Bacteremic pneumococcal pneumonia in HIV-seropositive and HIV-seronegative adults

HIV-related pneumococcal disease prevention in adults

INTRODUCTION

HIV-infected persons are particularly susceptible to the development of severe pneumococcal disease, even in the setting of combination antiretroviral therapy (cART), due to slow, incomplete recovery of anti-pneumococcal host defenses. This risk is increased by avoidable aspects of lifestyle, particularly smoking, which intensify immunosuppression. Clearly, more effective preventive measures are needed to counter this threat. Areas covered: This is a detailed review of the published literature focusing on currently available strategies for prevention of pneumococcal infection in HIV-infected patients, including cotrimoxazole prophylaxis, cART, pneumococcal vaccination, and smoking cessation strategies. This is preceded by a consideration of the epidemiology, clinical presentation, risk factors, and outcome of pneumococcal disease. Expert commentary: Cotrimoxazole prophylaxis has been shown to reduce morbidity and mortality in HIV-infected patients, although there is inconsistent data on the preventive efficacy against pneumococcal infections. Some recent studies have documented unchanged incidences of IPD in adult patients in the cART era. With regard to pneumococcal vaccination, routine acceptance of the efficacy of the PCV13/PPV23 sequential administration prime-boost strategy awaits the outcome of clinical trials in those with HIV infection. Smoking cessation, and discontinuation of excessive alcohol consumption and intravenous drug abuse, are priority strategies to prevent severe pneumococcal infection.

A Clinical Predictor Score for 30-Day Mortality among HIV-Infected Adults Hospitalized with Pneumonia in Uganda

Background

Pneumonia is a major cause of mortality among HIV-infected patients. Pneumonia severity scores are promising tools to assist clinicians in predicting patients’ 30-day mortality, but existing scores were developed in populations infected with neither HIV nor tuberculosis (TB) and include laboratory data that may not be available in resource-limited settings. The objective of this study was to develop a score to predict mortality in HIV-infected adults with pneumonia in TB-endemic, resource-limited settings.

Methods

We conducted a secondary analysis of data from a prospective study enrolling HIV-infected adults with cough ≥2 weeks and <6 months and clinically suspected pneumonia admitted to Mulago Hospital in Kampala, Uganda from September 2008 to March 2011. Patients provided two sputum specimens for mycobacteria, and those with Ziehl-Neelsen sputum smears that were negative for mycobacteria underwent bronchoscopy with inspection for Kaposi sarcoma and testing for mycobacteria and fungi, including Pneumocystis jirovecii. A multivariable best subsets regression model was developed, and one point was assigned to each variable in the model to develop a clinical predictor score for 30-day mortality.

Results

Overall, 835 patients were studied (mean age 34 years, 53.4% female, 30-day mortality 18.2%). A four-point clinical predictor score was identified and included heart rate >120 beats/minute, respiratory rate >30 breaths/minute, oxygen saturation <90%, and CD4 cell count <50 cells/mm³. Patients’ 30-day mortality, stratified by score, was: score 0 or 1, 12.6%, score 2 or 3, 23.4%, score 4, 53.9%. For each 1 point change in clinical predictor score, the odds of 30-day mortality increased by 65% (OR 1.65, 95% CI 1.39-1.96, p <0.001).

Conclusions

A simple, four-point scoring system can stratify patients by levels of risk for mortality. Rapid identification of higher risk patients combined with provision of timely and appropriate treatment may improve clinical outcomes. This predictor score should be validated in other resource-limited settings.

[Comparative diagnosis of bacterial pneumonia and pulmonary tuberculosis in HIV positive patients]

INTRODUCTION

Immunodepression induced by the human immunodeficiency virus (HIV) modifies the clinical, radiological and microbiological manifestations of pulmonary tuberculosis; leading to similarities between pulmonary tuberculosis and acute community-acquired bacterial pneumonia. A consequence is the high proportion of discordant pre- and post-mortem diagnoses of pneumonia. The aim of our study was to contribute to the improvement in the diagnosis of acute bacterial pneumonia in HIV positive patients in areas where tuberculosis is endemic.

METHODS

This retrospective study in HIV positive patients has compared 94 cases of positive smear cases pulmonary tuberculosis and 78 cases of acute community-acquired bacterial pneumonia.

RESULTS

Using logistic regression, the following features were positively associated with bacterial pneumonia: the sudden onset of signs (OR=8.48 [CI 95% 2.50-28.74]), a delay in the evolution of symptoms of less than 15 days (OR=3.70 [CI 95% 1.11-12.35]), chest pain (OR=2.81 [CI 95% 1.10-7.18]), radiological alveolar shadowing (OR=12.98 [CI 95% 4.66-36.12) and high leukocytosis (OR=3.52 [CI 95% 1.19-10.44]). These five variables allowed us to establish a diagnostic score for bacterial pneumonia ranging from 0 to 5. The area under the ROC curve was 0.886 [CI 95% 0.84-0.94, P<0.001]). Its specificity was >96.8% for a score of greater than or equal to 4.

CONCLUSION

The diagnostic score for acute community-acquired pneumonia may improve the management of bacterial pneumonia in areas where tuberculosis is endemic.

Bacterial Infections in Adult HIV-Infected Patients

PURPOSE

The purpose of this article is to critically review articles published from the pre-HAART era to the present on bacterial infections in adult HIV-infected patients.

METHOD

Literature search on bacterial infections in HIV-infected patients yields predominantly small case series from single centers, many of which are retrospectively collected.

RESULTS

Variations in case selection limit the utility of these articles for assessing the epidemiology and clinical features of a particular infection. Nonetheless, numerous articles indicate that certain bacterial infections occur most often when CD4 cell counts are < 200/mm3. In the pre-HAART era, others suggest that PcP prophylaxis with TMP/SMX and MAC prophylaxis with macrolides reduced rates of several bacterial infections. Since the advent of HAART, however, some articles suggest that the incidence of various infections has declined and that withdrawal of OI prophylaxis in patients who have had HAART restoration of CD4 cell counts has not led to an increase in certain bacterial infections.

