Salmonella osteomyelitis and arthritis in sickle cell disease

Acute multifocal osteomyelitis with septic arthritis caused by nontyphoidal Salmonella in an immunocompetent young adult: a case report

Nontyphoidal Salmonella (NTS) infection can lead to gastroenteritis, enteric fever, and bacteremia. However, bone and joint infections due to NTS are rarely encountered, accounting for only 0.8% of all Salmonella infections and 0.45% of all types of osteomyelitis. We herein report an extremely rare case of acute multifocal osteomyelitis (bilateral femurs and left tibia) with septic arthritis of the bilateral hips caused by Salmonella Dublin in an immunocompetent adult. We performed thorough debridement of the bilateral hips and surgical decompression of the involved bones. At 1 year of follow-up, the patient's inflammatory biomarkers were within normal limits, and clinical and radiologic examinations showed no signs of infection. We emphasize that invasive NTS can lead to multifocal bone and joint infections in immunocompetent adults. The manifestations of Salmonella osteomyelitis may be insidious; thus, we recommend performing a simultaneous magnetic resonance imaging examination of the bone adjacent to the infected joint to avoid missed or delayed diagnosis. Thorough surgical debridement combined with a long course of sensitive antibiotic therapy is essential to eradicate the infection.

Septic arthritis with osteomyelitis due to Salmonella enterica serotype Dublin: A case series

Background

Septic arthritis with osteomyelitis due to Salmonella enterica serotype Dublin is rare. We reviewed and analyzed cases of septic arthritis with osteomyelitis due to Salmonella enterica serotype Dublin seen at our institution.

Methods

The medical records of all patients diagnosed with Salmonella septic arthritis and/or Salmonella osteomyelitis during 2017-2022 were included. We reviewed the diagnosis, medical history, clinical management, and outcome of all cases.

Results

Five patients with Salmonella septic arthritis or Salmonella osteomyelitis were identified during the 5-year study period. They were all male; the median age was 53 years (range 15-56). Only one was immunodeficient. All five patients were infected at the hip joint and ipsilateral femur, while two suffered bilateral hip septic arthritis with femoral osteomyelitis. Salmonella Dublin was isolated from the hip joint fluid of all patients. Four presented with fever and constitutional signs within four weeks of symptom onset. Four had positive blood cultures, and only one patient had gastrointestinal symptoms. Four patients underwent surgical debridement as the primary surgical plan, and two underwent secondary two-stage exchange after primary surgical debridement failure. The last patient had a two-stage exchange directly as the first surgical treatment. All patients received intravenous antimicrobial therapy for a median duration of 6 (range 4-12) weeks and oral antimicrobial therapy for a median duration of 4 (range 4-6) weeks. All patients had a median duration of follow-up of 12 months (range 9-25), and none had evidence of recurrence of infection.

Conclusions

Septic arthritis due to Salmonella Dublin remains rare. It frequently occurs with ipsilateral femur osteomyelitis adjacent to the infected hip joint in our cases. Surgical debridement or two-stage exchange, along with 4-12 weeks of effective intravenous and followed by 4-6 oral antimicrobial therapy, could successfully eradicate the infection.

Extended drug-resistant Salmonella typhi osteomyelitis: a case report and literature review

Background

Salmonella typhi infection commonly results in gastroenteritis, bacteremia with or without secondary seeding, or asymptomatic carrier stage. Few cases of Salmonella typhi bacteremia later result in seeding and ultimately lead to further complications including osteomyelitis and rarely vertebral osteomyelitis.

Case presentation

We are discussing a case of a 38-year-old Asian male patient, with no known comorbids. He presented with fever and backache for 4 weeks. Based on the magnetic resonance imaging (MRI) findings of the spine and positive blood cultures, a diagnosis of XDR Salmonella typhi (S. typhi) osteomyelitis (OM) was made. Patient was started on intravenous therapy as per culture report which was later modified according to treatment response.

Conclusion

S. typhi has a broad spectrum of clinical manifestations including osteomyelitis however to the best of our knowledge this is the first reported case of XDR S. typhi vertebral osteomyelitis. We describe the clinical course of the patient and review the literature regarding the treatment of S.typhi vertebral osteomyelitis with a special focus on XDR S. typhi. Treatment course and complications in view of this new resistant strain have to be reported in order to devise general guidelines for the management in such particular cases.

Management and Outcomes of Salmonella Gastroenteritis in the Era of Rapid Molecular Testing

BACKGROUND AND OBJECTIVES

Molecular diagnostics provide a rapid and sensitive diagnosis of gastroenteritis compared with a stool culture. In this study, we seek to describe the changes in medical management and outcomes of children with Salmonella gastroenteritis as our hospital system adopted molecular diagnostics.

METHODS

This study is a retrospective chart review of children <18 years of age diagnosed with nontyphoidal Salmonella gastroenteritis between 2008 and 2018 at a large pediatric health care system in the southeastern United States. Those with immunocompromising conditions and hemoglobinopathies were excluded. Patients diagnosed via molecular testing were compared with those diagnosed solely by stool culture for aspects of management including admission rates, blood culture obtainment, and antibiotic administration.

RESULTS

Of 965 eligible patients with Salmonella gastroenteritis, 264 (27%) had a stool molecular test and 701 (73%) only had a stool culture performed. Groups were similar in age and presentation. Those diagnosed by molecular methods had higher hospitalization rates (69% vs 50%, P <.001), more blood cultures obtained (54% vs 44%, P <.01), and received more antibiotics (49% vs 34%, P <.001) despite statistically similar rates of bacteremia (11% vs 19%, P = .05).

