[Bacterial pneumonia in HIV-infected patients]

This case-control study assessed risk factors and prognostic indicators of 350 episodes of bacterial pneumonia in 285 HIV-infected patients. On univariate analysis, intravenous drug abuse (p<0.001), regular cigarette smoking (p<0.001), cirrhosis (p=0.04), and history of a previous episode of pneumonia (p=0.04), were risk factors for community-acquired episodes of bacterial pneumonia, whereas length of hospitalization (p=0.01) was a risk factor only for nosocomial bacterial pneumonia. The small amount of circulating T CD4+ cells, (<100/mmc) was a risk factor in both groups of pneumonia (p<0.05). Stepwise logistic regression analysis revealed that IVDA in community-acquired episodes and low levels of circulating T CD4+ cells, both in community-acquired and hospital-acquired episodes, were independent risk factors for the development of bacterial pneumonia. The case-fatality rate observed in our study was 27%. On stepwise logistic regression analysis, T CD4+ cell counts >100/mmc (p<0.02), neutropenia (p=0.04), PO2 arterial level <70 mmHg (p=0.01), and Karnofsky score <50 (p=0.04) were independent indicators of mortality. According to a personally developed prognostic score, 211 episodes of pneumonia (60%) were classified as mild, 63 (18%) as moderate, and 76 (22%) as severe. Clinicians must carefully evaluate those variables that can influence the prognosis of bacterial pneumonia to make early identification of affected patients and to promptly establish the most appropriate therapeutic strategy in each case.

[Central venous catheter-related sepsis: one year experience in a large university hospital]

Five hundred two central venous catheters (CVC) inserted in 366 patients were evaluated prospectively over a one-year period to determine the frequency and risk factors associated with CVC-related sepsis. A CVC-related infection was suspected in 190 cases (190/502, 38%). A catheter-related sepsis was established in 50 patients (10%). The infection rate was 0.8 cases of sepsis per 100 catheterdays. Staphylococcus epidermidis, Staphylococcus aureus, and Candida spp. were the most frequently isolated etiological agents of sepsis. On univariate analysis, six variables affecting the rate of catheter-related sepsis were identified: neutropenia > 8 days (p < 0.01); AIDS (p < 0.001); haematological malignancies (p < 0.001); total parenteral nutrition (p = 0.001); duration of site use (p = 0.04); high APACHE II score (p = 0.04). The logistic regression analysis revealed that AIDS and haematological malignancies were independent risk factors of catheter-related sepsis. In conclusion, although the incidence of established catheter infection is much lower than the incidence of suspected infection, in most cases it is wise to change the catheter with the guidewire technique and wait for culture of the tip, rather than to remove the catheter immediately.

Impact of highly active antiretroviral therapy (HAART) on the incidence of bacterial infections in HIV-infected subjects

The aim of this study was to evaluate the effect of highly active antiretroviral therapy (HAART) on the incidence of bacterial infections in HIV-infected patients. Two time periods were compared: (A) January 1992-December 1995 (before HAART) and (B) January 1997-December 2000 (after HAART). During the study periods, we observed 931 patients with bacterial infections, i.e. 322 with bacteremia, 369 with bacterial pneumonia and 240 with urinary tract infections, out of 4,242 HIV-infected subjects admitted to the Department of Infectious Diseases of a large university hospital. By comparing the overall incidence of bacterial infections during periods A and B, a statistically significant difference, from 32% to 18% (p<0.01), was observed. Analysis of risk factors of community- and hospital-acquired bacterial infections did not significantly differ in the two study periods. This study establishes that a significant reduction in bacterial infection incidence occurred in HIV-infected subjects when HAART became the standard therapy for HIV infection.

Correlation between cidofovir-associated uveitis and failing immunorestoration during HAART

In order to elucidate the factors related to the development of cidofovir-associated uveitis in AIDS patients receiving highly active antiretroviral therapy, the characteristics of 17 AIDS patients with Cytomegalovirus retinitis ( n=10) or progressive multifocal leukoencephalopathy ( n=7) treated with intravenous cidofovir were evaluated. Six cases of cidofovir-associated uveitis occurred among the patients with retinitis. No cases were detected among the patients with progressive multifocal leukoencephalopathy. Stepwise linear regression analysis revealed a significantly higher HIV-viremia level ( P=0.01) and a significantly lower CD4+ cell count ( P=0.009) among cases at the time of uveitis onset in comparison with patients who did not develop uveitis. Thus, cidofovir-associated uveitis seems to occur more frequently in AIDS patients with retinitis in whom highly active antiretroviral therapy fails to restore immunity.

