Does active hepatitis C virus infection increase the risk for infection due to Staphylococcus aureus?

Infections with Staphylococcus aureus may be more frequent in subjects with active hepatitis C virus (HCV) infection. In this retrospective dual-cohort study, we sought to determine whether persons with active HCV infection (positive HCV antibody, detectable blood HCV RNA) were at greater risk of S. aureus infection than those with spontaneously resolved HCV infection (positive HCV antibody, negative blood HCV RNA). Based on prestudy power calculation, we included 231 subjects with active HCV and 116 subjects with resolved HCV infection. The two groups were well matched at baseline, except that subjects with active HCV had a higher mean Charlson's comorbidity index (2.2 vs. 1.3; p < 0.0001). Cohorts were followed for a mean of 3.67 years. Thirty-one of the 231 (13%) subjects with active HCV infection developed ≥1 S. aureus infection(s) as compared to 4/116 (3.4%) subjects with resolved HCV (p = 0.004), with a trend towards more recurrent S. aureus infections in subjects with active HCV infection. The S. aureus infections were mostly serious, necessitating hospitalization and intravenous antibiotics. In the logistic regression, factors that independently predicted S. aureus infection were active HCV and Charlson's comorbidity index. Our regression models confirmed that the enhanced susceptibility to S. aureus infections was related to active HCV infection and not attributable solely to the increased number of comorbidities [adjusted odds ratio (OR) = 3.3, 95% confidence interval (CI) 1.1-9.8; p = 0.03]. This study shows that subjects with active HCV infection have a significantly higher incidence of serious S. aureus infections than those with spontaneously resolved HCV, even after adjustment for comorbidities.

Blastomyces dermatitidis of the perianal skin: report of a case.

Isolated fungal infections of the perianal skin are rare and their diagnosis is frequently overlooked. We report a case of a 78-year-old male patient who presented with a friable, violaceous, papulopustular lesion, with heaped-up edges along the anal verge. Biopsy revealed unicellular yeast consistent with blastomycosis. The patient was treated with itraconazole with resolution of this lesion. An extensive MEDLINE literature review from 1958 to the present indicates that this is an uncommon manifestation of cutaneous blastomycosis. A summary of the medical literature is presented with a review of the characteristics, diagnosis, and management of blastomycosis.

Changes in cytokine levels during reactivation of Toxoplasma gondii infection in lungs.

We studied cytokine proteins and mRNAs in mice with two forms of Toxoplasma gondii pneumonia resulting from reactivation of infection. In the first form, mice were infected with T. gondii, developed and recovered from systemic disease, and then developed pneumonia 3 weeks later. As pulmonary inflammation developed, levels of cytokine mRNAs for gamma interferon (IFN-gamma), interleukin-2 (IL-2), IL-4, and IL-10 increased in bronchoalveolar lavage (BAL) cells or lung tissue, and the level of IFN-gamma protein increased in BAL fluid. The second form of pneumonia occurred as a complication of primary cytomegalovirus (CMV) disease in mice with dormant T. gondii infection. During CMV disease, IL-2 mRNA levels decreased in lung tissue, IL-10 protein levels increased in lung tissue, and IL-10 protein levels increased in BAL fluid. As the mice recovered from CMV disease, T. gondii infection was reactivated in the lungs and was manifested as T. gondii pneumonia. During CMV-induced T. gondii pneumonia, IFN-gamma, IL-2, IL-4, and IL-10 mRNA levels increased in BAL cells or lung tissue, and both IFN-gamma and IL-2 protein levels increased in BAL fluid. We concluded that both forms of T. gondii pneumonia are accompanied by increases in both type 1 T-helper and type 2 T-helper cytokine levels in lungs. The mechanism of CMV-induced reactivation of T. gondii infection in lungs may involve local decreases in IL-2 levels and/or increases in IL-10 levels.

Neuroleptic malignant syndrome associated with olanzapine.

OBJECTIVE: To report a case of neuroleptic malignant syndrome (NMS) associated with the use of olanzapine. CASE SUMMARY: A 67-year-old white man with bipolar disorder developed nausea and vomiting. After 12 days, he became confused, delirious, and manic. His only medications were olanzapine 10 mg/d and divalproex sodium 500 mg bid. He was admitted to a hospital and treated for dehydration and mania. Olanzapine was given on 6 of the first 7 hospital days. On hospital day 6, typical NMS developed with the body temperature increasing to 39.9 degrees C, obtundation, rigidity, tremor, diaphoresis, fluctuating pupillary diameter, labile tachycardia and hypertension, hypernatremia, and elevated serum creatine kinase. Olanzapine was stopped after hospital day 7, and the syndrome resolved by hospital day 12. DISCUSSION: The patient had all of the major manifestations of NMS. There was no other likely explanation for his illness and he received no other drug likely to be associated with the syndrome. This is the first case reported in which NMS was associated with olanzapine.

