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Biomedical subjects

C F von Reyn

Publications and source records attributed to C F von Reyn.

At least 19 recordsLinked to original sources

Sources of disseminated Mycobacterium avium infection in AIDS.

OBJECTIVES: To identify the sources of disseminated Mycobacterium avium complex (MAC) infection in AIDS. METHODS: HIV positive subjects with CD4 counts <100/mm(3) in Atlanta, Boston, New Hampshire and Finland were entered in a prospective cohort study. Subjects were interviewed about potential MAC exposures, had phlebotomy performed for determination of antibody to mycobacterial lipoarabinomannin and for culture. Patient-directed water samples were collected from places of residence, work and recreation. Patients were followed for the development of disseminated MAC. Univariate and multivariate risk factors for MAC were analyzed. RESULTS: Disseminated MAC was identified in 31 (9%) subjects. Significant risks in univariate analysis included prior Pneumocystis carinii pneumonia (PCP) (hazard ratio 1.821), consumption of spring water (4.909), consumption of raw seafood (34.3), gastrointestinal endoscopy (2.894), and showering outside the home (0.388). PCP, showering and endoscopy remained significant in a Cox proportional hazards model. There was no association between M. avium colonization of home water and risk of MAC. In patients with CD4<25, median OD antibody levels to lipoarabinomannin at baseline were 0.054 among patients who did not develop MAC and 0.021 among patients who did develop MAC (P=0.077). CONCLUSIONS: MAC infection results from diverse and likely undetectable environmental and nosocomial exposures. Mycobacterial infection before HIV infection may confer protection against disseminated MAC in advanced AIDS.

AIDS-Related Opportunistic Infections↗

Nosocomial infections due to nontuberculous mycobacteria.

Nontuberculous mycobacteria (NTM) are ubiquitous in the environment and cause colonization, infection, and pseudo-outbreaks in health care settings. Data suggest that the frequency of nosocomial outbreaks due to NTM may be increasing, and reduced hot water temperatures may be partly responsible for this phenomenon. Attention to adequate high-level disinfection of medical devices and the use of sterile reagents and biologicals will prevent most outbreaks. Because NTM cannot be eliminated from the hospital environment, and because they present an ongoing potential for infection, NTM should be considered in all cases of nosocomial infection, and careful surveillance must be used to identify potential outbreaks. Analysis of the species of NTM and the specimen source may assist in determining the significance of a cluster of isolates. Once an outbreak or pseudo-outbreak is suspected, molecular techniques should be applied promptly to determine the source and identify appropriate control measures.

Cross Infection↗

Patient selection criteria and management guidelines for outpatient parenteral antibiotic therapy for native valve infective endocarditis.

Outpatient parenteral antibiotic therapy (OPAT) for infective endocarditis (IE) is being applied widely, despite the absence of controlled data that demonstrates that outcomes are equivalent to those with standard inpatient antibiotic therapy. We review existing OPAT guidelines, published data on the timing of complications from IE, and data on risk factors that can be used to predict complications. These data are used to propose more stringent criteria for patient selection and clinical management of OPAT for native valve IE. We recommend a conservative approach (inpatient or daily outpatient follow-up) during the critical phase (weeks 0-2 of treatment), when complications are most likely, and we recommend consideration of OPAT for the continuation phase (weeks 2-4 or 2-6 of treatment) when life-threatening complications are less likely.

Anti-Bacterial Agents↗

Bacteremia due to Mycobacterium tuberculosis or M. bovis, Bacille Calmette-Guérin (BCG) among HIV- positive children and adults in Zambia.

BACKGROUND: Among adults with advanced HIV infection in developing countries, bacteremia due to Mycobacterium tuberculosis (MTB) is common and bacteremia due to M. bovis (bacille Calmette-Guérin; BCG) is rare. Comparable data are not available for children with HIV. OBJECTIVE: To compare the prevalence of bacteremia due to M. tuberculosis or M. bovis BCG in hospitalized children and adults with HIV infection in a developing country with a high prevalence of tuberculosis and HIV and > 95% BCG immunization coverage. DESIGN: Descriptive cross-sectional study. METHODS: Prospectively hospitalized patients in Lusaka, Zambia who were suspected to have HIV infection underwent phlebotomy for HIV ELISA, HIV viral load, and lysis-centrifugation blood culture for mycobacteria. Histories were obtained and patients were examined for BCG scars. Mycobacterial isolates were identified using DNA probes for MTB complex (MTBC), multiplex PCR and IS6110 typing. RESULTS: The median age of 387 HIV-positive children was 15 months; 98% were BCG immunized. The median age of 344 HIV-positive adults was 32 years; 44% were BCG immunized. Blood cultures were positive for mycobacteria in six children (2%) and 38 adults(11%) (P < 0.001). The six pediatric isolates included five MTBC (40% clustered) and one BCG. The 38 adult isolates included 36 MTBC (16% clustered) and two M. avium complex. CONCLUSION: Bacteremia due to MTB is less common among children than adults with advanced HIV infection in Zambia. Bacteremia due to M. bovis BCG is rare even among children with recent BCG immunization and symptomatic HIV infection.