CONCLUSIONS

The rapid diagnosis of Salmonella gastroenteritis by molecular methods was associated with increased hospital admission rates, blood culture obtainment, and antibiotic use. This suggests possible overmedicalization of uncomplicated Salmonella gastroenteritis, and clinicians should remain cognizant of the possibility of providing low-value care for uncomplicated disease.

Salmonella Osteomyelitis in a Pediatric Patient with a Proximal Humerus Fracture: A Case Report

CASE

A 5-year-old previously healthy girl sustained a left proximal humerus fracture after a fall from a trampoline. The injury was initially treated nonoperatively, but during routine follow-up, the patient was found to have a previously unrecognized bony erosion at the fracture site. Workup was negative for neoplasm but instead demonstrated Salmonella osteomyelitis. The patient underwent debridement and treatment with antibiotics.

CONCLUSION

This is an unusual presentation of a humerus fracture in a child with concomitant Salmonella osteomyelitis. Osteomyelitis is an important diagnostic consideration when considering bony erosions in the pediatric patient, even in those patients without apparent risk factors.

Neglected tropical rheumatic diseases

The complexities of dealing with rheumatic diseases in tropical countries are diverse and likely due to limited health care infrastructure, lack of diagnostic and therapeutic facilities, impact of dominant prevailing diseases, and the challenges of differentiating from infectious and non-infectious disease mimics. Several tropical diseases present with musculoskeletal and rheumatic manifestations and often pose a diagnostic dilemma to rheumatologists. The diagnosis is often delayed or the disease is misdiagnosed, leading to poor patient outcomes. Endemic tropical diseases like tuberculosis and leprosy have myriad rheumatic presentations and remain important differentials to consider in patients with rheumatic manifestations. Infection with human immunodeficiency virus is a great masquerade and can mimic manifestations of multiple diseases. The role of viral infections in triggering and perpetuating autoimmunity is well known and chikungunya arthritis is a classic example of the same. This review highlights the rheumatic manifestations of tropical diseases and aims to create awareness among the caregivers. Key Points • It is crucial to be aware and identify infectious diseases presenting with rheumatic manifestations in the tropics. • Presentations akin to classic rheumatic syndromes such as rheumatoid arthritis, spondyloarthritis, systemic lupus erythematosus and vasculitis are common.

Invasive Non-typhoidal Salmonella (iNTS) Infections

Salmonella enterica invade the host via the intestinal tract. There are ~ 2 thousand distinct serovars of non-typhoidal Salmonella (NTS) that can cause gastroenteritis in normal hosts, but bacteremia is an uncommon complication of gastroenteritis except at the extremes of age [1]. In contrast, enteric fever and invasive NTS infections (iNTS) are each caused by only a few serovars of S. enterica (Table 1), and bacteremia not gastroenteritis is their principal manifestation.

Chronic Salmonella Osteomyelitis in a Healthy, Immunocompetent Man: A Case Report

CASE

A 26-year-old healthcare professional presented with knee pain and was found to have Salmonella osteomyelitis of the distal femur. Two operations, including antibiotic bead placement followed by a 6-week course of oral ciprofloxacin, were successful in eradicating the infection.

CONCLUSION

Salmonella osteomyelitis is a well-known complication of hemoglobinopathies but is unusual in healthy individuals. This case required molecular testing and multiple cultures to obtain a diagnosis. Treatment may require debridement and antibiotics.

Rare presentation of infective endocarditis due to Salmonella entrica subspecies salamae (subgroup ll) in a sickle cell anemia girl

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No reported case of infective endocarditis due to Salmonella enterica ss. salamae.

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Infective endocarditis should be considered in SCA patients with salmonella infections.

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Infective endocarditis due to Salmonella infections could require more than one sensitive antibiotics.

Sickle cell anemia (SCA) is a common inherited kind of hemolytic anemia in Africa and some areas of Asia. In Saudi Arabia, SCA is prevalent as well. The patient of SCA is prone to some bacteria species more than the others, and Salmonella is one of the most prevalent infections in SCA that were known to cause bacteremia, osteomyelitis, septic arthritis, and gastroenteritis. Herein, we report a 7-years old girl who presented with a history of fever for five days and jaundice with abdominal pain and mild respiratory distress. Later, the patient was diagnosed to have infective endocarditis due to Salmonella enterica subspecies salamae (subgroup II). The patient improved completely after receiving proper antibiotics. To the best of our knowledge, there is only one case of adult SCA that has been reported with infective endocarditis due to Salmonella entrica but no reported case in pediatric.

Salmonella Osteomyelitis in Adults: A Systematic Review

The aim of this systematic review was to characterize the clinical features of adults with Salmonella osteomyelitis and summarize diagnosis and treatment methods to provide guidance for clinicians. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines. We conducted a literature search in the PubMed, EMBASE, and Cochrane Library databases. Article screening and data extraction were performed by two reviewers individually. All the included studies were independently evaluated by two reviewers using the Methodological Index for Non‐Randomized Studies (MINORS) criteria. A total of 67 articles published between 1970 and 2019 were selected, which include 69 patients with an average age of 47.5 years (range, 18–79).The majority of cases (47.76%) occurred in immunocompetent adults without common risk factors. Aspiration and biopsy cultures were all positive in Salmonella osteomyelitis patients who underwent aspiration or biopsy. All infections were monomicrobial, and a total of 12 different serotypes were identified. The three most commonly reported Salmonella serotypes were Salmonella typhi (19 cases), Salmonella typhimurium (12 cases), and Salmonella enteritidis (11 cases). Only 12 of the 67 cases in our data (17.91%) had diarrhea symptoms, and 44 of the 67 cases (65.67%) had fever symptoms. Fifty‐nine of the 67 cases (88.06%) had local inflammatory manifestations, such as erythema, swelling, and tenderness in the affected area. The commonly reported involved sites were the vertebrae, femur, and tibia. Antibiotic therapy alone was utilized in 30 cases, and 24 patients (80.00%) were eventually cured. In total, 75.68% of patients achieved satisfactory results after treatment with surgery and antibiotics. Third‐generation cephalosporins were most commonly utilized, and antibiotic treatment was administered for an average of 11.3 weeks (95% CI, 8.31–14.37 weeks). Salmonella osteomyelitis should be considered in patients without any common risk factors. Aspiration or biopsy can facilitate the identification of pathogens to guide antibiotic choice. Empirical therapy with a third‐generation cephalosporin is recommended until the susceptibility of the strain is determined.

