Biomedical subjects

W M Morgan

Publications and source records attributed to W M Morgan.

At least 37 records · Page 2Linked to original sources

PubMed1994

HIV-1 incidence determined retrospectively among drug users in Bangkok, Thailand.

OBJECTIVE: To measure trends in the incidence of HIV-1 infection among drug users in treatment at Thailand's largest drug detoxification unit. DESIGN: A retrospective cohort was established using computed, existing HIV-1 test results of 26,396 inpatients and outpatients admitted for 47,907 drug detoxification treatment courses from August 1987 to August 1992. METHODS: Matching of patient record numbers showed that 10,050 (38.1%) patients had been admitted two or more times during the period. From these, we selected a cohort of 7807 initially HIV-negative patients. Subsequent seroconversions among them were assumed to have occurred with uniform probability throughout the interval between the last HIV-negative and the first HIV-positive tests. RESULTS: There were 2311 (29.6%) seroconversions in the cohort. HIV-1 incidence among the 5974 (76.5%) who were injecting drug users (IDU) escalated from 20 new infections per 100 person-years (PY) of observation in 1987 to a peak of 57 per 100 PY in 1988, then gradually declining to a stable rate of about 11 per 100 PY during 1991 and 1992. Non-IDU (smokers, inhalers) constituted 683 (8.8%) of the cohort patients, and had HIV-1 incidence rates varying from 0.2 to five per 100 PY. 'Mixed' drug users, defined as individuals reporting different routes of drug administration on different admissions, composed 1150 (14.7%) of cohort patients and had an HIV-1 incidence rate between that of IDU and non-IDU. Prevalence of HIV-1 seropositivity among all IDU increased rapidly, from about 1% in early 1988 to a peak of about 40% by early 1989, and has remained stable through 1992. CONCLUSIONS: Prevention efforts must continue for IDU, since recent annual HIV-1 incidence remains high at > 10 per 100 PY. Such a high rate suggests that this group should be considered for HIV-1 vaccine efficacy trials. Stable HIV-1 prevalence can mask substantial incidence in a population with high turnover.

Acquired Immunodeficiency Syndrome↗

PubMed1994

Laparoscopy for the nonpalpable testis.

Between 1988 and 1992, 287 infants and children have been evaluated for an undescended testis. In 35, the testis was not palpable. These 35 patients ranged in age between 10 months and 14 years, with a mean of 44 months and a median of 15 months. Thirteen patients had a nonpalpable right testis, 18 had a nonpalpable left testis, and four had bilateral nonpalpable testes. Diagnostic laparoscopy was performed in these 35 boys with a nonpalpable testis to allow a planned approach to management of this condition. In 11 children, a testis was visualized. The testis was in an inguinal hernia sac in seven, and single stage conventional orchiopexy was performed. In four children an intra-abdominal testis was seen, and three infants underwent laparoscopic clip ligation of the testicular vessels. One teenager underwent orchiectomy. In 21 of the remaining 24 boys, small, attenuated testicular vessels were noted to pass into the inguinal canal and inguinal exploration was required. A small testicular remnant was excised in 15 patients, but orchiopexy was possible in six boys. Diagnostic laparoscopy takes 7 to 10 minutes and enables the surgeon to develop a planned approach to this condition. With the information gathered at laparoscopy, the surgeon is best able to decide if an inguinal exploration is necessary or if a single-stage orchiopexy is possible. If a two-stage orchiopexy is required for an intra-abdominal testis, then clip ligation of the testicular vessels can be performed laparoscopically as the first stage, followed by Fowler-Stephens orchiopexy 6 to 9 months later.

Adolescent↗

PubMed1990

The changing incidence of Kaposi's sarcoma among patients with AIDS.

Kaposi's sarcoma (KS), the most common cancer in patients with acquired immunodeficiency syndrome (AIDS), occurs predominantly in homosexual men. However, the percentage of homosexual AIDS patients with KS has declined during the past 6 years. This and other findings suggest that one or more cofactors associated with the homosexual lifestyle, rather than a special viral strain, probably influence the development of KS in patients infected with the human immunodeficiency virus (HIV). Possible reasons for the decline include changes in homosexual behaviors, leading to the practice of safer sexual techniques, and a decrease in use of nitrite inhalants. Identification of the KS-AIDS cofactor(s) could be invaluable to developing prevention and treatment strategies.

Acquired Immunodeficiency Syndrome↗

PubMed1990

Kaposi's sarcoma in patients with AIDS: sex, transmission mode, and race.

We review epidemiologic studies aimed at identifying the cause(s) or cofactors for AIDS-related Kaposi's sarcoma (KS). The epidemiology of AIDS-related KS in the United States differs from that of other forms of KS. One important feature of the epidemiology of AIDS-related KS is that its occurrence by race is strikingly disproportional. We believe this maldistribution can shed light on recent discussions concerning the cause of AIDS-related KS, and we propose further studies to elucidate the etiology of AIDS-related KS.

