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Biomedical subjects

S C Hadler

Publications and source records attributed to S C Hadler.

At least 73 records · Page 4Linked to original sources
PubMed1990

The epidemiology of hepatitis B virus among family members in the Middle East.

In 1985, the authors studied the epidemiology of hepatitis B virus (HBV) in a healthy Middle Eastern population. Residents of three remote villages and urban areas of Jordan were assessed for seroprevalence of hepatitis B surface antigen (HBsAg) and HBV infection. Infection was defined as the presence of antibody to hepatitis B core antigen (total) and/or antibody to hepatitis B surface antigen, with or without HBsAg. The overall HBsAg prevalence was 9.9% and was not age-related, although significant differences were noted between the villages (range, 5.7%-12.8%). The prevalence of HBV infection was 36% and increased with age. In addition, there were differences between the villages in patterns of age-specific infection. A newly constructed socioeconomic index showed greater HBsAg prevalence in lower (14.4%) than in upper (2.4%) socioeconomic groups. A history of contact with a jaundiced person and socioeconomic status were independent risk factors for HBsAg-positive status, while contact with a jaundiced person, rural background, and age were independently related to HBV infection. There was evidence of familial clustering of HBV in two of the villages, with HBV carriers and infected children particularly aggregating around HBsAg-positive siblings. There was also a trend toward an association of HBsAg-positive children with HbsAg-positive mothers. HBV carrier prevalence correlated with family size, and HBV infection in the household increased proportionately with the number of carriers in the family. Hepatitis B e antigen was detected most frequently in children and antibody to hepatitis B e antigen in adults. Postnatal early childhood transmission through contact among children of poorer and larger families probably accounts for the high endemicity of HBV in this region.

Adolescent↗
PubMed1990

A multifocal outbreak of hepatitis A traced to commercially distributed lettuce.

From February 1 through March 20, 1988, 202 cases of hepatitis A were reported in and around Jefferson County, Kentucky. The epidemic curve indicated a common-source exposure. However, there was no apparent single source of exposure from a restaurant, or community gathering; nor was there a geographic clustering by residence. Cases were mainly adults 20-59 years old (89 percent); 51 percent were female. A case-control study using neighborhood controls found that factors associated with hepatitis A were: having eaten downtown (odds ratio [OR] = 4.0) and having dined at any one of three restaurants (OR = 21.0). Case-control studies of patrons of two of these restaurants found that eating green salad was strongly associated with acquiring hepatitis A: OR = 11.6 and OR = 4.4. The three implicated restaurants accounted for 71 percent of the cases. All three restaurants were supplied by the same fresh produce distributor; however, investigation suggested that contamination most likely occurred prior to local distribution. This outbreak of hepatitis A is the first in the United States apparently associated with fresh produce contaminated before distribution to restaurants, and raises important public health issues regarding the regulation of fresh produce.

Adult↗
PubMed1990

Hepatitis transmission among the Sioux Indians of South Dakota.

Hepatitis A continues to occur in cyclical community-wide epidemics on the Indian reservations of South Dakota. In June 1985 a population-based serosurvey for viral hepatitis involving 120 households was conducted at the Pine Ridge and Rosebud Sioux Indian reservations in South Dakota. The serosurvey was performed shortly after a large hepatitis A epidemic on the Pine Ridge reservation in 1983-84, and immediately before a large hepatitis A epidemic on the Rosebud reservation in 1985-86. The overall seroprevalence for antibodies to hepatitis A virus (anti-HAV) was 76.2 percent (Pine Ridge reservation 80.5 percent, Rosebud reservation 72.0 percent, relative risk = 1.12, 95 percent confidence interval = 1.01, 1.24). For age groups 0 to 4 years, 54.2 percent and 36.1 percent of children were seropositive at Pine Ridge and Rosebud, respectively. Seropositivity rose rapidly with age; by age 40, more than 90 percent of persons at both Pine Ridge and Rosebud were anti-HAV positive. Only 1.1 percent of persons tested were positive for hepatitis B markers. Anti-HAV seroprevalence rates in both communities are similar to rates observed in developing countries. The surprisingly high anti-HAV seroprevalence among young children at Rosebud, where clinical hepatitis A had been virtually absent in the previous seven years, indicates that high-grade silent transmission was taking place during the interepidemic period.