Orofacial manifestations of sickle cell disease: implications for dental clinicians

Sickle cell disease is a multisystem disease associated with episodes of acute illness and progressive organ damage. It is one of the most common severe monogenic disorders worldwide and is now the fastest growing genetic disorder in the UK. Dental awareness of orofacial manifestation varies geographically due to the inheritance pattern and patient population affected by the disease. This article details the epidemiology, pathophysiology and the orofacial manifestations in light of current literature.

Review/overview of pain in sickle cell disease

Sickle cell disease (SCD) is a highly complex inherited disorder of hemoglobin structure. Although the molecular lesion is a single-point mutation, the sickle gene is pleiotropic in nature causing multiple phenotypic expressions that constitute the various complications of the disease. Its manifestations could be acute, chronic, nociceptive, neuropathic that could occur singly or in various combinations. Pain continues to be the major factor of SCD phenotypic complications and the most common cause of admissions to the Emergency Department and/or the hospital. Although progress has been made in understanding the pathophysiology of SCD as well as in developing curative therapies such as hematopoietic stem cell transplantation and gene therapy, effective pain management continues to lag behind. Palliative therapies continue to be the major approach to the management of SCD and its complications. The advent of hydroxyurea made partial success in preventing the frequency of vaso-occlusive crises and l-glutamine awaits post-trial confirmation of benefits. The search for additional pharmacotherapeutic agents that could be used singly or in combination with hydroxyurea and/or l-glutamine awaits their dawn hopefully in the near future. The purpose of this review is to describe the various manifestations of SCD, their pathophysiology and their current management. Recent impressive advances in understanding the pathophysiology of pain promise the determination of agents that could replace or minimize the use of opioids.

Life-Threatening Infectious Complications in Sickle Cell Disease: A Concise Narrative Review

Sickle cell disease (SCD) results in chronic hemolytic anemia, recurrent vascular occlusion, insidious vital organ deterioration, early mortality, and diminished quality of life. Life-threatening acute physiologic crises may occur on a background of progressive diminishing vital organ function. Sickle hemoglobin polymerizes in the deoxygenated state, resulting in erythrocyte membrane deformation, vascular occlusion, and hemolysis. Vascular occlusion and increased blood viscosity results in functional asplenia and immune deficiency in early childhood, resulting in life-long increased susceptibility to serious bacterial infections. Infection remains a main cause of overall mortality in patients with SCD in low- and middle-income countries due to increased exposure to pathogens, increased co-morbidities such as malnutrition, lower vaccination rates, and diminished access to definitive care, including antibiotics and blood. Thus, the greatest gains in preventing infection-associated mortality can be achieved by addressing these factors for SCD patients in austere environments. In contrast, in high-income countries, perinatal diagnosis of SCD, antimicrobial prophylaxis, vaccination, aggressive use of antibiotics for febrile episodes, and the availability of contemporary critical care resources have resulted in a significant reduction in deaths from infection; however, chronic organ injury is problematic. All clinicians, regardless of their discipline, who assume the care of SCD patients must understand the importance of infectious disease as a contributor to death and disability. In this concise narrative review, we summarize the data that describes the importance of infectious diseases as a contributor to death and disability in SCD and discuss pathophysiology, prevalent organisms, prevention, management of acute episodes of critical illness, and ongoing care.

From Crosstalk between Immune and Bone Cells to Bone Erosion in Infection

Bone infection and inflammation leads to the infiltration of immune cells at the site of infection, where they modulate the differentiation and function of osteoclasts and osteoblasts by the secretion of various cytokines and signal mediators. In recent years, there has been a tremendous effort to understand the cells involved in these interactions and the complex pathways of signal transduction and their ultimate effect on bone metabolism. These crosstalk mechanisms between the bone and immune system finally emerged, forming a new field of research called osteoimmunology. Diseases falling into the category of osteoimmunology, such as osteoporosis, periodontitis, and bone infections are considered to have a significant implication in mortality and morbidity of patients, along with affecting their quality of life. There is a much-needed research focus in this new field, as the reported data on the immunomodulation of immune cells and their signaling pathways seems to have promising therapeutic benefits for patients.

Salmonella osteomyelitis: A rare extraintestinal manifestation of an endemic pathogen

Salmonella enterica serovar Typhi and Paratyphi usually cause enteric fever in humans characterized by fever and gastrointestinal symptoms such as diarrhea. Bacteremia is a constant feature of enteric fever, and occasionally, dissemination of bacilli throughout the body results in the establishment of one or more localized foci of persisting infection. This happens especially in patients with preexisting conditions such as hemoglobinopathies, previous joint trauma, surgery, connective tissue diseases, lymphoma, diabetes, alcoholism, immunosuppressive state, and extremes of ages. Rarely, these extraintestinal Salmonella infection cases have also been reported in immunocompetent individuals without any obvious predisposing factors. Salmonella osteomyelitis, a rare sequelae of typhoid, may occur as a result of hematogenous seeding of the bone or joints due to a bacteremic episode. It may also spread from nearby areas of infection or penetrating trauma. Timely diagnosis and treatment of this condition are necessary because if left untreated, it can lead to permanent functional deficits later on. We hereby present a case series with brief review of literature on Salmonella osteomyelitis in immunocompetent patients without any known predisposing conditions over a period of 1 year (2017-2018) from a Tertiary Care Teaching Hospital in Uttarakhand, India.