CONCLUSION

This review suggests that bacterial infections may have declined in the HAART era, as multicenter cohort studies have shown to be the case with AIDS-associated OIs. Nonetheless, preventive measures such as pneumococcal vaccination and smoking cessation remain effective strategies.

Population snapshot of Streptococcus pneumoniae causing invasive disease in South Africa prior to introduction of pneumococcal conjugate vaccines

We determined the sequence types of isolates that caused invasive pneumococcal disease (IPD) prior to routine use of pneumococcal conjugate vaccines (PCV) in South Africa. PCV-13 serotypes and 6C isolates collected in 2007 (1 461/2 437, 60%) from patients of all ages as part of on-going, national, laboratory-based surveillance for IPD, were selected for genetic characterization. In addition, all 134 non-PCV isolates from children <2 years were selected for characterization. Sequence type diversity by serotype and age category (children <5 years vs. individuals ≥5 years) was assessed for PCV serotypes using Simpson’s index of diversity. Similar genotypes circulated among isolates from children and adults and the majority of serotypes were heterogeneous. While globally disseminated clones were common among some serotypes (e.g., serotype 1 [clonal complex (CC) 217, 98% of all serotype 1] and 14 [CC230, 43%)]), some were represented mainly by clonal complexes rarely reported elsewhere (e.g., serotype 3 [CC458, 60%] and 19A [CC2062, 83%]). In children <2 years, serotype 15B and 8 were the most common serotypes among non-PCV isolates (16% [22/134] and 15% [20/134] isolates, respectively). Sequence type 7052 and 53 were most common among serotypes 15B and 8 isolates and accounted for 58% (7/12) and 64% (9/14) of the isolates, respectively. Serotype 19F, 14, 19A and 15B had the highest proportions of penicillin non-susceptible isolates. Genotypes rarely reported in other parts of the world but common among some of our serotypes highlight the importance of our data as these genotypes may emerge post PCV introduction.

Incidence and risk factors for invasive pneumococcal disease in HIV-infected and non-HIV-infected individuals before and after the introduction of combination antiretroviral therapy: persistent high risk among HIV-infected injecting drug users

BACKGROUND

Invasive pneumococcal disease (IPD) is an important cause of morbidity among individuals infected with human immunodeficiency virus (HIV). We described incidence and risk factors for IPD in HIV-infected and uninfected individuals.

METHODS

Nationwide population-based cohort study of HIV-infected adults treated at all Danish HIV treatment centers during 1995-2012. Nineteen population-matched controls per HIV-infected individual were retrieved. The risk of IPD was assessed using Poisson regression.

RESULTS

The incidence of IPD was 304.7 cases per 100 000 person-years of follow-up (PYFU) in HIV-infected and 12.8 per 100 000 PYFU in HIV-uninfected individuals. After adjusting for confounders, HIV infection (relative risk [RR], 24.4 [95% confidence interval [CI], 23.7-25.1]), male sex (RR, 1.20 [95% CI, 1.16-1.24]), increasing age (per year) (RR, 1.03 [95% CI, 1.03-1.04]), and calendar period (pre-cART RR, 2.80 [95% CI, 2.70-2.91] compared with late cART) were significantly associated with an increased risk of IPD. Among HIV-infected individuals, male sex (RR, 1.57 [95% CI, 1.49-1.66]), smoking (RR, 1.34 [95% CI, 1.26-1.42]), and injecting drug use (RR, 2.51 [95% CI, 2.26-2.67]) were associated with an increased risk of IPD. Detectable viral loads (RR, 1.88 [95% CI, 1.79-1.98]) and a relative fall in CD4 T-cell counts were also associated with an increased risk (≥500 to 350-500 CD4 T cells/µL: RR, 1.29 [95% CI, 1.21-1.37] and <100 cells/µL: RR, 7.4 [95% CI, 6.87-8.02]). The risk of IPD declined over time, although this was not the case for IDUs where the risk remained unchanged.

CONCLUSIONS

The incidence of IPD in HIV-infected individuals remained significantly higher than the incidence observed in non-HIV-infected subjects, despite the widespread use of cART. IDUs have a persistently high risk of IPD. Injecting drug use, smoking, and the receipt of cART are suitable targets for preventive measures in the future.

Outcome and reinfection after Staphylococcus aureus bacteraemia in individuals with and without HIV-1 infection: a case-control study

OBJECTIVES

Individuals infected with HIV-1 are at an increased risk of Staphylococcus aureus bacteraemia (SAB). The aim of this study was to investigate mortality rate and risk of reinfection associated with SAB in HIV-1-infected individuals compared to individuals without HIV-1 infection.

SETTING

University hospital treating a third of the estimated 5000 individuals with HIV infection in Denmark.

PARTICIPANTS

HIV-1-infected (n=82) and sex-matched and age-matched uninfected (n=163) individuals with SAB in the time period 1 January 1995 to 31 December 2010.

PRIMARY OUTCOME MEASURES

30-day and 365-day mortality rate ratio and relative risk of reinfection.

RESULTS

Individuals with HIV had an increased risk of death at day 30 (OR 11.90 (95% CI 2.15 to 65.85)) compared to individuals without HIV. Other factors associated with mortality were age, a foreign device and Pitt score. HIV-related factors did not associate to mortality. During follow-up, there were 43 episodes of reinfection; in individuals with HIV infection at an incidence rate of 7.8 (95% CI 4.7 to 10.9)/100 person-years compared with 2.2 (95% CI 1.2 to 3.2)/100 person-years for individuals without HIV. In multivariate analysis, HIV status (OR 2.91 (95% CI 1.29 to 6.58) and injection drug use (OR 3.51 (95% CI 1.06 to 11.63) were independently associated with an increased risk of reinfection.

