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Biomedical subjects

L Mascola

Publications and source records attributed to L Mascola.

At least 37 records · Page 2Linked to original sources
PubMed1995

Listeria monocytogenes infection and serotype distribution among HIV-infected persons in Los Angeles County, 1985-1992.

Persons infected with human immunodeficiency virus (HIV) are at greater risk of infection with Listeria monocytogenes (LM) than the general population. We quantify the risk of listeriosis in persons with acquired immune deficiency syndrome (AIDS) and HIV infection in Los Angeles County (LAC) and report the LM serotype distribution among HIV-infected patients with listeriosis. Active surveillance for listeriosis was performed in LAC during most of the period from 1985 through 1992. Thirty-four (10%) of 351 nonperinatal cases of listeriosis reported in LAC from 1985 through 1992 were in HIV-infected persons, 25 of whom met the 1987 AIDS case definition. The incidence of listeriosis was 95.8 and 8.8 cases per 100,000 person-years among persons with AIDS and all HIV-infected persons, respectively, but only 1.0 case per 100,000 person-years in the total population. Excluding cases from a 1985 listeriosis epidemic associated with consumption of contaminated Mexican-style cheese, 11 (65%) of 17 HIV-infected persons with available isolates were infected with LM serotype 1/2b, whereas only 64 (31%) of 208 other persons with listeriosis and available isolates were infected with LM serotype 1/2b (odds ratio = 4.1; 95% confidence interval = 1.3-14.1). LM serogroup 1/2b may have been more common among HIV-infected persons in LAC than among other persons with listeriosis because of differences in diet or sexual practices, or to chance alone. Persons with HIV-infection, especially those with AIDS, should be educated in avoiding foods at high risk of listerial contamination, such as soft cheeses, foods sold from delicatessen counters, and undercooked chicken.

Adolescent↗
PubMed1995

Reduction in the incidence of human listeriosis in the United States. Effectiveness of prevention efforts? The Listeriosis Study Group.

BACKGROUND: Food-borne transmission is now recognized as a major cause of human listeriosis. OBJECTIVE: To assess the impact of prevention efforts, listeriosis rates before interventions were initiated in 1989 were compared with more recent rates (1990 through 1993). DESIGN: From 1989 through 1993, multistate, laboratory-based active surveillance was conducted to identify all cases in which Listeria monocytogenes was isolated from cultures or ordinarily sterile sites in an aggregate population of more than 19 million. SETTING: All laboratories serving acute care hospitals in up to nine surveillance areas in the United States. INTERVENTIONS: In 1989, a well-publicized case report of listeriosis linked to processed poultry led US regulatory agencies to enforce aggressive food monitoring policies and prompted industry to invest in cleanup efforts. In May 1992, consumer guidelines for listeriosis prevention were disseminated. OUTCOME MEASURES: Cases of perinatal and nonperinatal listeriosis. RESULTS: The rate of listeriosis decreased in all surveillance areas. Projection of these rates to the US population suggests an estimated 1965 cases and 481 deaths occurred in 1989 compared with an estimated 1092 cases and 248 deaths in 1993, a 44% and 48% reduction in illness and death, respectively. Among adults 50 years of age and older, rates declined from 16.2 per 1 million in 1989 to 10.2 per 1 million in 1993 (P = .02). Perinatal disease decreased from 17.4 cases per 100,000 births in 1989 to 8.6 cases per 100,000 births in 1993 (P = .003). Three serotypes (1/2a, 1/2b, and 4b) of L monocytogenes accounted for more than 96% of cases during each year of the study (1989 through 1993). CONCLUSIONS: The incidence of listeriosis in study areas was substantially lower in 1993 than in 1989. The temporal association of this reduction with industry, regulatory, and educational efforts suggests these measures were effective.

Adolescent↗
PubMed1995

HIV transmission through donor artificial insemination.

