Infective endocarditis due to Staphylococcus aureus: deleterious effect of anticoagulant therapy

BACKGROUND

The use of anticoagulant therapy in patients with infective endocarditis (IE) is a controversial issue.

OBJECTIVE

To study the impact of anticoagulant therapy on the clinical outcome, mortality, and cause of death in a series of patients with native and prosthetic left-sided Staphylococcus aureus IE.

METHODS

This report is based on all consecutive cases of IE diagnosed at our hospital between 1975 to 1997. Clinical data, including the use of anticoagulant therapy at the time of diagnosis, were prospectively obtained, and antibiotic treatment and surgical indications were uniform throughout the study period. Computed tomographic scans of all clinical records were reviewed.

RESULTS

Of 637 consecutive patients with IE, 56 had left-sided S aureus IE affecting native valves in 35 patients and prosthetic valves in 21 patients. Of the patients with prosthetic valve IE, 19 (90%) were taking oral anticoagulant therapy at the time of diagnosis while no patient with native valve IE was receiving such treatment. There were no differences between native valve IE and prosthetic valve IE in age, sex, embolic episodes, and number of central nervous system complications. Mortality was higher in prosthetic valve IE than in native valve IE (71% vs 37%; P=.02). No patient with native valve IE died due to central nervous system complications, while 73% (11 of 15 patients) with prosthetic valve IE died due to central nervous system complications. The difference in the distribution of the type of death (stroke vs other) was significant (P<.007).

CONCLUSIONS

Our results suggest that in left-sided S aureus IE anticoagulant therapy is closely associated with death due to neurologic damage. According to our data, as soon as the clinical diagnosis of S aureus IE is indicated the use of anticoagulant therapy should be immediately stopped until the septic phase of the disease is overcome.

Efficacy of ampicillin plus ceftriaxone in treatment of experimental endocarditis due to Enterococcus faecalis strains highly resistant to aminoglycosides

The purpose of this work was to evaluate the in vitro possibilities of ampicillin-ceftriaxone combinations for 10 Enterococcus faecalis strains with high-level resistance to aminoglycosides (HLRAg) and to assess the efficacy of ampicillin plus ceftriaxone, both administered with humanlike pharmacokinetics, for the treatment of experimental endocarditis due to HLRAg E. faecalis. A reduction of 1 to 4 dilutions in MICs of ampicillin was obtained when ampicillin was combined with a fixed subinhibitory ceftriaxone concentration of 4 micrograms/ml. This potentiating effect was also observed by the double disk method with all 10 strains. Time-kill studies performed with 1 and 2 micrograms of ampicillin alone per ml or in combination with 5, 10, 20, 40, and 60 micrograms of ceftriaxone per ml showed a > or = 2 log10 reduction in CFU per milliliter with respect to ampicillin alone and to the initial inoculum for all 10 E. faecalis strains studied. This effect was obtained for seven strains with the combination of 2 micrograms of ampicillin per ml plus 10 micrograms of ceftriaxone per ml and for six strains with 5 micrograms of ceftriaxone per ml. Animals with catheter-induced endocarditis were infected intravenously with 10(8) CFU of E. faecalis V48 or 10(5) CFU of E. faecalis V45 and were treated for 3 days with humanlike pharmacokinetics of 2 g of ampicillin every 4 h, alone or combined with 2 g of ceftriaxone every 12 h. The levels in serum and the pharmacokinetic parameters of the humanlike pharmacokinetics of ampicillin or ceftriaxone in rabbits were similar to those found in humans treated with 2 g of ampicillin or ceftriaxone intravenously. Results of the therapy for experimental endocarditis caused by E. faecalis V48 or V45 showed that the residual bacterial titers in aortic valve vegetations were significantly lower in the animals treated with the combinations of ampicillin plus ceftriaxone than in those treated with ampicillin alone (P < 0.001). The combination of ampicillin and ceftriaxone showed in vitro and in vivo synergism against HLRAg E. faecalis.