CONCLUSIONS

HIV-1 infection is associated with an increased risk of 30-day mortality after SAB and a very high rate of reinfection. Age, a foreign device and Pitt score predicted outcome. For patients infected with HIV, neither CD4 T-lymphocyte counts nor plasma HIV RNA levels were associated with 30-day outcome.

TRIAL REGISTRATION NUMBER

The study was approved by the Danish Data Protection Agency (record no. 2007-41-1196).

HIV-associated bacterial pneumonia

Community-acquired bacterial pneumonia (CAP) remains one of the most common opportunistic infections in patients who are infected with the human immunodeficiency virus (HIV). The risk of CAP increases as the CD4 cell count decreases. The common bacterial pathogens that cause CAP in HIV-infected persons are similar to those in HIV-uninfected individuals, with the pneumococcus being the most common pathogen. Prevention of CAP remains critical and necessitates a comprehensive approach addressing, among many other factors, cigarette smoking cessation strategies, antiretroviral therapy adherence, and immunization against those infections for which effective vaccinations are available.

Estimating the burden of pneumococcal pneumonia among adults: a systematic review and meta-analysis of diagnostic techniques

Background

Pneumococcal pneumonia causes significant morbidity and mortality among adults. Given limitations of diagnostic tests for non-bacteremic pneumococcal pneumonia, most studies report the incidence of bacteremic or invasive pneumococcal disease (IPD), and thus, grossly underestimate the pneumococcal pneumonia burden. We aimed to develop a conceptual and quantitative strategy to estimate the non-bacteremic disease burden among adults with community-acquired pneumonia (CAP) using systematic study methods and the availability of a urine antigen assay.

Methods and Findings

We performed a systematic literature review of studies providing information on the relative yield of various diagnostic assays (BinaxNOW® S. pneumoniae urine antigen test (UAT) with blood and/or sputum culture) in diagnosing pneumococcal pneumonia. We estimated the proportion of pneumococcal pneumonia that is bacteremic, the proportion of CAP attributable to pneumococcus, and the additional contribution of the Binax UAT beyond conventional diagnostic techniques, using random effects meta-analytic methods and bootstrapping. We included 35 studies in the analysis, predominantly from developed countries. The estimated proportion of pneumococcal pneumonia that is bacteremic was 24.8% (95% CI: 21.3%, 28.9%). The estimated proportion of CAP attributable to pneumococcus was 27.3% (95% CI: 23.9%, 31.1%). The Binax UAT diagnosed an additional 11.4% (95% CI: 9.6, 13.6%) of CAP beyond conventional techniques. We were limited by the fact that not all patients underwent all diagnostic tests and by the sensitivity and specificity of the diagnostic tests themselves. We address these resulting biases and provide a range of plausible values in order to estimate the burden of pneumococcal pneumonia among adults.

Conclusions

Estimating the adult burden of pneumococcal disease from bacteremic pneumococcal pneumonia data alone significantly underestimates the true burden of disease in adults. For every case of bacteremic pneumococcal pneumonia, we estimate that there are at least 3 additional cases of non-bacteremic pneumococcal pneumonia.

Characteristics of Drug-Susceptible and Drug-Resistant Staphylococcus aureus Pneumonia in Patients with HIV

Objectives

To examine predictors and outcomes of Staphylococcus aureus Pneumonia (SAP) in people with HIV compared with Streptococcus pneumoniae Pneumonia (SPP), and to compare Methicillin-Resistant S. aureus (MRSA) with Methicillin-Sensitive S. aureus (MSSA) pneumonias in this population.

Methods

We conducted a retrospective case-control study of HIV-infected patients admitted to a single center with culture-proven S. aureus or S. pneumoniae pneumonia. We identified patients through a computerized database, conducted structured chart reviews, and performed bivariate and multivariate analyses using logistic regression.

Results

We compared 47 SAP episodes in 42 patients with 100 SPP episodes in 93 patients. Use of any antibiotics prior to admission (OR=3.5, p=0.02), a co-morbid illness (OR=4.2, p=0.04), and recent healthcare contact (OR=12.0, p<0.001) were significant independent predictors of SAP. Patients with SAP were more likely to require intensive care (OR=2.7, p=0.02) and mechanical ventilation (OR=3.1, p=0.02), but not to die. MRSA was more common (57% of cases) than MSSA, but outcomes were not significantly worse.

Conclusions

Patients with HIV and SAP have worse outcomes than those with SPP. Clinicians should consider empiric antibiotic coverage for MRSA in patients admitted with HIV and pneumonia, given the high prevalence of MRSA. Further studies are warranted to examine morbidity differences between HIV-associated MSSA and MRSA pneumonia.

Influence of HIV infection on the clinical presentation and outcome of adults with acute community-acquired pneumonia in Yaounde, Cameroon: a retrospective hospital-based study

Background

The impact of HIV infection on the evolution of acute community-acquired pneumonia (CAP) is still controversial. The aim of this study was to investigate possible differences in the clinical presentation and in-hospital outcomes of patients with CAP with and without HIV infection in a specialised service in Yaounde.

Methods

Medical files of 106 patients (51 men) aged 15 years and above, admitted to the Pneumology service of the Yaounde Jamot Hospital between January 2008 and May 2012, were retrospectively studied.

Results

Sixty-two (58.5%) patients were HIV infected. The median age of all patients was 40 years (interquartile range: 31.75-53) and there was no difference in the clinical and radiological profile of patients with and without HIV infection. The median leukocyte count (interquartile range) was 14,600/mm³ (10,900-20,600) and 10,450/mm³ (6,400-16,850) respectively in HIV negative and HIV positive patients (p = 0.002). Median haemoglobin level (interquartile range) was 10.8 g/dl (8.9-12) in HIV negative and 9.7 g/dl (8–11.6) in HIV positive patients (p = 0.025). In-hospital treatment failure on third day (39.5% vs. 25.5.1%, p = 0.137) and mortality rates (9% vs. 14.5%, p = 0.401) were similar between HIV negative and HIV positive patients.