Salmonella enterica serovar Typhi osteomyelitis in a young adult with sickle cell and thalassemia traits: A possible association

Salmonella osteomyelitis is known to occur in immunocompromised and sickle cell disease patients. It rarely occurs in other hosts. We present a case of chronic femoral osteomyelitis due to S. enterica serovar Typhi seen in a Maryland resident. Potential risk factors included traveling to an endemic area as well as a newly diagnosed sickle cell trait and thalassemia trait. It is postulated that less severe hemoglobinopathies may also contribute to an elevated risk of Salmonella osteomyelitis.

Severe, non specific symptoms in non-typhoidal Salmonella infections in adult patients with sickle cell disease: a retrospective multicentre study

BACKGROUND

Non-typhoidal salmonellosis (NTS) often occurs in children with sickle-cell disease (SCD) and remains a significant cause of mortality in developing countries. However, there is lack of reports on the clinical presentation, outcome and complications of NTS in adults with SCD.

METHODS

We performed a chart review between 2006 and 2016 of adults SCD diagnosed with NTS in 3 referral centers monitoring approximately 3500 SCD adults.

RESULTS

Twenty-three episodes of NTS were diagnosed among 22 SCD adults. Diagnosis was challenging: 65% (n = 15/23) of patients presented with vaso-occlusive crisis (VOC) and 30% had no fever. Isolated serotypes were: ser. Enteritidis (n = 8), ser. Typhimurium (n = 6), others (n = 3). We identified two patterns of infections: (1) bacteremic NTS (n = 15) with (n = 9) or without secondary foci of infections (n = 6); (2) non-bacteremic NTS with extra-intestinal foci of infection (n = 8), including primary bones/joints infections (n = 5). Half of patients with osteo-articular localization (n = 6/13) had a previous history of osteonecrosis (n = 2) or osteomyelitis (n = 4) at the same site. Morbidity was high, 6 patients (26%) were admitted to the intensive care unit, 14 patients (61%) required RBC transfusion for VOC. Half of the episodes (n = 12) required surgery (n = 10) or interventional radiology (n = 2) to control the infection. One patient presented a relapse of NTS bacteraemia one year after the first episode.

CONCLUSIONS

Besides bloodstream infections, clinical presentation of NTS in adults with SCD is non-specific at admission. A triad including bacteraemia, secondary focis of infection and bone localizations was observed in 30% of cases.

Nontyphoidal Salmonella Osteomyelitis in Immunocompetent Children Without Hemoglobinopathies: A Case Series and Systematic Review of the Literature

Salmonella osteomyelitis is well-described in children with hemoglobinopathies, particularly infection with Salmonella typhi. To characterize nontyphoidal osteomyelitis in otherwise healthy children without hemoglobinopathies, we performed a retrospective review of children discharged from our institution with this condition, supplemented with a systematic literature review. Among the 46 subjects identified, common risk factors for Salmonella infection were frequently absent and complications were common.

Fatal Systemic Salmonellosis in a Florida Manatee ( Trichechus manatus latirostris)

A subadult male Florida manatee ( Trichechus manatus latirostris) stranded dead on Florida's Atlantic coast in January 2015. Necropsy and histopathologic findings confirmed chronic systemic bacterial infection caused by Salmonella enterica serotype IV 50:z4,z23,:- involving renal, respiratory, lymphatic, and skeletal systems. This was a unique case of systemic salmonellosis in a Florida manatee.

Imaging of musculoskeletal manifestations in sickle cell disease patients

Sickle cell disease (SCD) is a hereditary red cell disorder with clinical manifestations secondary to sickling or crescent-shaped distortion of the red blood cells. Major clinical manifestations of SCD include haemolytic anaemia and vaso-occlusive phenomena resulting in ischaemic tissue injury and organ damage. Chronic sequelae of the anaemia and vaso-occlusive processes involving the musculoskeletal system include complications related to extramedullary haematopoiesis, osteonecrosis, myonecrosis and osteomyelitis. Sickle cell bone disease is one of the commonest clinical presentations. Awareness and knowledge of the imaging features related to these complications are essential for early diagnosis and prompt management. In this article, the pathophysiology and key imaging findings related to these complications are reviewed.

Nuclear Medicine Imaging in Pediatric Infection or Chronic Inflammatory Diseases

In this review article, we focus on the most recent applications of nuclear medicine techniques (mainly ^99mTc/¹¹¹In white blood cells (WBC) scan, [¹⁸F]-FDG-PET/CT, [¹⁸F]-FDG-PET/MRI, and ^99mTc-IL-2 scintigraphy) in the study of children affected by peripheral bone osteomyelitis, fungal infections, inflammatory bowel diseases, and type 1 diabetes, owing to recent important published evidences of their role in the management of these diseases. For osteomyelitis in children, both bone scintigraphy and [¹⁸F]-FDG-PET have a major advantage of assessing the whole body in one imaging session to confirm or exclude multifocal involvement, whereas WBC scan has a limited role. In children with fungal infections, [¹⁸F]-FDG-PET can help in defining the best location for biopsy and can help in evaluating the extent of the infection and organs involved (also sites that were not yet clinically apparent), although its main role is for therapy monitoring. In inflammatory bowel diseases, and Crohn disease in particular, WBC scan has been successfully used for many years, but it is now used only in case of doubtful magnetic resonance (MR) or when MR cannot be performed and endoscopy is inconclusive. By contrast, there is an accumulating evidence of the role of [¹⁸F]-FDG-PET in management of children with Crohn disease, and PET/MR could be a versatile and innovative hybrid imaging technique that combines the metabolic information of PET with the high soft tissue resolution of MR, particularly for distinguishing fibrotic from active strictures. Finally, there are several new radiopharmaceuticals that specifically target inflammatory cells involved in the pathogenesis of insulitis aiming at developing new specific immunotherapies and to select children candidates to these treatments for improving their quality of life.