Role of interferon-gamma in murine cytomegalovirus infection.

Interferon-gamma has well-documented antiviral and immunomodulatory activity, but its role in the control of cytomegalovirus (CMV) infection is not well studied. In a mouse model of murine CMV (MCMV) disease, interferon-gamma concentrations in serum but not in bronchoalveolar lavage fluid increased in response to viral infection. Serum interferon-gamma levels peaked at day 2 in the relatively resistant C57BL/6 mice, and, in contrast, did not peak until day 6 in susceptible BALB/c mice. Mice genetically lacking interferon-gamma (GKO) were more susceptible to MCMV, although strain differences persisted, with C57BL/6 GKO mice experiencing less severe MCMV disease than BALB/c GKO mice. Treatment of MCMV-infected BALB/c mice with exogenous interferon-gamma starting 2 days after viral infection had a modest protective effect at lower interferon-gamma doses (10(4) units), but interferon-gamma therapy markedly increased morbidity and mortality when higher doses (10(5) units) were used. We conclude that interferon-gamma plays a significant role in host response to MCMV and that the cytokine has dose- and time-dependent beneficial and adverse effects.

Diagnosis and outcome of 100 consecutive patients with extreme granulocytic leukocytosis.

PURPOSE: To determine the clinical features, causes, and prognostic significance of extreme leukocytosis in adults. PATIENTS AND METHODS: Medical records of 100 consecutive patients who presented at the Minneapolis Veterans Affairs Medical Center between March 1993 and January 1994 with more than 25,000 leukocytes/microL blood and with more than 50% granulocytes were reviewed. Demographic, clinical, and outcome information was recorded, and a cause of extreme leukocytosis was sought in each case. RESULTS: Extreme leukocytosis was attributed to infection in 48 cases, advanced malignancy in 13 cases, hemorrhage in 9 cases, glucocorticoids in 8 cases, and other causes in 22 cases. Four patients had previously diagnosed conditions resulting in chronic leukocytosis. Higher leukocyte counts were associated with malignancy (chi2 for trend=12.5, P <0.002). Fever was more common in patients with infection (weighted rate ratio=3.7, 95% Confidence interval [CI]=2.2 to 6.2). Mortality was high overall (31%), and was greater in patients with noninfectious diagnoses compared with infected patients, an association which persisted after stratification by leukocyte count (weighted rate ratio=2.5, 95% CI=1.2 to 4.9). CONCLUSION: Clinicians should be aware that extreme leukocytosis with a predominance of granulocytes is associated with infection in only 48% of cases. The presence of fever increases the likelihood that infection is the cause. Mortality is high, particularly in patients without infection.

Diagnosis of Toxoplasma parasitemia in patients with AIDS by gene detection after amplification with polymerase chain reaction.

We sought evidence of toxoplasma parasitemia among 37 people with active or dormant Toxoplasma gondii infection or no evidence of infection. DNA was extracted from erythrocyte-free portions of blood samples, and the T. gondii B1 gene was amplified by the polymerase chain reaction. Evidence of T. gondii parasitemia was found in six patients with severe immunosuppression from AIDS and clinical evidence suggestive of or compatible with toxoplasmosis. Results were negative for patients unlikely to have active toxoplasmosis. Gene detection after amplification with the polymerase chain reaction is a promising test for detection of parasitemia, and parasitemia should be tested for in patients with AIDS and unexplained fever or central nervous system abnormalities.

Detection of Toxoplasma gondii parasitemia by gene amplification, cell culture, and mouse inoculation.

Diagnosis of Toxoplasma gondii infection is difficult, especially in immunosuppressed people. The AIDS epidemic has increased the number of people at risk and increased the need for better diagnostic methods. We have compared three methods for detection of T. gondii parasitemia. Rabbits were infected subcutaneously with 10(4) T. gondii tachyzoites. Blood samples were obtained, and buffy coat or leukocyte fractions were prepared. We sought the T. gondii B1 gene by gene amplification by the polymerase chain reaction, and we sought viable T. gondii cells by inoculating fibroblast cell cultures and by mouse inoculation. Thirty-two blood samples were obtained from seven infected rabbits, and 18 were obtained from four control, uninfected rabbits. Parasitemia was detected in 20 of 32 samples (62%) from infected samples by mouse inoculation, 12 of 32 samples (37%) by gene amplification and detection, and 8 of 32 samples (25%) by cell culture. Mouse inoculation requires use of live animals and has a long turnaround time. Currently, cell culture is the least sensitive but most practical and widely available method for the detection of T. gondii parasitemia. Gene amplification and detection was more sensitive than cell culture and may become available in clinical laboratories as techniques are developed further and automated.

