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Biomedical subjects

E L Murphy

Publications and source records attributed to E L Murphy.

At least 19 recordsLinked to original sources
PubMed1992

A prospective study of transmission by transfusion of HTLV-I and risk factors associated with seroconversion.

To evaluate the risk of transfusion-related transmission of HTLV-I in Jamaica, a prospective study was initiated, prior to availability of a licensed HTLV-I serological screening assay. This information would prove useful in formulating strategies for blood-donor screening. We followed 118 pre-transfusion HTLV-I-negative transfusion recipients at monthly intervals post-transfusion for 1 year. Laboratory and questionnaire data were obtained at each visit to evaluate the clinical and immunological status of recipients. Cumulative incidence of HTLV-I seroconversion was estimated and risk-factor data associated with seroconversion among 66 HTLV-I-exposed transfusion recipients were analyzed. Seroconversion occurred in 24/54 (44%) of recipients of HTLV-I-positive cellular blood components, 0/12 recipients of positive non-cellular donor units and 0/52 recipients of HTLV-I-negative donor units. Significant risk factors associated with recipient seroconversion were receipt of a seropositive cellular blood component stored for less than one week [odds ratio (OR) = 6.34, 95% confidence interval (CI) = 1.83 to 21.92], male sex (OR = 4.79, 95% CI = 1.15 to 20.0) or use of immuno-suppressive therapy at time of transfusion (OR = 12.20, 95% CI = 0.95 to 156). Risk of blood-borne infection per person per year in Jamaica was estimated to be 0.009%. Our results confirm that blood transfusion carries a significant risk of HTLV-I transmission and that screening of donor blood effectively prevents HTLV-I seroconversion. Recipients at greatest risk for seroconversion were those who required multiple transfusions or who were receiving immunosuppressive therapy at the time of transfusion. These patients should be given priority in receiving selectively screened blood components, if universal blood-donor screening for HTLV-I is not possible.

Blood Donors↗
PubMed1992

Cost-benefit analysis of autologous blood donation in obstetrics.

OBJECTIVE: To determine whether there are predictors of peripartum transfusion, other than placenta previa, that identify a population of pregnant women whose risk of transfusion is high enough to justify antepartum autologous blood donation. METHODS: Using an established perinatal data base, we studied 14,267 consecutive term deliveries without placenta previa. Univariate and multivariate analyses were performed to assess ten predictors of peripartum transfusion that might reasonably be detected in the antepartum period. Costs were calculated for a hypothetical autologous blood donation program to prevent transfusion-related infection. RESULTS: Red-cell transfusion was used in 150 deliveries (1.1%). A total of 424 units was transfused (2.9 per 100 deliveries). Four risk factors were significantly (P less than .05) predictive of peripartum red-cell transfusion: preeclampsia (adjusted odds ratio 3.69), multiple gestation (2.82), elective cesarean (1.71), and nulliparity (1.51). Controlling for these, there was no association between transfusion and previous postpartum hemorrhage, previous cesarean with trial of labor, prior abortions, induction of labor, or ethnic group. A hypothetical antepartum blood donation program restricted to patients with three or more risk factors would cost $32,800-130,700 per case to prevent transfusion-related hepatitis and $26,000,000-78,000,000 per case to prevent human immunodeficiency virus infection. CONCLUSION: In obstetric patients without placenta previa, the need for peripartum red-cell transfusion cannot be predicted with sufficient accuracy to justify the costs of antepartum autologous blood donation.

Blood Transfusion, Autologous↗
PubMed1991

Evaluation of screened blood donations for human immunodeficiency virus type 1 infection by culture and DNA amplification of pooled cells.

BACKGROUND: Reports of transmission of the human immunodeficiency virus type 1 (HIV-1) from transfusions of screened blood and reports of silent, antibody-negative HIV-1 infections in persons at high risk continue to foster concern about the safety of the blood supply. Previous estimates of the risk of HIV-1 range from 1 in 38,000 to 1 in 300,000 per unit of blood but are based on either epidemiologic models or the demonstration of seroconversion in recipients. METHODS: We isolated peripheral-blood mononuclear cells from blood that was fully screened and found to be seronegative, combined them into pools of cells from 50 donors, and tested them for HIV-1 by viral culture and the polymerase chain reaction, using protocols specifically adapted for this analysis. RESULTS: The 1530 pools of mononuclear cells were prepared from 76,500 blood donations made in San Francisco between November 1987 and December 1989. Of these pools, 1436 (representing 71,800 donations) were cultured successfully; 873 (43,650 donations) were evaluated by the polymerase chain reaction. Only one pool was confirmed as HIV-1--infected by both methods. After adjustment for sample-based estimates of the sensitivity of the detection systems using culture and the polymerase chain reaction, the probability that a screened donor will be positive for HIV-1 was estimated as 1 in 61,171 (95 percent upper confidence bound, 1 in 10,695). CONCLUSIONS: Silent HIV-1 infections are exceedingly rare among screened blood donors, so the current risk of HIV-1 transmission from blood transfusions, even in high-prevalence metropolitan areas, is extremely low.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Human T-lymphotropic virus type I (HTLV-I) seroprevalence in Jamaica. I. Demographic determinants.