Adolescent↗
PubMed1990

Vaccines to prevent hepatitis B and hepatitis A virus infections.

Vaccines to prevent hepatitis B infection became available in 1982, and were recommended primarily for adults considered at high risk because of exposure in the workplace or lifestyles that lead to sexual or parenteral exposure to the virus. Plasma-derived and recombinant vaccines produced in yeast are highly immunogenic, safe, and effective for all age groups. Decreased response and protection by vaccine occur in older persons and in persons with immunosuppressive illnesses. The main issues concerning current vaccination programs include the possible use of lower doses to reduce the cost of the vaccine, the duration of protection and need for vaccine booster doses, and the need for postvaccination testing in hospitals. The failure of current vaccination programs to decrease disease incidence, a matter of great concern nationally, can be ascribed to failure to deliver vaccine to the groups at highest risk. More effective strategies for control, including the universal vaccination of infants or adolescents, must now be examined. Newer vaccines that incorporate other viral antigens and that may offer increased efficacy are being developed. Vaccines to prevent hepatitis A--both killed and live attenuated vaccines--are undergoing clinical trials and may become available in the next 5 years.

Hepatitis A↗
PubMed1990

Sexual behavior before AIDS: the hepatitis B studies of homosexual and bisexual men.

Data on sexual practices, collected during studies of hepatitis B virus (HBV) infection in 1978 and 1979, were analyzed for 4910 homosexual and bisexual men from Chicago, Denver, Los Angeles, San Francisco, and St Louis. Data on sexual practices in 1978 showed that white participants had larger numbers of non-steady male sexual partners and engaged in oral-genital activities more frequently but were equally likely to engage in anal intercourse as black and Hispanic participants. San Francisco participants had more non-steady sex partners and were more likely to engage in receptive anal intercourse with non-steady partners than participants from all other sites. Analysis of data on 606 HBV-antibody-negative men interviewed on three occasions in 1978 and 1979 showed no changes in risk indices for insertive and receptive anal intercourse between these years, except in San Francisco where significant declines occurred in insertive anal intercourse and receptive anal intercourse without ejacultion in a small, highly select group of participants.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Hepatitis B infection in the United States. Recent trends and future strategies for control.

Viral hepatitis is the second most common reportable infectious disease in the United States, with hepatitis B accounting for about 45 percent of cases. Although approximately 25,000 cases of hepatitis B are reported to the Centers for Disease Control each year, it is estimated that there are actually about 300,000 annual infections (up from 200,000 in the early 1980s). This increase has occurred despite the availability of a safe and effective hepatitis B vaccine since 1982. Hepatitis B occurs primarily in young adults because of lifestyle or occupationally related exposure. Reported cases in homosexual men have decreased, probably because of changes in behavior related to the acquired immunodeficiency syndrome epidemic. Cases due to heterosexual transmission and intravenous drug use are increasing. The proportion of cases in health care workers has decreased, possibly because 30 to 40 percent of high-risk health care workers have been vaccinated. Because of the increase in hepatitis B infection, the strategy of controlling this disease by vaccinating high-risk groups must be reconsidered. Alternative strategies include selective or universal immunization of infants or adolescents. Although integrating hepatitis B vaccine into infant immunization programs takes advantage of the existing system, it would not lead to measurable disease reduction for two decades. Immunizing adolescents would more rapidly reduce the incidence of hepatitis B, but currently no structured health care setting reaches them.

Diagnosis, Differential↗
PubMed1989

Importance of heterosexual activity in the transmission of hepatitis B and non-A, non-B hepatitis.