Azole susceptibility patterns and genetic relationship among oral Candida strains isolated in the era of highly active antiretroviral therapy

We performed a cross-sectional study to analyze patterns of azole susceptibility of oral isolates in the highly active antiretroviral therapy (HAART) era and compared current data with those obtained for isolates from 1994. We further identified patients with relapsing oral pharyngeal candidiasis (OPC) who had been included in a similar study in 1994. For these subjects, we compared the susceptibility pattern for the OPC isolates, and if a modification of azole resistance was observed, we analyzed the genotypic pattern for the 1994 and 2000 isolates to determine whether the dominant strain was closely related. We included 69 consecutive HIV-infected subjects with 137 episodes of OPC who were admitted to our ward from January to June 2000. Ninety-two strains (67%) and 21 non- strains (15%) were isolated. We identified 24 episodes of OPC caused by two different species. Compared with the pre-HAART era, the fluconazole resistance of isolates significantly decreased from 45% to 10% (p <.001). Itraconazole resistance decreased from 37% to 7% (p <.001). Ketoconazole resistance (3% in 1994) was not detected more. Nine patients whose isolate was susceptible to all azole drugs had a previous isolate resistant to all azole drugs. We observed that these isolates exhibited different fingerprint profiles. Our findings demonstrate that most cases of HIV-associated OPC observed in the HAART era are caused by azole-susceptible strains. The reversion of an isolate from azole resistant to azole susceptible is related to strain replacement.

Risk factors and predictors of mortality of methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia in HIV-infected patients

OBJECTIVES

To define the incidence, risk factors and short-term predictors of mortality of methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia in HIV-infected patients.

PATIENTS AND METHODS

All HIV-infected subjects with S. aureus bacteraemia were consecutively enrolled in a case-control study between January 1, 1991 and December 31, 2000 and prospectively followed up.

RESULTS

In the study period, 129 of 419 (31%) HIV-infected patients with bacteraemia had a diagnosis of S. aureus bacteraemia. The comparative analysis of incidence of S. aureus bacteraemia in the period 1991-96 and 1997-2000 showed a significant decrease (P < 0.001). The same trend was observed for MRSA bacteraemia (P = 0.002). The analysis of antimicrobial resistance showed that among 129 S. aureus strains, 88 (68%) were methicillin susceptible and 41 (32%) were methicillin resistant. The majority of MRSA bacteraemia was hospital acquired (78%). Previous administration of beta-lactams (P < 0.001), multiple previous hospital admissions (P < 0.001) and low numbers of CD4+ peripheral cells (P < 0.001) were found to be independent risk factors of methicillin resistance at multivariate analysis. The mortality rate was 34% in the cases and 11% in the controls (P = 0.002). Multivariate analysis indicated that a high Acute Physiology and Chronic Health Evaluation (APACHE) III score (P < 0.001) and high HIV viraemia (P = 0.02), but not methicillin resistance, predicted an increased risk of death in patients with S. aureus bacteraemia.

CONCLUSION

Individual exposure to beta-lactams, in association with a history of multiple hospitalizations and low CD4+ cell number, plays a pivotal role as a risk factor for the development of methicillin resistance in HIV-infected patients. Methicillin resistance does not influence the outcome of S. aureus bacteraemia when included in a multivariate analysis.

Risk factors and prognostic indicators of bacterial meningitis in a cohort of 3580 postneurosurgical patients

In order to identify the incidence, risk factors and prognostic indicators of postneurosurgical bacterial meningitis, a 9-y retrospective cohort study was performed. The cohort comprised 3580 individuals who underwent neurosurgical operations at the Department of Neurosurgery of Catholic University, Rome, a 1,700-bed university hospital. We observed 52 episodes of postneurosurgical meningitis, with infection rates of 1.4/100 patients, 0.8/100 operations for craniotomies and 2.6/100 operations for internal cerebrospinal fluid (CSF) shunt or ventriculostomy with external drainage. The overall infection rate decreased from 2.5/100 operations in 1989 to 0.9/100 in 1997 (p = 0.03). Logistic regression analysis indicated that duration of ventriculostomy with external drainage [p < 0.01; odds ratio (OR) = 9.67; 95% confidence interval (CI) = 2.44-38.321 and increasing value of the APACHE III score (p <0.01; OR = 8.51; 95% CI = 2.15-33.68) were independent risk factors for development of meningitis. The overall case fatality rate was 8%. Predictors of mortality were low ( < 1.66 mmol/l) CSF glucose concentration (p = 0.001), increasing value of the APACHE IIl score (p = 0.002) and Gram-negative aetiology (p = 0.003).

Antiretroviral therapy with protease inhibitors has an early, immune reconstitution-independent beneficial effect on Candida virulence and oral candidiasis in human immunodeficiency virus-infected subjects

Highly active antiretroviral therapies (HAARTs) that contain human immunodeficiency virus (HIV) protease inhibitors (PIs) or nonnucleoside reverse-transcriptase inhibitors (NNRTIs) were compared for their effect on secretory aspartyl proteinase (Sap), a virulence trait for mucosal candidiasis. In therapy-naive HIV-positive subjects, oral Sap was detected in 11, 6, 3, 0, and 0 of 15 subjects treated with PI-HAART and in 7, 7, 9, 6, and 5 of 15 subjects treated with NNRTI-HAART, on days 0, 14, 30, 90, and 180 of treatment, respectively. In another 30 subjects, Sap was detected in 0 and 7 of 15 subjects after 1 year of treatment with PI-HAART or NNRTI-HAART, respectively. The anti-Sap effect of PI-HAART was associated with clinical resolution of oral candidiasis but not with late and inconstant recovery of anticandidal cellular immunity. In all subjects, the 2 therapeutic regimens compared well in increasing CD4(+) cell count and abating viremia. Thus, PIs exert an early, immune reconstitution-independent effect on Candida virulence in the oral cavities of HIV-positive subjects.