During 1985 and 1986, the authors measured antibodies to human T-lymphotropic virus type I (HTLV-I) in a cohort of 13,260 Jamaicans from all parts of the island who applied for food-handling licenses. HTLV-I seroprevalence was strongly age and sex dependent, rising from 1.7% (10-19 years) to 9.1% (greater than or equal to 70 years) in men and from 1.9% (10-19 years) to 17.4% (greater than or equal to 70 years) in women. In a logistic regression analysis, women were more likely to be seropositive than were men, and farmers, laborers, and the unemployed were more likely to be HTLV-I seropositive than were those reporting student or professional occupations. In men, African ethnicity was associated with HTLV-I seropositivity in the univariate analysis but was not a risk factor after adjustment for age and sex. There was a trend toward higher age-stratified HTLV-I seroprevalence among younger women who reported more pregnancies, but older multigravidas had lower rates of HTLV-I seropositivity. Persons born outside Jamaica had significantly lower seroprevalence than did those born in Jamaica, but they were of slightly different ethnic and occupational compositions than those born in Jamaica.

Adolescent↗
PubMed1991

Human T-lymphotropic virus type I (HTLV-I) seroprevalence in Jamaica. II. Geographic and ecologic determinants.

An island-wide cohort of 13,260 Jamaicans who applied for food-handling licenses during 1985 and 1986 were tested for antibodies to human T-cell lymphotropic virus type I (HTLV-I). Demographic and residence history data were linked to geographic and ecologic measures of elevation, rainfall, crop-growing areas, population density, and additional measures of urbanization and correlated with HTLV-I antibody status. By logistic regression analysis (performed separately for men and women), men and women who currently resided at low elevation (less than or equal to 1,000 ft (305 m)) were more likely to be HTLV-I infected than were those residing at high elevation. Men, but not women, who were born in citrus-growing areas were more likely to be HTLV-I infected than were men who were born in other areas. By univariate analysis, there was a significant positive trend of increasing HTLV-I seroprevalence with increasing amount of annual rainfall associated with birthplace and primary residence areas. However, these associations did not remain significant after adjusting for age and sex. These environmental associations raise the possibility of new modes of viral transmission or host response to infection, although they may simply be surrogates for socioeconomic status, breastfeeding habits, or sexual behavior, which are known determinants of HTLV-I zero prevalence.

Adolescent↗
PubMed1991

Detection of early human T-cell lymphotropic virus type I antibody patterns during seroconversion among transfusion recipients.

From a cohort of human T-cell lymphotropic virus type I (HTLV-I) exposed transfusion recipients (N = 71) enrolled in the Jamaican Transfusion Study, 11 were selected for detailed laboratory evaluation. All recipients were followed at monthly intervals for 6 months and then bimonthly up to 1 year for evidence of HTLV-I seroconversion. Without regard to results on screening assays, pretransfusion and posttransfusion samples were tested with two licensed HTLV-1 whole-virus screening enzyme immunoassays (EIAs), recombinant EIAs for antibody against tax (p40x) and p21e envelope, standard whole virus Western blot (WB), WB enhanced with recombinant p21e, and radioimmunoprecipitation assay (RIPA). In the early period posttransfusion, antibody to gag core protein was predominant with anti-p24 generally appearing before anti-p19. Recombinant anti-p21e envelope protein, in EIA and WB format, was frequently the earliest envelope reactivity detected, while anti-gp46 in WB and anti-gp61/68 in RIPA system appeared later. Anti-tax antibodies appeared later in the time course of seroconversion. The whole-virus EIAs were less sensitive than the confirmatory assays. The combination of WB and RIPA or WB enhanced with recombinant p21e appeared equally effective in confirming samples as positive by the Public Health Service two gene group confirmatory algorithm. However, specificity of this assay approach could not be addressed in this study.