Conclusion

Clinical and radiological features as well as response to treatment and in hospital fatal outcomes are similar in adult patients hospitalised with acute community-acquired pneumonia in Yaounde. In contrast, HIV infected patients tend to be more anaemic and have lower white cell counts than HIV negative patients. Larger prospective studies are needed to consolidate these findings.

CD8+ T cells and risk for bacterial pneumonia and all-cause mortality among HIV-infected women

BACKGROUND

Bacterial pneumonia risk is disproportionately high among those infected with HIV. This risk is present across all CD4(+) T-cell levels (TCLs), suggesting that additional factors govern susceptibility. This study examines CD8(+) TCLs and risk for HIV-associated bacterial pneumonia and all-cause mortality.

METHODS

Demographic, clinical, and laboratory data were obtained for 885 HIV-infected women enrolled in the HIV Epidemiologic Research Study (HERS). Bacterial pneumonia cases were identified using clinical, microbiological, and radiographic criteria. CD8(+) TCLs were assessed at 6-month intervals. Statistical methods included Cox proportional hazards regression modeling and covariate-adjusted survival estimates.

RESULTS

Relative to a referent CD8(+) TCL of 401-800 cells per cubic millimeter, risk for bacterial pneumonia was significantly higher when CD8(+) TCLs were <400 (hazard ratio 1.65, P = 0.017, 95% confidence interval 1.10 to 2.49), after adjusting for age, CD4(+) TCL, viral load, and antiretroviral use. There was also a significantly higher risk of death when CD8(+) TCLs were ≤400 cells per cubic millimeter (hazard ratio 1.45, P = 0.04, 95% confidence interval 1.02 to 2.06). Covariate-adjusted survival estimates revealed shorter time to pneumonia and death in this CD8(+) TCL category, and the overall associations of the categorized CD8(+) TCL with bacterial pneumonia and all-cause mortality were each statistically significant (P = 0.017 and P < 0.0001, respectively).

CONCLUSIONS

CD8(+) TCL ≤400 cells per cubic millimeter was associated with increased risk for pneumonia and all-cause mortality in HIV-infected women in the HERS cohort, suggesting that CD8(+) TCL could serve as an adjunctive biomarker of pneumonia risk and mortality in HIV-infected individuals.

Persistent high burden of invasive pneumococcal disease in South African HIV-infected adults in the era of an antiretroviral treatment program

Background

Highly active antiretroviral treatment (HAART) programs have been associated with declines in the burden of invasive pneumococcal disease (IPD) in industrialized countries. The aim of this study was to evaluate trends in IPD hospitalizations in HIV-infected adults in Soweto, South Africa, associated with up-scaling of the HAART program from 2003 to 2008.

Methods

Laboratory-confirmed IPD cases were identified from 2003 through 2008 through an existing surveillance program. The period 2003-04 was designated as the early-HAART era, 2005–06 as the intermediate-HAART era and 2007–08 as the established-HAART era. The incidence of IPD was compared between the early-HAART and established-HAART eras in HIV-infected and–uninfected individuals.

Results

A total of 2,567 IPD cases among individuals older than 18 years were reported from 2003 through 2008. Overall incidence of IPD (per 100,000) did not change during the study period in HIV-infected adults (207.4 cases in the early-HAART and 214.0 cases in the established-HAART era; p = 0.55). IPD incidence, actually increased 1.16-fold (95% CI: 1.01; 1.62) in HIV-infected females between the early-and established-HAART eras (212.1 cases and 246.2 cases, respectively; p = 0.03). The incidence of IPD remained unchanged in HIV-uninfected adults across the three time periods.

Conclusion

Despite a stable prevalence of HIV and the increased roll-out of HAART for treatment of AIDS patients in our setting, the burden of IPD has not decreased among HIV-infected adults. The study indicates a need for ongoing monitoring of disease and HAART program effectiveness to reduce opportunistic infections in African adults with HIV/AIDS, as well as the need to consider alternate strategies including pneumococcal conjugate vaccine immunization for the prevention of IPD in HIV-infected adults.

High rate of pneumococcal bacteremia in a prospective cohort of older children and adults in an area of high HIV prevalence in rural western Kenya

BACKGROUND

Although causing substantial morbidity, the burden of pneumococcal disease among older children and adults in Africa, particularly in rural settings, is not well-characterized. We evaluated pneumococcal bacteremia among 21,000 persons > or =5 years old in a prospective cohort as part of population-based infectious disease surveillance in rural western Kenya from October 2006-September 2008.

METHODS

Blood cultures were done on patients meeting pre-defined criteria--severe acute respiratory illness (SARI), fever, and admission for any reason at a referral health facility within 5 kilometers of all 33 villages where surveillance took place. Serotyping of Streptococcus pneumoniae was done by latex agglutination and quellung reaction and antibiotic susceptibility testing was done using broth microdilution. We extrapolated incidence rates based on persons with compatible illnesses in the surveillance population who were not cultured. We estimated rates among HIV-infected persons based on community HIV prevalence. We projected the national burden of pneumococcal bacteremia cases based on these rates.

