Focal infections due to non-typhi Salmonella in patients with AIDS: report of 10 cases and review

Salmonella typhimurium necrotizing fasciitis: a case report

BACKGROUND

Necrotizing fasciitis is an aggressive disease that causes necrosis in the muscular fascia and subcutaneous tissues. The infection spreads rapidly along the fascia and perifascial planes, followed by extension of the infection to nearby soft tissues and muscles. Necrotizing fasciitis can be attributed to different pathogens, namely Staphylococcus aureus, group A streptococci, and Clostridium perfringes. Only a few cases of skin and soft tissue infections from Salmonella species have been reported to date. Herein we report a case of Salmonella non-typhi necrotizing fasciitis, an exceedingly rare entity. This case report may serve as a potential management plan in similar cases in light of the scarcity of evidence.

CASE PRESENTATION

A 20-year-old Caucasian male patient with congenital cardiac anomaly presented with diarrhea and unilateral lower extremity cellulitis causing septic shock. Cultures from blood and the bullae associated with the lower extremity cellulitis grew Salmonella typhimurium. Surgical debridement was performed. Intraoperative tissue cultures were positive for Salmonella typhimurium, and surgical pathology confirmed the diagnosis of necrotizing fasciitis. After a total of 6 weeks of appropriate antimicrobial therapy, another surgical debridement was executed for poor wound healing. New intraoperative cultures grew Fusarium species, and the patient received voriconazole with an adequate response. Immunologic studies showed humoral and cellular immunodeficiency.

CONCLUSION

It is important to maintain a high index of suspicion for rare entities that can cause skin and soft tissue infections, such as Salmonella non-typhi, in particular in immunosuppressed patients where a delay in diagnosis and management may have significant morbidity and mortality.

Non-typhoid Salmonella endocarditis complicated by cardiac failure and acute limb ischaemia in a person living with HIV and hepatitis C: A Case Report and literature review

Salmonella infections are responsible for a large burden of disease worldwide. Non-typhoidal Salmonella (NTS) species cause a myriad of disease manifestations, particularly amongst severely immunocompromised individuals. We present a rare case of endocarditis caused by the NTS species Salmonella Enteritidis in an individual living with HIV and hepatitis C. In this case, endocarditis was complicated by embolization and acute arterial occlusion of the left arm, as well as mitral valve perforation resulting in cardiac failure. A review of the available literature shows few cases of NTS causing endocarditis in people living with HIV, with the earliest reported case in 1983. Our case demonstrates the potential complications of NTS endocarditis and highlights the importance of evaluating patients with NTS-associated blood stream infection for cardiovascular involvement. Prompt surgical intervention in addition to appropriate antimicrobial therapy is essential to reduce the high morbidity and mortality associated with NTS endocarditis.

Slither Into the Heart: Salmonella Endocarditis Following Rattlesnake Meat Ingestion

Salmonellae foodborne infections are a well described and documented entity, however cardiac complications of Salmonellae foodborne infections including infective endocarditis (IE) are rare. Here we present a case of infective endocarditis as a result of bacteremia caused by multiple species of Salmonella. The patient initially presented with chest pain, fever and altered mental status. Troponin and ECG were unremarkable. The patient was started on empiric antibiotics. Blood cultures grew Salmonella species serotype O&H. Transesophageal echocardiogram (TEE) confirmed aortic valve vegetation. Regional cultural practices suggested possible contamination attributed to ingestion of rattlesnake meat, a practice that has been previously described and well-established in various Hispanic folk practices. Upon further history taking, the patient was found to be regularly consuming dried rattlesnake meat preparations, a rather common practice in Chihuahua desert region. Surgery was not indicated, and the patient was treated with six weeks of antibiotics. This case presents an opportunity to gain insight into such a unique manifestation of Salmonellae, offering a potential facet of information for clinicians to better understand its presentation, susceptibility, and potential adverse outcomes.

Biologic Therapy in HIV: To Screen or Not to Screen

Biologic therapy has revolutionized the management of chronic inflammatory diseases, including inflammatory bowel disease (IBD). Before the initiation of therapy, it is critical to rule out prior infection of chronic hepatitis B virus (HBV) and tuberculosis (TB). However, screening for human immunodeficiency virus (HIV) is not as routinely completed. We present a case of a 56-year-old male on ustekinumab for the management of Crohn's disease, found to have undiagnosed human immunodeficiency virus (HIV) with progression to acquired immunodeficiency syndrome (AIDS).

The Many Faces of Bacterium-Endothelium Interactions during Systemic Infections

A wide variety of pathogens reach the circulatory system during viral, parasitic, fungal, and bacterial infections, causing clinically diverse pathologies. Such systemic infections are usually severe and frequently life-threatening despite intensive care, in particular during the age of antibiotic resistance. Because of its position at the interface between the blood and the rest of the organism, the endothelium plays a central role during these infections. Using several examples of systemic infections, we explore the diversity of interactions between pathogens and the endothelium. These examples reveal that bacterial pathogens target specific vascular beds and affect most aspects of endothelial cell biology, ranging from cellular junction stability to endothelial cell proliferation and inflammation.

Pleural empyema due to Salmonella enterica serovar Enteritidis in an immunocompetent elderly patient: a case report

INTRODUCTION

Pleural empyema as a focal infection due to Salmonella enterica serovar Enteritidis is rare and most commonly described among immunosuppressed patients or patients who suffer from sickle cell anaemia and lung malignancies.