Influence of human immunodeficiency virus 1 infection and degree of immunosuppression in the clinical characteristics and outcome of infective endocarditis in intravenous drug users

BACKGROUND

Immunosuppression caused by human immunodeficiency virus 1 (HIV) infection appears to modify the clinical characteristics and to increase the severity of several bacterial infections. The impact of HIV infection and the degree of immunosuppression on the clinical characteristics and outcome of infective endocarditis (IE) in intravenous (IV) drug users has not been well characterized.

METHODS

Prospective cohort study among 292 consecutive IV drug users with IE diagnosed in 2 academic institutional hospitals in Barcelona, Spain, from January 1, 1984, to October 31, 1995. Serostatus of HIV infection was documented in 283 patients. We measured demographics, clinical and biological data, cause, echocardiographic findings, HIV serostatus and classification, CD4 cell count, complications, and mortality.

RESULTS

Among the 283 episodes of IE, 216 (76.3%) were in HIV-infected patients and 67 (23.7%) in non-HIV-infected patients. Rate of IE per 1000 admissions ranged from 0.17 to 0.82 per year, peaking in 1989. Characteristics of IE independently associated with HIV infection were right-side involvement (odds ratio [OR], 7.6; 95% confidence interval [CI], 3.5-16.7), a micro-organism different from viridans streptococci (OR, 2.5; 95% CI, 1.1-5.9), duration of drug abuse longer than 5 years (OR, 5.0; 95% CI, 2.4-10.3), and white blood cell count of no more than 10 X 10(9)/L (OR, 2.2; 95% CI, 1.1-4.2). There were no significant differences in mortality due to IE according to HIV serostatus. Among the 216 patients with HIV infection, the variables independently associated with worse outcome were CD4 cell count lower than 0.200 x 10(9)/L and left-sided or mixed IE.

CONCLUSIONS

Although there is a difference in clinical presentation in IE in IV drug users, outcome was similar according to their HIV status. However, among HIV-infected patients, severe immunosuppression and mixed or left-side valvular involvement were strong risk factors for mortality.

Favorable prognosis of purulent meningitis in patients infected with human immunodeficiency virus

We prospectively reviewed all cases of purulent meningitis among human immunodeficiency virus (HIV) type 1-infected patients > 14 years old that occurred at the Hospital General Vall d'Hebron (Barcelona) during the period 1 January 1985 through 31 March 1997. There were 12 episodes of purulent meningitis in nine of 2,150 HIV-1-infected patients. The annual rate of purulent meningitis was 0.465 cases per 1,000 patients, a rate that is 150 times higher than that for the general population. During 10 episodes, CD4+ lymphocyte counts were < 200/mm3. The etiologic organism was Streptococcus pneumoniae in nine episodes (seven episodes occurred in four splenectomized patients), and Escherichia coli, Streptococcus agalactiae, and Enterococcus faecium each caused one episode. Clinical features and cerebrospinal fluid abnormalities were similar to those observed among patients without HIV-1 infection. All patients had bacteremia. The overall mortality was 8.3%. We conclude that purulent meningitis, particularly pneumococcal meningitis, is more frequent among HIV-1-infected patients than in the general population. The prognosis for HIV-1-infected patients is better than for HIV-1-negative patients.

Rhodococcus equi pneumonia in patients infected with the human immunodeficiency virus. Report of 2 cases and review of the literature

Rhodococcus equi is a cause of lung infection in immunosuppressed hosts. Since the start of the HIV epidemic, 76 cases of R. equi lung infection (MEDLINE 1985-96) affecting this population have been described. We report 2 additional cases and review the clinical data, radiological findings, treatment and outcome of these 78 patients. The mean age of these patients was 33 y; 69 were male. 71 met the criteria for AIDS (CDC 1993). Fever and cough were the presenting complaints in the majority of patients (84.3%). A single cavitary lung lesion in the upper lobes was the most common radiological finding (57.7%), although multiple cavitations, alveolar infiltrates and pleural effusion were also found. Treatment usually was based on synergistic antibiotic combinations for a long period of time determined on an individual basis. Surgery was performed only in 11 patients. Death attributable directly to R. equi infection is low (15.4%), however only half of the patients (53.8%) were completely cured. We conclude that R. equi infection should be strongly considered in any HIV patient who presents with cavitary lesions in the lung, especially if mycobacteria are not identified. Treatment must be based on synergistic antibiotic combinations, and surgery relegated to cases of chronic single cavitary lesions not responding to antibiotics.