To identify previously unrecognized sources for acquiring acute hepatitis B and non-A, non-B (NANB) hepatitis, we interviewed patients with these types of hepatitis who were reported to two county health departments in the United States and matched control subjects for known and potential risk factors for acquiring hepatitis. Of 218 patients with hepatitis B and 140 patients with NANB hepatitis, 46% and 53%, respectively, had no commonly recognized source for infection. When these patients were compared with control subjects, significantly more patients with hepatitis B had multiple heterosexual partners, accounting for 14% of all hepatitis B infections; more patients with NANB hepatitis either had sexual or household contact with a person who had hepatitis in the past or had multiple heterosexual partners, accounting for 11% of all NANB infections. This is the first study to suggest that heterosexual transmission may play an important role in the spread of NANB hepatitis.

Adult↗
PubMed1989

Hepatitis D virus infection in Illinois state facilities for the developmentally disabled. Epidemiology and clinical manifestations.

OBJECTIVE: To define the epidemiology and clinical manifestations of hepatitis D virus infection in an institutionalized population. DESIGN: A case-control study of hepatitis B carriers with and without serologic evidence of hepatitis D virus infection. Demographic, institutional, and medical data were obtained through questionnaires and chart review. Clinical status was assessed by liver function assays. SETTING: Thirteen Illinois state facilities for the developmentally disabled. PARTICIPANTS: Clients (238) who were hepatitis B carriers. RESULTS: Antibody to hepatitis D virus (anti-HDV) was detected in 71 of 238 (30%) hepatitis B carriers. Nine of thirteen facilities housed positive clients. Previous residence at one facility, designated B, was the strongest correlate of anti-HDV positivity; 85% of positive persons had lived there compared with 16% of negative controls (odds ratio 28.3 [95% CI, 13.2 to 60.7], P less than 0.001). Past hepatitis episodes were more common among anti-HDV-positive clients (37% compared with 7%) (odds ratio, 7.5 [95% CI, 3.0 to 19.1], P less than 0.001) and occurred mainly at facility B from 1950 to 1975. Liver function tests were infrequently abnormal among anti-HDV-positive clients. CONCLUSIONS: Results show widespread hepatitis D virus infection in our institutionalized population and suggest that transmission occurred mainly in the past at the overcrowded facility B. The low prevalence of laboratory evidence of chronic liver disease in the anti-HDV-positive clients may be explained by increased mortality among those originally infected from 1950 to 1975.

Acute Disease↗
PubMed1989

A common-source outbreak of fulminant hepatitis B in a hospital.

A nosocomial outbreak of fulminant hepatitis B infection at a medical center in Haifa, Israel, between 7 and 26 June 1986, involved five patients who had been hospitalized previously in the medical ward in late April and early May (first generation). This outbreak had an unusual clinical course, with fulminant hepatic failure associated with acute renal failure from acute glomerulonephritis, leading to death within a few days. The onset dates of hepatitis were tightly clustered temporally and incubation periods were short. Extensive laboratory and epidemiologic evaluation showed that the probable common-source vehicle of transmission was a multiple-dose vial of heparin and normal saline flush solution that may have been contaminated by blood of a known HBsAg carrier, who was positive for anti-HBe, hospitalized at the same time. A sixth patient died in August 1986 (second generation), after his initial admission in June that coincided with the terminal hospitalizations of three first-generation patients. Those patients had marked coagulopathies, and transmission to the sixth patient most probably occurred through environmental contamination by patients or through cross-contamination between patients through staff. The unusually high mortality rate (5 of 6) in this outbreak has not been definitely explained.

Aged↗
PubMed1989

Duration of immunogenicity and efficacy of hepatitis B vaccine in a Yupik Eskimo population.