CASE PRESENTATION

Here, we present an 81-year-old immunocompetent Greek woman with bacteraemia and pleural empyema due to Salmonella Enteritidis without any gastrointestinal symptoms.

CONCLUSION

In our case, we suggest that patient's pleural effusion secondary to heart failure was complicated by empyema and that focal intravascular infection was the cause of bacteraemia.

Time to positivity in blood cultures of adults with nontyphoidal Salmonella bacteremia

BACKGROUND

Nontyphoidal Salmonella (NTS) is an important bacterial etiology of diarrheal disease, and it causes invasive diseases in immunocompromised hosts. For bacteremia from some species, blood culture with a rapid time to positivity (TTP) is associated with greater mortality. This study investigated TTP of NTS bacteremia and its relationship to clinical parameters and prognosis.

METHODS

Adult patients with NTS bacteremia who were admitted to a tertiary care facility in northern Taiwan from January 2010 to December 2012 were enrolled. Demographics, clinical and microbiological characteristics, and treatment response were reviewed. The TTP for each patient was retrieved from the automated machine.

RESULTS

Sixty-six adult patients (mean age, 66.1 years; range, 27-96 years) with NTS bacteremia were identified by the following serogroup distributions: serogroup B (23.4%), serogroup C1 (1.6%), serogroup C2 (6.3%), and serogroup D (68.8%). The in-hospital mortality, 14-day mortality, and 30-day mortality were 15.2%, 7.6%, and 12.1%, respectively. The TTP ranged 6.5-41.7 hours (median: 11.5 hours). Patients with rapid TTP (less than 10 hours), compared to patients without rapid TTP, were more likely to have liver cirrhosis (31.6% vs. 6.4%, p = 0.013), endovascular lesions (21.1% vs. 4.3%, p = 0.05), higher bacteremia score, intensive care unit admission (57.9% vs. 25.5%, p = 0.021), and septic shock (63.2% vs. 12.8%, p < 0.001). There were no significant differences in the in-hospital mortality and 14-day mortality between patients with TTP <10 hours and patients with TTP ≥10 hours.

CONCLUSION

The TTP of blood cultures, interpreted with a cut-off point of <10 hours, in patients with NTS bacteremia may provide useful diagnostic and prognostic information.

Nontyphoidal cardiac salmonellosis: two case reports and a review of the literature

Nontyphoidal Salmonella, especially Salmonella enterica, is a rare cause of endocarditis and pericarditis that carries a high mortality rate. Proposed predisposing conditions include immunodeficiency states, congenital heart defects, and cardiac valve diseases. We present 2 cases of cardiovascular salmonellosis. The first case is that of a 73-year-old woman with mechanical mitral and bioprosthetic aortic valves who died from sequelae of nontyphoidal Salmonella mitral valve vegetation, aortic valve abscess, and sepsis. The second case is that of a 62-year-old man with a recent systemic lupus erythematosus exacerbation treated with oral steroids, who presented with obstructive features of tamponade and sepsis secondary to a large S. enteritidis purulent pericardial cyst. He recovered after emergent pericardial drainage and antibiotic therapy. Identifying patients at risk of cardiovascular salmonellosis is important for early diagnosis and treatment to minimize sequelae and death. We reviewed the literature to identify the predisposing risk factors of nontyphoidal Salmonella cardiac infection.

Non-typhoidal Salmonella group D bacteremia and urosepsis in a patient diagnosed with HIV Infection

Urinary tract infections caused by non-typhoid Salmonella are rare and usually develops in patients with predisposing factors such as immune deficiency or occult urologic problems. This report describes a case where Salmonella Group D was isolated from the blood and urine of a patient with documented human acquired immunodeficiency syndrome who developed urosepsis and was successfully treated with antibiotics.

Salmonellosis as a differential diagnosis

With a low incidence of Salmonella infection, salmonellosis is an uncommon problem in Scotland. It occurs in both immune-compromised and immune-competent patients. We present two cases of salmonellosis in immune-competent patients who had had a history of gastroenteritis. Diagnosis was delayed in one patient; however, both patients received appropriate treatment and made good recovery following their respective illnesses. Apart from acting as a reminder to consider salmonellosis as a differential diagnosis when managing patients with infective process, the cases also highlight the importance of concise history taking, and the importance of cultures-and-sensitivities in managing infectious cases.

Defense at the border: the blood-brain barrier versus bacterial foreigners

Bacterial meningitis is among the top ten causes of infectious disease-related deaths worldwide, with up to half of the survivors left with permanent neurological sequelae. The blood-brain barrier (BBB), composed mainly of specialized brain microvascular endothelial cells, maintains biochemical homeostasis in the CNS by regulating the passage of nutrients, molecules and cells from the blood to the brain. Despite its highly restrictive nature, certain bacterial pathogens are able to gain entry into the CNS resulting in serious disease. In recent years, important advances have been made in understanding the molecular and cellular events that are involved in the development of bacterial meningitis. In this review, we summarize the progress made in elucidating the molecular mechanisms of bacterial BBB-crossing, highlighting common themes of host-pathogen interaction, and the potential role of the BBB in innate defense during infection.