Cytomegalovirus disease as a risk factor for graft loss and death after orthotopic liver transplantation

To determine whether cytomegalovirus (CMV) disease is an independent risk factor for graft loss and death after orthotopic liver transplantation, we performed a 3-year follow-up study of 143 consecutive liver transplant recipients and six patients who underwent retransplantation. Thirty-seven patients (25%) had had CMV disease and were alive after treatment. Fifty-two deaths and eight graft losses occurred. The cumulative incidence of graft failure at 1 and 3 years of follow-up were 40% and 63%, respectively, for patients with CMV disease, compared with 22% and 33%, respectively, for those without CMV disease (P < .05, logrank test). Cumulative probabilities of survival for patients with and without CMV disease were 64% and 82%, respectively, at 1 year and 46% and 69%, respectively, after 3 years (P < .05, logrank test). Multivariate analysis with use of a time-dependent Cox model showed that previous CMV disease was an independent risk factor for graft loss at 1 and 3 years of follow-up (P = .04 and P = .007) and for patient survival (P = .04 and P = .01). Our results indicate that CMV disease is a significant independent risk factor for graft loss and patient survival after liver transplantation.

Response to acyclovir in two cases of herpes zoster leukoencephalitis and review of the literature

Herpes zoster leukoencephalitis is a rare complication of varicella-zoster virus infection. Associated with high mortality, the majority of cases have been discovered postmortem; today, however, magnetic resonance imaging is being used successfully as an aid in the diagnosis of this disease. The first two reported cases of HIV-infected patients with herpes zoster leukoencephalitis who recovered clinically and showed complete resolution of the magnetic resonance demyelination images after acyclovir treatment are described. In addition, the cases of herpes zoster leukoencephalitis reported in the literature to date are reviewed.

Two grams daily of oral acyclovir reduces the incidence of cytomegalovirus disease in CMV-seropositive liver transplant recipients

Our objective in this study was to determine the efficacy of 2 grams a day of oral acyclovir administered for 16 weeks after transplantation for the prevention of cytomegalovirus (CMV) infection and disease in CMV-seropositive liver transplant recipients. Seventy-three adult liver transplant recipients, seropositive for CMV, were randomized to receive either 2 grams a day of oral acyclovir for 16 weeks after transplantation or no prophylaxis. The incidence of CMV disease was significantly lower in the acyclovir group (5%) than in the control group (27%; P < 0.05). By log-rank analysis, the differences in the probability of presenting CMV disease over the first 16 weeks and over the 1st year were also significant (P < 0.05). We conclude that 2 grams a day of oral acyclovir provides effective prophylaxis against CMV disease in CMV-seropositive liver transplant recipients.

Two grams daily of oral acyclovir reduces the incidence of cytomegalovirus disease in CMV-seropositive liver transplant recipients

Our objective in this study was to determine the efficacy of 2 grams a day of oral acyclovir administered for 16 weeks after transplantation for the prevention of cytomegalovirus (CMV) infection and disease in CMV-seropositive liver transplant recipients. Seventy-three adult liver transplant recipients, seropositive for CMV, were randomized to receive either 2 grams a day of oral acyclovir for 16 weeks after transplantation or no prophylaxis. The incidence of CMV disease was significantly lower in the acyclovir group (5%) than in the control group (27%; P < 0.05). By log-rank analysis, the differences in the probability of presenting CMV disease over the first 16 weeks and over the 1st year were also significant (P < 0.05). We conclude that 2 grams a day of oral acyclovir provides effective prophylaxis against CMV disease in CMV-seropositive liver transplant recipients.

