal model systems.

Cross Infection↗