Search

Background: Defining the primary characteristics of persons infected with hepatitis C virus (HCV) enables physicians to more easily identify persons who are most likely to benefit from testing for the disease. Objective: To describe the HCV-infected population in the United States. Design: Nationally representative household survey. Setting: U.S. civilian, noninstitutionalized population. Participants: 15 079 participants in the National Health and Nutrition Examination Survey between 1999 and 2002. Measurements: All participants provided medical histories, and those who were 20 to 59 years of age provided histories of drug use and sexual practices. Participants were tested for antibodies to HCV (anti-HCV) and HCV RNA, and their serum alanine aminotransferase (ALT) levels were measured. Results: The prevalence of anti-HCV in the United States was 1.6% (95% CI, 1.3% to 1.9%), equating to an estimated 4.1 million (CI, 3.4 million to 4.9 million) anti-HCV-positive persons nationwide; 1.3% or 3.2 million (CI, 2.7 million to 3.9 million) persons had chronic HCV infection. Peak prevalence of anti-HCV (4.3%) was observed among persons 40 to 49 years of age. A total of 48.4% of anti-HCV-positive persons between 20 and 59 years of age reported a history of injection drug use, the strongest risk factor for HCV infection. Of all persons reporting such a history, 83.3% had not used injection drugs for at least 1 year before the survey. Other significant risk factors included 20 or more lifetime sex partners and blood transfusion before 1992. Abnormal serum ALT levels were found in 58.7% of HCV RNA-positive persons. Three characteristics (abnormal serum ALT level, any history of injection drug use, and history of blood transfusion before 1992) identified 85.1% of HCV RNA-positive participants between 20 and 59 years of age. Limitations: Incarcerated and homeless persons were not included in the survey. Conclusions: Many Americans are infected with HCV. Most were born between 1945 and 1964 and can be identified with current screening criteria. History of injection drug use is the strongest risk factor for infection.

The factors associated with tetanus and diphtheria immunity among the women in the United States is examined. The result indicates that obstetricians and gynecologists who are the medical providers for women should be familiar with the advisory community on immunization practices recommendations regarding diphtheria toxoid booster vaccines.

Background: Serologic data on diseases that are preventable by vaccine are useful to evaluate the success of immunization programs and to identify susceptible subgroups. Objective: To provide national estimates of immunity to diphtheria and tetanus by measurement of serum antibody levels. Design: Examination of data from the Third National Health and Nutrition Examination Survey, a representative cross-sectional sample of the U.S. population. Setting: 89 randomly selected locations throughout the United States. Participants: 18 045 persons 6 years of age of older who were examined from 1988 to 1994. Measurements: Serum samples obtained at a single time point were tested for diphtheria and tetanus antitoxin. Results: Overall, 60.5% of Americans 6 years of age or older had fully protective levels of diphtheria antibody (>=0.10 IU/mL) and 72.3% had protective levels of tetanus antibody (>0.15 IU/mL). Ninety-one percent of Americans 6 to 11 years of age had protective levels of both diphtheria and tetanus antibody; this proportion decreased to approximately 30% among persons 70 years of age (29.5% for diphtheria and 31.0% for tetanus). Adult Mexican-Americans were slightly less likely to have protective levels of antibody to both toxins. Only 47% of persons 20 years of age or older had levels that were protective against both diseases, and only 63% of adults who were protected against tetanus were also protected against diphtheria. Conclusions: A substantial proportion of adults in the United States do not have antibody levels that are protective against diphtheria and tetanus. In addition, although the recommended vaccine is a combination of tetanus and diphtheria, only 63% of adults with protective antibody to tetanus also had protective antibody to diphtheria.