In 1981, a hepatitis B virus vaccine demonstration project was conducted in 1630 Yupik Eskimos in southwest Alaska. Levels of antibody to hepatitis B surface antigen and markers for hepatitis B virus infection in vaccinees were monitored yearly for 5 years. After 5 years of follow-up, 19% of those who initially had an immune response to vaccine of 10 sample ratio units or greater subsequently had levels of antibody to hepatitis B surface antigen lower than 10 sample ratio units. During the 5 years after the first dose of vaccine, in three responders and one person with an antibody to hepatitis B surface antigen response lower than 10 sample ratio units, antibody to hepatitis B core antigen developed, and the level of antibody to hepatitis B surface antigen was boosted. Hepatitis B surface antigen did not develop in any subjects, and none had clinical hepatitis. In the 5 years following the demonstration project, the annual incidence of hepatitis B virus infection decreased from 50 cases per 1000 population before the vaccine trial to 0.45 per 1000.

Adolescent↗
PubMed1989

Delta hepatitis in homosexual men in the United States.

To assess the incidence and prevalence of delta hepatitis in homosexual men, we tested serum specimens for delta markers in participants in two previous studies: a hepatitis B vaccine trial among homosexual men conducted in the early 1980's and the Centers for Disease Control sentinel counties hepatitis study for 1983-1984. In the vaccine trial, men found to be hepatitis B surface antigen positive at the time of enrollment and those men who had serologic evidence of new hepatitis B virus infection during follow-up were tested. In the sentinel counties study that determined risk factors for viral hepatitis in reported cases, all homosexual men with acute and chronic hepatitis B virus infections were tested for delta markers. Specimens were tested for delta antigen and IgM and total delta antibody. In seven different cities, among 321 men found to be HBsAg positive at the time of screening, eight (2%) were positive for any delta marker. Among 290 men with new hepatitis B virus infections during follow-up, three (two coinfections, one superinfection) had serologic evidence of delta hepatitis. In the sentinel counties study, 0/63 acute hepatitis B virus infections in homosexual men were associated with delta hepatitis. This study indicates that the delta agent is an infrequent cause of viral hepatitis in homosexual men in the United States.

Hepatitis D↗
PubMed1989

Effect of timing of hepatitis B vaccine doses on response to vaccine in Yucpa Indians.

In a large hepatitis B prevention programme, hepatitis B vaccine was given in standard doses to greater than 1000 susceptible Yucpa Indians between 1983 and 1985. Thirteen months after the programme began, 373 vaccine recipients were tested using commercial radioimmunoassay to titre antibody response to the vaccine. Because of logistic difficulties, only 32% had received vaccine by the recommended schedule (second and third doses at one and six months after the first, respectively). The second and third doses were received early by 4 and 31%, respectively, and 27 and 16% received these doses later than intended. Overall response to vaccine was excellent: 98% of vaccinees developed anti-HBs greater than 10 mIU (geometric mean titre 688 mIU). Multivariate analysis showed that the response to vaccination was inversely related to the age of the vaccinee and directly related to the timing of the third vaccine dose. In particular, those receiving the third vaccine dose late (greater than 7 months after the first dose) developed antibody titres two-fold higher than those receiving the third dose on schedule (p less than 0.01). The response to vaccination was not significantly related to the timing of the second dose. A satisfactory response was obtained with various schedules of dose timing, including early second and third doses, late second and third doses and late second but normal third doses. These findings suggest that the response to hepatitis B vaccine is not highly dependent on timing of vaccine doses and that modest alterations in timing of doses, such as those necessary to integrate hepatitis B vaccine with other childhood vaccines, do not affect the excellent response to this vaccine.

Adolescent↗
PubMed1989

Effect of anatomic injection site, age and smoking on the immune response to hepatitis B vaccination.