Glycopeptide resistance among coagulase-negative staphylococci that cause bacteremia: epidemiological and clinical findings from a case-control study

A 1-year prospective case-control study (ratio of control patients to case patients, 3:1) was performed to assess the incidence, risk factors, and genotypic patterns of bacteremia caused by glycopeptide-resistant coagulase-negative staphylococci (CoNS) and their correlation with hospital glycopeptide use. Among 535 subjects with CoNS bacteremia, 20 subjects had a glycopeptide-resistant strain (19 strains were resistant to teicoplanin and 1 was resistant to both teicoplanin and vancomycin). The percentage of resistant isolates recovered in 1 year was 8% in intensive care units and 3% and 2% in medical and surgical wards, respectively. Genotypic analysis of resistant strains showed different patterns with a high degree of polymorphism. Use of glycopeptides in individual wards was not statistically associated with the percentage of resistance. Previous exposure to beta-lactams and glycopeptides, multiple hospitalization in the previous year, and concomitant pneumonia were significantly associated with the onset of glycopeptide-resistant CoNS bacteremia. Mortality rates were 25% among case patients and 18% among control patients, and they were significantly higher among patients who presented with concomitant pneumonia and a high Acute Physiology and Chronic Health Evaluation III score.

Case report: Retinopathy after malaria prophylaxis with chloroquine

Chloroquine retinopathy (CR) is a major complication of long-term malaria prophylaxis (LTMP) causing permanent visual dysfunction and occasionally blindness. After an extensive review of the published accounts of CR, we concluded that the risk of retinopathy in subjects receiving LTMP is limited to a cumulative dose that does not exceed 140 g. We present a case of CR that occurred after 8 years of malaria prophylaxis with chloroquine at a cumulative dose of 125 g. Because a threshold dose of chloroquine for retinal toxicity has not been established, careful, ongoing screening is required, especially as the cumulative dose increases.

Changes in incidence and risk factors of Mycobacterium avium complex infections in patients with AIDS in the era of new antiretroviral therapies

The aim of the study presented here was to determine the incidence, risk factors and prognostic indicators of Mycobacterium avium complex (MAC) infection in HIV-infected subjects prior to and after the introduction of highly active antiretroviral therapy (HAART). In the HAART era, the incidence of MAC infection decreased significantly from 3.7 to 0.9 per 100 person-years. Using logistic regression analysis, a high acute physiology and chronic health evaluation (APACHE) III score, a low number of CD4+ cells/ mm3 and a high level of HIV viremia were found to be independent predictors of the risk to develop MAC disease; however, a high APACHE III score was the only prognostic indicator associated with an unfavourable outcome of a disseminated MAC infection. These results indicate that MAC infections, although considerably less frequent in the HAART era, are still responsible for cases of severe disease.

Nosocomial bacterial pneumonia in human immunodeficiency virus infected subjects: incidence, risk factors and outcome

The presented study examined the incidence, risk factors and outcome of nosocomial bacterial pneumonia (NBP) in human immunodeficiency virus (HIV)-infected subjects. Forty-two cases of NBP were ascertained by a 5-yr prospective surveillance and were matched to 84 controls. NBP incidence was 10.8 per 10,000 hospital patient-days. In particular, the incidence of NBP was 13.9 per 10,000 patient-days in the period 1994-1996 and 5.6 per 10,000 patient-days in the period 1997-1998 (p=0.01). By using regression analysis, predictors for developing NBP were an increasing value of Acute Physiology and Chronic Health Evaluation (APACHE) III score (p<0.01) and the presence of acquired immune deficiency syndrome (AIDS)-related central nervous system (CNS) diseases (p=0.01). The additional hospital stay attributable to NBP was 15 days. The attributable mortality rate was estimated to be 29%. Nosocomial bacterial pneumonia is more common in patients with advanced human immunodeficiency virus infection, high Acute Physiology and Chronic Health Evaluation III score and central nervous system diseases. Although the incidence of nosocomial bacterial pneumonia, as well of other opportunistic infections, decreased considerably in the era of highly active antiretroviral therapy, it still represents an important cause of mortality.

Effect of highly active antiretroviral therapy on the incidence of bacterial pneumonia in HIV-infected subjects

The aim of the study was to assess the incidence of hospital and community acquired bacterial pneumonia in HIV-infected subjects prior to and after the introduction of highly active antiretroviral therapy (HAART). We studied 266 patients with bacterial pneumonia over two separate periods, 154 in the first period and 112 in the second period. A statistically significant difference in the incidence of bacterial pneumonia in the two study periods was observed ranging from 13.1 to 8.5 episodes per 100 persons. The incidence of community-acquired bacterial pneumonia decreased from 10.7 to 7.7 (P=0.01), while that of nosocomial episodes decreased from 2.4 to 0.8 episodes (P=0.003). Low levels of peripheral CD(4+) cells (<100/mm(3)) and intravenous drug abuse (IVDA) were significantly associated with the development of community-acquired bacterial pneumonia, while an increasing value of APACHE III score and prolonged hospitalisation increased the risk of nosocomial bacterial pneumonia in both study periods.