[Salmonella enteritidis bacteraemia as clinical onset of acquired immune deficiency syndrome]

The case is presented of a 38 year-old patient who was admitted in the Emergency Department due to a severe acute respiratory failure and who was transferred to the Critical Care Unit with a suspected initial diagnosis of community acquired pneumonia caused by an atypical microorganism, which was complicated with an acute respiratory distress syndrome. This was able to be treated with non-invasive mechanical ventilation. At 48 hours after admission, the growth of Gram negative bacilli in the blood culture was reported, which was subsequently identified as Salmonella enteritidis. This information, along with the lymphopenia suffered by the patient, suggested an immunodepressed state, thus serological tests were performed which showed positive for HIV. Antibiotic treatment was started based on the microbiological findings, with a favourable clinical outcome for the patient.

High-resolution single nucleotide polymorphism analysis distinguishes recrudescence and reinfection in recurrent invasive nontyphoidal Salmonella typhimurium disease

Invasive nontyphoidal Salmonella Typhimurium disease is a common and frequently recurrent cause of bacteremia across sub-Saharan Africa. We use high-resolution single nucleotide polymorphism analysis to distinguish between reinfection and recrudescence in disease recurrence within single individuals over time.

Background. Bloodstream infection with invasive nontyphoidal Salmonella (iNTS) is common and severe among human immunodeficiency virus (HIV)–infected adults throughout sub-Saharan Africa. The epidemiology of iNTS is poorly understood. Survivors frequently experience multiply recurrent iNTS disease, despite appropriate antimicrobial therapy, but recrudescence and reinfection have previously been difficult to distinguish.

Methods. We used high-resolution single nucleotide polymorphism (SNP) typing and whole-genome phylogenetics to investigate 47 iNTS isolates from 14 patients with multiple recurrences following an index presentation with iNTS disease in Blantyre, Malawi. We isolated nontyphoidal salmonellae organisms from blood (n = 35), bone marrow (n = 8), stool (n = 2), urine (n = 1), and throat (n = 1) samples; these isolates comprised serotypes Typhimurium (n = 43) and Enteritidis (n = 4).

Results. Recrudescence with identical or highly phylogenetically related isolates accounted for 78% of recurrences, and reinfection with phylogenetically distinct isolates accounted for 22% of recurrences. Both recrudescence and reinfection could occur in the same individual, and reinfection could either precede or follow recrudescence. The number of days to recurrence (23–486 d) was not different for recrudescence or reinfection. The number of days to recrudescence was unrelated to the number of SNPs accumulated by recrudescent organisms, suggesting that there was little genetic change during persistence in the host, despite exposure to multiple courses of antibiotics. Of Salmonella Typhimurium isolates, 42 of 43 were pathovar ST313.

Conclusions. High-resolution whole-genome phylogenetics successfully discriminated recrudescent iNTS from reinfection, despite a high level of clonality within and among individuals, giving insights into pathogenesis and management. These methods also have adequate resolution to investigate the epidemiology and transmission of this important African pathogen.

Recurrent Meningitis and Subarachnoid Hemorrhage Due to Salmonella in an HIV+ Patient: Case Report and Mini-Review of the Literature

Meningitis due to non-typhi salmonella is infrequent in HIV-positive adults.

We report a case of a patient with >300 CD4+ cells/mm3 who presented with five episodes of recurrent meningitis, focal subarachnoid hemorrhage and cerebral vasculitis ultimately attributed to Salmonella choleraesuis infection. Even within the cART era invasive salmonellosis can occur in unusual ways in HIV-infected patients.

Polyserositis due to Salmonellaenterica serovar Enteritidis

Salmonella enterica serovar Enteritidis (S. Enteritidis), a non-typhoid Salmonella, is an important emerging pathogen that usually causes gastroenteritis. Here, we report polyserositis with right-sided pleural effusion and loculated collection of fluid in the peritoneum caused by S. Enteritidis in a 60-year-old man from southern India. The patient was immunocompetent and did not have preceding gastroenteritis or any local structural abnormality. Malnutrition and old age might have been the predisposing factors. The patient received intravenous ceftriaxone for 2 weeks followed by oral ciprofloxacin. Pleurocentesis and abdominal paracentesis were also done. The patient was cured as evidenced by clinical improvement and radiological disappearance of the fluid collection.

Focal Salmonella enteritidis infection in a patient with HIV infection and other multiple causes of immunodeficiency

An HIV-infected man receiving antiretroviral therapy-who also had lupus-like vasculitis and membranous glomerulonephritis (treated with prednisolone and azathioprine), beta-thalassaemia minor trait and post-radiotherapy functional asplenia (mimicking sickle cell disease-induced hyposplenism)-developed focal soft issue and bone infection caused by Salmonella enteritidis at the site of previous mycobacterial infection.

Primary macrophages from HIV-infected adults show dysregulated cytokine responses to Salmonella, but normal internalization and killing

BACKGROUND

Adults with advanced HIV are susceptible to invasive and recrudescent infections with nontyphoidal salmonellae.

OBJECTIVES

To examine whether persistence and recurrence of salmonella infection results from HIV-related defects in macrophage internalization and intracellular killing or from ineffective type 1 cytokine responses. Such defects could be a direct consequence of macrophage HIV infection or secondary to reduced enhancement of macrophage effector functions by interferon-gamma (IFNgamma) as CD4 cell count falls.