OBJECTIVE: To investigate and report cases of human immunodeficiency virus (HIV) transmission through donor artificial insemination (AI) before 1986 at five infertility clinics. DESIGN: Two types of look-back studies were performed: (1) identification of an HIV-infected woman who reported previous AI, followed by identification of the infected donor(s) and contact tracing of women who were inseminated with his semen, and (2) identification of an HIV-infected donor and subsequent examination of women receiving AI procedures using his semen. SETTING: Five infertility clinics in Los Angeles County, California; San Diego County, California; Arizona; and Vancouver, British Columbia. PATIENTS: A total of 230 women were inseminated with semen from any one of the five identified HIV-infected donors; 199 (87%) consented to HIV testing. MAIN OUTCOME MEASURE: Seropositivity for HIV among AI recipients. RESULTS: Seven (3.52%) of the 199 women (95% confidence interval, 1.55% to 7.41%) who were artificially inseminated with semen from any of five HIV-infected donors and consented to HIV testing tested HIV-seropositive. Information on HIV risk was available for three of the five donors; all three reported a history of having sex with men. Four HIV-infected women were identified through uncommon circumstances, rather than through routine look-back studies of donors. CONCLUSION: Infection with HIV through donor AI performed before routine HIV screening of semen donors represents a potentially serious threat to women who underwent AI procedures. Public health policies requiring retrospective identification of HIV-infected semen donors and patients receiving AI before 1986, especially in acquired immunodeficiency syndrome (AIDS)-prevalent areas, should be considered routine. Women diagnosed with AIDS or HIV infection, in whom no identified risk of HIV acquisition is established, should be questioned about previous AI procedures.

AIDS Serodiagnosis↗
PubMed1995

A comparison of hospital policies for measles, mumps, and rubella infection control in Los Angeles County, 1989 and 1992.

BACKGROUND: A survey was conducted in 1992 in Los Angeles County, California, to assess changes since an earlier survey in 1989 in the numbers of acute care hospitals that had established policies on measles, mumps, and rubella infection control and the extent to which these policies were implemented. METHODS: A questionnaire inquiring about measles, mumps, and rubella infection control was sent to ICPs of 133 acute care hospitals in Los Angeles County. The results were compared with those of a similar survey conducted in 1989. The increase in the number of hospitals with such policies between 1989 and 1992 was analyzed. RESULTS: In 1989, 29 (28%), 9 (9%), and 65 (64%) of the 102 respondent hospitals had measles, mumps, and rubella infection control policies, respectively. Larger proportions of the 95 respondent hospitals in 1992 had measles (56, 59%), mumps (15, 16%), and rubella (69, 73%) infection control policies. CONCLUSIONS: The number of hospitals with infection control policies for measles, mumps, and rubella increased from 1989 to 1992. Efficiency and scope of such policies varied, however, and could be improved by making the policies mandatory, requiring written documentation of employee immunity, and extending policies to cover all employees. The most dramatic increase was in the number of hospitals with infection control policies for measles; this increase may have been caused by the 1987 to 1989 measles epidemic in Los Angeles County, by increased awareness of the Immunization Practices Advisory Committee recommendations, or by increased sensitivity to the issue of infection control triggered by the 1989 survey.

California↗
PubMed1994

Diagnosis and treatment of cholera in the United States. Are we prepared?

OBJECTIVE: To assess cholera recognition and treatment by US health care workers in the largest cholera outbreak in the United States this century. DESIGN: We reviewed the medical records of passengers from a flight on which a cholera outbreak occurred. To determine the availability of oral rehydration solutions, we surveyed treatment facilities and referral pharmacies. SETTING: On February 14, 1992, more than 100 passengers on a flight from South America to Los Angeles, Calif, were infected with toxigenic Vibrio cholerae O1. SUBJECTS: Fifty-four of 67 passengers who sought care in California and Nevada. RESULTS: We reviewed the records of 54 passengers, including 39 with diarrhea and 15 without symptoms. All 17 persons who sought treatment before the outbreak was widely reported by the media had diarrhea. For 12 of these persons, recent travel to South America was noted, but only those four whose records listed cholera as a possible diagnosis were immediately hospitalized. Seven sought care again within 3 days; three were dehydrated, two of these three were hospitalized, and one of these two died. None of the 26 patients suspected to have cholera received appropriate fluids; severely dehydrated patients did not receive Ringer's lactate solution and those not severely dehydrated did not receive an oral rehydration solution. None of the facilities and pharmacies involved stocked World Health Organization oral rehydration salts solution, the preferred solution for treating cholera and other diarrheal diseases. CONCLUSIONS: Treatment of cholera in the United States was suboptimal. Oral fluids appropriate for the treatment of cholera and other diarrheal diseases were generally unavailable. Widespread cholera in the developing world means that US physicians should be prepared to treat "imported" cases. Physicians evaluating patients with diarrhea should obtain a travel history, should consider cholera in patients returning from countries with endemic or epidemic cholera, and should instruct patients in appropriate use of World Health Organization oral rehydration salts solution or other oral rehydration solutions containing 75 to 90 mmol/L of sodium. Pharmacies and medical facilities should stock these solutions.