RESULTS

Among 1,301 blood cultures among persons > or =5 years, 52 (4%) yielded pneumococcus, which was the most common bacteria isolated. The yield was higher among those > or =18 years than 5-17 years (6.9% versus 1.6%, p < 0.001). The highest yield was for inpatients with SARI (10%), compared with SARI outpatients (3%) and acute febrile outpatients (1%). Serotype 1 pneumococcus was most common (42% isolates) and 71% were serotypes included in the 10-valent pneumococcal conjugate vaccine (PCV10). Non-susceptibility to beta-lactam antibiotics was low (<5%), but to trimethoprim-sulfamethoxazole was high (>95%). The crude rate of pneumococcal bacteremia was 129/100,000 person-years, and the adjusted rate was 419/100,000 person-years. Nineteen (61%) of 31 patients with HIV results were HIV-positive. The adjusted rate among HIV-infected persons was 2,399/100,000 person-years (Rate ratio versus HIV-negative adults, 19.7, 95% CI 12.4-31.1). We project 58,483 cases of pneumococcal bacteremia will occur in Kenyan adults in 2010.

CONCLUSIONS

Pneumococcal bacteremia rates were high among persons > or =5 years old, particularly among HIV-infected persons. Ongoing surveillance will document if expanded use of highly-active antiretroviral treatment for HIV and introduction of PCV10 for Kenyan children (anticipated in late 2010) result in substantial secondary benefits by reducing pneumococcal disease in adults.

[Characteristics of supposedly bacterial community acute pneumonia among HIV-positive patients: prospective preliminary study]

INTRODUCTION

Community-acquired pneumonia (CAP) is the second leading cause of hospitalization in the respirology department in Abidjan after tuberculosis. Frequently associated with HIV infection, it has a high mortality rate of about 20% to 30%. The aim of this study is to identify the specificities and severity factors associated with bacterial CAP (BCAP) outcome in HIV-positive patients.

METHODS

The authors conducted a prospective and comparative preliminary study on two groups of patients: 29 HIV-positive patients with BCAP and 21 HIV-negative patients with BCAP. All of the patients were hospitalized for BCAP with symptoms of severity according to the usual score of severity.

RESULTS

The sociodemographic, clinical and paraclinical characteristics were similar in both groups. Failures and deaths were more frequent in the group with HIV infection. In particular, HIV infected patients with a body mass index under 18.5 and a rate of T CD4 lymphocytes lower than 200/mm(3) presented the least favourable evolution.

CONCLUSIONS

A more extensive study should help define the appropriate severity criteria for BCAP associated with HIV infection.

HIV seropositivity predicts longer duration of stay and rehospitalization among nonbacteremic febrile injection drug users with skin and soft tissue infections

BACKGROUND

Skin/soft tissue infections (SSTIs) are the leading cause of hospital admissions among injection drug users (IDUs).

METHODS

We performed a retrospective investigation to determine the epidemiology of SSTIs (ie, cellulitis and/or abscesses) in febrile IDUs, with a focus on bacteriology and potential predictors of increased health care utilization measured by longer length of stay and rehospitalization. Subjects were drawn from a cohort of febrile IDUs presenting to an inner-city emergency department from 1998 to 2004.

RESULTS

Of the 295 febrile IDUs with SSTIs, specific discharge diagnoses were cellulitis only (n = 143, 48.5%), abscesses only (n = 113, 38.3%), and both (n = 39, 13.2%). Documented HIV infection rate was 28%. Of note, 10 subjects were newly diagnosed with HIV infection during their visits. Staphylococcus aureus was the leading pathogen, and increasing rates of methicillin-resistant S. aureus emerged over time (before 2001: 4%, 2001-2004: 56%, P < 0.01). HIV seropositivity predicted rehospitalization within 90 days [adjusted hazard ratios and 95% confidence intervals: 2.90 (1.20 to 7.02)]. HIV seropositivity also predicted increased length of stay in those who were nonbacteremic [adjusted hazard ratios and 95% confidence intervals: 1.49 (1.11 to 2.01)].

CONCLUSIONS

Among febrile IDUs with SSTIs, a strong association between HIV seropositivity and health care resource utilization was found. Accordingly, attention to HIV serostatus should be considered in clinical disposition decisions for this vulnerable high-risk population.

The evidence for using conjugate vaccines to protect HIV-infected children against pneumococcal disease

Pneumococcal conjugate vaccines (PCVs) are a potentially useful complement to existing treatment strategies in HIV-infected children, for whom pneumococcal infections are common and serious. This Review summarises available data on the burden of pneumococcal disease and the safety and efficacy of PCVs in HIV-infected children. The data demonstrate that children with HIV have significantly increased risk of pneumococcal disease compared with uninfected children; the serotypes included in currently licensed or near-licensure conjugate vaccines include most serotypes that cause invasive pneumococcal disease (IPD) in HIV-infected children and adults; PCVs provide substantial protection against IPD and clinical pneumonia when given to HIV-infected infants; and HIV-infected adults gain an indirect benefit when children in the community are vaccinated. PCV should be considered as an important intervention for improving the lives of HIV-infected children.

Bacteraemic pneumococcal pneumonia: Impact of HIV on clinical presentation and outcome

OBJECTIVES

The objectives of this study were to investigate the clinical and laboratory features, hospital course and outcome of patients with bacteraemic pneumococcal pneumonia, comparing HIV with non-HIV patients, as well as HIV patients from different parts of the world.

METHODS

This was a multicentre prospective observational study of consecutive adult cases with bacteraemic pneumococcal pneumonia in 10 countries on 6 continents.

RESULTS

A total of 768 cases were recruited, of which 200 were HIV-infected; 166 were from South Africa. Lower age, i.v. drug use, fewer co-morbid illnesses, and a higher frequency of respiratory symptoms were significantly more likely to occur in HIV patients. The 14-day mortality for the group as a whole was 14.5%, being 16% in the HIV patients and 13.9% in the non-HIV patients (not significant). When adjustments were made for age and severity of illness, HIV patients had significantly higher 14-day mortality with significant trend for increasing 14-day mortality in those with lower CD4 counts. Despite differences in various clinical and laboratory parameters in patients from different parts of the world, on multivariate analysis, when adjusting for regional differences, the HIV-infected patients were still noted to have poorer 14-day mortality.