DESIGN

Ex-vivo scientific case-control study.

METHODS

Primary ex-vivo human alveolar macrophages (huAM) from HIV-negative and HIV-positive subjects were challenged with Salmonella typhimurium under unprimed and IFNgamma-primed conditions to study internalization and intracellular killing of bacteria and cytokine responses of huAM.

RESULTS

Priming of huAM with IFNgamma reduced bacterial internalization but enhanced microbicidal activity against intracellular salmonellae. HuAM from HIV-positive subjects showed unimpaired internalization and intracellular killing of salmonellae, with and without IFNgamma priming. Opsonic and mannose receptor (CD206)-mediated entry was not required for optimal internalization. HuAM from HIV-positive subjects, however, exhibited increased secretion of tumour necrosis factor alpha (TNFalpha), interleukin (IL)-10 and IL-12 in response to S. typhimurium challenge, regardless of IFNgamma priming. This cytokine dysregulation showed a trend to a curvilinear relationship with peripheral CD4 cell count, with marked decline at values < 250 cell/mul.

CONCLUSIONS

Dysregulation of proinflammatory cytokine release, including IL-12, by macrophages during salmonella infection may underlie the susceptibility to severe salmonellosis in patients with AIDS. This defect was not reversed by IFNgamma and may represent a proinflammatory effect of HIV infection upon the macrophage or the alveolar milieu.

Acute bacterial meningitis in HIV, pacients in southern Brazil: Curitiba, Paraná, Brazil

Acute communitarian bacterial meningitis and AIDS are prevalent infectious disease in Brazil. The objective of this study was to evaluate the frequency of acute communitarian bacterial meningitis in AIDS patients, the clinical and cerebrospinal fluid (CSF) characteristics. It was reviewed the Health Department data from city of Curitiba, Southern Brazil, from 1996 to 2002. During this period, 32 patients with AIDS fulfilled criteria for acute bacterial meningitis, representing 0.84% of the AIDS cases and 1.85% of the cases of bacterial meningitis. S. pneumoniae was the most frequent bacteria isolated. The number of white blood cells and the percentage of neutrophils were higher and CSF glucose was lower in the group with no HIV co-infection (p 0.12; 0.008; 0.04 respectively). Bacteria not so common causing meningitis can occur among HIV infected patients. The high mortality rate among pneumococcus meningitis patients makes pneumococcus vaccination important.

Extraintestinal focal infections in adults with nontyphoid Salmonella bacteraemia: predisposing factors and clinical outcome

BACKGROUND

Nontyphoid Salmonella (NTS) isolates lead to not only self-limited, acute gastrointestinal infections, but also bacteraemia with or without extraintestinal focal infections (EFIs). The risk factors associated with EFIs in adults with NTS bacteraemia were not clearly elucidated.

METHODS

In a medical center in southern Taiwan, patients aged > or = 18 years with NTS bacteraemia between January 1999 and June 2005 were included for analysis.

RESULTS

Of 129 patients, 51 (39.5%) were complicated with EFIs. The most common EFI was mycotic aneurysm, followed by pleuropulmonary infections and spinal osteomyelitis. Compared to patients with primary bacteraemia, those with EFIs had higher leucocyte counts (P = 0.004) and higher serum levels of C-reactive protein (P < 0.0001). The development of EFIs was associated with a higher mortality, more severe septic manifestations, longer hospital stays and duration of antimicrobial therapy. Univariate analysis revealed that diabetes mellitus (P = 0.02), hypertension (P = 0.02) and chronic lung disease (P = 0.006) were significantly associated with EFIs. However, patients with malignancy (P = 0.01) and immunosuppressive therapy (P = 0.03) were less likely to develop EFIs. On the basis of multivariate analysis, an independent factor for the occurrence of EFIs was age [adjusted odds ratio (aOR) 1.05; 95% confidence interval (CI) 1.02-1.07; P < 0.0001], whilst malignancy was negatively associated with EFIs (aOR 0.16; 95% CI 0.14-0.78; P = 0.01).

CONCLUSION

Amongst patients with NTS bacteraemia, EFIs often occurred in the aged, and were associated with a higher mortality and morbidity. Recognition of specific host factors is essential for identification of EFIs which often demand early surgical interventions and prolonged antimicrobial therapy.

Native-valve infective endocarditis caused by Enterobacteriaceae: report on 9 cases and literature review

Although the demographic characteristics of patients who develop infective endocarditis (IE) have changed over the last few decades, Enterobacteriaceae remain rarely responsible. We report the clinical and epidemiological characteristics of 9 patients with native-valve Enterobacteriaceae IE from 6 French medical intensive care units over a 10-y period and have identified 29 additional cases in the literature. Nearly a third of the 38 patients were immunocompromised and/or had previously known valvular heart disease. Salmonella spp. and Yersinia spp. were the most frequently isolated microorganisms reported in the literature. The overall mortality rate was 24% (9/38) and was lower for operated patients (10% (1/10)) compared to those who did not undergo valve surgery (31% (8/26)). Our results confirmed the rarity of native-valve endocarditis caused by Enterobacteriaceae, pathogens frequently responsible for nosocomial and community-acquired bacteraemias. This paradox may be explained by susceptibility to the bactericidal action of serum and the inability of these bacteria to colonize the endocardium.