Cholera↗
PubMed1994

Eradication of Haemophilus influenzae type b disease in southern California. Kaiser-UCLA Vaccine Study Group.

OBJECTIVE: To assess the effects of Haemophilus influenzae vaccination of infants. RESEARCH DESIGN: We evaluated H influenzae type b (Hib) disease rates in Los Angeles County, California (population, 9 million; 1983 through 1992), and in the Southern California Kaiser Health Plan (2.5 million enrollees; 1988 through 1992) during the past decade. Cases were obtained through active and passive disease surveillance in the two populations. The following vaccines were used during the study period (1983 through 1992): (1) Hib polysaccharide vaccine (polyribosyl ribitol phosphate) (used from 1985 through 1987 for children 24 through 60 months of age); (2) Hib polysaccharide-diphtheria toxoid conjugate, Hib polysaccharide CRM197 mutant diphtheria toxoid conjugate vaccine, and Hib polysaccharide outer-membrane protein of group B meningococcus conjugate vaccine in older children (1988 through 1990; ages 15 through 60 months); and (3) Hib polysaccharide CRM197 mutant diphtheria toxoid conjugate vaccine and Hib polysaccharide outer-membrane protein of group B meningococcus conjugate vaccine used in infants (1991 through 1992). MEASUREMENTS AND RESULTS: Between 1983 and 1988, the Hib disease incidence in Los Angeles County was unchanged (32.7 to 42.5/100,000 person-years in children younger than 5 years). In 1989 through 1990, before Hib conjugate licensure for infant use, Hib disease rates in all age groups declined. After licensure of Hib vaccines for infants in 1990, there was a further fivefold decrease in infants. More dramatic decreases occurred in the better-immunized Kaiser Health Plan children aged 0 through 60 months (53 cases in 1989, only two cases in 1992). CONCLUSIONS: The Hib disease has been nearly eradicated in a fully immunized population (Kaiser Health Plan), and significant reductions have also occurred in Los Angeles County.

California↗
PubMed1994

Listeriosis: a previously unreported medical complication in women with multiple gestations.

OBJECTIVE: Our purpose was to determine whether women pregnant with multiple gestations are at greater risk for perinatal listeriosis than are women pregnant with singletons. STUDY DESIGN: Active surveillance for perinatal listeriosis was carried out in Los Angeles County, California, medical records were reviewed, and rates of listeriosis were calculated from live birth and fetal death data. RESULTS: From January 1985 through December 1992, 12 (4.0%) of 301 perinatal listeriosis cases occurred in pregnant women with multiple gestations, almost four times the overall multiple gestation rate in Los Angeles County. Rates of listeriosis in pregnant women per 100,000 live births and fetal deaths were 19.8 for singleton and 74.9 for multiple gestations (risk ratio 3.8, 95% confidence interval 2.1 to 6.8). Compared with singleton pregnancies, greater risk of listeriosis was observed in pregnancies with triplet gestations (risk ratio 38.4, 95% confidence interval 9.6 to 153.3) than in those with twin gestations (risk ratio 3.2, 95% confidence interval 1.7 to 6.0). Increased risk of listeriosis during multiple-gestation pregnancies was most notable among women > or = 35 years (risk ratio 13.6, 95% confidence interval 5.2 to 35.5) and Hispanic women (risk ratio 5.3, 95% confidence interval 2.8 to 10.0). CONCLUSIONS: To reduce the risk of listeriosis, obstetricians should incorporate dietary recommendations into routine prenatal nutritional counseling for all pregnant women and should especially counsel women pregnant with multiple gestations of their greater risk.

Adult↗
PubMed1994

Municipal drinking water and cryptosporidiosis among persons with AIDS in Los Angeles County.

To assess unfiltered drinking water as a source of cryptosporidium infection in patients with the acquired immunodeficiency syndrome (AIDS) the prevalence of cryptosporidiosis among persons with AIDS in Los Angeles County was assessed by water service area. One water distributor, serving approximately 60% of the county's residents (area B), has consistently employed filtration. The other company, which serves the remainder of the county (area A), did not institute filtration until mid-December 1986. This difference provided a 'natural experiment' in which to assess the effect of municipal water filtration on the level of cryptosporidiosis among persons with AIDS. The prevalence of cryptosporidiosis among AIDS patients was compared for the two water service areas for the time period (1983-6) preceding the implementation of filtration in area A. From 1983 to 1986 the age-standardized prevalence of cryptosporidiosis among AIDS patients was 32% lower in area A (4.2%), which received unfiltered water, than in area B (6.2%). Following addition of filtration in area A, the prevalence of cryptosporidiosis among AIDS patients decreased by 20%; however, a decline, of 47%, was also observed in area B. The similar baseline levels of cryptosporidiosis and the corresponding post-filtration decline in both areas suggest that filtration had no effect on levels of cryptosporidiosis among persons with AIDS. Thus it does not appear that municipal drinking water is an important risk factor for cryptosporidiosis in AIDS patients residing in Los Angeles County.