Bilateral Salmonella Septic Arthritis of the Hip in a Patient with Crohn Disease: A Case Report

CASE

A 27-year-old immunocompromised man with Crohn disease presented with bilateral septic hip arthritis due to Salmonella enterica serotype Typhi. The diagnosis was confirmed by synovial membrane and effusion culture specimens that were obtained during arthroscopic debridement of both hips.

CONCLUSION

Prolonged antimicrobial therapy, bilateral femoral head resection, and placement of cement spacers for 5 months, followed by bilateral total hip arthroplasty, was a radical and effective treatment for a patient with Crohn disease and bilateral Salmonella septic arthritis of the hip.

How we prevent and manage infection in sickle cell disease

Sickle cell disease (SCD) affects approximately 100,000 people in the US, 12,500 in the UK, and millions worldwide. SCD is typified by painful vaso-occlusive episodes, haemolytic anaemia and organ damage. A secondary complication is infection, which can be bacterial, fungal or viral. Universal newborn screening, routine use of penicillin prophylaxis, availability of conjugated vaccines against S. pneumoniae and comprehensive care programmes instituted during the past few decades in industrialized countries have dramatically reduced childhood mortality and improved life expectancy. Yet patients with SCD remain at increased risk of infection. Unfortunately, the treatment of most bacterial infections that are common in SCD is not based on the results of randomized controlled clinical trials. In their absence, treatment decisions are based on consensus guidelines, clinical experience or adapting treatment applied in other diseases. This leads to wide variation in treatment among institutions and even between treating physicians in a single institution. Prevention of infection, when possible, is most important and we focus on prevention through targeted prophylaxis and vaccination. We will share our management strategies for managing the more common infections in SCD and provide the rationale for our recommendations.

Ultrasound Detection of Salmonella Septic Arthritis in a Rheumatoid Arthritis Patient on Anti-TNF Treatment

We report a case of Salmonella septic arthritis detected by ultrasound in a 40-year-old man with rheumatoid arthritis while he was on anti–tumor necrosis factor-α monoclonal antibody certolizumab. An aspirate of his left elbow joint showed Salmonella enteritidis infection that was sensitive to ceftraixone. This was preceded by a brief episode of loose stools following a visit to the Far East. He was treated with antibiotics and made a good recovery. There have only been a few case reports of Salmonella septic arthritis in a rheumatoid arthritis patient on anti–tumor necrosis factor treatment but none previously in association with certolizumab.

Apoptosis-associated uncoupling of bone formation and resorption in osteomyelitis

The mechanisms underlying the destruction of bone tissue in osteomyelitis are only now being elucidated. While some of the tissue damage associated with osteomyelitis likely results from the direct actions of bacteria and infiltrating leukocytes, perhaps exacerbated by bacterial manipulation of leukocyte survival pathways, infection-induced bone loss predominantly results from an uncoupling of the activities of osteoblasts and osteoclasts. Bacteria or their products can directly increase osteoclast formation and activity, and the inflammatory milieu at sites of infection can further promote bone resorption. In addition, osteoclast activity is critically regulated by osteoblasts that can respond to bacterial pathogens and foster both inflammation and osteoclastogenesis. Importantly, bone loss during osteomyelitis is also brought about by a decline in new bone deposition due to decreased bone matrix synthesis and by increased rates of osteoblast apoptosis. Extracellular bacterial components may be sufficient to reduce osteoblast viability, but the causative agents of osteomyelitis are also capable of inducing continuous apoptosis of these cells by activating intrinsic and extrinsic cell death pathways to further uncouple bone formation and resorption. Interestingly, bacterial internalization appears to be required for maximal osteoblast apoptosis, and cytosolic inflammasome activation may act in concert with autocrine/paracrine death receptor-ligand signaling to induce cell death. The manipulation of apoptotic pathways in infected bone cells could be an attractive new means to limit inflammatory damage in osteomyelitis. However, the mechanism that is the most important in bacterium-induced bone loss has not yet been identified. Furthermore, it remains to be determined whether the host would be best served by preventing osteoblast cell death or by promoting apoptosis in infected cells.

Osteoarticular involvement in sickle cell disease

The osteoarticular involvement in sickle cell disease has been poorly studied and it is mainly characterized by osteonecrosis, osteomyelitis and arthritis. The most frequent complications and those that require hospital care in sickle cell disease patients are painful vaso-occlusive crises and osteomyelitis. The deoxygenation and polymerization of hemoglobin S, which results in sickling and vascular occlusion, occur more often in tissues with low blood flow, such as in the bones. Bone microcirculation is a common place for erythrocyte sickling, which leads to thrombosis, infarct and necrosis. The pathogenesis of microvascular occlusion, the key event in painful crises, is complex and involves activation of leukocytes, platelets and endothelial cells, as well as hemoglobin S-containing red blood cells. Osteonecrosis is a frequent complication in sickle cell disease, with a painful and debilitating pattern. It is generally insidious and progressive, affecting mainly the hips (femur head) and shoulders (humeral head). Dactylitis, also known as hand-foot syndrome, is an acute vaso-occlusive complication characterized by pain and edema in both hands and feet, frequently with increased local temperature and erythema. Osteomyelitis is the most common form of joint infection in sickle cell disease. The occurrence of connective tissue diseases, including rheumatoid arthritis and systemic lupus erythematosus, has rarely been reported in patients with sickle cell disease. The treatment of these complications is mainly symptomatic, and more detailed studies are required to understand the pathophysiological mechanisms involved in the complications and propose more adequate and specific therapies.