Acquired Immunodeficiency Syndrome↗

PubMed1988

Epidemiology of HIV infection and AIDS in the United States.

By the end of 1987, nearly 50,000 cases of acquired immunodeficiency syndrome (AIDS) had been reported since 1981, 20,745 in the past year alone. Black and Hispanic adults and children have reported rates 3 to 12 times as high as whites. This can be largely attributed to higher reported rates in black and Hispanic intravenous (IV) drug abusers, their sex partners, and infants. In 1986, reported AIDS deaths increased adult male and female mortality in the United States by an estimated 0.7 and 0.07%, respectively, with much greater increases in selected age groups or areas of the country. The greatest variation in infection with the human immunodeficiency virus (HIV) (0 to 70%) has been found in surveys of IV drug abusers, while surveys of homosexual men reveal infection rates of 20 to 50%. Infection with HIV ranged from 0 to 2.6% in limited sexually transmitted disease clinic surveys of heterosexual men and women without a history of IV drug abuse or known sexual contact with persons at increased risk. The modes of HIV transmission are now well understood, but a large amount of biologic variability in efficiency of transmission remains to be explained. The period between initial infection with HIV and the development of AIDS is variable, but the risk for disease progression increases with duration of infection.

Acquired Immunodeficiency Syndrome↗

PubMed1988

Estimating AIDS infection rates in the San Francisco cohort.

Between 1978 and 1980 a cohort of approximately 6700 homosexual and bisexual men were recruited from the San Francisco City Clinic to participate in studies of sexually transmitted hepatitis B. Testing frozen blood specimens collected at intervals from these patients provides a means of tracking the spread of the AIDS virus since 1978. The rate of spread of HIV was estimated by fitting different survival curves to interval-censored serological data using maximum likelihood techniques. The curves were compared using the Akaike Information Criterion (AIC) to select that which best describes the data. The best was found to be a log-logistic model, which suggested that between 1978 and 1981 the virus spread rapidly, infecting 44% of the then uninfected cohort members. More recently the rate of spread has declined, with an additional 32% of the cohort becoming infected between 1981 and 1987.

Acquired Immunodeficiency Syndrome↗

PubMed1986

The economic impact of the first 10,000 cases of acquired immunodeficiency syndrome in the United States.

Acquired immunodeficiency syndrome (AIDS) is a serious, fatal disease affecting a relatively young population and has a great economic impact. Expenditures for hospitalization and economic losses from disability and premature death were estimated for the first 10,000 patients with AIDS reported in the United States. Extrapolation of data from surveys done in New York City, Philadelphia, and San Francisco suggests that these 10,000 patients with AIDS will require an estimated 1.6 million days in the hospital, resulting in over $1.4 billion in expenditures. Losses incurred for the 8,387 years of work that will be lost from disability and from the premature death of the 10,000 patients will be over $4.8 billion. The total economic burden of the AIDS epidemic will continue to rise as the number of diagnosed cases increases. These estimates reinforce the need for effective disease prevention strategies to reduce the number of cases.

Acquired Immunodeficiency Syndrome↗

PubMed1986

A model-based approach for estimating the mean incubation period of transfusion-associated acquired immunodeficiency syndrome.

The incubation period, representing the interval between the date of exposure and the date of diagnosis, can be firmly ascertained in transfusion-associated cases of acquired immunodeficiency syndrome (AIDS). However, because the observation period of all transfusion-infected persons may be short compared with the average incubation period for AIDS, many cases with long incubation periods have not yet been diagnosed. Thus, the simple average of 2.6 years tends to underestimate the true mean. To correct for this underestimation bias, we assumed that the underlying distribution of the incubation periods is a member of a broad class of probability densities. Then, by maximum likelihood techniques, the mean incubation period for transfusion-associated AIDS was estimated to be 4.5 years, with the 90% confidence interval ranging from 2.6 to 14.2 years. The long incubation period has important consequences for infected individuals and implications for public health intervention and prevention policy.

Acquired Immunodeficiency Syndrome↗

PubMed1985

The epidemiology of AIDS: current status and future prospects.