AIDS-Related Opportunistic Infections↗
PubMed1994

Protection provided by Haemophilus influenzae type b conjugate vaccines in Los Angeles County: a case-control study.

The objective was to assess the degree of disease control and to evaluate the protective efficacy of licensed Haemophilus influenzae type b (Hib) conjugate vaccines (HbOC, PRP-OMP, PRP-D) used routinely in children 2 to 35 months of age. We conducted a case-control study in Los Angeles County between January 1, 1991, and December 31, 1992, and a cohort analysis of Hib cases between 1983 and 1992. For the case-control study 105 cases of invasive Hib disease were identified and 767 geographically and age-matched controls were selected by random digit telephone dialing. Sixteen HbOC vaccine failures occurred > 14 days after a single dose of vaccine, 6 vaccine failures after 2 doses and 3 failures after 3 doses; 2 cases occurred 6 and 12 days, respectively, after an initial dose of HbOC. The protective efficacy of a single HbOC vaccine dose was 71.1% (95% confidence interval (CI), 37.5 to 87.2%). After 2 doses the efficacy was 88.8% (95% CI, 59.5 to 96.9%) and after 3 doses it was 94.4% (95% CI, 68.0% to 99.0%). Similar 95% CIs were seen for 1 and 2 doses of PRP-OMP vaccine. Adjustment of efficacy estimates for potential confounding variables did not significantly alter the results. Despite relatively low rates of immunization (20 to 60%) the rates of Hib disease decreased strikingly between 1990 and 1992 (from 24.2 to 4.4/100,000 children < 5 years of age). The HbOC conjugate vaccine, used predominantly but incompletely during this period, provided substantial protection against invasive Hib disease in children immunized between 2 and 35 months of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Case-Control Studies↗
PubMed1994

Progression of human immunodeficiency virus disease among infants and children infected perinatally with human immunodeficiency virus or through neonatal blood transfusion. Los Angeles County Pediatric AIDS Consortium and the Los Angeles County-University of Southern California Medical Center and the University of Southern California School of Medicine.

Using community-based surveillance data for pediatric human immunodeficiency virus (HIV) infection, we examined disease progression using survival analysis among perinatally HIV-infected children and children HIV-infected through a neonatal blood transfusion. As of December 31, 1991, 238 HIV-infected children (classified P-1 or P-2 according to the Centers for Disease Control and Prevention classification system) were identified. Median symptom-free survival time from birth to symptomatic infection (P-2) was different for perinatally acquired (n = 166) and neonatal transfusion-acquired (n = 72) infection (6.4 months vs. 17.8 months, respectively; P < 0.001). Survival after development of symptomatic infection (P-2) did not differ by transmission mode. Survival differences from birth to death were significant at P < 0.05 (75% of perinatally HIV-infected children survived 44 months vs. 71 months for transfusion-associated children). Although survival estimates improved for those receiving antiretroviral treatment, differences by mode were still observed. For perinatally HIV-infected children, mortality was highest in the first year of life (12%). Those remaining symptom-free beyond their first year demonstrated survival experiences similar to those for children with transfusion-associated infection.

AIDS Serodiagnosis↗
PubMed1994

Listeria infection of silicone breast implant.

A case of breast implant infection with L. monocytogenes is presented. The nature of this organism, its usual mode of transmission, and factors predisposing to the development of listeriosis are reviewed. We speculate that, in this case, the organism was acquired during a natural period of depressed immunity due to pregnancy, and it initiated a low-grade infection around the breast prosthesis. Possible implications of this scenario are discussed.

Adult↗
PubMed1994

An increase in Haemophilus influenzae type B vaccination among preschool-aged children in inner-city Los Angeles, 1990 through 1992.