Salmonella serovars isolated from humans in São Paulo State, Brazil, 1996-2003

Salmonellosis remains an important cause of diarrheal illness in humans in São Paulo State, Brazil. In this study were identified 3554 Salmonella isolates from human infections, during the period 1996-2003. Among 68 different serovars determined, S. Enteritidis was the most frequent one in gastrointestinal and extra-intestinal infections accounting for 67.4% of all isolates. S. Typhimurium and S. enterica subsp. enterica (4,5,12:i:-) were most frequently isolated from children aged < 1-4 year-old, in contrast, people with S. Enteritidis infections were most likely to be 20-50 year-old. In our geographic area the continued laboratorial surveillance of salmonellosis, including serotyping, has showed the trends in Salmonella serovars causing infections in humans throughout the time.

Salmonellosis with liver abscess mimicking hepatocellular carcinoma in a diabetic and cirrhotic patient: a case report and review of the literature

Salmonellosis with liver abscess in a cirrhotic liver is extremely rare. We report the first case of Salmonellosis with septic shock and liver abscess in a diabetic and cirrhotic patient. The image studies of liver initially favored hepatocellular carcinoma. But no definite focus of sepsis was found. After close follow-up of the liver space-occupied lesion, ultrasound examination revealed the features of liver abscesses at space-occupied lesion later. Ultrasound-guided liver aspiration proved abscess. The clinical and radiological responses were good after antibiotics treatment.

Salmonella group C necrotizing fasciitis: a case report and review of the literature

Localized salmonella soft tissue infections have been rarely described in humans. We report a case of necrotizing fasciitis caused by Salmonella serogroup C in a patient with systemic lupus erythematosus who was successfully treated with surgical debridement and cefoperazone-sulbactam. In addition, we provide a literature review on risk factors and treatment of this uncommon disease sequelae.

[Incidence and impact of HIV infection among patients with bacterial pleurisy in Lomé (Togo)]

A prospective study was made in the Tokoin university hospital in Lomé (Togo) to determine the incidence and the impact of HIV among patients with bacterial pleurisy. Two hundred cases of bacterial pleurisy were consecutively included over 17 months. The HIV diagnostic was performed using ELISA (Vironostika HIV Uni-Form II plus O and HIV1 and 2 Bispot Immunocomb II). The 200 cases of pleurisy included 152 (76%) tuberculous pleural effusion and 48 (24%) pleural empyema. Staphylococcus aureus (32%), Streptococcus pneumoniae (14.9%), and Pseudomonas (14.9%) were the main causes of pleural empyema. The HIV incidence was 61% (122/200). The mortality rate ranged from 26.2% in the HIV positive group to 5.1% in HIV negative group (P = 0.0001). The bacterial aspect of pleural empyema was heterogeneous in both groups but Salmonella Enteritidis and Salmonella Typhimurium were identified only among patients with HIV.

Risk factors for bacteraemia and endovascular infection due to non-typhoid salmonella: a reappraisal

BACKGROUND

Endovascular infections are rare complications of non-typhoid salmonellosis. The diagnosis is frequently not established until the infection is advanced. It is important to identify high-risk patients and treat them as early as possible.

AIM

To identify risk factors for bacteraemia and endovascular infection in patients with non-typhoid salmonellosis.

DESIGN

Retrospective study.

SETTING

A single tertiary-care hospital in Taiwan.

METHODS

Data were collected by retrospective chart review. Log-logistic regression modelling was used to identify independent risk factors for bacteraemia and endovascular infection. We analysed the characteristics of patients with gastroenteritis vs. those with bacteraemia, and of bacteraemic patients with vs. without endovascular infection.

RESULTS

Between 1984 and 2004, there were 373 adult cases of non-typhoid salmonellosis. There were 76 intestinal Salmonella infections, 290 bloodstream infections (including 47 endovascular infections), and 7 extra-intestinal non-bacteraemic infections. The independent positive predictors of bacteraemia were systemic lupus erythematosus, liver cirrhosis, HIV infection, and solid organ cancers. The only independent positive predictor of endovascular infection was atherosclerosis. The independent negative predictors of endovascular infection were solid organ cancers and immunodeficiency.

DISCUSSION

Risk factors for atherosclerosis predisposed our patients with bacteraemia to endovascular infection. Although immunodeficiency predisposed patients to bacteraemia, it was associated with a low incidence of endovascular infection.

Pharmacotherapy, vaccines and malaria advice for HIV-infected travellers

Since the introduction of effective antiretroviral therapy (ART), HIV-infected individuals are travelling more frequently and international travel has become much safer. Specific concerns include the safety of ART during travel, drug adherence and interaction considerations, and effects of immunosuppression. This review describes potentially important infections, vaccine effectiveness, safety and special approaches for their use, and HIV-related issues regarding predeparture counselling. With advanced immunosuppression (CD4+ T-cell count < 200/microl or < 14%), the immunogenicity of several vaccines is reduced, complications could occur after live attenuated vaccines and certain infections acquired during travel may be more frequent or severe. Challenges include the best options for malaria chemoprophylaxis, standby treatment and medical follow-up of the increasing number of HIV-infected long-term travellers.