The reported incidence of acquired immune deficiency syndrome (AIDS) continues to increase in countries throughout the world. On the basis of a polynomial model for extrapolation, the cumulative number of cases diagnosed and reported since 1981 in the United States is expected to double during the next year with over 12,000 additional cases projected to be diagnosed by July 1986. The annual incidence rates for single (never-married) men in Manhattan and San Francisco, intravenous drug users in New York City and New Jersey, and persons with hemophilia A ranged from 261 to 350 per 100,000 population during 1984. For single men aged 25 to 44 years in Manhattan and San Francisco, AIDS was the leading cause of premature mortality in 1984 as measured by years of potential life lost. Infection with HTLV-III/LAV is considerably more common than reported AIDS in high-risk populations and can persist at least for several years, so the presence of specific antibody should be considered presumptive evidence of current infection. The screening of donated blood and plasma for antibody to HTLV-III/LAV and use of safer clotting factor concentrates should greatly reduce HTLV-III/LAV transmission through blood and blood products. Most HTLV-III/LAV infections occur through sexual transmission, use of contaminated needles, and as a result of infected mothers passing the virus to newborns. Continued research commitment is needed to develop an HTLV-III/LAV vaccine and therapy for this infection. In the interim, widespread community efforts are needed to minimize transmission.

Acquired Immunodeficiency Syndrome↗

PubMed1985

The incidence rate of acquired immunodeficiency syndrome in selected populations.

Population figures were obtained, and incidence rates of acquired immunodeficiency syndrome (AIDS) for the 12 months from June 1, 1983, to May 31, 1984, were estimated for single (never-married) men aged 15 years or older, intravenous (IV) drug users, Haitians living in the United States, persons with hemophilia A and B, female sexual contacts of male IV drug users, and blood transfusion recipients. Single men in San Francisco and Manhattan, IV drug users in New York City and New Jersey, hemophilia A patients, and recent Haitian entrants had the highest rates of disease (82.0 to 268.9 per 100,000). Male IV drug users and male Haitians were two to four times as likely to experience development of AIDS as were females in each group. Persons with hemophilia A had six times the incidence rate of AIDS as did those with hemophilia B. Persons with severe hemophilia A had three times the rate of those with moderate and seven times the rate of those with mild clotting factor deficiency. Although blood transfusion recipients and female sexual contacts of male IV drug users had much lower average yearly rates than did persons in the four other groups (0.4 to 9.4 per 100,000), they still had a higher incidence rate of AIDS than did persons not belonging to any of these groups (0.1 per 100,000).

Acquired Immunodeficiency Syndrome↗

PubMed1985

Pseudomonas cepacia colonization in patients with cystic fibrosis: risk factors and clinical outcome.

During the period of 1979 to 1983, 38 patients with cystic fibrosis (CF) at the CF center of St. Christopher's Hospital for Children in Pennsylvania developed respiratory tract colonization with Pseudomonas cepacia. Seventeen (45%) of the patients with colonization died. Yearly incidence rates of P. cepacia colonization fluctuated between 1.3% and 6.1%, suggesting an endemic phenomenon. Case-control studies showed that severe underlying CF, use of aminoglycosides, and having a sibling with CF and P. cepacia colonization were significant risk factors for P. cepacia colonization. Once colonized with P. cepacia, patients with CF were likely to be hospitalized longer (P = 0.008) and to die sooner (P = 0.0001) than control patients with CF. Environmental and microbiologic studies did not identify a common source or mode of transmission of P. cepacia among patients. The results of this investigation suggest that P. cepacia colonization of patients with CF was endemic in the hospital, occurred more frequently in those with severe disease, and was associated with adverse clinical outcome.

Adolescent↗

PubMed1985

Update from the SENIC project. Hospital infection control: recent progress and opportunities under prospective payment.

From a survey of all U.S. hospitals in 1976 and of a random sample in 1983, we found that the intensity of infection surveillance and control activities greatly increased, and the percentage of hospitals with an infection control nurse per 250 beds increased from 22% to 57%. The percentage with a physician trained in infection control remained low (15%), and there was a drop in the percentages of hospitals doing surgical wound infection surveillance (from 90% down to 79%) and reporting surgeon-specific rates to surgeons (from 19% down to 13%). There was an increase in the percentage of hospitals with programs shown to be effective in preventing urinary tract infections, bacteremias, and pneumonias, but not surgical wound infections. The percentage of nosocomial infections being prevented nationwide appears to have increased from 6% to only 9%, whereas 32% could be prevented if all hospitals adopted the most effective programs.

Cross Infection↗

PubMed1985

The nationwide nosocomial infection rate. A new need for vital statistics.

From a random sample of patients and hospitals and extrapolation ratios derived from the best available sources of data, the authors estimate that the nationwide nosocomial infection rate among the 6,449 acute-care US hospitals in 1975-1976 was 5.7 nosocomial infections per 100 admissions and that over 2 million nosocomial infections occurred in a 12-month period in these hospitals. Nosocomial urinary tract infections constituted 42% of the infections, surgical wound infections 24%, nosocomial pneumonia 10%, nosocomial bacteremia 5%, and nosocomial infections at all other sites 19%. If adjustments are made for the accuracy of the diagnostic method, the increasing nationwide secular trend, and the number of nosocomial infections in nursing homes, however, as many as 4 million nosocomial infections per year may now be occurring. This greatly exceeds previous estimates and calls for timely and accurate vital statistics on the problem.