Cytomegalovirus-induced reactivation of Toxoplasma gondii pneumonia in mice: lung lymphocyte phenotypes and suppressor function.

Active cytomegalovirus (CMV) infection is associated with immunosuppression and predisposes to the development of life-threatening superinfections in immunocompromised patients. In a mouse model of virus-induced immunosuppression, acute murine CMV (MCMV) infection induced reactivation of dormant Toxoplasma gondii infection, producing Toxoplasma pneumonia. Changes in lung lymphocyte numbers and phenotypes appeared to be integral to the pathogenesis of MCMV-induced reactivation of T. gondii pneumonia. Numbers of lung CD4+ cells decreased during acute MCMV infection in mice with dormant T. gondii infection as well as in previously uninfected mice. Dually infected mice subsequently developed reactivation of Toxoplasma pneumonia. The pneumonia was characterized by a large influx of T lymphocytes, predominantly CD8+ cells, into the lungs. These lung lymphocytes markedly suppressed the ability of immune splenocytes to proliferate in response to T. gondii antigens and concanavalin A in vitro. These results suggested that the initial fall in the numbers of lung CD4+ cells observed after MCMV infection may have induced reactivation of T. gondii infection in the lungs. The subsequent pneumonia appeared to be a manifestation of a massive influx of T lymphocytes, especially CD8+ cells, into the lungs.

Pulmonary toxoplasmosis: a review.

Toxoplasma pneumonia is being recognized with increased frequency, especially in patients with AIDS. We reviewed the English-, French-, and Spanish-language literature from January 1966 through February 1991 to identify cases of postnatally acquired pneumonia associated with Toxoplasma gondii. We identified two distinct clinical syndromes, one in immunocompetent patients and one in patients with defects in cell-mediated immunity. Shortness of breath and cough were the most common symptoms and fever and rales the most common signs in both groups of patients. Lymphadenopathy and hepatosplenomegaly were reported more frequently for immunocompetent patients. Chest roentgenographs usually revealed bilateral interstitial infiltrates, but a variety of other roentgenographic findings were reported. Serological findings were suggestive of active toxoplasmosis in immunocompetent but not in immunosuppressed patients. In early reports, identification of T. gondii as the etiologic agent of pneumonia was based on serology or autopsy findings. In more recent reports, open lung biopsy and especially bronchoalveolar lavage were used for diagnosis. Mortality among patients with toxoplasma pneumonia was 55%. However, in cases of T. gondii pneumonia diagnosed during life, mortality was 0 for immunocompetent patients and 40% for immunosuppressed patients. In immunosuppressed patients, improvement was associated with specific antitoxoplasma drug therapy. Unfortunately, relapses were common. We also reviewed data on series of patients with disseminated toxoplasmosis manifested predominantly in extrapulmonary sites and found that 33% of these patients had evidence of subclinical pulmonary involvement even though pneumonia had not been diagnosed clinically.

Phenotypes, proliferative responses, and suppressor function of lung lymphocytes during Toxoplasma gondii pneumonia in mice.

Toxoplasma gondii pneumonia has emerged as an important problem in immunocompromised patients, especially those with AIDS. The characteristics of lung lymphocytes, including their phenotypes, proliferative responses, and suppressor function during T. gondii pneumonia were studied. During primary acute T. gondii infection, the numbers of T lymphocytes in the lungs increased even though mice lacked histologic evidence of pneumonia. As mice recovered from acute toxoplasmosis, numbers of lung CD4+ cells and the ratio of CD4+ to CD8+ cells decreased. Subsequently, T. gondii infection reactivated, manifested as pneumonia. During pneumonia, lung T lymphocytes, especially CD8+ cells, increased even more. Lung lymphocytes from mice with T. gondii pneumonia decreased the proliferative responses of splenocytes from T. gondii-immune mice to both concanavalin A and T. gondii lysate antigens in vitro. The striking increase in lung CD8+ cells and suppressor activity appear to be integral to the pathogenesis of T. gondii pneumonia.

Preventing secondary infections among HIV-positive persons.