CONCLUSIONS

This study, in contrast to previous investigations, indicates that there are significant differences in the clinical presentation and outcome of bacteraemic pneumococcal pneumonia when comparing HIV and non-HIV patients.

Pneumonia severity index in the immunocompromised

BACKGROUND

The pneumonia severity index (PSI) accounts for many comorbidities, but not immunosuppression.

OBJECTIVES

To document the utility of the PSI to predict mortality in immunocompromised patients (IP) with community-acquired pneumonia (CAP).

METHODS

Charts of 284 patients with immunosuppression and CAP were reviewed, and these patients were compared with a contemporary sample of non-IP with CAP. The ability of the PSI to predict mortality was assessed by using multiple logistic regression. Discrimination of the PSI was studied by using the concordance index.

RESULTS

Thirty-nine of 284 IP died. Mortality varied according to the etiology of the immunosuppression. Patients with HIV, solid organ transplantation or treatment with immunosuppressive drugs (n=118) had a low in-hospital mortality (4.3%) and were classified as low risk. IP with hematological malignancies, chemotherapy, chest radiation or marrow transplantation (n=166) had a high mortality (20%) and were classified as high risk. Compared with non-IP, low-risk IP had similar PSI-controlled mortality (OR=0.9, P=0.80), whereas high-risk IP had significantly greater mortality (OR=2.8, P<0.0001). The concordance index revealed similar discrimination for the PSI in low-risk IP (0.77) and in non-IP (0.7), but inferior discrimination in high-risk patients (0.6).

CONCLUSIONS

Patients with CAP and immunosuppression can be divided into low-risk and high-risk groups. The low-risk IP have mortality similar to non-IP and can be risk stratified by using the PSI.

Bacterial pneumonia, HIV therapy, and disease progression among HIV-infected women in the HIV epidemiologic research (HER) study

BACKGROUND

To determine the rate and predictors of community-acquired bacterial pneumonia and its effect on human immunodeficiency virus (HIV) disease progression in HIV-infected women, we performed a multiple-site, prospective study of HIV-infected women in 4 cities in the United States.

METHODS

During the period of 1993-2000, we observed 885 HIV-infected and 425 HIV-uninfected women with a history of injection drug use or high-risk sexual behavior. Participants underwent semiannual interviews, and CD4+ lymphocyte count and viral load were assessed in HIV-infected subjects. Data regarding episodes of bacterial pneumonia were ascertained from medical record reviews.

RESULTS

The rate of bacterial pneumonia among 885 HIV-infected women was 8.5 cases per 100 person-years, compared with 0.7 cases per 100 person-years in 425 HIV-uninfected women (P < .001). In analyses limited to follow-up after 1 January 1996, highly active antiretroviral therapy (HAART) and trimethoprim-sulfamethoxazole (TMP-SMX) use were associated with a decreased risk of bacterial pneumonia. Among women who had used TMP-SMX for 12 months, each month of HAART decreased bacterial pneumonia risk by 8% (adjusted hazard ratio [HR(adj)], 0.92; 95% confidence interval [CI], 0.89-0.95). Increments of 50 CD4+ cells/mm3 decreased the risk (HR(adj), 0.88; 95% CI, 0.84-0.93), and smoking doubled the risk (HR(adj), 2.12; 95% CI, 1.26-3.55). Bacterial pneumonia increased mortality risk (HR(adj), 5.02; 95% CI, 2.12-11.87), with adjustment for CD4+ lymphocyte count and duration of HAART and TMP-SMX use.

CONCLUSIONS

High rates of bacterial pneumonia persist among HIV-infected women. Although HAART and TMP-SMX treatment decreased the risk, bacterial pneumonia was associated with an accelerated progression to death. Interventions that improve HAART utilization and promote smoking cessation among HIV-infected women are warranted.

HIV infection in women utilizing a major hospital in Andhra Pradesh, India, 1993-2004

BACKGROUND

Despite the high prevalence rates of HIV infection in women, epidemiological studies conducted exclusively on HIV-reactive women are very sparse, particularly from the state of Andhra Pradesh, India, where the overall prevalence rate among antenatal women is 2.1%.

STUDY POPULATION

Medical records of 2643 HIV-reactive women, identified during a 12-year period, were reviewed for epidemiological and clinical information about HIV in women.

RESULTS

The overall prevalence of HIV-reactive women was 1.6% and trends were in parallel with those observed by the HIV sentinel surveillance study from our state. Overall 24.5% of HIV-infected cases were women, ranging from 6.3% in 1993 to 28.9% in 2004. HIV infection was increasingly found in women over 30 years of age. Heterosexual contact (87.3%) was the most common route of HIV transmission. The majority (75.2%) of the women were asymptomatic. Women, compared to men, suffered more from respiratory and bacterial infections, often pneumonia, and from gender-specific manifestations like vaginal candidal infections. Following the introduction of antiretroviral (ARV) therapy in our hospital in 1999, only 8.5% of HIV-reactive women have received ARV treatment.

CONCLUSION

There is a need for gender- and age-specific HIV surveillance among women, especially from areas of high prevalence. Our study shows that there are good reasons to be concerned about the effects of HIV in women. We stress the importance of increasing the focus of attention on the impact of this pandemic on women as we enter the 25th year since its emergence.

[Infectious pulmonary complications in HIV-infected patients in the high by active antiretroviral therapy era in Spain]

Pulmonary complications in HIV-infected patients are at present a first-rate problem. They are the main cause of hospital admission of these patients in our country. Most HIV-patients have a pulmonary complication during the evolution of the infection. The main etiologic diagnosis is bacterial pneumonia, especially pneumococcal pneumonia; the second most frequent cause is Pneumocystis jiroveci (previously named P. carinii) pneumonia and the third cause is mycobacteriosis, particularly Mycobacterium tuberculosis. From early studies, important changes in the epidemiology of HIV-related pulmonary complications have occurred. General prescription of P. jiroveci primary prophylaxis is probably one of the main causes, and, more recently, the use of highly active antiretroviral therapy may also be an underlying explanation. In this review, epidemiology, diagnosis and outcome of HIV-related pulmonary complications in our country are update.