Bacteremia due to Campylobacter species: clinical findings and antimicrobial susceptibility patterns

From 1979 to 1996, 58 patients (mean age, 39.4 years) were treated for bacteremia due to Campylobacter species at the Hospitals Vall d'Hebron in Barcelona, Spain. Bacteremia was considered to be hospital acquired in 30% of these patients. Almost all the patients (93%) had underlying conditions; liver cirrhosis was the most frequent (34% of patients), and neoplasia, immunosuppressive therapy, and human immunodeficiency virus disease were also common. Of the 58 Campylobacter strains isolated, 81% were C. jejuni, 10% were Campylobacter species, 7% were C. fetus, and one (2%) was C. coli. Resistance rates were: cephalothin, 82%; co-trimoxazole, 79%; quinolones, 54%; ampicillin, 20%; amoxicillin/clavulanate, 4%; erythromycin, 7%; gentamicin, 0; and tetracyclines, 0. Even though the majority of patients were immunocompromised, mortality was low (10.5%), and only one patient relapsed. Because of the high level of resistance to the quinolones in Campylobacter species, these drugs should not be used as empirical treatment, at least in Spain. Although the macrolides remain the antibiotics of choice, amoxicillin/clavulanate may be an effective alternative therapy.

Treatment of experimental pneumonia due to penicillin-resistant Streptococcus pneumoniae in immunocompetent rats

A model of pneumonia due to Streptococcus pneumoniae resistant to penicillin was developed in immunocompetent Wistar rats and was used to evaluate the efficacies of different doses of penicillin, cefotaxime, cefpirome, and vancomycin. Adult Wistar rats were challenged by intratracheal inoculation with 3 x 10(9) CFU of one strain of S. pneumoniae resistant to penicillin (MICs of penicillin, cefotaxime, cefpirome, and vancomycin, 2, 1, 0.5, and 0.5 microg/ml, respectively) suspended in brain heart broth supplemented with 0.7% agar. The rats experienced a fatal pneumonia, dying within 5 days and with peak mortality (70 to 80%) occurring 48 to 72 h after infection, and the bacterial counts in the lungs persisted from 8.87 +/- 0.3 log10 CFU/g of lung at 24 h of the infection to 9.1 +/- 0.3 log10 CFU/g at 72 h. Four hours after infection the animals were randomized into the following treatment groups: (i) control without treatment, (ii) penicillin G at 100,000 IU/kg of body weight every 2 h, (iii) penicillin G at 250,000 IU/kg every 2 h, (iv) cefotaxime at 100 mg/kg every 2 h, (v) cefpirome at 200 mg/kg every 2 h, and (vi) vancomycin at 50 mg/kg every 8 h. Two different protocols were used for the therapeutic efficacy studies: four doses of beta-lactams and one dose of vancomycin or eight doses of beta-lactams and two doses of vancomycin. Results of the therapy for experimental pneumonia caused by penicillin-resistant S. pneumoniae showed that initially, all the antimicrobial agents tested had similar efficacies, but when we prolonged the treatment, higher doses of penicillin, cefotaxime, and cefpirome were more effective than penicillin at lower doses in decreasing the residual bacterial titers in the lungs. Also, when we extended the treatment, vancomycin was more efficacious than penicillin at lower doses but was less efficacious than higher doses of penicillin or cefpirome. The model that we have developed is simple and amenable for inducing pneumonia in immunocompetent rats and could be used to explore the pathophysiology and to evaluate optimal therapy of this infection in the immunocompetent host.

Clinical outcome and long-term prognosis of late prosthetic valve endocarditis: a 20-year experience

A prospective study of the clinical characteristics and evolutionary patterns of 59 cases of late prosthetic valve endocarditis (LPVE) that occurred between January 1975 and December 1994 was performed. Of these 59 cases of LPVE, 48 involved mechanical valves and 11 involved biological valves. Etiologies were as follows: streptococci, 41% of cases; staphylococci, 25%; enterococci, 13%; and miscellaneous, 21%. Echocardiography documented vegetations in 21 patients, paravalvular abscesses in 10, and prosthetic leaks in 34. Emboli occurred in 22 patients, and heart failure in 19 patients. Forty-two patients received medical treatment alone, and 17 received medical treatment and underwent valve replacement surgery. The in-hospital mortality rate was 25%; staphylococcal infection caused 67% of deaths, streptococcal infection caused 5%, and other etiologies caused 23% (P = .0004). After adjustment for age and type of prosthesis, multiple logistic regression revealed an odds ratio for death due to nonstreptococcal infections of 9.67. The overall survival rate was 59% at 5 years and 52% at 10 years. During follow-up, 17 patients needed new valves. At the end of follow-up, only 13 patients remained alive and had the same prosthesis that they had at the time of the diagnosis of LPVE.

