An unusual case of a large, sporadic intra-abdominal abscess due to group B Streptococcus and a review of the literature.

Group B streptococcal infections among non-pregnant adults have dramatically increased over the past two decades. Most infections involve skin/soft tissue infections and bacteremia, but whether more unusual clinical manifestations due to this organism will arise in clinical practice remains unclear. This report is the first case in the literature of a sporadic, large intra-abdominal abscess due to group B Streptococcus in an immunocompetent adult. Given the rising number of invasive group B streptococcal infections among adults, unusual presentations of this organism may increasingly be seen in clinical practice. This report reviews the literature regarding invasive group B Streptococcus infections, including intra-abdominal/pelvic abscesses, and discusses the clinical presentation and management of this emerging pathogen.

Fatal case of necrotizing fasciitis due to Myroides odoratus.

Myroides sp., previously known as Flavobacterium odoratum, is a relatively unknown organism with unclear human pathogenicity. While Myroides sp. has been implicated in human infections, many reports have described the organism as a relatively avirulent opportunistic pathogen. We present an unusual case of rapidly fatal necrotizing fasciitis and septic shock due to Myroides odoratus. Our case demonstrates the pathogenicity of Myroides, and highlights potential risk factors for infection including underlying liver disease and open wounds. The recognition of Myroides is of particular importance given its resistance to multiple antibiotics. We review the literature on Myroides sp. skin and soft tissue infections, including necrotizing forms, and discuss the clinical presentation and management of this potentially emerging pathogen.

Glomerular filtration rate estimated using creatinine, cystatin C or both markers and the risk of clinical events in HIV-infected individuals.

OBJECTIVES: The accuracy and precision of glomerular filtration rate (GFR) estimating equations based on plasma creatinine (GFR(cr)), cystatin C (GFR(cys)) and the combination of these markers (GFR(cr-cys)) have recently been assessed in HIV-infected individuals. We assessed the associations of GFR, estimated by these three equations, with clinical events in HIV-infected individuals. METHODS: We compared the associations of baseline GFR(cr), GFR(cys) and GFR(cr-cys) [using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations] with mortality, cardiovascular events (CVEs) and opportunistic diseases (ODs) in the Strategies for the Management of Antiretroviral Therapy (SMART) study. We used Cox proportional hazards models to estimate unadjusted and adjusted hazard ratios per standard deviation (SD) change in GFR. RESULTS: A total of 4614 subjects from the SMART trial with available baseline creatinine and cystatin C data were included in this analysis. Of these, 99 died, 111 had a CVE and 121 had an OD. GFR(cys) was weakly to moderately correlated with HIV RNA, CD4 cell count, high-sensitivity C-reactive protein, interleukin-6, and D-dimer, while GFR(cr) had little or no correlation with these factors. GFR(cys) had the strongest associations with the three clinical outcomes, followed closely by GFR(cr-cys), with GFR(cr) having the weakest associations with clinical outcomes. In a model adjusting for demographics, cardiovascular risk factors, HIV-related factors and inflammation markers, a 1-SD lower GFR(cys) was associated with a 55% [95% confidence interval (CI) 27-90%] increased risk of mortality, a 21% (95% CI 0-47%) increased risk of CVE, and a 22% (95% CI 0-48%) increased risk of OD. CONCLUSIONS: Of the three CKD-EPI GFR equations, GFR(cys) had the strongest associations with mortality, CVE and OD.

Determinants of incident chronic kidney disease and progression in a cohort of HIV-infected persons with unrestricted access to health care.

OBJECTIVES: As socioeconomic factors may impact the risk of chronic kidney disease (CKD), we evaluated the incidence and risk factors of incident CKD among an HIV-infected cohort with universal access to health care and minimal injecting drug use (IDU). METHODS: Incident CKD was defined as an estimated glomerular filteration rate (eGFR) <60 ml/min/1.73 m(2) for ≥ 90 days. eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Rates were calculated per 1000 person-years (PY). Associations with outcomes were assessed using two separate Cox proportional hazard models, adjusting for baseline and time-updated covariates. RESULTS: Among 3360 participants [median age 29 years; 92% male; 44% African American (AA)] contributing 23,091 PY of follow-up, 116 developed incident CKD [5.0/1000 PY; 95% confidence interval (CI) 4.2-6.0/1000 PY]. The median first eGFR value was 97.0 mL/min/1.73 m(2) [interquartile range (IQR) 85.3-110.1 mL/min/1.73 m(2)]. Baseline factors associated with CKD included older age, lower CD4 count at HIV diagnosis [compared with CD4 count ≥ 500 cells/µL, hazard ratio (HR) 2.1 (95% CI 1.2-3.8) for CD4 count 350-499 cells/µL; HR 3.6 (95% CI 2.0-6.3) for CD4 count 201-349 cells/µL; HR 4.3 (95% CI 2.0-9.4) for CD4 count ≤ 200 cells/µL], and HIV diagnosis in the pre-highly active antiretroviral therapy (HAART) era. In the time-updated model, low nadir CD4 counts, diabetes, hepatitis B, hypertension and less HAART use were also associated with CKD. AA ethnicity was not associated with incident CKD in either model. CONCLUSIONS: The low incidence of CKD and the lack of association with ethnicity observed in this study may in part be attributable to unique features of our cohort such as younger age, early HIV diagnosis, minimal IDU, and unrestricted access to care. Lower baseline CD4 counts were significantly associated with incident CKD, suggesting early HIV diagnosis and timely introduction of HAART may reduce the burden of CKD.

Skin and soft tissue infections among HIV-infected persons in the late combination antiretroviral therapy era.