Soon after the plasma-derived hepatitis B vaccine became available in the US, the Centers for Disease Control and the manufacturer received over 100 reports of vaccinated groups with unexpectedly low levels of vaccine-induced antibody. To confirm previous retrospective surveys relating these failures to buttock injection and to evaluate the effect of other host factors on vaccine-induced antibody responses, we conducted a clinical trial in healthy health-care workers. Participants were randomly assigned to one of three treatment groups: 1-Ar, 1-inch needle injection in the arm; 1-Bu, 1-inch needle injection in the buttock; 2-Bu, 2-inch needle injection in the buttock. All participants were administered vaccine according to the standard vaccine dosage schedule of 20 micrograms at 0, 1 and 6 months. Antibody response rates (antibody to hepatitis B surface antigen greater than or equal to 10 sample ratio units by radioimmunoassay) and geometric mean titres of antibody two months after the third vaccine dose were 93% and 1454 mIU ml-1 for group 1-Ar, 72% and 85 mIU ml-1 for group 1-Bu, and 83% and 387 mIU ml-1 for group 2-Bu. Seroconversion rates and titres of antibody in the three groups were significantly different from each other statistically. Increasing age, increasing total skinfold thickness and cigarette smoking were independently associated with lower antibody responses in persons receiving buttock injections but not in persons receiving arm injections.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Hepatitis A in Mauritius: an apparent transition from endemic to epidemic transmission patterns.

Between January 1984 and December 1985 a large outbreak of viral hepatitis occurred in the island nation of Mauritius (population 986,000). No hepatitis epidemics had occurred there since the 1930s. The outbreak involved 2428 reported cases; however, reporting levels were thought to be extremely low. All of the island's nine geographical districts were affected, but cases were concentrated in five districts mostly in the central and northern parts of the island. The highest attack rate occurred in children aged five to nine; persons above age 14 were almost unaffected. The male:female ratio of cases was 1.1:1. Evidence to support hepatitis A virus (HAV) as the infecting agent included; (1) clinical illness was compatible with hepatitis A; (2) the age profile of cases was typical for community-wide hepatitis A outbreaks; (3) the rate of positive tests for hepatitis B surface antigen in suspected hepatitis patients did not increase during the outbreak; and (4) nine of nine clinically ill children tested were serum-positive for IgM anti-hepatitis A virus antibody. Transmission was probably by the person-to-person route; no common source was implicated. The outbreak appears to represent a transition from a 40-year pattern of endemic HAV transmission on the island to an epidemic pattern.

Adolescent↗
PubMed1989

Hepatitis B virus transmission between children in day care.

We investigated two situations involving hepatitis B virus exposure among children in day care. In the first a 4-year-old boy who attended a day care center developed acute hepatitis B; another child at the center, who had a history of aggressive behavior (biting/scratching), was subsequently found to be a hepatitis B carrier. No other source of infection among family and other contacts was identified and no other persons at the center became infected. In the second situation a 4-year-old boy with frequently bleeding eczematous lesions was discovered to be a hepatitis B carrier after having attended a day care center for 17 months. Testing of contacts at the center revealed no transmission to other children or staff (representing 887 person months of exposure). Nationwide surveillance data showed that for the period 1983 to 1987, 161 children 1 to 4 years of age were reported with acute hepatitis B. After children with known hepatitis B risk factors were excluded, 25% (7 of 28) of children with known day care status were reported as day care attendees, a percentage comparable to national estimates of day care attendance by this age group. This is the first reported case of hepatitis B virus transmission between children in day care in the United States. Although it appears that day care transmission of hepatitis B is infrequent, further studies are needed to define the risk more accurately.

Adult↗
PubMed1989

Vaccines of importance in the hospital setting. Problems and developments.

Hospital personnel may be exposed to or transmit certain vaccine-preventable diseases. Using immunizing agents optimally in hospitals will protect personnel as well as patients. Preventing illness in hospitals through comprehensive immunization policies can be more cost-effective than case management and outbreak control. Hospital-based immunization programs for patients provide an important strategy for immunizing high-risk patients. Immunizing patients protects them against preventable illnesses that may be acquired in the hospital or the community following discharge.

Cross Infection↗