Bacterial endocarditis presenting as acute monoarthritis

Rare manifestations of infective endocarditis: the long known, never to be forgotten diagnosis

Infective endocarditis (IE) is a life-threatening condition often manifesting as a multisystem disease; its heterogeneous features present a diagnostic challenge. We report two cases of IE masquerading as rare extracardiac complications: a splenectomised patient with a periarticular ankle abscess and acute encephalopathy; and a young man with a cutaneous vasculitis following a spontaneous intracerebral haemorrhage. In both cases, the diagnosis was suspected following detection of afebrile bacteraemia and confirmed with echocardiography. Risk factors included a pneumococcal bacteraemia in the asplenic patient and a previously undiagnosed bicuspid aortic valve in the second patient. Both patients recovered well with appropriate antibiotic therapy followed by valve surgery. IE is an important diagnosis to consider in patients with systemic symptoms or organ specific, otherwise unexplained relevant pathology especially in the presence of a cardiac murmur or risk factors for IE including structural heart disease, prosthetic valves or intravascular devices, and in immunosuppressed patients.

Streptococcus suis, an important pig pathogen and emerging zoonotic agent-an update on the worldwide distribution based on serotyping and sequence typing

Streptococcus suis is an important pathogen causing economic problems in the pig industry. Moreover, it is a zoonotic agent causing severe infections to people in close contact with infected pigs or pork-derived products. Although considered sporadic in the past, human S. suis infections have been reported during the last 45 years, with two large outbreaks recorded in China. In fact, the number of reported human cases has significantly increased in recent years. In this review, we present the worldwide distribution of serotypes and sequence types (STs), as determined by multilocus sequence typing, for pigs (between 2002 and 2013) and humans (between 1968 and 2013). The methods employed for S. suis identification and typing, the current epidemiological knowledge regarding serotypes and STs and the zoonotic potential of S. suis are discussed. Increased awareness of S. suis in both human and veterinary diagnostic laboratories and further establishment of typing methods will contribute to our knowledge of this pathogen, especially in regions where complete and/or recent data is lacking. More research is required to understand differences in virulence that occur among S. suis strains and if these differences can be associated with specific serotypes or STs.

Streptococcus suis causes septic arthritis and bacteremia: phenotypic characterization and molecular confirmation

Streptococcus suis is a swine pathogen that causes meningitis, septicemia, pneumonia, and endocarditis. The first case of human S. suis infection was reported in Denmark in 1968, and since then, this infection with has been reported in many countries, especially in Southeast Asia because of the high density of pigs in this region. We report the case of a patient with septic arthritis and bacteremia caused by S. suis. Cases in which S. suis is isolated from the joint fluid are very rare, and to the best of our knowledge, this is first case report of S. suis infection in Korea. The identity of this organism was confirmed by phenotypic characterization and 16S rRNA sequence analysis. An 81-yr-old Korean woman who presented with fever, arthralgia, and headache was admitted to a secondary referral center in Korea. Culture of aspirated joint fluid and blood samples showed the growth of S. suis biotype II, which was identified by the Vitek2 GPI and API 20 Strep systems (bioMérieux, USA), and this organism was susceptible to penicillin G and vancomycin. The 16S rRNA sequences of the blood culture isolates showed 99% homology with those of S. suis subsp. suis, which are reported in GenBank. The patient's fever subsided, and blood and joint cultures were negative for bacterial growth after antibiotic therapy; however, the swelling and pain in her left knee joint persisted. She plans to undergo total knee replacement.

Streptococcus suis: an emerging zoonotic pathogen

Streptococcus suis is a major porcine pathogen worldwide, and can be transmitted to human beings by close contact with sick or carrier pigs. S suis causes meningitis, septicaemia, endocarditis, arthritis, and septic shock in both pigs and human beings, and mortality is high. Human infection with S suis occurs mainly among certain risk groups that have frequent exposure to pigs or pork. Outbreaks of human S suis infection are uncommon, although several outbreaks have occurred in China in recent years. In July, 2005, the largest outbreak of human S suis infection occurred in Sichuan province, China, where 204 people were infected and 38 of them died. There have been 409 cases of human S suis infection worldwide, most of which have occurred in China, Thailand, and the Netherlands, and these infections have led to 73 deaths. This review provides background information on the biology and molecular characteristics of this Gram-positive bacterium, and describes the clinical signs, pathology, epidemiology, diagnosis, and treatment of human infection with S suis.