Morbidity associated with central venous catheter-use in a cohort of 212 hospitalized subjects with HIV infection

Technical complications and nosocomial bloodstream infections associated with short-term central venous catheterization remain a heavy burden in terms of morbidity, mortality and cost in HIV-positive subjects. Between 1994 and 1997, 327 central venous catheters (CVCs) inserted in 212 patients for a total of 5005 catheter days were investigated. Forty-two technical complications (13%) occurred in 40 patients. Logistic regression analysis revealed that a high APACHE III score was associated with development of CVC-related complications (P = 0.01). One hundred and eight of 327 CVCs (33%) were suspected as being infected. However only 61 episodes (61/327, 19%) were finally diagnosed as CVC-related sepsis. Three variables affecting the rate of CVC-related sepsis were identified: 1) administration of TPN (P = 0.01); 2) low number of circulating CD4+ cells (P = 0.04); 3) high APACHE III score (P = 0. 04). Doctors responsible for AIDS patients should carefully consider the relative risks and benefits of CVC insertion in an individual patient.

HIV-associated bacteremia: how it has changed in the highly active antiretroviral therapy (HAART) era

To evaluate the changing characteristics of HIV-associated bacteremia in the highly active antiretroviral therapy (HAART) era, we conducted a prospective case control study, comparing two periods of time, before (period A) and after (period B) the introduction of HAART. In total, 174 patients with bacteremia and 348 controls were studied. By comparing incidence in periods A and B, a statistically significant reduction of bacteremia, from 11.8 to 6.3/100 person-years (PY), was observed (p = .0001). Incidence of hospital-acquired bacteremia decreased from 5.8 episodes/100 PY in period A to 2.4/100 PY in period B (p = .0005). A similar trend was also observed for community-acquired episodes of bacteremia, with a value close to statistical significance. Logistic regression analysis indicated that intravenous drug abuse, central venous catheter (CVC) use, high value on APACHE III score, and neutropenia were independent risk factors for bacteremia in both the study periods. Interestingly, comparing the prevalence of bacteremia risk factors in the two study periods, we observed a significant reduction in the use of CVC (p = .04, period A versus period B) and in neutropenia (p = .04). The crude mortality rate was 31% in period A and 23% in period B (p = not significant [ns]). Logistic regression analysis indicated that an high value of Acute Physiology and Chronic Health Evaluation III (APACHE III) score (p < .001) predicted an increased risk of death. Analysis of prognostic factors of bacteremia did not significantly differ in both the study periods. We conclude that HAART has determined a significant reduction of the incidence and a modification of the characteristics of bacteremia. This reduced incidence may produce a substantial impact on future morbidity and health care costs of patients with HIV.

Non-AIDS-defining neoplasms and HIV infection

The purpose of this study was to characterise the epidemiological and the clinical features of non-AIDS-defining neoplasms (NAN) in HIV-infected subjects in the era of highly active antiretroviral therapy (HAART). A retrospective cohort of 4,041 subjects was established. Patients were recruited from January 1989 to December 1998. We observed 51 NAN over the study period. The overall incidence rate was 0.21 per 100 person-years (PY) and it remained stable, also after the introduction, in 1996 of HAART. Moreover, stratifying according to the type of neoplasms there was no statistically significant difference in the incidence of NAN over the study period. While the epidemiological features of NAN generally was not different from that observed in immunocompetent individuals, the neoplasms had a more aggressive clinical course and a poor prognosis. Survival analysis showed that the presence of NAN significantly reduced the survival of patients with AIDS (P=0.01; OR=0.62; 95% CI=0.47-0.96) compared with matched controls. The overall mortality-rate was 63% with an incidence rate of 0.13 per 100 PY. Although the incidence rate of NAN is not of great magnitude, as the number of HIV-infected individuals continues to increase and their survival improves, the number of HIV-infected subjects with NAN might consequently increase as well as the related morbidity and mortality.

In vitro and in vivo anticandidal activity of human immunodeficiency virus protease inhibitors

Highly active antiretroviral therapy that includes human immunodeficiency virus (HIV) aspartyl protease inhibitors (PIs) causes a decline in the incidence of some opportunistic infections in AIDS, and this decline is currently attributed to the restoration of specific immunity. The effect of two PIs (indinavir and ritonavir) on the enzymatic activity of a secretory aspartyl protease (Sap) of Candida albicans (a major agent of mucosal disease in HIV-infected subjects) and on growth and experimental pathogenicity of this fungus was evaluated. Both PIs strongly (>/=90%) and dose dependently (0.1-10 microM) inhibited Sap activity and production. They also significantly reduced Candida growth in a nitrogen-limited, Sap expression-dependent growth medium and exerted a therapeutic effect in an experimental model of vaginal candidiasis, with an efficacy comparable to that of fluconazole. Thus, besides the expected immunorestoration, patients receiving PI therapy may benefit from a direct anticandidal activity of these drugs.