Adolescent↗
PubMed1991

Gastrointestinal parasitic infection in healthy Jamaican carriers of HTLV-I.

A subsample (1.6%; n = 13,260) of a healthy Jamaican population of food-handlers, studied by Murphy et al. (1991), who were serologically positive (n = 99) or negative (n = 113) for HTLV-I was investigated for intestinal parasitic infection using coprological methods. Helminth infection included Ascaris lumbricoides (2.8%), Trichuris trichiura (7.1%) and hookworms (6.1%). Entamoeba coli was found in 21.8% of samples, while E. hartmanni, Giardia lamblia, Endolimax nana, Iodamoeba bütschlii and Chilomastix mesnili each occurred in less than 10% of responders. T. trichiura displayed a higher prevalence (10.6 vs 3%) (chi 2 = 4.623; P = 0.03) in the HTLV-I negative group. G. lamblia was detected more frequently among HTLV-I carriers compared to controls (9.1 and 3.5%, respectively), but the association was not statistically significant (chi 2 = 2.825; P = 0.09). Infection with intestinal parasites is likely to occur independent of HTLV-I status: however, possible HTLV-I-induced immunosuppression may lead to higher intensity infections of certain organisms thus facilitating easier detection using parasitological methods. The immunomodulatory potential of HTLV-I infection in the aetiology of non-malignant diseases requires further investigation.

Analysis of Variance↗
PubMed1991

The clinical significance of HTLV-I and HTLV-II infection in the AIDS epidemic.

Although early reports of an etiological role of HTLV-I in AIDS are not supported by subsequent epidemiologic and biologic data, all AIDS specialists should be aware of the possible infection of AIDS risk group members with the HTLV viruses. In the United States, HTLV-II and HIV co-exist in high prevalence among IVDU, and coinfected IVDU may progress more quickly to AIDS. The health effects of solitary HTLV-II infection are currently unknown. In Africa and the Caribbean, where HTLV-I is endemic, the epidemic of HIV infection will likewise produce coinfection and possibly faster progression to AIDS. In addition, adult T-cell leukemia/lymphoma and HTLV-associated myelopathy (HAM/TSP) may occur in persons infected with HTLV-I alone. Clinical care of HTLV infected patients is difficult because of societal confusion of these viruses with HIV. The full health effects of both HTLV-I and HTLV-II are not yet known, and even the two known disease outcomes of HTLV-I infection occur in only a few percent of those infected. Without prognostic indicators, and with the long latency from infection to disease, counseling and medical follow-up of patients is difficult. Further research into the clinical effects of HTLV-I and HTLV-II is urgently needed.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Factors associated with postpartum hemorrhage with vaginal birth.

A case-control study was performed to study risk factors for postpartum hemorrhage. Cases of hemorrhage were defined by a hematocrit decrease of 10 points or more between admission and post-delivery or by the need for red-cell transfusion. Patients with antenatal bleeding were excluded. Among 9598 vaginal deliveries, postpartum hemorrhage occurred in 374 cases (3.9%). Three controls were matched to each case and multiple logistic regression was used to control for covariance among predictor variables. Factors having a significant association with hemorrhage were prolonged third stage of labor (adjusted odds ratio 7.56), preeclampsia (odds ratio 5.02), mediolateral episiotomy (4.67), previous postpartum hemorrhage (3.55), twins (3.31), arrest of descent (2.91), soft-tissue lacerations (2.05), augmented labor (1.66), forceps or vacuum delivery (1.66), Asian (1.73) or Hispanic (1.66) ethnicity, midline episiotomy (1.58), and nulliparity (1.45). These data may help predict postpartum hemorrhage and may be useful in counseling patients about the advisability of home delivery, intravenous access in labor, or autologous blood donation.

Case-Control Studies↗
PubMed1991

Factors associated with hemorrhage in cesarean deliveries.

A case-control study was performed to study risk factors for hemorrhage in cesarean deliveries. Hemorrhage was defined by a pre- to post-delivery hematocrit decrease of 10 points or more or by the need for red-cell transfusion. Patients with antenatal bleeding were excluded. Among 3052 cesarean deliveries, hemorrhage occurred in 196 cases (6.4%). Three controls were matched to each case and multiple logistic regression was used to control for covariance among predictor variables. Factors having a significant association with hemorrhage were: general anesthesia (adjusted odds ratio 2.94), amnionitis (odds ratio 2.69), preeclampsia (2.18), protracted active phase of labor (2.40), second-stage arrest (1.90), and Hispanic ethnicity (1.82). After adjustment for these variables, a classic uterine incision had a small but significant association (odds ratio 1.06) with hemorrhage. Previous cesarean, parity, gestational age, and several other factors had no association with hemorrhage. These data allow one to anticipate hemorrhage in patients at risk and may be useful in planning appropriate use of blood bank resources, including antepartum autologous blood donation.