Background: The prevalence of Chlamydia trachomatis genital infection in the United States population is unknown. Using a new urine test for C. trachomatis, we conducted a pilot survey as part of the National Health and Nutrition Examination Survey III (NHANES III). Goal: To determine whether the prevalence of chlamydial infection in a convenience sample of NHANES participants was high enough to justify testing for C. trachomatis in a national survey. Study Design: NHANES III, conducted from 1988 to 1994, was based on a stratified multistage probability sample of the United States population. Non-Hispanic blacks and Mexican-Americans were oversampled. Using the ligase chain reaction assay for C. trachomatis, we tested urine from participants 12 to 39 years of age from 10 of the 89 sites of NHANES III. The prevalence of infection was calculated by racial or ethnic group. Results: We tested 1,144 study participants, of whom 65% were female, 30% were non-Hispanic blacks, and 30% were Mexican-American. Prevalence was higher for non. Hispanic blacks (7%) than for Mexican-Americans (3%) and non-Hispanic whites (2%). Prevalence was higher for women than men in non-Hispanic blacks (7% vs. 6%), Mexican-Americans (5% vs. 2%), and non-Hispanic whites (2% vs. 1%). In 15- to 19-year-old women, prevalence was 13% in non-Hispanic blacks, 11% in Mexican-Americans, and 5% in non-Hispanic whites. Conclusion: The prevalence of C. trachomatis genital infection was high enough to suggest that a reliable national prevalence estimate could be obtained in a national probability sample survey., There appears to be enough Chlamydia trachomatis genital infections in the US to justify a national disease prevalence survey. Chlamydia can cause pelvic inflammatory disease, pain, and infertility in women. Researchers tested 1,144 people for the condition, and found that 7% of blacks, 3% of Mexican-Americans, and 2% of whites were infected. Women were consistently infected at higher rates than men, and the infection was most common among 15-19 year old women.

Data from the third National Health and Nutrition Examination Survey (NHANES III) indicate that about half a million US residents are infected with the AIDS virus. Of the 11,203 people in the survey tested for HIV, 59, or 0.32%, were HIV-positive. This translates to 461,000 people nationwide. However, the survey participants were between the ages of 18 and 59 and resided in households. Thus, the survey did not include homeless people, prisoners and others at high risk of infection.

African-Americans may be more likely to be HIV positive than whites, and men may be more likely than women to be infected. A portion of participants in a national health and nutrition survey provided blood samples that were tested anonymously for HIV antibodies. Among 5,430 adults between the ages of 18 and 59, 29 had positive tests. Analysis of the demographic data showed that African-Americans were 4.3 times more likely than whites and 2.7 times more likely than Mexican Americans to be HIV positive. Men were estimated to be three to four times as likely as women to be HIV positive. Most of the study participants who tested positive for HIV were in the younger age group, that is from 18 to 39. The prevalence estimates might be lower than actual prevalence if persons more likely to be HIV positive declined to participate in the study. Also, the survey covered only civilian persons living in households, excluding prisoners and homeless people.

Although infections of the genital tract by human papillomavirus (HPV) may be associated with genital warts, they are not clinically obvious in many cases and must be diagnosed by sophisticated laboratory assays. To learn more concerning the prevalence of HPV infection in an inner-city group of women who visited a clinic that treated sexually transmitted diseases (STDs), a study of 116 patients was carried out. The patients were interviewed and underwent gynecological examinations during which specimens were collected. Tests were carried out for several STDs in addition to HPV infection. A comparison of the results of different tests for diagnosing HPV was made. STDs were common among this clinic population: 14 percent of the patients tested positive for gonorrhea; 15 percent were infected with Chlamydia trachomatis (which causes chlamydia); 21 percent had signs of Trichomonas vaginalis (which causes trichomoniasis); and 23 percent had bacterial vaginosis. Between 12 percent and 41 percent of the women were infected with HPV; the results varied according to the diagnostic test used. Evaluation of Pap smears for pathologic changes associated with HPV led to the highest estimation of the prevalence of HPV, while diagnoses based on the presence of warts led to a much lower estimate. Each diagnostic approach has strengths and weaknesses, and almost one-fifth of the specimens could not be evaluated for HPV by all methods. The difficulty in obtaining appropriate specimens hinders the accurate diagnosis of the disease. Diagnosing HPV infection presents an important problem for STD clinics. (Consumer Summary produced by Reliance Medical Information, Inc.)