Candidemia in HIV-infected subjects

The epidemiological features of 37 episodes of candidemia in HIV-infected subjects were analysed in a retrospective matched case-control study conducted over an 8-year period (1990-1997). Univariate analysis identified eight risk factors that were significantly associated with candidemia (P<0.05): i) use of central venous catheters; ii) administration of total parenteral nutrition; iii) previous antifungal therapy; iv) previous therapy with glycopeptides; v) presence of oral/ esophageal candidiasis; vi) concomitant bacterial infections; vii) neutropenia; and viii) concomitant AIDS dementia complex. Stepwise logistic regression analysis revealed that the only independent risk factor for developing candidemia was the use of central venous catheters (P = 0.0001). Candida albicans was the most frequently isolated pathogen, accounting for 18 (48%) episodes of candidemia, followed by Candida tropicalis (19%) and Candida glabrata (11%). The crude mortality rate was 62%. On univariate analysis concomitant opportunistic infections, presence of non-Candida albicans species of Candida and neutropenia were shown to be predictive of death. Multivariate analysis revealed that the presence of non-Candida albicans strains of Candida was the only significant factor associated with a worse prognosis (P = 0.001). In conclusion, candidemia appears to be more common in patients with advanced HIV disease. Of the factors which influenced the onset of candidemia, use of central venous catheters seemed to be the most important one.

Role of protease inhibitors in preventing recurrent oral candidosis in patients with HIV infection: a prospective case-control study

This study was conducted to evaluate the efficacy of highly active anti-retroviral therapy (HAART) in preventing recurrence of oral candidosis (OC) associated with HIV. A prospective case-controlled observational study was performed in an inner-city university-hospital HIV/AIDS clinic. Ninety-three HIV-positive study subjects with a history of recurrent OC were divided into two groups: protease inhibitors (PI)-treated patients (group 1, n = 30) and non-PI-treated patients (group 2, n = 63). Study subjects were matched for sex, age, stage of HIV infection, and peripheral CD4+ T-cell counts. The non-PI-treated group was further subdivided into the following three subgroups: HIV-positive study subjects treated with reverse transcriptase inhibitors (RTI; groups 2a and 2c) and HIV-positive study subjects not treated with RTIs (group 2b). Group 2c met the same inclusion criteria as group 2a had but was matched 6 months after the beginning of the study. We also assessed in vitro peripheral blood mononuclear cells (PBMC) and their lymphoproliferative response, as well as cutaneous delayed-type hypersensitivity (DTH) response to Candida-associated antigens in a randomly selected sample of study subjects divided into those treated with PIs and those who were not. During a 1-year follow-up, OC was diagnosed in 2 (7%) PI-treated and 23 (36%) non-PI-treated patients (p<.001). In addition to comparing findings in group 1 with those in group 2c, OC was detected in 14 (50%) non-PI-treated patients compared with no HAART-treated study subjects (p<.001). Only 41% of PI-treated study subjects had positive lymphoproliferative response in PBMCs and none was positive in terms of DTH to Candida antigens (p = not significant versus non-PI-treated study subjects). While objectively demonstrating a beneficial effect of HAART in preventing recurrence of OC infections, our findings suggest this effect cannot be not fully accounted for by reconstitution of anti-Candida cell-mediated immunity, given that other mechanisms, even of a nonimmune nature, could have some effect.

Nosocomial bloodstream infections in HIV-infected patients: attributable mortality and extension of hospital stay

A 3-year prospective matched case-control study was performed to investigate the potential risk factors, prognostic indicators, extension of hospital stay, and attributable mortality of nosocomial bloodstream infections in HIV-infected patients. Matching variables were: age, gender, number of circulating CD4+ T lymphocytes, cause of hospital admission, hospitalization in the same ward within the 6 weeks of diagnosis of the case, and length of stay before the day of infection in the case. Eighty-four cases and 168 matched controls were studied. Nosocomial bloodstream infections complicated about 3 of 1000 hospital days per patient in the study period. With step-wise logistic regression analysis, the most important predictors for developing nosocomial bloodstream infections were: increasing value of Acute Physiology and Chronic Health Evaluation (APACHE II) score (p = .001) and use of central venous catheter (CVC) (p = .002). The excess of hospital stay attributable to nosocomial bloodstream infections was 17 days. The crude mortality rate was 43%. The attributable mortality rate was estimated to be 27% (95% confidence interval [CI] = 13%-48%). The estimated risk ratio for death was 3.91 (95% CI = 2.06-7.44). Multivariate analysis identified two prognostic indicators that were significantly associated with unfavorable outcome of bloodstream infections: number of circulating CD4+ T cells <100/mm3 (p = .002) and APACHE II score >15 (p = .01). Nosocomial bloodstream infections are more common in patients with advanced HIV disease. Important cofactors are high APACHE II score and use of CVC. These infections can cause an excess mortality and significantly prolong the hospital stay of HIV-infected patients.

