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Biomedical subjects

S C Hadler

Publications and source records attributed to S C Hadler.

At least 109 records · Page 6Linked to original sources
PubMed1984

The low risk of hepatitis B in rural hospitals. Results of a seroepidemiologic survey.

To determine the risk of hepatitis B virus infection for rural hospital employees, we obtained serum and a completed questionnaire from each of 2,064 employees of 11 rural hospitals. Only 96 (4.7%) employees had hepatitis B virus markers. Increased marker prevalence was significantly associated with prior residence in a city with a population of greater than 100,000 (odds ratio, 2.9; 95% confidence interval, 1.6 to 5.2) and increasing blood contact (odds ratio, 1.6; confidence interval, 1.2 to 2.3); however, the association with blood contact was not significant when we limited analysis to the 836 employees who had never lived in a city. We conclude that the risk of hepatitis B virus infection for these rural hospital employees is low, probably because the incidence of hepatitis B in rural areas is low.

Hepatitis B↗
PubMed1984

Occurrence of hepatitis A, B, and non-A/non-B in the United States. CDC sentinel county hepatitis study I.

To determine the relative occurrence of hepatitis A, B, and non-A/non-B in the United States, serum samples and epidemiologic data were collected from patients with hepatitis in five selected counties. Overall, 41, 33, and 26 percent of the patients had hepatitis A, hepatitis B, and hepatitis non-A/non-B, respectively. The incidence, especially of hepatitis A, varied considerably. All three types of hepatitis occurred more frequently in those 15 to 44 years of age. Hepatitis A predominated in those less than 15 years of age and non-A/non-B predominated in those older than 44 years. There was a male predominance (65 to 62 percent) for hepatitis A and hepatitis B, but non-A/non-B occurred equally in both sexes. There was no seasonal pattern for any type. Risk factors for hepatitis A were previous contact with a patient with hepatitis (26 percent), homosexual (male) preference (15 percent), and day-care center contact (11 percent). For hepatitis B, risk factors included drug use (26 percent), previous contact with an infected person (22 percent), homosexual preference (12 percent), and a health-care occupation (12 percent). For hepatitis non-A/non-B, risk factors included drug use (16 percent), transfusion (12 percent), and previous contact with an infected person (12 percent). Previous hospitalization appeared to be a risk factor for both hepatitis B and hepatitis non-A/non-B.

Adolescent↗
PubMed1984

Epidemiological analysis of the significance of low-positive test results for antibody to hepatitis B surface and core antigens.

To determine the significance of certain serological test results commonly encountered in hepatitis B virus testing, we reviewed serological test data from nine studies of hepatitis B conducted between 1980 and 1982. Three tests, for hepatitis B surface antigen and for antibodies to hepatitis B surface antigen and hepatitis B core antigen (anti-HBs and anti-HBc), were used to measure hepatitis B virus infection risk in various populations. Two results, low levels of anti-HBs alone and low levels of anti-HBc alone, occurred at constant frequencies (2.72 and 0.4%, respectively), regardless of the prevalence of HBV infection in the population. Positivity for low levels of anti-HBs alone persisted for 1 year in less than one-half of those studied; in addition, response to hepatitis B virus vaccine was augmented in only one-third of this group. Positivity for low levels of anti-HBc alone did not persist in any of 11 persons studied. These findings indicate that presently available tests for anti-HBs and anti-HBc at low levels are often nonspecific and should be interpreted with caution.

Alaska↗
PubMed1984

Delta virus infection and severe hepatitis. An epidemic in the Yucpa Indians of Venezuela.

Over a 3-year period, 149 Yucpa Indians in Venezuela developed hepatitis; 34 persons died and at least 22 developed chronic hepatitis. Children and young adults were primarily affected, especially males. Serologic testing showed that hepatitis B virus infection was highly endemic in this population, but also that 65% of patients had hepatitis B virus surface antigen (HBsAg) during or after illness. Most patients had evidence of delta-agent superinfection; 86% of HBsAg-positive patients had delta antibody, and delta antigen was found in specimens taken during autopsies on 7 of 9 patients. Serologic data suggested that most infections were due to delta superinfection of hepatitis B carriers, and that more than 60% of these infections progressed to chronic disease. Delta agent infection, and particularly delta superinfection of hepatitis B carriers, appears to be an ominous occurrence that may develop in populations among whom hepatitis B virus infection is endemic, and who have no other risk factor for delta infection.

Adolescent↗
PubMed1983

Effect of immunoglobulin on hepatitis A in day-care centers.