Differences in presentation and outcome of invasive pneumococcal disease among patients with and without HIV infection in the pre-HAART era

Invasive pneumococcal disease (PD) occurs frequently among HIV-infected patients, but it is unclear whether its manifestations and outcome are different compared to those observed among patients without HIV-1 infection. Because the immune reconstitution that accompanies antiretroviral therapy may change some of these features and because most cases of HIV- 1 infection occur in resource-poor settings of the world where access to antiretroviral agents is limited, we compared PD among patients with and without HIV-1 infection in a North American population before the introduction of highly active antiretroviral therapy (HAART). The records of all pneumococcal cultures processed at this medical center over a period of 20 months were used to identify patients with invasive PD. Hospital records were reviewed for 103 of these patients (52 with and 51 without HIV-1 infection) and demographic, clinical, laboratory, radiographic, and microbiologic information was abstracted and subsequently analyzed. Despite similarities in presenting signs and symptoms, we found a higher incidence of bacteremia but a more favorable outcome with less frequent requirements for intubation and admission to intensive care units and better survival among individuals with HIV infection. Factors such as less advanced age, the presence of fewer comorbid conditions, or a less florid inflammatory response among HIV-infected individuals may account for differences in outcome of invasive PD.

Global strategies to prevent bacterial pneumonia in adults with HIV disease

We examined the peer-reviewed literature on the burden of bacterial pneumonia and the effectiveness of interventions for its prevention among HIV-infected adults in developed and developing countries. Bacterial pneumonia rates were up to 25-fold higher among HIV-infected adults than in the general community, with rates increasing as CD4+ T-cell count decreases. In developed countries, cohort studies showed that highly active antiretroviral therapy (HAART) had the most consistent effect on reducing pneumonia. In a prospective cohort and case-control studies from these regions, pneumococcal polysaccharide vaccine reduced pneumococcal disease in certain subgroups, particularly those with higher CD4+ T cells/microL. In patients with fewer than 200 CD4+ T cells/microL, antimicrobial prophylaxis was usually effective in reducing pneumonia. In sub-Saharan Africa, randomised controlled trials concluded that co-trimoxazole prophylaxis decreased rates of bacterial pneumonia, but pneumococcal polysaccharide vaccine prevented neither pneumonia nor invasive pneumococcal disease. Although not yet fully evaluated in Africa, based on experience in industrialised nations, use of HAART in Africa may have substantial potential to prevent bacterial pneumonia.

Changes in the epidemiology of pneumococcal bacteremia in a Swiss university hospital during a 15-year period, 1986-2000

OBJECTIVE

To evaluate changes in epidemiological characteristics and outcome of patients with pneumococcal bacteremia during a 15-year period in a Swiss university hospital.

PATIENTS AND METHODS

We reviewed the medical records of all hospitalized adults at the University Hospital Basel, Basel, Switzerland, whose blood culture yielded Streptococcus pneumoniae from January 1, 1986, through December 31, 2000.

RESULTS

We analyzed 405 episodes of pneumococcal bacteremia in 394 patients. The mean annual incidence of 1.78 episodes per 1000 hospital admissions was inversely related to the mean atmospheric temperature of the area. During the study period, penicillin nonsusceptibility increased from 0% to 17%. The overall case-fatality rate was 25%, which decreased from 33% to 17% between the first and the second half of the study period (P<.001). The proportion of women with pneumococcal bacteremia increased from 37% to 52%. Independent risk factors for fatal outcome were coronary artery disease (P<.001; relative risk [RR], 4.3; 95% confidence interval [CI], 3.4-5.1), neutropenia (P=.001; RR, 3.2; 95% CI, 1.9-4.8), and age 65 years or older (P=.001; RR, 2.9; 95% CI, 1.8-4.2), whereas prior respiratory tract infection (P=.03; RR, 0.3; 95% CI, 0.1-0.5) and the occurrence of pneumococcal bacteremia in the second half of the study period (P=.01; RR, 0.4; 95% CI, 0.2-0.6) were independent predictors of survival. The case-fatality rate in human immunodeficiency virus (HIV)-infected patients was significantly lower than in patients not infected with HIV or in those with unknown HIV status (9% vs 27%; P=.006), which correlated with the younger mean +/- SD age of HIV-infected patients (33.2+/-6.6 years) compared with patients not infected with HIV (63.1+/-18.1 years) (P<.001).

CONCLUSIONS

The case-fatality rate of patients with pneumococcal bacteremia decreased significantly between the first and second half of the study period, despite the increased prevalence of penicillin-nonsusceptible isolates. Independent risk factors for fatal outcome were coronary artery disease, neutropenia, and age 65 years or older, whereas prior respiratory tract infection and the occurrence of pneumococcal bacteremia in the second half of the study period were independent predictors of survival. HIV infection was a predisposing factor for pneumococcal bacteremia but was not a risk factor for fatal outcome.

Immunization of immunocompromised persons

Advances in medicine, science, and technology have led to increasing numbers of people in the general population with altered host defenses. The risk for clinical infection in an immunocompromised host, such as a person who has received a solid organ transplant, is determined largely by the interaction between two factors: the epidemiologic exposures the person encounters and the person's net state of immunosuppresson. Vaccination represents a crucial approach for preventing infection in the general public and immunocompromised persons. This article reviews the benefits of and risks for immunization in immunocompromised persons and provides recommendations for the use of specific vaccines.

