Alicia I. Hidron

Risk Factors for Colonization with Methicillin-Resistant Staphylococcus aureus (MRSA) in Patients Admitted to an Urban Hospital: Emergence of Community-Associated MRSA Nasal Carriage

BACKGROUND Surveillance cultures performed at hospital admission have been recommended to identify patients colonized with methicillin-resistant Staphylococcus aureus (MRSA) but require substantial resources. We determined the prevalence of and risk factors for MRSA colonization at the time of hospital admission among patients cared for at a public urban hospital. METHODS Anterior nares cultures were obtained within 48 h after admission during a 1-month period. A case-control study and molecular typing studies were performed. RESULTS A total of 53 (7.3%) of 726 patients had a nares culture positive for MRSA, and 119 (16.4%) had a nares culture that was positive for methicillin-susceptible S. aureus. In multivariate analysis, risk factors for MRSA colonization included antibiotic use within 3 months before admission (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.2-5.0), hospitalization during the past 12 months (OR, 4.0; 95% CI, 2.0-8.2), diagnosis of skin or soft-tissue infection at admission (OR, 3.4; 95% CI, 1.5-7.9), and HIV infection. A total of 47 (89%) of 53 case patients colonized with MRSA had at least 1 of these independent risk factors, in contrast to 343 (51%) of 673 control patients (OR, 7.5; 95% CI, 3.2 -17.9). Molecular typing demonstrated that 16 (30%) of 53 MRSA nares isolates (2.2% of the 726 isolates) belonged to the USA300 community-associated MRSA (CA-MRSA) genotype. CONCLUSION The prevalence of MRSA colonization at the time of patient admission was high (>7%). Limiting surveillance cultures to patients with >or=1 of the identified risk factors may allow for targeted screening. The emergence of CA-MRSA colonization represents a new, unrecognized reservoir of MRSA within hospitals, potentially increasing the risk for horizontal transmission.

Emergence of community-acquired meticillin-resistant Staphylococcus aureus strain USA300 as a cause of necrotising community-onset pneumonia

Meticillin-resistant Staphylococcus aureus (MRSA), usually known as a nosocomial pathogen, has emerged as the predominant cause of skin and soft-tissue infections in many communities. Concurrent with the emergence of community-acquired MRSA (CA-MRSA), there have been increasing numbers of reports of community-acquired necrotising pneumonia in young patients and others without the classic health-care-associated risk factors. Community-onset necrotising pneumonia due to CA-MRSA is now recognised as an emerging clinical entity with distinctive clinical features and substantial morbidity and mortality. A viral prodrome (eg, influenza or influenza-like illness) followed by acute onset of shortness of breath, sepsis, and haemoptysis is the most frequent clinical presentation. The best treatment of this partly toxin-mediated disease has not been clearly defined. Whereas cases of CA-MRSA pneumonia have now been reported from almost every continent, the overall burden of disease of this emerging syndrome remains incompletely described. We report two related cases of community-onset pneumonia due to the MRSA USA300 genotype and review the literature regarding the emergence of CA-MRSA pneumonia.

Chagas disease: an impediment in achieving the Millennium Development Goals in Latin America

BackgroundAchieving sustainable economic and social growth through advances in health is crucial in Latin America within the framework of the United Nations Millennium Development Goals.DiscussionHealth-related Millennium Development Goals need to incorporate a multidimensional approach addressing the specific epidemiologic profile for each region of the globe. In this regard, addressing the cycle of destitution and suffering associated with infection with Trypanosoma cruzi, the causal agent of Chagas disease of American trypanosomiasis, will play a key role to enable the most impoverished populations in Latin America the opportunity to achieve their full potential. Most cases of Chagas disease occur among forgotten populations because these diseases persist exclusively in the poorest and the most marginalized communities in Latin America.SummaryAddressing the cycle of destitution and suffering associated with T. cruzi infection will contribute to improve the health of the most impoverished populations in Latin America and will ultimately grant them with the opportunity to achieve their full economic potential.

Chagas Cardiomyopathy in the Context of the Chronic Disease Transition

Background Patients with Chagas disease have migrated to cities, where obesity, hypertension and other cardiac risk factors are common. Methodology/Principal Findings The study included adult patients evaluated by the cardiology service in a public hospital in Santa Cruz, Bolivia. Data included risk factors for T. cruzi infection, medical history, physical examination, electrocardiogram, echocardiogram, and contact 9 months after initial data collection to ascertain mortality. Serology and PCR for Trypanosoma cruzi were performed. Of 394 participants, 251 (64%) had confirmed T. cruzi infection by serology. Among seropositive participants, 109 (43%) had positive results by conventional PCR; of these, 89 (82%) also had positive results by real time PCR. There was a high prevalence of hypertension (64%) and overweight (body mass index [BMI] >25; 67%), with no difference by T. cruzi infection status. Nearly 60% of symptomatic congestive heart failure was attributed to Chagas cardiomyopathy; mortality was also higher for seropositive than seronegative patients (p = 0.05). In multivariable models, longer residence in an endemic province, residence in a rural area and poor housing conditions were associated with T. cruzi infection. Male sex, increasing age and poor housing were independent predictors of Chagas cardiomyopathy severity. Males and participants with BMI ≤25 had significantly higher likelihood of positive PCR results compared to females or overweight participants. Conclusions Chagas cardiomyopathy remains an important cause of congestive heart failure in this hospital population, and should be evaluated in the context of the epidemiological transition that has increased risk of obesity, hypertension and chronic cardiovascular disease.