AIDS-Related Opportunistic Infections↗

Skin test reactions to Mycobacterium tuberculosis purified protein derivative and Mycobacterium avium sensitin among health care workers and medical students in the United States.

SETTING: Health care workers and medical students in the United States subject to annual tuberculin skin testing. OBJECTIVE: To use skin testing with Mycobacterium avium sensitin (MAS) to determine contemporary rates of infection with non-tuberculous mycobacteria (NTM) and their effect on reactions to M. tuberculosis purified protein derivative (PPD). DESIGN: Dual skin testing was performed with PPD and MAS on 784 health care workers and medical students in the northern and southern US. MAS reactions that were > or = 5 mm and also > or = 3 mm larger than the PPD reaction were defined as MAS dominant and due to NTM. RESULTS: MAS reactions were > or = 5 mm in 40% and > or = 15 mm in 18% of subjects; 95% were MAS dominant. MAS dominant reactions were more common in the south than the north (P < 0.001). PPD reactions were > or = 15 mm in 3% of subjects. PPD reactions > or = 15 mm were more common among males, foreign born subjects and subjects with BCG immunization (all P < 0.001). MAS dominant reactions were found in 82% of subjects with 5-9 mm PPD reactions and 50% with 10-14 mm PPD reactions; these reactions were more common among whites (P = 0.046), US-born (P = 0.038) and subjects without BCG immunization (P = 0.004). CONCLUSIONS: Infections with NTM are responsible for the majority of 5-14 mm PPD reactions among US-born health care workers and medical students subject to annual tuberculin testing.

Adult↗

Safety and immunogenicity of a five-dose series of inactivated Mycobacterium vaccae vaccination for the prevention of HIV-associated tuberculosis.

Five doses of inactivated Mycobacterium vaccae vaccine were administered intradermally to 22 human immunodeficiency virus (HIV)-infected patients (11 bacille Calmette-Guérin [BCG]-positive and 11 BCG-negative) in Zambia whose CD4 lymphocyte counts were >/=200 cells/mm(3). HIV viral load and lymphocyte proliferation responses were compared for vaccine recipients and 22 HIV-infected control patients (11 BCG-positive and 11 BCG-negative). Immunization was safe and well tolerated in all patients, and induration at the vaccine site decreased from dose 1 to dose 5. A transient decrease in HIV viral load was observed in BCG-positive vaccine recipients after dose 3 but not after subsequent doses. Median lymphocyte stimulation indices to M. vaccae were 6.0 in vaccine recipients and 2.3 in control patients (P<.001). Stimulation indices were >/=3.0 in 19 vaccine recipients (86%) and 7 control patients (32%; P=.001). A 5-dose series of vaccination with inactivated M. vaccae is safe in HIV-infected patients and induces lymphocyte proliferation responses to the vaccine antigen. M. vaccae vaccine is a candidate for the prevention of tuberculosis in HIV infection.

AIDS-Related Opportunistic Infections↗

Randomised trial of intradermal Mycobacterium vaccae or intradermal hepatitis B immunisation in children with HIV infection.

This study assessed the safety of inactivated Mycobacterium vaccae as a candidate vaccine to prevent disseminated mycobacterial disease in children with HIV infection. 35 children ages 1-8 with CD4 counts > or =300/mm3 in New Hampshire, Boston and Chicago were randomised in a 2:1 schedule to receive a 3-dose series of intradermal M. vaccae vaccine (MV) or hepatitis B vaccine (HBV) at 2-month intervals. Immunisation was safe and well tolerated; 2-day median vaccine site in duration was 5 mm in MV recipients and 0 mm in HBV recipients (p < 0.001). There were no significantly different changes in viral load or CD4 count between the two vaccine groups. No PPD skin test conversions occurred after immunisation. MV is safe and well tolerated and deserves further evaluation as a vaccine to prevent mycobacterial disease in HIV-infected children.

Administration, Cutaneous↗

High rates of disseminated infection due to non-tuberculous mycobacteria among AIDS patients in Finland.