Beyond the definitions of the phenotypic complications of sickle cell disease: an update on management

The sickle hemoglobin is an abnormal hemoglobin due to point mutation (GAG → GTG) in exon 1 of the β globin gene resulting in the substitution of glutamic acid by valine at position 6 of the β globin polypeptide chain. Although the molecular lesion is a single-point mutation, the sickle gene is pleiotropic in nature causing multiple phenotypic expressions that constitute the various complications of sickle cell disease in general and sickle cell anemia in particular. The disease itself is chronic in nature but many of its complications are acute such as the recurrent acute painful crises (its hallmark), acute chest syndrome, and priapism. These complications vary considerably among patients, in the same patient with time, among countries and with age and sex. To date, there is no well-established consensus among providers on the management of the complications of sickle cell disease due in part to lack of evidence and in part to differences in the experience of providers. It is the aim of this paper to review available current approaches to manage the major complications of sickle cell disease. We hope that this will establish another preliminary forum among providers that may eventually lead the way to better outcomes.

Tuberculous spondylodiscitis in a patient with a sickle-cell disease: CT findings

Background:

Although sickle-cell anemia (SCA) is common in black Americans, Sub-Saharan Africa and in the Mediterranean area, the disease is rare in the temperate climate zone. The manifestations of the disease are related mainly to the production of abnormal hemoglobin that leads to organ ischemia and increased susceptibility to infection caused by functional asplenia.

Case Report:

The authors present CT findings in a 39-year-old black woman diagnosed due to abdominal pain, lymphadenopathy and fever. CT of the thorax and abdomen demonstrated changes in the liver, spleen, and skeletal system suggestive of SCA complicated with spondylodiscitis in the thoracic spine.

Discussion:

Hepatomegaly and small calcified spleen are typical findings in older homozygotic patients with SCA. The lesions in the skeleton may be related either to intramedullary hematopoiesis or osteonecrosis and osteomyelitis. In the latter case, diffuse osteosclerosis and H-shaped vertebrae are most typical. Tuberculous spondylodiscitis is characterized by the location in the thoracic region, preferential involvement of anterior elements, relative sparing of intervertebral discs, and cold abscesses.

Post-splenectomy and hyposplenic states

The spleen is crucial in regulating immune homoeostasis through its ability to link innate and adaptive immunity and in protecting against infections. The impairment of splenic function is defined as hyposplenism, an acquired disorder caused by several haematological and immunological diseases. The term asplenia refers to the absence of the spleen, a condition that is rarely congenital and mostly post-surgical. Although hyposplenism and asplenia might predispose individuals to thromboembolic events, in this Review we focus on infectious complications, which are the most widely recognised consequences of these states. Because of the high mortality, the fulminant course, and the refractoriness to common treatment of overwhelming infections caused by encapsulated bacteria, prevention through vaccination and antibiotic prophylaxis is the basis of the management of patients who have had splenectomy or have hyposplenism. In this Review, we critically assess clinical and diagnostic aspects of splenic dysfunction and highlight new perspectives in the prevention of overwhelming post-splenectomy infections.

Community-acquired Salmonella bacteraemia in patients with sickle-cell disease 1969-2008: a single centre study

We document the aetiology of community-acquired bacteraemia in sickle-cell disease (SCD) patients and present clinical aspects of 11 cases of Salmonella bacteraemia. Prospective computerized records of all significant bacteraemic episodes presenting to our institution from 1969 to 2008 were analysed. Additional clinical information was drawn from hospital medical records. Six thousand three hundred and sixty-nine community-acquired bacteraemic episodes were documented, with 66 occurring in SCD patients. Salmonella species were the third most frequently isolated organism in SCD patients; 18% of bacteraemias in SCD patients were caused by Salmonella species vs 3% in non-SCD patients (p < 0.0001). Moreover, the proportion of community-acquired Salmonella bacteraemic episodes caused by non-Typhi species was significantly higher in SCD compared to other patients (p = 0.0015). Focal infection was identified in 7 of the 11 cases of Salmonella bacteraemia in SCD patients, with bone and joint accounting for 6 of these. Infection may have been acquired during travel to the tropics in 4 patients. Our study supports the view that SCD patients are particularly susceptible to Salmonella infection. These infections frequently require multiple surgical interventions and prolonged hospital stays. SCD patients should be advised to pay particular attention to food hygiene while travelling to the tropics.

[Juvenile arthritides]

Arthritis in children represents a diagnostic and therapeutic challenge. The diagnostic spectrum is broad and a very precise indication for diagnostic and therapeutic procedures, especially in small children, is important. In addition to acute arthritides - viral arthritis, reactive arthritis, Lyme arthritis and septic arthritis - secondary chronic arthritis related to an underlying disease as well as juvenile idiopathic arthritis (JIA), the most common chronic inflammatory systemic disease in children, need to be considered. This overview is a guide to the diagnosis of arthritis in childhood and to evidence-based therapy of JIA in particular. This consists of a combination of nonsteroidal anti-inflammatory drugs, systemic and intraarticular corticosteroids, traditional DMARDs such as sulfasalazine, methotrexate and leflunomide, the TNF inhibitors etanercept, adalimumab and, with restrictions, infliximab, other biopharmaceuticals such as anakinra, canakinumab and rilonacept, and tocilizumab and finally, abatacept.