Research in sexually transmitted diseases (STD) has been primarily directed at biological and clinical aspects. Recently, the more common STDs have become more difficult to control and contain, and new STDs have appeared that are not responsive to the usual therapies. Alternative approaches are required for prevention. Behavior modification as one of these alternatives was shown to be successful in homosexual males in response to the AIDS epidemic. These behavioral changes have also resulted in reduced levels of syphilis and gonorrhea for this population. Changes in sexual habits, earlier onset of sexual activity in women, unplanned pregnancies, and problems of youth make the need for educational and behavioral interventions more urgent. Many of the high risk persons are users of inner city STD clinics and these clinics provide an important point for the dissemination of health and related information. A study group of 116 African-American women, 16 to 43 years old, were selected from those attending an inner city clinic. The patients were consecutively selected, and the usual routine tests were conducted as indicated by patient complaints and symptoms. Each woman was interviewed and questioned regarding sexual behavior, age at first intercourse, number of partners, frequency, pregnancies, sanitary product and douche usage, knowledge of the Pap test, social and smoking habits, and other general and sex related questions. Responses strongly indicated a lack of rudimentary information and the need for both clinical and social education. The STD clinic provides a suitable setting for the delivery of this information. (Consumer Summary produced by Reliance Medical Information, Inc.)

The prevalence of hepatitis B virus (HBV) infection was determined using sera from persons participating in the second National Health and Nutrition Examination Survey, conducted from 1976 to 1980. Of 14,488 scientifically selected participants aged 12 to 74, 821 had evidence of past or present infection with HBV. In the white population, the weighted estimate of hepatitis B infection was 3.2 percent (95 percent confidence interval, 3.1 to 4.2). A steady increase with age was seen; by ages 65 to 74, the prevalence was 6.9 percent (95 percent confidence interval, 5.2 to 8.5). In the black population, the overall weighted estimate of prevalence was 13.7 percent (95 percent confidence interval, 11.6 to 15.8). In this racial group, there was a dramatic increase with age, with the oldest age groups having a prevalence of 39.6 percent (95 percent confidence interval, 29.1 to 50.0). In both racial groups, there was a low prevalence of infection in young children that began to rise between ages 12 and 18. In a multivariate analysis of factors associated with infection, there was an interaction of race with age; therefore, the odds ratio for race is presented for four ages. This ratio ranged from 3.0 (95 percent confidence interval, 1.8 to 4.2) for a 15-year-old to 8.2 (95 percent confidence interval, 6.5 to 10.3) for a 70-year-old. These relative odds estimates were not substantially affected by adjustment for the available information on risk factors for HBV infection. The results of this study in a representative sample of the United States population show that adult black Americans are at high risk for hepatitis B infection. Other independent predictors of HBV positivity include male sex; residing in the South, Northeast, or West; residing in a city of 250,000 or more people; serving in the armed forces; living below the poverty level; and having a positive treponemal test for syphilis. These data suggest that the immunization practices for controlling this disease should be re-examined., From 1976 to 1980, the National Center for Health Statistics examined 20,322 people from a total representative sample of 27,802. Of these, sufficient volume of blood was obtained to measure hepatitis B markers in 14,488. Various risk factors were determined from the patient histories of those testing positive. The prevalence of hepatitis B infection in the white population was 3.2 percent, whereas it was 13.7 percent among blacks. Other significant risk factors included being male, living in the Northeast, South, or West, and living in a city of population greater than 250,000. Also included in the risk factors were service in the armed forces, living below poverty level, and testing positive for syphilis. Many of these risk factors are related to behavioral risk factors such as male homosexuality, intravenous drug use, and criminal behavior resulting in imprisonment. However, many potential vaccine recipients will deny belonging to one of these risk groups. The authors recommend, therefore, that vaccines be made available to all persons at risk based on the epidemiology rather than on the basis of self-reported high-risk behaviors. (Consumer Summary produced by Reliance Medical Information, Inc.)