OBJECTIVE: to determine the rate of disseminated infection due to non-tuberculous mycobacteria (NTM) among Finnish AIDS patients, and to analyse the epidemiology of these infections. METHODS: in a prospective cohort study HIV-infected patients with CD4 counts < 200 x 10(6)/l were interviewed, and had mycobacterial blood cultures performed at baseline and at 6 months, then subsequently for clinical indications; autopsies were performed on patients who died. The cohort was followed at least for 24 months or to death. Water samples were collected from the homes of patients and from the environment and cultured for organisms of the Myobacterium avium complex (MAC). Environmental and clinical isolates were compared using pulsed field gel electrophoresis (PFGE). RESULTS: NTM infection occurred in 22 (43%) of 51, 19 isolates were Mycobacterium avium, two M. genavense and one M. intracellulare. Multivariate analysis identified urban residence (P=0.04) and eating raw fish (P=0.04) as independent risk factors. Molecular analysis revealed two clusters of related isolates (three M. avium, two M. genavense) among urban residents. CONCLUSION: AIDS patients in Finland have high rates of disseminated infection due to NTM. Clusters of identical organisms and association with urban residence suggests that these are newly acquired infections in advanced AIDS.

AIDS-Related Opportunistic Infections↗

Isolation of mycobacteria from indoor swimming pools in Finland.

The presence of mycobacteria in seven indoor pools in Finland was evaluated by multiple culture methods. Replicate samples, with and without inactivation of chlorine by sodium thiosulfate, were cultured in two laboratories. Laboratory I used two methods: (A) no decontamination and (B) cetylpyridinium chloride (0.005%, 20 min); and Laboratory II two methods: (C) cetylpyridinium chloride (0.005%, 18 h) and (D) oxalic acid (5%, 15 min). Samples processed by methods (A) and (B) were cultured on different egg media of pH 6.3 or 5.8; by method (C) on Middlebrook and Cohn 7H10 (+OADC) agar of pH 5.5; and by method (D) on Middlebrook and Cohn 7H10 agar (+OADC) with cycloheximide (500 microg/ml). Mycobacteria were recovered from five (71%) of seven pools. Detection of mycobacteria depended on the method used. High isolation rates (36-46% of the samples) were obtained by methods (A), (B) and (D). Contamination was a problem only with method (A). Inactivation of chlorine had a variable impact on mycobacterial detection. Isolates included M. kansasii, M. gordonae, M. fortuitum complex, M. sphagni, and M. vaccae, as well as M. simiae-like and M. chubuense-like organisms. In addition, a group of slowly growing and a group of rapidly growing isolates with previously unknown fatty acid and alcohol composition were isolated. No M. avium was detected. Mycobacterial counts were highest in a small pool with high temperature, low pH, and low content of free available chlorine.

Finland↗

Cellular immune responses to ESAT-6 discriminate between patients with pulmonary disease due to Mycobacterium avium complex and those with pulmonary disease due to Mycobacterium tuberculosis.

ESAT-6 (for 6-kDa early secreted antigenic target) is a secreted antigen found almost exclusively in organisms of the Mycobacterium tuberculosis complex. We compared in vitro gamma interferon (IFN-gamma) responses by peripheral blood mononuclear cells to this antigen in patients with pulmonary disease due to either Mycobacterium avium complex (MAC) or Mycobacterium tuberculosis with those in healthy, skin test-negative, control subjects. Significant IFN-gamma responses to ESAT-6 were detected in 16 (59%) of 27 M. tuberculosis pulmonary disease patients, 0 (0%) of 8 MAC disease patients, and 0 (0%) of 8 controls. Significant IFN-gamma responses to M. tuberculosis purified protein derivative were detected in 23 (85%) of 27 M. tuberculosis disease patients, 2 (25%) of 8 MAC disease patients, and 5 (63%) of 8 healthy controls. M. avium sensitin was recognized in 24 (89%) of 27 M. tuberculosis disease patients, 4 (50%) of 8 MAC disease patients, and 1 (13%) of 8 controls. IFN-gamma responses to ESAT-6 are specific for disease due to M. tuberculosis and are not observed in patients with MAC disease or in healthy controls.

Adult↗

The effects of BCG immunization and human immunodeficiency virus infection on dual skin test reactions to purified protein derivative and Mycobacterium avium sensitin among adults in Zambia.

SETTING: University hospital in Lusaka, Zambia. OBJECTIVE: To determine the effects of childhood bacille Calmette-Guerin (BCG) immunization and human immunodeficiency virus (HIV) infection on dual skin test reactions to purified protein derivative (PPD) and Mycobacterium avium sensitin (MAS) in a developing country. DESIGN: Descriptive cross-sectional study. RESULTS: Dual skin testing was performed on 112 adults, 58 HIV-positive and 54 HIV-negative. Forty-seven (42%) of 112 had PPD reactions > or =10 mm and 52 (46%) had MAS reactions > or =10 mm. PPD reactions > or =10 mm were present in 30 (63%) of 48 BCG-positive subjects compared to 17 (27%) of 64 BCG-negative subjects (P<0.001). Nineteen (33%) of 58 PPD or MAS skin test positive subjects were PPD dominant, 15 (26%) were MAS dominant, and 24 (41%) were non-dominant. MAS dominant and non-dominant reactions were significantly reduced in HIV-positive subjects, and non-dominant reactions were increased in BCG-positive subjects. CONCLUSIONS: Childhood BCG immunization is associated with PPD reactions > or =10 mm among adults. Reduced PPD reaction rates in HIV-positive adults appear to be due to a loss of BCG-induced PPD reactivity. Prior infection with M. avium complex is detectable in a significant proportion of adults in a developing country.