Bacterial pneumonia in HIV-infected patients: analysis of risk factors and prognostic indicators

This case control study assessed risk factors and prognostic indicators of 350 episodes of bacterial pneumonia in 285 HIV-infected patients. On univariate analysis, intravenous drug abuse (i.v.DA; p < .001 versus controls), regular cigarette smoking (p < .001), cirrhosis (p = .04), and history of a previous episode of pneumonia (p = .04) were risk factors for community-acquired episodes of bacterial pneumonia, whereas length of hospitalization (p = .01) was a risk factor only for nosocomial bacterial pneumonia. The small amount of circulating T CD4+ cells (<100/ mm3) was a risk factor in both groups of pneumonia (p < .05). Stepwise logistic regression analysis revealed that i.v.DA in community-acquired episodes and low levels of circulating T CD4+ cells, both in community-acquired and hospital-acquired episodes, were independent risk factors for the development of bacterial pneumonia. The case-fatality rate observed in our study was 27%. On stepwise logistic regression analysis, T CD4+ cell counts < or = 100/mm3 (p = .02), neutropenia (p = .04), PO2 arterial level < or = 70 mm Hg (p = .01), and Karnofsky score < or = 50 (p = .04) were independent indicators of mortality. According to a personally developed prognostic score, 211 episodes of pneumonia (60%) were classified as mild, 63 (18%) as moderate, and 76 (22%) as severe. Clinicians must carefully evaluate those variables that can influence the prognosis of bacterial pneumonia to make early identification of affected patients and to promptly establish the most appropriate therapeutic strategy in each case.

Risk factors, nutritional status, and quality of life in HIV-infected patients with enteric salmonellosis

AIMS

To define the potential risk factors, prognostic indicators, and quality of life of HIV-infected patients with enteric salmonellosis.

METHODS

A five-year matched (1:2) case-control study was performed. Thirty cases and 60 matched controls were studied.

RESULTS

Univariate analysis (p < 0.05) identified six risk factors for enteric salmonellosis: 1) increasing value of APACHE II score, 2) altered nutritional status, 3) previous antibiotic therapy, 4) ingestion of "risk" foods, 5) multiple (> or = 2) previous opportunistic infections, 6) stage C of HIV infection. Using the multivariate analysis, the most powerful predictors for developing an enteric salmonellosis were: increasing value of APACHE II score and altered nutritional status. The response to therapy was favourable in all episodes. Five (17%) patients suffered from one or more relapses. Multivariate analysis identified that a low number of circulating CD4+ (< 100/mm3) and a high APACHE II score (> 15) predict an increased risk of relapses.

CONCLUSIONS

HIV-associated enteric salmonellosis occurs more frequently in patients with advanced stage of HIV infection and with impaired nutritional status. We stress the need for a prompt and accurate diagnosis and treatment since the possible haematogenous spread and relapses appear reduced under early and prolonged antibiotic therapy.

Osteoarticular bacterial infections are rare in HIV-infected patients. 14 cases found among 4,023 HIV-infected patients

Among 4,023 HIV-infected patients admitted to a large Italian university hospital in the period 1985-1996, 14 had concomitant HIV and bacterial osteoarticular infections. Staphylococcus aureus infections were commonest and were diagnosed in 8 patients. Intravenous drug addiction was the only risk factor significantly associated with the development of osteoarticular infection (p = 0.04). In contrast, no statistical correlations were found with age, sex, absolute number of circulating T-CD4+ lymphocytes, neutrophils and stage of HIV infection. In conclusion, osteoarticular infections are uncommon in HIV-infected patients and are more directly related to parenteral drug abuse than to HIV.

Bacteremia in patients with hematological malignancies. Analysis of risk factors, etiological agents and prognostic indicators

BACKGROUND AND OBJECTIVE

Patients with hematological malignancies are at increased risk for developing bacteremia. No previous study has investigated the risk and prognostic indicators of bacteremia in such patients using a statistical approach.

METHODS

A case-control study was performed in 106 patients with hematological malignancies (group A). Two hundred and twelve patients were included as controls and divided into two groups: 106 patients with hematological malignancy without bacteremia (group B) and 106 HIV-infected patients with bacteremia (group C).

RESULTS

At univariate analysis, bacteremia risk factors in group A were: neutropenia for more than six days (p = 0.03 vs. group B), central venous catheter usage (p = 0.04) and absence of antibiotic prophylaxis (p = 0.03). At multivariate analysis, the use of CVC and neutropenia were independent bacteremia risk factors. The most frequent etiological agents were: Staphylococcus epidermidis and Pseudomonas aeruginosa. Comparing groups A and C, the distribution of Staphylococcus spp. was different, with S. epidermidis being prevalent in hematological patients only. As regards gram-negative organisms, it is of note that no episode of NT-Salmonella bacteremia was observed in group A, unlike group C, where they represent the second leading etiological agents. In group A, 14% of the patients died. Persistent neutropenia (p = 0.01) and the presence of relapsed neoplasm (p = 0.04) were prognostic indicators of bacteremia.

INTERPRETATION AND CONCLUSIONS

Our findings suggest that bacteremia in patients with hematological malignancies strictly correlates with the intensity and length of neutropenia and CVC usage. Although we observed a low mortality rate, we stress that this clinical condition requires special attention from the physician, who must recognize and treat it promptly.