Salmonella enterica enteritidis arthritis following trauma in a child with thalassemia major

Osteoarticular infections caused by Non-typhi Salmonella are exceptionally encountered. We report a case of a bacteriologically documented knee joint infection due to Salmonella enterica serotype enteritidis, following trauma in a child with thalassemia major. Emergency arthrotomy combined with antimicrobial therapy was helpful in eradication of infection. Physicians should be aware of this rare manifestation of Non-typhi Salmonella infections in thalassemic patients.

Septic arthritis in adults with sickle cell disease often is associated with osteomyelitis or osteonecrosis

BACKGROUND

Septic arthritis is a known complication of sickle cell disease (SCD) in children, and the association with osteomyelitis and osteonecrosis has been described. However, it is unclear whether this association applies to adults.

QUESTIONS/PURPOSES

We therefore asked whether septic arthritis is a frequent complication in adults with SCD and whether it also is associated with osteomyelitis or osteonecrosis.

METHODS

We retrospectively reviewed the charts of 2000 consecutive adult patients diagnosed with SCD and recorded symptoms, select findings during physical examination, laboratory data, and select radiographic CT, and MRI observations.

RESULTS

Fifty-nine of the 2000 patients (3%) had septic arthritis, 56 of the 59 patients had hemoglobin SS. Thirty-six of the 59 infections (61%) were in the hip. The most frequent findings were pain, swelling, fever greater than 38.2 degrees C (71% of cases), a leukocyte count exceeding 15,000/mm(3) (range, 7900-32,300/mm(3)), a Westergren sedimentation rate greater than 24 mm/hour, and C-reactive protein exceeding 20 mg/L. Cultures were positive in 96% of the joint aspirates. Staphylococcus and Gram-negative infection predominated; no patients had Salmonella joint infections. Preexisting factors of bacterial arthritis included osteonecrosis (29 patients) and osteomyelitis (37 cases) in childhood. Diabetes, rheumatoid arthritis, glucocorticoids, and immunoparesis related to medical treatment by hydroxyurea were associated comorbidities. CT and MRI confirmed the diagnosis of associated osteonecrosis or osteomyelitis and allowed joint aspiration and detection of soft tissue abscess.

CONCLUSIONS

The incidence of septic arthritis in adults with SCD is low, but often is associated with osteomyelitis or osteonecrosis.

LEVEL OF EVIDENCE

Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Osteoblasts express NLRP3, a nucleotide-binding domain and leucine-rich repeat region containing receptor implicated in bacterially induced cell death

Bacterially induced osteoblast apoptosis may be a major contributor to bone loss during osteomyelitis. We provide evidence for the functional expression in osteoblasts of NLRP3, a member of the NLR family of cytosolic receptors that has been implicated in the initiation of programmed cell death.

INTRODUCTION

Osteoblasts undergo apoptosis after exposure to intracellular bacterial pathogens commonly associated with osteomyelitis. Death of this bone-forming cell type, in conjunction with increased numbers and activity of osteoclasts, may underlie the destruction of bone tissue at sites of bacterial infection. To date, the mechanisms responsible for bacterially induced apoptotic osteoblast cell death have not been resolved.

MATERIALS AND METHODS

We used flow cytometric techniques to determine whether intracellular invasion is needed for maximal apoptotic cell death in primary osteoblasts after challenge with Salmonella enterica. In addition, we used real-time PCR and immunoblot analyses to assess osteoblast expression of members of the nucleotide-binding domain leucine-rich repeat region-containing family of intracellular receptors (NLRs) that have been predicted to be involved in the induction of programmed cell death. Furthermore, we have used co-immunoprecipitation and siRNA techniques to confirm the functionality of such sensors in this cell type.

RESULTS

In this study, we showed that invasion of osteoblasts by Salmonella is necessary for maximal induction of apoptosis. We showed that murine and human osteoblasts express NLRP3 (previously known as CIAS1, cryopyrin, PYPAF1, or NALP3) but not NLRC4 (IPAF) and showed that the level of expression of this cytosolic receptor is modulated after bacterial challenge. We showed that osteoblasts express ASC, an adaptor molecule for NLRP3, and that these molecules associate after Salmonella infection. In addition, we showed that a reduction in the expression of NLRP3 attenuates Salmonella-induced reductions in the activity of an anti-apoptotic transcription factor in osteoblasts. Furthermore, we showed that NLRP3 expression is needed for caspase-1 activation and maximal induction of apoptosis in osteoblasts after infection with Salmonella.

CONCLUSIONS

The functional expression of NLRP3 in osteoblasts provides a potential mechanism underlying apoptotic cell death of this cell type after challenge with intracellular bacterial pathogens and may be a significant contributory factor to bone loss at sites of infection.

Musculoskeletal Manifestations of Sickle Cell Disease

Sickle cell disease results from the presence of abnormal beta globin chains within hemoglobin and may be manifested in anemia, vaso-occlusion, and superimposed infection. The gene that causes sickle cell disease is particularly prevalent in populations of African origin; approximately 8% of African Americans and 40% of the members of some African tribes carry the gene for hemoglobin S. Over time, the disease produces various musculoskeletal abnormalities as a result of chronic anemia; these include marrow hyperplasia, reversion of yellow marrow to red marrow, and, occasionally, extramedullary hematopoiesis. Familiarity with the imaging features of sickle cell disease is important for the diagnosis and management of complications. Ischemia and infarction are common complications that may have long-term effects on the growth of bone; these conditions have characteristic radiographic appearances. Infection may be more difficult to identify. Both infection and infarction may occur in muscle and soft tissue alone, without involving bone. However, osteomyelitis must be diagnosed early and treated immediately to prevent bone destruction and deformity; therefore, care must be taken to achieve an accurate diagnosis by identifying or excluding bone involvement. The clinical and radiographic features of acute osteomyelitis may be particularly difficult to distinguish from those of bone infarction. In that context, magnetic resonance (MR) imaging may be useful. At MR imaging, findings of cortical defects, adjacent fluid collections in soft tissue, and bone marrow enhancement are suggestive of infection.