Haemophilus influenzae type b (Hib) vaccination coverage and disease incidence were measured among preschool-aged children residing in inner-city Los Angeles. Among children 1.5 to 14 months of age, vaccination coverage of at least one dose increased from 0% in 1990 to 82% (95% confidence interval [CI] = 73%, 91%) in 1992. Among children 15 to 59 months old, vaccination coverage of at least one Hib dose administered at or after age 15 months increased from 35% (95% CI = 29%, 41%) in 1990 to 63% (95% CI = 56%, 70%) in 1992. Although Hib vaccination has reduced disease incidence in this population, greater use of vaccine can result in further reductions.

Child, Preschool↗
PubMed1994

Investigation of an epidemic of invasive aspergillosis: utility of molecular typing with the use of random amplified polymorphic DNA probes.

When seven immunocompromised patients developed invasive aspergillosis during construction at a hospital, new methods were performed to compare fungal isolates and a case-control study was conducted to determine risks for infection. Typing of Aspergillus flavus with the use of restriction endonuclease analysis and restriction fragment length polymorphism using random amplified polymorphic DNA reactions to generate DNA probes revealed different patterns between isolates from two patients and a similar pattern among those from one patient, a health care worker, and an environmental source. Case patients were more likely than controls to have longer periods of hospitalization (median, 83 vs. 24 days; P < 0.01), neutropenia (median, 33 vs. 6 days; P < 0.05), and exposure to broad spectrum antimicrobials (median, 56 vs. 15 days; P = 0.08). No patients restricted to protected areas developed aspergillosis. Risk of exposure of immunocompromised patients to opportunistic organisms stirred up by construction activity may be decreased by admitting these patients to protected areas away from construction activity and by restricting traffic from construction sites to these areas. Although typing of A. flavus isolates did not reveal a single type or source of organism responsible for infection, this method may facilitate epidemiologic investigation of possible nosocomial sources and transmission in similar settings.

Adolescent↗
PubMed1993

A cluster of coagulase-negative staphylococcal bacteremias associated with peripheral vascular catheter colonization in a neonatal intensive care unit.

BACKGROUND: A cluster of six neonatal cases of coagulase-negative staphylococcal bacteremias occurred in a Los Angeles County neonatal intensive care unit in March 1989. METHODS: A retrospective cohort study assessed the impact of host-and delivery-related variables, length of hospitalization, duration of antibiotic treatment, performance or duration of invasive procedures, and staffing variables on risk of coagulase-negative staphylococcal bacteremia. RESULTS: Unstratified analyses yielded eight risk factors with risk ratios greater than 2. After stratification by gestational age (less than 29 weeks) and low birth weight (less than 1500 gm), frequency of blood transfusions, duration of respiratory therapy, heparin lock and central vascular line placement, and hyperalimentation remained associated with elevated risk. Two species were identified, arguing against a common source of infection. Of four cohort months with more than 15 very low birth weight infants in the neonatal intensive care unit, an elevation of coagulase-negative staphylococcus-positive blood cultures and diagnosed bacteremias occurred in only two. CONCLUSIONS: This cluster of coagulase-negative staphylococcal bacteremia was probably caused by frequent manipulation of catheters in neonates who were at heightened risk because of low birth weight and prematurity.

Bacteremia↗
PubMed1993

A survey of hospital postpartum and postabortion rubella vaccination policies in Los Angeles County, 1992.

OBJECTIVE: To determine the proportion of Los Angeles County (LAC) hospitals offering obstetrical services that have postpartum and postabortion rubella vaccination policies. DESIGN: A survey was sent to the infection control practitioners (ICPs) of all operational acute care hospitals (N = 133) in LAC in 1992. A remainder and second survey was mailed to ICPs who did not respond to the first mailing. RESULTS: Of 75 hospitals with obstetrical departments, 56 (75%) responded. Thirty-four (61%) of the 56 respondent hospitals had post-partum rubella vaccination policies. Of the 34 hospitals with policies, 30 (88%) accepted only a written record of rubella seropositivity as proof of immunity, 30 (88%) screened women with unknown immunity status before hospital discharge, and 32 (94%) vaccinated susceptible women before hospital discharge. Of the 32 hospitals that performed induced abortions, only two (6%) provided screening and vaccination services for these women. CONCLUSION: Only 61% of hospitals in LAC offering obstetrical services had postpartum rubella vaccination policies while only minimal screening and vaccination occurred in association with abortion services. Widespread implementation of postabortion screening and vaccination, and more stringent compliance with Advisory Committee on Immunization Practices recommendations for postpartum screening and vaccination in hospitals offering obstetrical services would reduce the number of rubella-susceptible women who have been missed by other prevention strategies.

Female↗