Pneumothorax in HIV-infected patients: role of Pneumocystis carinii pneumonia and pulmonary tuberculosis

Patients with acquired immune deficiency syndrome (AIDS) are at increased risk for pneumothorax, which usually occurs in the setting of Pneumocystis carinii pneumonia. The rationale of the present study was based on the hypothesis that the increased incidence of pulmonary tuberculosis in human immunodeficiency virus (HIV)-infected patients could favour the development of pneumothorax in such patients. A case-control study was performed comprising 140 HIV-infected patients grouped as follows: 35 patients with pneumothorax and 105 matched controls without pneumothorax. Univariate analysis identified four risk factors for pneumothorax: 1) previous P. carinii pneumonia (p=0.01); 2) current P. carinii pneumonia (p=0.02); 3) pulmonary tuberculosis (p=0.01); and 4) cysts, pneumatoceles or bullae on chest radiographs (p<0.001). Multivariate analysis indicated that current P. carinii pneumonia (p=0.01) and pulmonary tuberculosis (p=0.04) were both independent risk factors for pneumothorax. In conclusion, our findings demonstrate that, in addition to Pneumocystis carinii pneumonia, pulmonary tuberculosis enhances the risk of pneumothorax in patients with acquired immune deficiency syndrome.

Fluconazole resistant oral candidiasis in HIV-infected patients

OBJECTIVE

To evaluate the risk factors associated with the emergence of fluconazole resistant Candida spp. in HIV-infected patients with oral candidiasis.

METHODS

Candida spp. were isolated from oral swabs and tested in vitro for resistance to fluconazole. The factors potentially correlated with vazole-resistent Candida spp. infections were investigated.

RESULTS

Fifty-one out of 118 patients (43%) with oral candidiasis had fluconazole resistant Candida spp. The following factors were significantly associated with the development of fluconazole resistance: (1) more than five episodes of oral candidiasis in the previous year (P < 0.001); (2) fluconazole therapy in the previous 6 months (P < 0.001); (3) C3 category of HIV infection (P < 0.001); and (4) low number of TCD4+ cells (< 50 mm3, P = 0.002). According to multivariate analysis, previous therapy with fluconazole was the only risk factor that independently influenced the development of Candida spp. resistance (P = 0.003).

CONCLUSIONS

The prophylaxis and therapy of mild fungal infections in HIV-infected patients, which may lead to azole resistance, should be carefully considered.

Gastric cryptosporidiosis complicating HIV infection: case report and review of the literature

Gastric cryptosporidiosis is rarely reported despite the fact that Cryptosporidium has been recognized with increasing frequency as an aetiological agent of severe chronic diarrhoeal enteritis in patients with human immunodeficiency virus (HIV) infection. We report a case of gastric cryptosporidiosis that occurred in an AIDS patient. Fifteen previously reported cases of gastric cryptosporidiosis are also reviewed. The review of all cases reported in the literature, including our own, showed that 12 patients had digestive symptoms. In 14 out of 16 patients the diagnosis was achieved by biopsy of the gastric mucosa rather than by examination of the stools. Gastric localization of Cryptosporidium is a rare and severe manifestation of intestinal cryptosporidiosis in patients with AIDS, and no single drug regimen has yet been found to be effective in eradicating this organism.

Central venous catheter-related sepsis in a cohort of 366 hospitalised patients

Five hundred two central venous catheters inserted in 366 patients were evaluated prospectively over a one-year period to determine the frequency and risk factors associated with catheter-related sepsis. For study purposes, in cases in which catheter infection was suspected but the initial blood cultures were negative, the catheters were replaced by guidewire technique; otherwise, the catheters were routinely changed after 21 days by guidewire technique. A catheter-related infection was suspected in 190 cases (190/502, 38%). A diagnosis of catheter-related sepsis was established in 50 patients, which represents 10% of the total number of lines (502). Over a total of 6428 days of catheter use, the infection rate was 0.8 cases of sepsis per 100 catheter-days. Staphylococcus epidermidis, Staphylococcus aureus, and Candida spp. were the most frequently isolated aetiological agents of sepsis. On univariate analysis, six variables affecting the rate of catheter-related sepsis were identified: neutropenia for more than eight days (p < 0.001); AIDS (p < 0.001); haematological malignancy (p < 0.001); administration of total parenteral nutrition (p = 0.001); duration of site use (p = 0.04); and high APACHE II score (p = 0.04). The logistic regression analysis revealed that AIDS and haematological malignancies were independent risk factors of catheter-related sepsis. Catheter replacement over a guidewire was no more likely to be associated with sepsis than was percutaneous catheter insertion. In conclusion, although the incidence of established catheter infection is much lower than the incidence of suspected infection, in most cases of suspected infection it is wise to change the catheter with the guidewire technique and wait for culture of the tip, rather than to remove the catheter immediately. Such a policy may help reduce the number of unnecessary catheter removals.