Septic arthritis in Western and sub-Saharan African children - a review

This article reviews what is known about the incidence, aetiology, presentation, bacteriology and management of septic arthritis in children. It compares where possible the different presentations and characteristics of this condition in the Western and sub-Saharan African regions.

Unusual sites of Salmonella osteoarthritis in patients with sickle cell disease: two cases

Salmonella osteoarticular infections involve mainly long bones such as the femur, tibia, and humerus in patients with sickle cell disease (SCD). We report here two unusual cases of Salmonella osteoarthritis affecting sacroiliac and sternoclavicular joints in two patients with SCD, one patient also being followed for rheumatoid arthritis. Because of misleading presentation, diagnosis of septic osteoarthritis in patients with SCD requires a high index of suspicion and an early treatment.

Osteoblast responses to bacterial pathogens: a previously unappreciated role for bone-forming cells in host defense and disease progression

Although the primary roles of osteoblasts are to synthesize the components of bone matrix and to regulate the activity of bone resorbing osteoclasts, there is growing realization that osteoblasts have an additional function during bone diseases, such as osteomyelitis. Based on our recent studies, we propose a novel role for osteoblasts during bacterial infections of bone, namely, the initiation and maintenance of inflammatory immune responses. In this article, we describe how these nonleukocytic cells can perceive bacterial pathogens of bone to initiate the production of an array of immune regulatory molecules. This pattern of expression is one that could promote the recruitment of leukocytes to sites of bacterial challenge, initiate antigen-specific activation of infiltrating cells, and facilitate the development of cell-mediated host responses to intracellular pathogens of bone tissue, thereby identifying this cell type as a previously unappreciated component in host responses.

[Scintigraphic findings in a patient with sickle-cell thalassemia and recurrent pain attacks]

The case of an eight years old African boy who suffers from sickle cell-thalassemia is presented. In the course of the disease frequent pain attacks occurred within the abdomen and extremities, recently also within the trunk. Local pain, at some occasions in combination with local swelling and always positive laboratory parameters for inflammation, hindered a solely clinical differentiation between bone infarcts and osteomyelitis. Bone scintigraphy, eventually in combination with bone marrow scintigraphy, can assist the clinician in the differentiation of aseptic bone infarcts versus secondary osteomyelitis. Based on the presented case scintigraphic results for bone infarcts, osteomyelitis and special scintigraphic pattern seen in sickle cell disease are presented. Furthermore, problems regarding the interpretation of the scintigraphies in relation to the delayed time after the beginning of pain attacks are discussed.

Anaesthetic management of the child with sickle cell disease

Sickle cell disease (SCD) is a relatively common inherited disorder of haemoglobin with significant morbidity and mortality. This review describes the epidemiology and pathophysiology of the disease, and discusses the clinical manifestations found in children with SCD. A discussion of the evidence concerning the perioperative management of such children is presented.

Bacterium-induced CXCL10 secretion by osteoblasts can be mediated in part through toll-like receptor 4

Two common pathogens known to cause bone infection, Salmonella and Staphylococcus aureus, were investigated to determine their abilities to induce chemokine expression in cultured mouse and human osteoblasts. While these cells are responsible for bone formation, we were surprised to find that they could respond to bacterial infection by upregulating expression of the chemokine CXCL10 (IP-10). However, there were significant differences in the abilities of the gram-negative bacterium Salmonella and the gram-positive bacterium S. aureus to induce expression of CXCL10. Reverse transcription-PCR and enzyme-linked immunosorbent assay analyses showed high levels of Salmonella-induced CXCL10 mRNA and protein expression, respectively, whereas the osteoblast response to S. aureus was significantly less. Consistent with these findings, Salmonella-derived lipopolysaccharide (LPS), but not S. aureus-derived peptidoglycan, could induce expression of CXCL10. An antibody against toll-like receptor 4 (TLR4) could block the LPS-induced CXCL10 production, demonstrating the functional expression of TLR4 by osteoblasts. Despite the inducible nature of TLR2 mRNA expression by bacterium-infected osteoblasts, peptidoglycan failed to stimulate CXCL10 secretion. Immunofluorescent staining of bacterium-infected calvaria (i.e., skull bone) demonstrated the presence of CXCL10 in osteoblasts. The fact that osteoblasts did not express CXCR3 mRNA, whereas T lymphocytes can express high levels of this receptor, suggests that osteoblast-derived CXCL10 may recruit T lymphocytes to the sites of bone infections.

Salmonella prosthetic joint septic arthritis

We describe a case of Salmonella enteritidis infection of a prosthetic knee joint that was cured with ceftriaxone therapy for 6 weeks and replacement of the tibial component of the prosthesis. Eleven other cases of salmonella prosthetic joint infection have been reported in the English-language literature. Five infections occurred within 20 days of prosthesis placement, and seven occurred several months to years later; ten of 12 infections involved hip prostheses. Nine of 12 patients who had prosthesis removal were cured of the infection. Two of the three patients with retention of the prosthesis required long-term suppressive antibiotic therapy.