Adult↗

An epidemic of Malassezia pachydermatis in an intensive care nursery associated with colonization of health care workers' pet dogs.

BACKGROUND: Malassezia species are lipophilic yeasts that are emerging as nosocomial pathogens, particularly in low-birth-weight neonates who receive lipid emulsions. When a cluster of patients with Malassezia pachydermatis infection was identified in an intensive care nursery, we initiated an investigation. METHODS: A case patient was defined as any infant in the intensive care nursery who had a positive culture for M. pachydermatis between October 17, 1993, and January 18, 1995. We conducted a cohort study to identify risk factors for colonization and infection with M. pachydermatis. We collected cultures from the infants and the health care workers and from the health care workers' pets, since this organism has been associated with otitis externa in dogs. RESULTS: Fifteen infants met the case definition: eight with bloodstream infections, two with urinary tract infections, one with meningitis, and four with asymptomatic colonization. The case patients were significantly more likely than the other infants to weigh 1300 g or less (15 of 65 vs. 0 of 419, P<0.001). In a multivariate analysis of infants weighing 1300 g or less, the independent risk factors for colonization or infection with M. pachydermatis were a greater severity of concomitant illness (odds ratio, 19.7; P=0.001), arterial catheterization for nine or more days (odds ratio, 29.5; P=0.027), and exposure to Nurse A (odds ratio, 74.7; P=0.004). In a point-prevalence survey, 9 additional infants, 1 health care worker, and 12 of the health care workers' pet dogs had positive cultures for M. pachydermatis. The isolates from all 15 case patients, the 9 additional colonized infants, 1 health care worker, and 3 of the 12 dogs had identical patterns of restriction-fragment-length polymorphisms. CONCLUSIONS: In this outbreak, it is likely that M. pachydermatis was introduced into the intensive care nursery on health care workers' hands after being colonized from pet dogs at home. The organism persisted in the nursery through patient-to-patient transmission.

Animals↗

Dual skin testing with Mycobacterium avium sensitin and purified protein derivative to discriminate pulmonary disease due to M. avium complex from pulmonary disease due to Mycobacterium tuberculosis.

Skin testing with Mycobacterium avium sensitin (MAS) RS 10/2 and purified protein derivative (PPD) was conducted on patients with pulmonary disease due to M. avium complex (MAC) or Mycobacterium tuberculosis (MTB) and no known immunodeficiency. Reactions > or = 5 mm to either MAS or PPD were present in 37 (84%) of 44 MAC patients and 28 (97%) of 29 MTB patients. MAC patients had a mean MAS reaction of 13.8 (+/-8.3) mm and a mean PPD reaction of 3.5 (+/-8.6) mm (P < .001). MTB patients had a mean MAS reaction of 17.9 (+/-9.4) mm and a mean PPD reaction of 22.9 (+/-11.4) mm (P < .001). MAS-dominant skin tests (MAS reaction > or = 5 mm larger than PPD reaction) were present in 32 (73%) of 44 MAC patients and 1 (3%) of 29 MTB patients. MAS-dominant skin tests had a specificity of 97% for discriminating MAC disease from MTB disease.

Adult↗

Cellular immune responses to mycobacteria in healthy and human immunodeficiency virus-positive subjects in the United States after a five-dose schedule of Mycobacterium vaccae vaccine.

The safety and immunogenicity of heat-killed Mycobacterium vaccae vaccine were investigated in a pilot study assessing the feasibility of immunization to prevent mycobacterial disease in patients with human immunodeficiency virus (HIV) infection. Fifteen (seven healthy and eight HIV-positive subjects) received five doses of M. vaccae vaccine. Lymphocyte proliferation assays (LPAs) were performed using Mycobacterium avium sensitin (MAS) and M. vaccae sonicate (MVS). Vaccine was well tolerated in all 15 subjects with minimal induration at the vaccine site. LPAs for four of seven healthy vaccines were positive for MAS after immunization. Median responses to MAS and MVS that were determined by LPAs were consistently higher for the eight HIV-positive vaccinees than for the seven healthy controls. A five-dose series of M. vaccae vaccine is safe for both healthy and HIV-positive subjects and deserves further evaluation as a vaccine to prevent HIV-associated mycobacterial disease.

Bacterial Vaccines↗