Secondary infectious diseases contribute substantially to morbidity and mortality of people infected with human immunodeficiency virus (HIV). The authors developed comprehensive, practical recommendations for prevention of infectious complications in HIV-infected people. Recommendations are concerned with the pathogens that are more common or more severe in HIV-infected people. Several infectious complications can be prevented by avoiding ingestion of contaminated food or water. Zoonoses can be prevented by precautions to be taken in contacts with animals. The risk of several fungal diseases can be reduced if activities likely to lead to inhalation of spores are avoided. HIV-infected people should be advised how to lower adverse health effects of travel, especially international travel. The potential for infectious complications of sexual activity and illicit drug use should be stressed, and recommendations to reduce the risk are discussed. Recommendations for use of vaccines in HIV-infected people are reviewed. Blood CD4+ lymphocyte concentrations, tuberculin skin testing, Toxoplasma serology, and sexually transmitted disease screening should be performed in certain subsets of HIV-infected people. Guidelines for chemoprophylaxis against Pneumocystis carinii and tuberculosis are presented. Recent data suggest that intravenous immunoglobulin therapy may prevent bacterial infections in HIV-infected children.

Effect of clindamycin on pneumonia from reactivation of Toxoplasma gondii infection in mice.

Clindamycin was used to treat the reactivation of a chronic Toxoplasma gondii infection in mice. Clindamycin reduced mortality by 44% when used prophylactically (P less than 0.001) but appeared to be less effective when used to treat clinically apparent reactivation. Further studies should be conducted to establish the efficacy of clindamycin for the treatment of toxoplasmosis in humans.

Infection in the myelodysplastic syndromes.

PURPOSE: To determine the incidence, characteristics, and outcome of infection in patients with myelodysplastic syndromes (MDS) and risk factors that may lead to infection. PATIENTS AND METHODS: We reviewed infections that occurred in 86 consecutive patients with MDS who received care from 1968 to 1986 at a university-affiliated Veterans Affairs Medical Center. Time lines charting the course of each patient with MDS were created and included infections, MDS subgroup at the time of presentation and at the time of each infection, peripheral neutrophil counts, and therapies for MDS. RESULTS: Infections occurred at a rate of nearly one per patient year of observation. Infection rates were associated with MDS subgroup as follows: refractory anemia with or without ringed sideroblasts (RA +/- RS) less than refractory anemia with excess blasts (RAEB) less than RAEB in transformation (RAEB-T). The group of RA +/- RS patients who had erythroid abnormalities but minimal or no dyspoiesis of other cell lines had the lowest rate of infections. Infection rates were higher in patients with less than or equal to 1,000 neutrophils/microL blood than in patients with greater than 1,000 neutrophils/microL blood for each classifiable MDS subgroup. Neutrophil concentration and MDS subgroup were independent risk factors for infection in patients with MDS. Bacterial pneumonias and skin abscesses were the most common infections. Infection was the most common cause of death during MDS, accounting for 64% of deaths, and was more common than transformation to acute leukemia as a cause of death. CONCLUSION: Infection is a common, life-threatening problem in patients with MDS. Neutropenia and MDS subgroup are each risk factors for infection. Clinicians should aggressively evaluate patients with fever and MDS for infection, especially pneumonia and skin infections.

Effects of immobilization stress on the pathogenesis of acute murine toxoplasmosis.

Stress modulates a variety of immune responses. We investigated the effects of immobilization stress on the pathogenesis of acute murine toxoplasmosis, an infection in which cell-mediated immunity is of major importance in host defense. Repetitive overnight immobilization beginning 3 days prior to infection enhanced (p less than 0.05) the mortality of mice infected with a virulent strain (C56) of Toxoplasma gondii (77% vs 15% mortality in restrained and control mice, respectively). Daily immobilization for 14 days prior to infection abrogated (p less than 0.05) the lethal effect of immobilization, suggesting an adaptive mechanism. To explore the effect of immobilization with a less virulent strain, the Me49 strain of T. gondii was studied. Acute infection with T. gondii Me49 resulted in anorexia and weight loss, while spleen size and respiratory burst activity of peritoneal exudate cells were enhanced (p less than 0.01). Immobilization (twice daily for 2 h) did not significantly alter survival or other clinical features of acute T. gondii infection. In addition, immobilization suppressed (p less than 0.05) phorbol myristate acetate-stimulated release of superoxide anion by peritoneal exudate cells in healthy naive mice, but not in infected mice. These findings indicate that immobilization stress can alter the pathogenesis of acute T. gondii infection in healthy mice, but the effect of this stress paradigm will be influenced, in part, by the timing of the immobilization and the virulence of the strain of T. gondii.