Transplantation and tropical infectious diseases

The number of transplant recipients with tropical infectious diseases is growing due to increasing international travel and the rising number of transplants taking place in the tropics and subtropics. With increases in population migration, the prevalence of individuals infected with geographically restricted organisms also rises. There are three potential categories of tropical infections in transplant patients: (1) donor-related infections transmitted by the graft or through transfusion of blood products; (2) reactivation or recrudescence of latent infections in the donor recipient; and (3) de novo acquisition of infection in the post-transplant period through the traditional route of infection. We present an overall discussion of the association of parasitic (protozoa and helminths) and non-parasitic (viral, bacterial, and fungal) tropical infectious diseases and solid-organ and hematopoietic transplantation. We also suggest potential screening guidelines for some of these tropical infections.

Methicillin-resistant Staphylococcus aureus in HIV-infected patients.

Concordant with the emergence of methicillin-resistant Staphylococcus aureus (MRSA) in the community setting, colonization and infections with this pathogen have become a prevalent problem among the human immunodeficiency virus (HIV)-positive population. A variety of different host- and, possibly, pathogen-related factors may play a role in explaining the increased prevalence and incidence observed. In this article, we review pathophysiology, epidemiology, clinical manifestations, and treatment of MRSA in the HIV-infected population.

The rise and fall of methicillin-resistant Staphylococcus aureus infections in HIV patients.

We evaluated the annual and weighted incidence of methicillin-resistant Staphylococcus aureus infections by specific risk factors in a prospective cohort of HIV patients. We found 228 infections in 167 patients from 2002 to 2009. Higher rates were seen in men who have sex with men and intravenous drug users, patients with lower CD4 cell counts, patients not on antiretrovirals and younger patients. The annual incidence peaked in 2007 and has decreased since.

Risk Factors for Vitamin D Deficiency among Veterans with and without HIV Infection

Objectives We aimed to describe and compare the prevalence of vitamin D deficiency between HIV-negative and HIV-infected veterans in the southern United States, and to determine risk factors for vitamin D deficiency for HIV infected patients. Methods Cross-sectional, retrospective study including all patients followed at the Atlanta VA Medical Center with the first 25-hydroxyvitamin D [25(OH)D] level determined between January 2007 and August 2010. Multivariate logistic regression analysis was used to determine risk factors associated with vitamin D deficiency (< 20 ng/ml). Results There was higher prevalence of 25(OH)D deficiency among HIV-positive compared to HIV-negative patients (53.2 vs. 38.5%, p <0.001). Independent risk factors for vitamin D deficiency in HIV + patients included black race (OR 3.24, 95% CI 2.28–4.60), winter season (OR 1.39, 95% CI 1.05–1.84) and higher GFR (OR 1.01, CI 1.00–1.01); increasing age (OR 0.98, 95% CI 0.95–0.98), and tenofovir use (OR 0.72, 95% CI 0.54–0.96) were associated with less vitamin D deficiency. Conclusions Vitamin D deficiency is a prevalent problem that varies inversely with age and affects HIV-infected patients more than other veterans in care. In addition to age, tenofovir and kidney disease seem to confer a protective effect from vitamin D deficiency in HIV-positive patients.

Prolonged survival of a patient with AIDS and central nervous system aspergillosis.

In HIV-infected patients, central nervous system (CNS) aspergillosis is rare. Historically, the outcome of such infections has been almost invariably fatal. We report a case involving an AIDS patient with an Aspergillus fumigatus brain abscess who survived for longer than 10 months after surgical drainage and therapy with voriconazole.

Circulating Serum Markers and QRS Scar Score in Chagas Cardiomyopathy

Approximately 8 million people have Trypanosoma cruzi infection, and nearly 30% will manifest Chagas cardiomyopathy (CC). Identification of reliable early indicators of CC risk would enable prioritization of treatment to those with the highest probability of future disease. Serum markers and electrocardiogram (EKG) changes were measured in 68 T. cruzi-infected individuals in various stages of cardiac disease and 17 individuals without T. cruzi infection or cardiac disease. T. cruzi-infected individuals were assigned to stage A (normal EKG/chest x-ray [CXR]), B (abnormal EKG/normal CXR), or C (abnormal EKG/cardiac structural changes). Ten serum markers were measured using enzyme-linked immunosorbent assay (ELISA)/Luminex, and QRS scores were calculated. Higher concentrations of transforming growth factor-β1 (TGFβ1), and TGFβ2 were associated with stage B compared with stage A. Matrix Metalloproteinase 2 (MMP2), Tissue Inhibitors of MMP 1, QRS score, and Brain Natriuretic Protein rose progressively with increasing CC severity. Elevated levels of several markers of cardiac damage and inflammation are seen in early CC and warrant additional evaluation in longitudinal studies.