Effectiveness of cloxacillin with and without gentamicin in short-term therapy for right-sided Staphylococcus aureus endocarditis. A randomized, controlled trial

BACKGROUND

It is often difficult to administer extended antibiotic therapy in the hospital for right-sided Staphylococcus aureus endocarditis. Although the effectiveness of single-drug therapy given for 4 to 6 weeks and that of two-drug therapy given for 2 weeks have been shown, no data are available on the effectiveness of short-course single-drug therapy.

OBJECTIVE

To compare the efficacy of cloxacillin alone with that of cloxacillin plus gentamicin for the 2-week treatment of right-sided S. aureus endocarditis in intravenous drug users.

DESIGN

Open, randomized study.

SETTING

An academic tertiary care hospital in Barcelona, Spain.

PATIENTS

90 consecutive intravenous drug users who had isolated tricuspid valve endocarditis caused by methicillin-susceptible S. aureus, had no allergy to study medications, and had no systemic infectious complications that required prolonged therapy. An efficacy subset consisted of 74 of these patients who did not meet an exclusion criterion.

INTERVENTION

Cloxacillin (2 g intravenously every 4 hours for 14 days) alone or combined with gentamicin (1 mg/kg of body weight intravenously every 8 hours for 7 days).

MEASUREMENTS

Clinical or microbiological evidence of active infection after 2 weeks of therapy, relapse of staphylococcal infection, or death.

RESULTS

In an analysis of the efficacy subset, treatment was successful in 34 of the 38 patients who received cloxacillin alone (89% [95% CI, 75% to 97%]) and 31 of the 36 patients who received cloxacillin plus gentamicin (86% [CI, 71% to 95%]). Three patients died: one in the cloxacillin group and two in the combination therapy group. Of the 37 patients who completed 2-week treatment with cloxacillin, 34 (92%) were cured, and 3 (8%) needed prolonged treatment to cure the infection. Of the 34 patients who completed 2-week treatment with cloxacillin plus gentamicin, 32 (94%) were cured and 2 (6%) required treatment for 4 weeks. One patient in the combination group had relapse.

CONCLUSIONS

A penicillinase-resistant penicillin used as single-agent therapy for 2 weeks was effective for most patients with isolated tricuspid endocarditis caused by methicillin-susceptible S. aureus. Adding gentamicin did not appear to provide any therapeutic advantages. Additional studies to confirm the therapeutic equivalence of short-course therapy with penicillinase-resistant penicillin alone and therapy with combined regimens are warranted.

Nontuberculous mycobacterial meningitis: report of two cases and review

Nontuberculous mycobacterial meningitis (NTMM) is still a rare disease despite the increase in the number of cases of disseminated mycobacterial infection related to the AIDS epidemic. Moreover, there are doubts as to the clinical relevance of the isolation of mycobacteria other than Mycobacterium tuberculosis from cerebrospinal fluid. After analyzing the clinical and pathological data, we classified the cases of NTMM into three groups: definitive (28 cases), probable (19), and doubtful (5). We found that Mycobacterium avium is the most commonly isolated species (60% of cases). M. avium meningitis presents as a disseminated disease, is usually related to serious underlying conditions (mainly immunosuppression), and is associated with a death rate that approaches 70%. Mycobacterium fortuitum meningitis is associated with previous neurosurgery or back trauma; the prognosis for this infection is better when the concomitant abscesses are drained. The clinical characteristics of Mycobacterium kansasii meningitis are similar to those of M. tuberculosis meningitis, but the mortality related to M. kansasii meningitis is high despite appropriate antibiotic treatment. Herein, we present two cases of NTMM that occurred at our center, and we review 50 additional cases reported in the English-language literature.

[Digestive cytomegalovirus disease in AIDS patients]

BACKGROUND

In this paper we study the digestive manifestations of cytomegalovirus (CMV) in AIDS patients. Also, we evaluate the antiviral treatment and the necessity of maintenance therapy.