Salmonella enterica subsp houtenae serogroup O:16 in a HIV positive patient: case report

We described a case of salmonellosis in a 33-year old HIV-infected patient. The patient presented oral and esophageal candidiasis, intense epigastric and retrosternal pain. During the physical examination he was hypochloraemic, acyanotic, hypohydrated, anicteric and afebrile. Admittance laboratorial tests indicated: red cells 3.6 millions/mm³; hemoglobin, 10.1 g/dL; leukocyte count, 3,000/mm³, with 1% of eosinophils, 14% of non-segmented and 53% of segmented neutrophils and 31% of lymphocytes. The blood culture was positive for Salmonella enterica subsp houtenae serogroup O:16. This is probably the first human report of bacteremia due to Salmonella enterica subsp houtenae in Brazil associated to HIV-infected patient.

The spectrum of cardiovascular infections due to Salmonella enterica: a review of clinical features and factors determining outcome

Cardiovascular infections due to Salmonella enterica are infrequently reported, so their clinical features, prognosis, and optimal treatment are not completely known. Mortality associated with aortitis and endocarditis caused by nontyphoidal Salmonella remains exceedingly high. In this review of cases of cardiovascular infections due to Salmonella enterica studied in 2 hospitals in Madrid, we tried to assess the clinical manifestations and the procedures leading to diagnosis in addition to treatment and outcome. To complete the spectrum of infections related to cardiovascular surgery, cases of postoperative mediastinitis, pericarditis, and infections associated with cardiac devices were also included.Twenty-three patients were reviewed: 11 had mycotic aneurysms; 7 had endocarditis; 2 had device-related infections; and 3 had pericarditis, mediastinitis, and infection of an arteriovenous fistula, respectively. The risk of endovascular infection in patients older than 60 years with bacteremia due to nontyphoidal Salmonella was 23%. Most patients with aortitis had risk factors for atherosclerosis, and 6 had preexisting atherosclerotic aortic aneurysms. All except 1 patient with endocarditis had underlying cardiac disorders. Acquired immunodeficiency disease (AIDS) was a major risk factor for salmonella bacteremia in 1 patient with aortitis and 1 with endocarditis. Fever, unremitting sepsis, "breakthrough" and relapsing bacteremia were the most common clinical findings. In addition, abdominal or thoracic pain and cardiac failure and pericarditis were common features in patients with aortitis and endocarditis respectively. Computed tomography (CT) scan, arteriography, and echocardiography were the main diagnostic tools. Mortality associated with mycotic aneurysms and endocarditis due to S. enterica was 45% and 28%, respectively. Thoracic aneurysms, rupture, and shock at the time of diagnosis were associated with increased mortality in patients with aortitis. In situ bypass grafting was successfully performed in most cases. After surgery, antimicrobial therapy was continued for 4-9 weeks. No relapses were observed after a mean follow-up of 64 months. Antimicrobial therapy alone or combined with valve replacement or excision of a ventricular aneurysm was successful treatment for most patients with salmonella endocarditis. Combined medical and surgical treatment was required for patients with mediastinitis and pericarditis, and patients with device-related infections needed removal of the complete device. Diagnosis of aortitis due to nontyphoidal Salmonella should be established as early as possible to reduce mortality. Patients older than 60 years who have positive blood cultures for Salmonella along with fever and back, abdominal, or chest pain should have an extensive workup for infective aortitis. Immediate bactericidal antimicrobial therapy should be started and a CT scan should be performed on an emergency basis. If a mycotic aneurysm is found, surgical resection should follow as soon as possible. Resection of the aneurysm with in situ bypass grafting is the procedure of choice. Postoperative antimicrobial therapy for 6-8 weeks seems enough to avoid relapses. Optimal treatment of patients with endocarditis occurring on ventricular aneurysms must include resection of the aneurysmal sac. Salmonella endocarditis can be successfully treated with antimicrobials alone. Valve replacement should be reserved for patients with cardiac failure or persisting sepsis, and for those who relapse after discontinuation of antimicrobial therapy.

Non-typhoidal salmonella (NTS) bacteraemia in Malawian adults: a severe, recrudescent, HIV-associated illness

Non-typhoidal salmonella (NTS) bacteraemia is a common, recurrent illness in HIV-infected African adults. We aimed to describe the presentation and outcome of NTS bacteraemia, the pattern of recurrence, and to determine whether recurrence results from re-infection or recrudescence. 100 consecutive adult inpatients with NTS bacteraemia in Blantyre, Malawi were treated with chloramphenicol (500mg qid for 14 days). Survivors were prospectively followed to detect bacteraemic recurrence. Index and recurrent isolates were typed by antibiogram, pulsed field gel electrophoresis and plasmid analysis to distinguish recrudescence from re-infection. Inpatient mortality was 47%, and 1-year mortality was 77%. 77/78 cases were HIV positive. Anaemia was associated with inpatient death, and several features of AIDS were associated with poor outpatient survival. Among survivors, 43% (19/44) had a first recurrence of NTS bacteraemia at 23-186 days. Among these, 26% (5/19) developed multiple recurrences up to 245 days. No recurrence was seen after 245 days, despite follow-up for up to 609 days (median 214). Suppurative infections were not found at presentation, and were only seen twice at recurrence. Index and recurrent paired isolates were identical by phenotyping and genotyping, consistent with recrudescence, rather than re-infection. NTS bacteraemia has a high mortality (47%) and recurrence rate (43%) in HIV-infected African adults. Recurrence is caused by recrudescence rather than re-infection. Since focal infections were rarely found, recrudescence may often be a consequence of intracellular tissue sequestration. There is an urgent need for improved primary treatment and secondary prophylaxis in Africa.