Over a 21-month interval, we investigated the effectiveness of immunoglobulin (lg) in preventing hepatitis A spread in day-care centers. Immunoglobulin was given to all center and employees whenever hepatitis occurred in one center child or employee or parents in two families. Immunoglobulin programs were completed in 91 centers during the trial within an average of 17 days of onset of illness in the index case. Immunoglobulin intervention caused significant reduction in the average size of a day-care hepatitis outbreaks, from 7.3 cases in historically untreated centers to 6.0 cases in Ig-treated centers. Cases in center children and employees virtually ceased two weeks after Ig intervention, while those in household contacts decreased significantly within six weeks. Reported cases of hepatitis type A or unspecified in the community decreased 75%, and the number of new hepatitis outbreaks decreased 77% during the trial. A decrease occurred not only in day-care-associated cases, but in cases not directly associated with centers, probably due to decreased tertiary spread from day-care families into the community. Use of Ig to prevent hepatitis spread in day-care centers seems to be an excellent means of controlling this disease, both within the centers and the general community.

Arizona↗
PubMed1983

Serologic investigation of an outbreak of hepatitis A in a rural day-care center.

We studied an outbreak of hepatitis A in a day-care center in a rural community where less than 7 per cent of the population possessed anti-HAV. Serotesting for IgM specific antibody to hepatitis A virus identified 78 cases in center attendees, staff, and families. Thirty-five per cent of the center children were seropositive. In children under age three anicteric infection was at least 17 times more frequent than icteric infection, but in older children and adults icterus was a predominant manifestation of the disease. Clinical suspicion should be high in any day-care child with nausea, emesis, diarrhea, or arthralgia. The low incidence of icterus in infected children suggested that outbreak reports reaching public health departments are likely to be incomplete and poorly indicative of outbreak magnitude. The high frequency of intrafamilial transmission and anicteric infection appeared to justify administration of immune serum globulin to household contacts of center children under age three when a day-care outbreak is detected.

Antibodies, Viral↗
PubMed1982

Risk factors for hepatitis A in day-care centers.

Outbreaks of hepatitis in day-care centers in Maricopa County, Arizona, were studied over a two-year period to learn which center characteristics affected the spread of hepatitis A. Of the 279 licensed center, 85 (30%) had outbreaks of hepatitis affecting three or more families. Outbreaks occurred in 63% of centers enrolling infants younger than one year of age, 32% of centers enrolling children one year of age or older, and 2.5% of centers enrolling children two years of age or older (P less than 0.0001). Outbreaks were also significantly more frequent in large centers enrolling greater than or equal to 51 children, centers open greater than 15 hours per day, and centers operated for profit. The introduction of hepatitis into a center was related strongly to the number of hours open and to the size and age enrollment, but the spread of hepatitis was related solely to the presence of children younger than two years of age. These data strongly link the spread of hepatitis A in day-care centers to the presence of very young children and provide a framework for designing disease-control strategies.

Age Factors↗
PubMed1982

Hepatitis B in homosexual men: prevalence of infection and factors related to transmission.

Of 3,816 homosexual men examined in five sexually transmitted disease clinics in the United States, 6.1% had hepatitis B surface antigen, 52.4% had antibody to hepatitis B surface antigen, and 3.0% of the men who had no other indicator of infection with hepatitis B virus (HBV) had antibody to hepatitis B core antigen. The rate of seropositivity for HBV indicated by the presence of one or more of these serologic markers was 61.5%; seropositivity was significantly related to the duration of regular homosexual activity and to the number of nonsteady male sexual contacts in the four months before the patients were interviewed. Anal-genital intercourse, oral-anal intercourse, and rectal douching were significantly related to evidence of HBV infection, but oral-oral contact and oral-genital contact were not. Trauma to the rectal mucosa is a feature common to the practices that were significantly related to seropositivity for HBV.

Adolescent↗
PubMed1982

The prevention of hepatitis B with vaccine. Report of the centers for disease control multi-center efficacy trial among homosexual men.

A randomized, double-blind, vaccine/placebo trial of the Merck 20-micrograms hepatitis B virus (HBV) vaccine was done among 1402 homosexual men attending venereal disease clinics in five American cities. Vaccination was followed by only minimal side effects. Two doses of vaccine induced antibody in 80% of vaccine recipients. A booster dose 6 months after the first dose induced antibody in 85% of recipients and markedly increased the proportion of recipients who produced high antibody titers. The incidence of HBV events was markedly less in the vaccine recipients compared to that in the placebo recipients (p = 0.0004). Between month 3 and 15 after the first dose, 56 more significant HBV events (hepatitis, or hepatitis B surface antigen positive, or both) occurred in the placebo group while only 11 occurred in the vaccine group. Ten of the 11 HBV events in the vaccine recipients occurred in hypo- or nonresponders to the vaccine. This vaccine appears to be safe, immunogenic, and efficacious in preventing infection with hepatitis B virus.