METHODS

Retrospective review of medical charts of all patients with AIDS and digestive CMV disease diagnosed and followed-up since 1983 to december 1993.

RESULTS

Of 720 AIDS patients, 96 presented a CMV disease. Among them, 30 patients (31%) complained digestive manifestations. These were 26 males and 4 females, mean age: 37.4 y-old. Risk factors for HIV were: 13 homosex and 12 intravenous drug abusers. Average of time between AIDS diagnosis and digestive CMV disease: 13.4 months. Fourteen patients had esophagitis, 9 proctocolitis, 3 hepatitis, 3 pancreatitis, 2 gastric ulcerations, one small bowel disease and other an oral ulceration. Two patients had a concomitant CMV chorioretinitis. CD4 lymphocytes were below 0.05 x 10(9)/l in 29 patients. Twenty-four patients received antiviral treatment during the acute disease period, with a clinical curation rate of 60%. Seven patients received maintenance therapy and remained free of CMV disease until death. Eleven patients didn't received maintenance treatment. Of them, one patient presented a digestive relapse and two developed a CMV chorioretinitis. Mortality in the first month from diagnosis was 23% and the median of survival time for patients who cured and initial episode of digestive CMV disease was 208 days, wether or not the patient received maintenance therapy or not.

CONCLUSIONS

One third of ours patients with AIDS and CMV infection have a digestive disease. This CMV digestive disease appears in patients with a severe immunosuppression. Acute phase mortality was 23%. The median survival was 7 months, independently or receiving maintenance treatment or not.

Prophylaxis of visceral leishmaniasis in human immunodeficiency virus-infected patients

OBJECTIVE

To assess the effectiveness of two regimens with allopurinol or pentavalent antimony as secondary prophylaxis for visceral leishmaniasis (VL) in human immunodeficiency virus (HIV)-infected patients.

DESIGN

Retrospective, nonrandomized, open trial.

SETTING

A 1,000-bed academic tertiary institutional hospital in Barcelona.

PATIENTS

Forty-six individuals over 14 years old with HIV infection, who recovered from an episode of VL between January 1988 and February 1995.

INTERVENTIONS

Twenty patients did not receive any prophylaxis, nine received 300 mg/8 h of allopurinol, and 17 received 850 mg once-a-month of pentavalent antimony. Patients were followed-up every 3 months, and the endpoint of study was relapse of VL.

RESULTS

Twenty-one patients had recurrent VL: 13 of 20 in the control group (65%), 5 of 9 in the allopurinol group (56%), and 3 of 17 in the antimonial group (18%). Kaplan-Meier estimates of the probability of remaining relapse-free at 12 months were 9% without prophylaxis (95% CI, 0-22%), 21% with allopurinol (95% CI, 0-51%), and 93% with antimonials (95% CI, 82-100%) (P < 0.001). Multivariate analysis showed that the only significant variables related to relapsing course of VL were assignment to the antimonial group, and the fact that the patient had experienced a previous episode of VL.

CONCLUSIONS

Pentavalent antimony given once a month is effective in the prevention of VL relapses in HIV-infected individuals. It is a low-cost treatment that proved to be well tolerated. Therefore, pentavalent antimony should be considered a suitable agent for secondary prophylaxis against VL.

[Pleural cryptococcosis in patients with human immunodeficiency virus infection]

Four cases of pleural cryptococcosis as the form of onset of cryptococcosis in patients with human immunodeficiency virus (HIV) infection are reported. In two out of the four cases cryptococci were simultaneously isolated in other localizations (blood and meninges). In the two remaining patients the pleura was the only site of the disease, with serum determination of the cryptococci antigen being negative in one. The four patients evolved favourably, with three being exclusively treated with fluconazol. Pleuritis is an infrequent manifestation in cryptococcosis although it may be the form of onset and the only localization of the disease. Only 10 cases have been reported in patients with HIV infection. The present four cases represent 11% of the authors' series of cryptococcosis in AIDS patients. The diagnostic possibility of cryptococcosis should be considered in patients with human immunodeficiency virus infection presenting pleural effusion.