Risk factors for primary bacteremia and endovascular infection in patients without acquired immunodeficiency syndrome who have nontyphoid salmonellosis

This study sought to find the risk factors for primary bacteremia, endovascular infection, and in-hospital death for patients without acquired immunodeficiency syndrome who have nontyphoid salmonellosis. From September 1995 through September 2001, 301 patients with nontyphoid salmonellosis were admitted to our hospital; of these patients, 121 had primary bacteremia, and 28 had endovascular infection. Of the 121 patients with primary bacteremia, 64 were aged >50 years, and 26 had endovascular infection. Overall, 90 patients (29.9%) had immunodeficiency. Predictors of primary bacteremia were age; presence of systemic lupus erythematosus; group B, group C, or group D Salmonella infection; and immunodeficiency. The positive predictor of endovascular infection in adult patients with primary bacteremia was group C Salmonella infection, and negative predictors were immunodeficiency and solid-organ cancer. The overall in-hospital mortality rate was 12%; for primary bacteremia, it was 24.8%; for endovascular infection, it was 14.3%. Predictors of in-hospital death were age, extraintestinal infection, and solid-organ malignancy.

Liver abscess due to Salmonella enteritidis in a returned traveler with HIV infection: case report and review of the literature

Bacteremia due to non-typhi Salmonella is more frequent in patients infected with the human immunodeficiency virus (HIV). However, focal complications have been rarely described. We report a case of liver abscess due to Salmonella enteritidis in an HIV-infected patient who recently returned to Sao Paulo, Brazil, from a trip in the Caribbean. A good clinical and radiological response was seen with both percutaneous catheter drainage and antibiotic treatment. To our knowledge, this is the first culture proven case of non-typhi Salmonellaliver abscess in an HIV-infected patient in Brazil.

Genetic regulation of host responses to Salmonella infection in mice

Salmonella spp are Gram-negative bacteria capable of infecting a wide range of host species, including humans, domesticated and wild mammals, reptiles, birds and insects. The outcome of an encounter between Salmonella and its host is dependent upon multiple factors including the host genetic background. To facilitate the study of the genetic factors involved in resistance to this pathogen, mouse models of Salmonella infection have been developed and studied for years, allowing identification of several genes and pathways that may influence the disease outcome. In this review, we will cover some of the genes involved in mouse resistance to Salmonella that were identified through the study of congenic mouse strains, cloning of spontaneous mouse mutations, use of site-directed mutagenesis or quantitative trait loci analysis. In parallel, the relevant information pertaining to genes involved in resistance to Salmonella in humans will be discussed.

Changes in Escherichia coli resistance to co-trimoxazole in tuberculosis patients and in relation to co-trimoxazole prophylaxis in Thyolo, Malawi

In Thyolo district, Malawi, an operational research study is being conducted on the efficacy and feasibility of co-trimoxazole prophylaxis in preventing deaths in HIV-positive patients with tuberculosis (TB). A series of cross-sectional studies were carried out to determine i) whether faecal Escherichia coli (E.coli) resistance to co-trimoxazole in TB patients changed with time and ii) whether the resistance pattern was different in HIV positive TB patients who were taking co-trimoxazole prophylaxis. Co-trimoxazole resistance among E.coli isolates in TB patients at the time of registration was 60% in 1999 and 77% in 2001 (p<0.01). Resistance was 89% among HIV-infected TB patients (receiving co-trimoxazole), while in HIV negative patients (receiving anti-TB therapy alone) it was 62% (p<0.001). The study shows a significant increase of E.coli resistance to co-trimoxazole in TB patients which is particularly prominent in HIV infected patients on co-trimoxazole prophylaxis. Since a high degree of plasmid-mediated transfer of resistance exists between E.coli and the Salmonella species, these findings could herald limitations on the short and long term benefits to be anticipated from the use of co-trimoxazole prophylaxis in preventing non-typhoidal salmonella bacteraemia and enteritis in HIV infected TB patients in Malawi.

Non-typhoidal salmonella bacteraemia among HIV-infected Malawian adults: high mortality and frequent recrudescence

OBJECTIVE

Non-typhoidal salmonella (NTS) bacteraemia is a common, recurrent illness in HIV-infected African adults. We aimed to describe the presentation and outcome of NTS bacteraemia, the pattern of recurrence, and to determine whether recurrence results from re-infection or recrudescence.

DESIGN

One hundred consecutive adult inpatients with NTS bacteraemia in Blantyre, Malawi, were treated with chloramphenicol. Survivors were prospectively followed to detect bacteraemic recurrence.

METHODS

Index and recurrent isolates were typed by antibiogram, pulsed-field gel electrophoresis and plasmid analysis to distinguish recrudescence from re-infection.

RESULTS

Inpatient mortality was 47%, and 1-year mortality was 77%. A total of 77 out of 78 cases were HIV positive. Anaemia was associated with inpatient death, and several features of AIDS were associated with poor outpatient survival. Among survivors, 43% (19/44) had a first recurrence of NTS bacteraemia at 23-186 days. Among these, 26% (5/19) developed multiple recurrences up to 245 days. No recurrence was seen after 245 days, despite follow-up for up to 609 days (median 214). Suppurative infections were not found at presentation, and were only seen twice at recurrence. Index and recurrent paired isolates were identical by phenotyping and genotyping, consistent with recrudescence, rather than re-infection.