Comparative analysis of prognostic indicators of aspergillosis in haematological malignancies and HIV infection

The objective of this study was to identify the prognostic factors influencing the outcome of aspergillosis in two models of immunodeficiency, namely haematological malignancies and HIV infection. The study is based on a 5 year prospective logistic regression analysis of risk factors, clinical features, radiological findings and therapy affecting the prognosis of aspergillosis in 43 patients, i.e. 27 haematological neoplastic patients (group A) and 16 HIV infected patients (group B). Univariate analysis indicated that neutropenia (P = 0.02), haemoptysis (P = 0.03) and concomitant AIDS (P = 0.02), negatively influenced the prognosis of aspergillosis. Comparing the two groups of patients, significant differences emerged in the prognostic indicators. In particular respiratory failure (P = 0.02) and radiological bilateral involvement of the lungs were associated with a poor prognosis in group A (P = 0.04) and low (2100/mm3) T CD4+ cell count in group B (P = 0.02). At variance, a better prognosis was documented in patients treated with sequential therapy (amphotericin B and itraconazole) only within the group of haematological patients (P = 0.003). On multivariate analysis sequential therapy (P = 0.01) and AIDS (P = 0.03) were independent prognostic indicators of aspergillosis. In conclusion, our prospective study indicates that aspergillosis, although an uncommon event in patients with HIV infection, has a more severe prognosis in comparison to haematological patients. Future prospective clinical trials are necessary to confirm the real importance of the sequential therapy, with amphotericin B and itraconazole, in patients with aspergillosis.

Predictors of Staphylococcus aureus pneumonia associated with human immunodeficiency virus infection

This study is based on a retrospective logistic regression analysis of all human immunodeficiency virus (HIV)-infected patients with Staphylococcus aureus pneumonia (SAP) admitted to the Department of Infectious Diseases, Catholic University, Rome, Italy between January 1986 and December 1994. Nineteen patients with 24 episodes of SAP were enrolled in the study. A control group of 38 HIV-infected patients without pneumonia was included. The attack rate of SAP was 8.31/1000 HIV-related hospital admissions and the frequency, out of the total number of bacterial pneumonia observed in the study period, was 16% (24 of 154 patients). The large majority of SAP was community acquired. On the univariate analysis, intravenous drug abuse (IVDA) (P = 0.02), history of previous Pneumocystis carinii pneumonia (PCP) (P = 0.03) and cirrhosis (P = 0.03) were significant risk factors for SAP. In addition, IVDA and previous PCP were independent risk factors on multivariate analysis. All patients presented with fever associated with cough (74%), chest pain (26%) or shortness of breath (37%). Chest X-ray documented lobar pneumonia (78%), predominantly in the lower lobes, consolidation with cavitation (11%), and interstitial-nodular infiltrates (11%). Pleural effusion was present in 31% of patients. The response to therapy was favourable in 79% of patients. Recurrence occurred in 26% and death occurred in 21% of patients. Death was significantly associated with the low level (< 50 mm-3) of circulating T CD4+ cells (P = 0.03) and the recurrence of pneumonia (P = 0.03). In conclusion, the present study indicates that S. aureus is an important aetiologic agent of bacterial pneumonia in HIV-infected patients, especially if they are drug abusers with previous PCP.

Analysis of the risk factors associated with the emergence of azole resistant oral candidosis in the course of HIV infection

The objective of this case-control study, conducted in a large Italian university hospital over a 12-month period, was to evaluate the risk factors associated with the emergence of azole resistant oral candidosis in 64 Human Immunodeficiency Virus (HIV) infected patients. A swab was obtained from each patient by brushing candidal lesions. Candida albicans was isolated in 41 patients (64%), Candida glabrata in ten (16%), Candida krusei in five (8%), Candida kefyr in two (3%), Candida tropicalis in two (3%), and Candida lipolytica and Candida guilliermondii in one case, respectively. Two patients suffered a double infection i.e. C. albicans+C. krusei and C. albicans+C. glabrata, respectively. Candida species were tested in vitro for their susceptibility to ketoconazole, fluconazole, itraconazole and amphotericin B. MICs of the four antifungal drugs were obtained for each yeast using a microdilution broth method developed in our laboratory. Twenty four (37%) of the isolated strains were resistant both to itraconazole and fluconazole, five (8%) to fluconazole alone, and two (3%) to ketoconazole alone, while none of the isolated strains was resistant to amphotericin B. Patients with oral candidosis caused by a strain resistant to one or more azole drug were compared to control patients with azole-susceptible oral candidosis. On univariate analysis, more than five episodes of oral candidosis in the last year (P = 0.01), previous use of azole therapy (P = 0.001), C2-3 category of HIV infection (P = 0.01) and low number of circulating CD4+ T-cells (P = 0.03) were significantly associated with an increased risk for the development of azole resistance. However, previous use of azole therapy was the only factor selected by a stepwise logistic regression analysis which was independently associated with the isolation of azole resistant strains (P = 0.003). Our findings indicate that, in view of the potential risk for the emergence and selection of azole resistant strains of Candida in patients with AIDS, it is important to carefully choose the antifungal drug for the therapy of mild fungal infections after evaluation of the in-vitro susceptibility of the isolated strains.