Blood Loss, Surgical↗
PubMed1990

Type-specific antigens for serological discrimination of HTLV-I and HTLV-II infection.

55 HTLV-I (human T-cell lymphotropic virus) and 45 HTLV-II carriers, confirmed by HTLV-type specific polymerase chain reaction (PCR), were distinguished by western blot assays with recombinant HTLV I or II envelope glycoproteins. Recombinant protein (RP) B1 contains aminoacids 166-201 from HTLV-I exterior glycoprotein gp46 and was reactive with HTLV-I samples only. RP-IIB, which contains aminoacids 96-235 from HTLV-II exterior glycoprotein gp52, was reactive with all HTLV-II samples. 39 patients (86.6%) had high reactivity by densitometry. Of 55 HTLV-I samples, 35 (65.5%) had antibody reactivity to RP-IIB, but only 1 (1.8%) had high reactivity by densitometry. RP B1 and IIB western blot assays may replace the PCR test in diagnosis of HTLV infection.

Blotting, Western↗
PubMed1990

Determination of a unique and immunodominant epitope of human T cell lymphotropic virus type I.

The identification and isolation of unique and immunogenic recombinant epitopes for human T cell lymphotrophic virus (HTLV) type I might allow the development of an antibody-based assay to differentiate between HTLV-I and HTLV-II infections. To test the feasibility of this approach, an HTLV-I envelope epitope was isolated by immunoscreening of a lambda gt11 recombinant HTLV-I DNA library with a human monoclonal antibody to HTLV-I. This recombinant epitope. MTA-4, when tested with sera from HTLV-I- or HTLV-II-infected individuals, was reactive with all HTLV-I and nonreactive with all HTLV-II antisera. These results indicate that MTA-4 is a unique and immunodominant epitope on HTLV-I and confirm the usefulness of human-derived monoclonal antibodies in an experimental approach to dissect the human humoral response to a viral pathogen.

Antibodies, Monoclonal↗
PubMed1989

Sexual transmission of human T-lymphotropic virus type I (HTLV-I).

STUDY OBJECTIVE: To study the seroprevalence of human T-lymphotropic virus type I (HTLV-I) in a sexually active population and to determine sexual behavior risk factors for infection. DESIGN: Cross-sectional seroprevalence study using enzyme-linked immunosorbent assay (ELISA) and Western blot. Risk-factor data were gathered by administered questionnaire and chart review. SETTING: Two urban, primary care clinics for persons with sexually transmitted diseases run by the Jamaican Ministry of Health. PATIENTS: Of the 2050 consecutive patients presenting with new episodes of sexually transmitted disease, 1977 patients were eligible for analysis. MEASUREMENTS AND RESULTS: Overall HTLV-I seroprevalence was 5.7%; prevalence increased with age from 1.6% (age, 14 to 19 years) to 5.1% (age, 30 years and older) in men and from 5.3% (age, 14 to 19 years) to 14.1% (age, 30 years and older) in women. Compared with a reference cohort of food service employees, age-adjusted HTLV-I seroprevalence was increased in female patients with sexually transmitted disease (odds ratio = 1.83; CI, 1.41 to 2.83) but not in male patients with sexually transmitted disease. Independent risk factors for HTLV-I infection in women included having had more than ten lifetime sexual partners (odds ratio = 3.52, CI, 1.28 to 9.69) and a current diagnosis of syphilis (odds ratio = 2.12; CI, 1.12 to 3.99). In men, a history of penile sores or ulcers (odds ratio = 2.13; CI, 1.05 to 4.33) and a current diagnosis of syphilis (odds ratio = 3.56; CI, 1.24 to 10.22) were independent risk factors for HTLV-I infection. Of 1977 patients, 5 (0.3%) had antibodies to human immunodeficiency virus type 1 (HIV-1), including 2 with HTLV-I and HIV-1 coinfection. CONCLUSIONS: We conclude that HTLV-I is transmitted from infected men to women during sexual intercourse. Our data are consistent with the lower efficiency of female-to-male sexual transmission of HTLV-I, but penile ulcers or concurrent syphilis may increase a man's risk of infection.

Adolescent↗