CONCLUSION

NTS bacteraemia has a high mortality (47%) and recurrence (43%) rate in HIV-infected African adults. Recurrence is caused by recrudescence rather than re-infection. As focal infections were rarely found, recrudescence may often be a consequence of intracellular tissue sequestration. There is an urgent need for improved primary treatment and secondary prophylaxis in Africa.

Nontyphoidal salmonella bacteremia and pneumonia as the initial manifestation of human immunodeficiency virus infection in a four-year-old child

This report describes the case of a 4-year-old human immunodeficiency virus (HIV)-infected girl with Salmonella typhimurium bacteremia and pneumonia. The girl presented with a history of fever for 1 month and mild pulmonary symptoms. Subsequent studies revealed previously undiagnosed HIV disease.

Salmonella meningitis in adults infected with HIV: case report and review of the literature

We report a case of Salmonella infantis meningitis in a patient infected with HIV who was successfully treated with 4 weeks of therapy and has had no relapses after 12 months of follow-up. Only 10 episodes of Salmonella species meningitis in patients infected with HIV are reported in the literature.

Epidemiology and microbiology of cellulitis and bacterial soft tissue infection during HIV disease: a 10-year survey

BACKGROUND

Cellulitis and soft tissue infection are underestimated complications of HIV disease.

PATIENTS AND METHODS

Sixty-seven bacteriologically proven consecutive episodes were identified among 2221 HIV-infected patients hospitalized in a 10-year period, and assessed according to several epidemiological, microbiological and clinical variables.

RESULTS

Staphylococcus aureus was the most frequently cultured pathogen (50% of 92 isolates), followed by Pseudomonas spp., Escherichia coli and Streptococcus pyogenes; a polymicrobial infection was present in 38.1% of episodes. Drug addiction (p < 0.003) and male gender (p < 0.04) were significantly associated with the occurrence of these complications, which were community-acquired in 83.6% of cases. While a remarkable variation in the severity of underlying immunodeficiency was shown, hematogenous dissemination occurred in 25.4% of episodes, and proved significantly related to a low CD4+ lymphocyte count, and neutropenia. A 21.7% methicillin-resistance rate was shown among S. aureus isolates. All episodes were favorably treated in 5-16 days, in over 60% of cases with associated beta-lactam-aminglycoside antibiotics; a recurrence of staphylococcal cellulitis occurred in four patients only.

CONCLUSION

Skin and soft tissue infections are continuing causes of morbidity in HIV-infected patients, even in the highly active antiretroviral therapy era.

Changes in Escherichia coli resistance to co-trimoxazole in tuberculosis patients and in relation to co-trimoxazole prophylaxis in Thyolo, Malawi

In Thyolo district, Malawi, an operational research study is being conducted on the efficacy and feasibility of co-trimoxazole prophylaxis in preventing deaths in HIV-positive patients with tuberculosis (TB). A series of cross-sectional studies were carried out in 1999 and 2001 to determine (i) whether faecal Escherichia coli resistance to co-trimoxazole in TB patients changed with time, and (ii) whether the resistance pattern was different in HIV-positive TB patients who were taking co-trimoxazole prophylaxis. Co-trimoxazole resistance among E. coli isolates in TB patients at the time of registration was 60% in 1999 and 77% in 2001 (P < 0.01). Resistance was 89% among HIV-infected TB patients (receiving cotrimoxazole), while in HIV-negative patients (receiving anti-TB therapy alone) it was 62% (P < 0.001). The study shows a significant increase of E. coli resistance to co-trimoxazole in TB patients which is particularly prominent in HIV-infected patients on co-trimoxazole prophylaxis. Since a high degree of plasmid-mediated transfer of resistance exists between E. coli and the Salmonella species, these findings could herald limitations on the short- and long-term benefits to be expected from the use of co-trimoxazole prophylaxis in preventing non-typhoid Salmonella bacteraemia and enteritis in HIV-infected TB patients in Malawi.

The role of antibiotics in the treatment of infectious diarrhea

Infectious diarrhea is a significant cause of morbidity and mortality and a common complaint in clinical practice. Routine empirical use of antibiotics for infectious diarrhea should be avoided because of the self-limited nature of most cases, the cost of antibiotics, and the potential to worsen the already significant problem of antibiotic resistance of enteric pathogens. For patients with severe invasive or prolonged diarrhea or who are at high risk of complications, such as the elderly, diabetics, cirrhotics, and immunocompromised patients, empirical treatment with a quinolone antibiotic for 3 to 5 days can be considered. Antibiotic treatment can be highly effective for Shigella, ETEC, and V. cholerae infections, and metronidazole is indicated for C. difficile colitis. The impact of antibiotics for other specific pathogens is modest, and antibiotic therapy should be reserved for the same group of patients who would be considered for empirical treatment. The most significant problem in the antibiotic treatment of infectious diarrhea is the progressive increase in resistance among enteric pathogens; only the prudent use of antimicrobials in all areas of daily practice can limit or delay the impact of this serious problem.