Skin and soft tissue infections (SSTIs) occur at higher rates among HIV-infected persons, but current trends and risk factors are largely undefined. We evaluated SSTIs among a prospective cohort of HIV-infected persons during the late combination antiretroviral therapy (cART) era (2006-2010). Of the 1918 HIV-infected persons evaluated, 379 (20%) developed an SSTI during a median of 3.7 years of follow-up; of these, 118 (31%) developed at least one recurrent SSTI. The incidence rate of SSTIs was 101 (95% confidence interval [CI] 93-109) cases per 1000 person-years, and rates did not significantly change during the study period. Compared with not receiving cART and having an HIV RNA level >1000 copies/mL, patients receiving cART with an HIV RNA level <1000 copies/mL had a reduced risk of an SSTI (hazard ratio 0.64, 95% CI 0.48-0.86, P < 0.01). In summary, initial and recurrent SSTIs are common among HIV-infected persons, and HIV control is associated with a lower risk of SSTIs.

Immunoglobulin G subclass levels and antibody responses to the 2009 influenza A (H1N1) monovalent vaccine among human immunodeficiency virus (HIV)-infected and HIV-uninfected adults.

Immunoglobulin (Ig)G levels are important for antibody vaccine responses and IgG subclass deficiencies have been associated with severe 2009 influenza A (H1N1) infections. Studies have demonstrated variations in immune responses to the H1N1 vaccine, but the aetiology of this is unknown. We determined the associations between pre-vaccination overall and influenza-specific IgG subclass levels and 2009 H1N1-specific antibody responses post-vaccination (robust versus poor at day 28) stratified by human immunodeficiency virus (HIV) status. Logistic regression models were utilized to evaluate whether pre-vaccination IgG subclass levels were associated with the antibody response generated post-vaccination. We evaluated 48 participants as part of a clinical study who were stratified by robust versus poor post-vaccination immune responses. Participants had a median age of 35 years; 92% were male and 44% were Caucasian. HIV-infected adults had a median CD4 count of 669 cells/mm(3) , and 79% were receiving highly active anti-retroviral therapy. HIV-infected participants were more likely to have IgG2 deficiency (<240 mg/dl) than HIV-uninfected individuals (62% versus 4%, P < 0·001). No association of pre-vaccination IgG subclass levels (total or influenza-specific) and the antibody response generated by HIN1 vaccination in either group was found. In summary, pre-vaccination IgG subclass levels did not correlate with the ability to develop robust antibody responses to the 2009 influenza A (H1N1) monovalent vaccine. IgG2 deficiencies were common among HIV-infected individuals but did not correlate with poor influenza vaccine responses. Further investigations into the aetiology of disparate vaccine responses are needed.

Methicillin-resistant Staphylococcus aureus (MRSA) infections among HIV-infected persons in the era of highly active antiretroviral therapy: a review of the literature.

OBJECTIVES: Despite the rise of methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTIs) among HIV-infected persons during the era of highly active antiretroviral therapy (HAART), the precise relationship between these two infections has not been fully elucidated. Therefore, we provide a comprehensive, literature-based review of MRSA infections among HIV-infected persons. METHODS: A systematic search of MEDLINE using the search terms "HIV" and "MRSA" identified references published during the HAART era (January 1996 to January 2011). Relevant articles on MRSA in the general population were also reviewed for comparison. RESULTS: The most common type of MRSA infection among HIV-infected persons is SSTI caused by USA300, Panton-Valentine leukocidin (PVL)-positive strains. HIV-infected persons have an increased risk for both initial MRSA infections and recurrent infections compared with the general population. Risk factors for MRSA infections in this population include immunosuppression, comorbid conditions and certain lifestyle behaviours such as high-risk sexual behaviours and illicit drug use. Further research is needed on the optimal treatment and prevention strategies for MRSA infections among HIV-infected persons. CONCLUSIONS: HIV-infected persons have a propensity for MRSA SSTI and a high rate of recurrent disease. The reasons for the elevated rates of MRSA infections among HIV-infected persons appear to be multifactorial, but may be mitigated with optimized HIV control and reductions in associated risk factors.

An update on Cryptococcus among HIV-infected patients.

Cryptococcus remains an important opportunistic infection in HIV patients despite considerable declines in prevalence during the highly active antiretroviral therapy era. This is particularly apparent in sub-Saharan Africa, where Cryptococcus continues to cause significant mortality and morbidity. This review discusses the microbiology, epidemiology, pathogenesis and clinical presentation of cryptococcal infections in HIV patients. Additionally, a detailed approach to the management of cryptococcosis is provided.

Syphilis co-infection does not affect HIV disease progression.

HIV and syphilis are often seen as co-infections since they share a common mode of transmission. During episodes of syphilis, CD4 counts transiently decrease and HIV viral loads increase; however, the effect of syphilis co-infection on HIV disease progression (time to AIDS or death) is unclear. We analysed prospectively collected information on 2239 persons with estimated dates of HIV seroconversion (205 [9.2%] with confirmed syphilis and 66 [2.9%] with probable syphilis) in order to determine the effect of syphilis co-infection on HIV disease progression. In multivariate models censored at highly active antiretroviral therapy (HAART) initiation or last visit, adjusting for CD4 count, age, race, gender, and hepatitis B and C status, syphilis (confirmed + probable) was not associated with increased hazard of AIDS or death (hazard ratio 0.99, 95% CI 0.73-1.33). Treating HAART as a time-varying covariate or limiting the analysis to only confirmed syphilis cases did not significantly alter the results. Despite transient changes in CD4 counts and viral loads, syphilis does not appear to affect HIV disease progression.