Adult↗
PubMed1981

An outbreak of hepatitis B in a dental practice.

In September 1978, cases of hepatitis B in two patients treated by the same dentist led to investigation of a dental practice in Baltimore, Maryland. The dentist had had acute hepatitis B in June 1978 and had remained positive for hepatitis B surface antigen and hepatitis B e antigen over the ensuing 6 months. He had continued to work while infected, wearing surgical gloves to minimize the risk of transmitting infection. Serologic follow-up of 764 patients showed that a total of six patients, three of whom were symptomatic, had developed hepatitis B infection after dental treatment. All six were among a group of 395 patients treated before the dentist began wearing gloves. In this group, patients having highly traumatic dental work (attack rate 6.9%) were at significantly higher risk than patients having either less traumatic work (attack rate 0.5%) or nontraumatic work (attack rate = 0, p less than 0.02). None of 369 patients treated only when the dentist wore gloves became infected, suggesting that gloves could reduce the risk of virus transmission by the dentist.

Adolescent↗
PubMed1980

Hepatitis A in day-care centers. A community-wide assessment.

We investigated the spread of viral hepatitis in day-care centers in Maricopa County, Ariz. Over a 10-month period, 398 (40 per cent) of 1008 reported cases of hepatitis Type A or viral hepatitis of unspecified type occurred in persons closely associated with day-care centers. Outbreaks of hepatitis comprising 310 cases were identified in 30 of 308 centers in the county. In 28 outbreaks investigated, the majority of symptomatic cases occurred in household contacts or close relatives of children who attended day-care centers, with 16 per cent of the cases occurring in children who attended the centers and 15 per cent occurring in employees. Hepatitis in both employees and household contacts was strongly related to contact with children one to two years of age who attended the centers (P less than 0.001). Day-care centers appear to be important in the spread of hepatitis A in the United States.

Adolescent↗
PubMedDate not supplied

Hepatitis delta virus infection and Labrea hepatitis. Prevalence and role in fulminant hepatitis in the Amazon Basin.

To define more exactly the epidemiology of delta virus infection and confirm its role in causing fulminant Labrea hepatitis in the Amazon Basin, we studied the prevalence of delta virus infection among persons with acute and chronic hepatitis B virus infection in the Boca do Acre district of the southern Amazon Basin. Delta virus infection was found in 24% of asymptomatic hepatitis B virus carriers, 29% of acute nonfulminant hepatitis B cases, 74% of fulminant hepatitis B cases, and 100% of chronic hepatitis B cases. Chronic delta virus infection occurred primarily in older children and adults, while acute and fulminant delta virus infection occurred in young children as well. In fulminant hepatitis cases, delta virus superinfection of hepatitis B virus carriers was the most common serological pattern; histopathologic examination showed features identical to those described in fulminant hepatitis cases of similar etiology in Colombia and Venezuela. Delta virus infection is highly endemic in the southern Amazon Basin and is the principal cause of Labrea hepatitis.

Acute Disease↗
PubMedDate not supplied

Histologic studies of severe delta agent infection in Venezuelan Indians.

To supplement a detailed epidemiologic study of an outbreak of viral hepatitis in Venezuelan Indians in isolated valleys, apparently resulting from delta agent infection, 10 autopsy specimens were studied histologically and immunocytochemically, and five biopsy specimens were examined. The patients were children and young adults and predominantly males. A sequence of hepatitis from focal necrosis with conspicuous small-droplet steatosis, through massive necrosis, prolonged postnecrotic collapse to early cirrhosis with massive collapse was postulated. The histologic changes tentatively suggest a cytopathic effect of the delta agent without significant indication of lymphocytotoxicity, at least in the parenchyma. Delta agent was demonstrated in hepatocyte nuclei in moderate amounts in the focal-necrotic stage and in isolated cells in the massive-necrotic stage, but in large amounts during the transition to cirrhosis. Whether these patients, in whom neither HBcAg nor HBsAg were demonstrable in the liver, suffered exclusively from superinfection of hepatitis B virus carriers and/or coinfection of hepatitis B virus with the delta agent remains to be resolved. Delta infection may occur in isolated settings with no relation to Italian origin, drug addiction, or polytransfusion. The infection is far more widely spread than previously assumed.

Adolescent↗