Adult↗

PubMed1985

Increased recognition of infectious diseases in US hospitals through increased use of diagnostic tests, 1970-1976.

To assess the influence of physicians' diagnostic practices on the recognition of nosocomial infections, the authors analyzed data collected on 339,044 patients selected randomly from admissions in 1970 and 1975-1976 to 338 randomly selected hospitals representative of all acute-care US hospitals. Eight rates representing the frequency of cultures or chest x-rays among patients with or without signs of infection were calculated. These varied widely among hospitals, were highest in teaching hospitals and in the Northeast, but increased more among small hospitals and in the South and West. Rates of performing urine cultures and reporting colony counts were highly correlated with observed rates of nosocomial urinary tract infection. Analogous measures were moderately correlated with observed bacteremia rates and pneumonia rates but were only weakly associated with surgical wound infection rates. These data indicate that the nationwide increase in the use of these diagnostic tests increased the recognition of infectious diseases in US hospitals.

Cost Control↗

PubMed1985

The efficacy of infection surveillance and control programs in preventing nosocomial infections in US hospitals.

In a representative sample of US general hospitals, the authors found that the establishment of intensive infection surveillance and control programs was strongly associated with reductions in rates of nosocomial urinary tract infection, surgical wound infection, pneumonia, and bacteremia between 1970 and 1975-1976, after controlling for other characteristics of the hospitals and their patients. Essential components of effective programs included conducting organized surveillance and control activities and having a trained, effectual infection control physician, an infection control nurse per 250 beds, and a system for reporting infection rates to practicing surgeons. Programs with these components reduced their hospitals' infection rates by 32%. Since relatively few hospitals had very effective programs, however, only 6% of the nation's approximately 2 million nosocomial infections were being prevented in the mid-1970s, leaving another 26% to be prevented by universal adoption of these programs. Among hospitals without effective programs, the overall infection rate increased by 18% from 1970 to 1976.

Adult↗

PubMed1985

Identifying patients at high risk of surgical wound infection. A simple multivariate index of patient susceptibility and wound contamination.

To predict the likelihood that a patient will develop a surgical wound infection from several risk factors, the authors used information collected on 58,498 patients undergoing operations in 1970 to develop a simple multivariate risk index. Analyzing 10 risk factors with stepwise multiple logistic regression techniques, they developed a model combining information on four of the risk factors to predict a patient's probability of getting a surgical wound infection. Then, with information collected on another sample of 59,352 surgical patients admitted in 1975-1976, the validity of this index as a predictor of surgical wound infection risk was verified. With the simplified index, a subgroup, consisting of half the surgical patients, can be identified in whom 90% of the surgical wound infections will develop. By the inclusion of factors measuring the risk due to the patient's susceptibility as well as that due to the level of wound contamination, the simplified index predicts surgical wound infection risk about twice as well as the traditional classification of wound contamination (Goodman-Kruskal G = 0.67 vs. 0.36, p less than 0.0001). Use of this new index might substantially increase the efficiency of routine surgical wound infection surveillance and control.

Abdomen↗

PubMed1985

The acquired immunodeficiency syndrome in gay men.

The acquired immunodeficiency syndrome (AIDS) is a major health problem for gay men in the United States. About three fourths of all reported cases have occurred in this population, and the number is projected to double in the next year. In Manhattan and San Francisco, AIDS is now the leading cause of premature mortality in men aged 25 to 44 years who have never married. In a sample of a cohort of gay men enrolled in a San Francisco clinic, 2.7% of the men had the syndrome and 26% had related conditions in 1984. Antibody to human T-lymphotropic virus, type III/lymphadenopathy-associated virus was found in sera from 67% of the men, including 58% of asymptomatic men. Behavioral factors associated with an increased risk of AIDS include large numbers of sexual partners, receptive anal intercourse, and "fisting." The adoption of safer lifestyles is currently the basis of attempts to control the syndrome in gay men.

Acquired Immunodeficiency Syndrome↗

PubMed1985

Epidemiological trends of AIDS in the United States.

The incidence of acquired immunodeficiency syndrome (AIDS) in the United States has increased rapidly since the first reports in 1981. Highest estimated rates are among single (never-married) men in Manhattan and San Francisco, men and women who have abused drugs intravenously, and persons with hemophilia. Serosurveys among populations at increased risk for AIDS have demonstrated a high prevalence of antibody to human T-cell leukemia virus III-lymphadenopathy-associated virus (HTLV-III/LAV), the virus which causes AIDS. The discovery of the virus and the widespread availability of serological tests greatly increase the ability to understand AIDS and to study the natural history of HTLV-III/LAV infection.

Acquired Immunodeficiency Syndrome↗