Review of human immunodeficiency virus type 1-related opportunistic infections in sub-Saharan Africa

Understanding the natural history of human immunodeficiency virus type 1 (HIV-1) and opportunistic infections in sub-Saharan Africa is necessary to optimize strategies for the prophylaxis and treatment of opportunistic infections and to understand the likely impact of antiretroviral therapy. We undertook a systematic review of the literature on HIV-1 infection in sub-Saharan Africa to assess data from recent cohorts and selected cross-sectional studies to delineate rates of opportunistic infections, associated CD4 cell counts, and associated mortality. We searched the MEDLINE database and the Cochrane Database of Systematic Reviews and Cochrane Clinical Trials Register for English-language literature published from 1990 through April 2002. Tuberculosis, bacterial infections, and malaria were identified as the leading causes of HIV-related morbidity across sub-Saharan Africa. Of the few studies that reported CD4 cell counts, the range of cell counts at the time of diagnosis of opportunistic infections was wide. Policies regarding the type and timing of opportunistic infection prophylaxis may be region specific and urgently require further study.

Surveillance of resistance in bacteria causing community-acquired respiratory tract infections

Bacterial resistance to antibiotics in community-acquired respiratory tract infections is a serious problem and is increasing in prevalence world-wide at an alarming rate. Streptococcus pneumoniae, one of the main organisms implicated in respiratory tract infections, has developed multiple resistance mechanisms to combat the effects of most commonly used classes of antibiotics, particularly the beta-lactams (penicillin, aminopenicillins and cephalosporins) and macrolides. Furthermore, multidrug-resistant strains of S. pneumoniae have spread to all regions of the world, often via resistant genetic clones. A similar spread of resistance has been reported for other major respiratory tract pathogens, including Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pyogenes. To develop and support resistance control strategies it is imperative to obtain accurate data on the prevalence, geographic distribution and antibiotic susceptibility of respiratory tract pathogens and how this relates to antibiotic prescribing patterns. In recent years, significant progress has been made in developing longitudinal national and international surveillance programs to monitor antibiotic resistance, such that the prevalence of resistance and underlying trends over time are now well documented for most parts of Europe, and many parts of Asia and the Americas. However, resistance surveillance data from parts of the developing world (regions of Central America, Africa, Asia and Central/Eastern Europe) remain poor. The quantity and quality of surveillance data is very heterogeneous; thus there is a clear need to standardize or validate the data collection, analysis and interpretative criteria used across studies. If disseminated effectively these data can be used to guide empiric antibiotic therapy, and to support-and monitor the impact of-interventions on antibiotic resistance.

The burden of invasive pneumococcal disease and the potential for reduction by immunisation

Streptococcus pneumoniae causes invasive disease world-wide and in all age groups. The reported incidence varies geographically and is increased in certain population groups. The incidence is highest in children less than 2 years and is also increased in the elderly. Mortality remains substantial even in the developed world despite appropriate antimicrobial therapy. The emergence of penicillin-resistant pneumococci highlights the importance of immunisation as a means to prevent disease. This review discusses the burden of invasive pneumococcal disease, identifies high-risk patients and analyses evidence for vaccine efficacy and cost-effectiveness.

Pneumococcal vaccination: current and future issues

Infection with Streptococcus pneumoniae remains a major global health burden meaning the development of effective vaccines is urgently needed. The current 23-valent polysaccharide vaccine has been shown to prevent pneumococcal pneumonia in immunocompetent young adults, but not in elderly persons. However, in prevention of invasive pneumococcal disease, the vaccine is efficacious in the elderly and may also be effective in some groups of immunocompromised patients. The polysaccharide vaccine is, therefore, recommended in all older (> or = 55-65 yrs of age) adults and in young children (>2 yrs of age) who have a high risk for pneumococcal disease. Revaccination can be safely performed and is recommended 5 yrs after the first dose. In children <2 yrs of age, the new polysaccharide-protein conjugate vaccines, including 7-11 serotypes, seem to be effective in the prevention of invasive disease, severe pneumonia and serotype-specific (and vaccine-related types) otitis media. The low serotype coverage, need for repeated doses, and high price, may decrease the usefulness of the new conjugates. However, the included serotypes correspond to those most often associated with penicillin resistance and vaccination is, therefore, a possible tool in limiting the spread of antibiotic-resistant pneumococci.

Gram-Positive Pneumonia

Gram-positive pneumonia is a leading cause of morbidity and mortality throughout the world. Of the gram-positive pathogens that cause pneumonia, Streptococcus pneumoniae and Staphylococcus aureus are the most common. The diagnosis of gram-positive pneumonia remains less than satisfactory, and newer diagnostic techniques such as antibody- and polymerase chain reaction-based antigen detection have yet to prove themselves. Drug resistance among gram-positive organisms is now endemic throughout the world and remains a serious therapeutic problem despite the availability of new antimicrobials. Efforts to control the spread of resistant strains include, in the case of S. aureus, stringent isolation policies and topical treatment to reduce carriage and, for S. pneumoniae, increased use of available vaccines and the develop- ment of more immunogenic vaccines.

Human immunodeficiency virus and respiratory infection

Pulmonary disease remains a major problem for the 33 million individuals who are thought to be infected with human immunodeficiency virus (HIV) worldwide. Respiratory infections are responsible for a large number of the 2 million deaths that occur each year in association with HIV disease. In countries where the majority of the population can access highly active antiretroviral therapy, morbidity and mortality rates have been cut by up to 80%. This has allowed the withdrawal of specific opportunistic infection prophylaxis when immune restoration is deemed to be adequate. Recommendations have been published concerning Pneumocystis carinii prophylaxis. This year has also seen further reports of drug-resistant isolates of Pneumocystis carinii. The clinical relevance of this is still debated. Tuberculosis remains a global problem. The complexity of the interactions between specific anti-HIV and anti-tuberculous treatment have been highlighted. In the developing world, the importance of immunization and prophylaxis (against bacteria and mycobacteria) have recently been further defined in a number of studies.