Streptococcus suis infection: a series of 41 cases from Chiang Mai University Hospital

OBJECTIVES

The objectives of this study were (1) to assess the clinical manifestations, treatment, and outcome of Streptococcus suis infection in adult patients in northern Thailand, (2) to evaluate the anti-microbial sensitivity pattern and (3) to determine the predicting factors of high mortality rate.

METHODS

A retrospective study was conducted at Chiang Mai University Hospital from May 2000 to December 2002. Anti-microbial susceptibility test was performed by agar disk diffusion and the minimal inhibitory concentration (MIC) by E-test.

RESULTS

Forty-one patients (32 men and nine women, mean age 51 years) with S. suis infection were identified. Three patients had a history of exposure to pig or pork and one patient had a history of raw beef consumption. Clinical manifestations included infective endocarditis, meningitis, sepsis, spondylodiscitis, and endophthalmitis in 16, 13, 10, 1, and 1 patients, respectively. The overall mortality rate was 19.5%. On univariate analysis, low serum albumin, high serum total bilirubin, low platelet, and rapid onset of illness were significantly correlated with high mortality rate. All isolates were sensitive to penicillin (mean MIC90=0.027 microg/ml).

CONCLUSIONS

S. suis infection is not uncommon in northern Thailand. High suspicion and early detection are important and could lead to the successful treatment.

Streptococcal septic arthritis in adults. A study of 55 cases with a literature review

OBJECTIVES

To evaluate the rate of occurrence and characteristics of streptococcal septic arthritis.

METHODS

Retrospective single-center study of patients with bacteriologically documented septic arthritis admitted to a rheumatology department over a 20-year period.

RESULTS

Of 303 cases of septic arthritis, 55 (18%) were due to streptococci and 166 (55%) to Staphylococcus aureus (55%). As compared to patients with S. aureus arthritis, patients with streptococcal arthritis was more likely to be in female (56% vs. 36%, P < 0.006) and older than 60 years of age (71% vs. 58%), less likely to have comorbidities (36% vs. 56%), rheumatoid arthritis (5% vs. 19%, P < 0.01), or diabetes (2% vs. 15%, P < 0.01), and more likely to have cancer (13% vs. 7%). Involved joints and proportions of patients with arthritis in multiple joints were similar in two groups. Mortality was lower in the group with streptococcal infection (3.6% vs. 7.8%). The streptococci were distributed as follows: group A (n = 7), group B (n = 12), group C (n = 4), group D (n = 7), group F (n = 1), group G (n = 2), nongroupable (n = 14), nontypable (n = 1), and Streptococcus pneumoniae (n = 7). Groups A and B and nongroupable strains mainly affected women; group A selectively involved younger patients and group B very elderly patients. Comorbidity, most notably cancer, was common in patients with S. pneumoniae or group D streptococci. The portal of entry was often a skin lesion for groups A and B and a medical procedure for group D. Multiple joint involvement was common with groups A and B and prosthetic joint infection with groups B and C. Group A and S. pneumoniae were associated with severe systemic symptoms and extra articular foci of infection, whereas a smoldering course was more common with groups D and G and with nongroupable strains. Residual joint abnormalities were noted in half the patients, with no differences across groups.

CONCLUSIONS

The features of streptococcal septic arthritis vary according to the group of the causative organism and differ from those of S. aureus arthritis.

Osteoarticular infection complicating enterococcal endocarditis

Despite the common occurrence of musculoskeletal complaints in patients with infective endocarditis, infectious osteoarticular complications are diagnosed infrequently. Moreover, although enterococcal infection is the third most common cause of infective endocarditis, infectious osteoarticular complications are rare. We report a case of disk space infection in a patient with enterococcal endocarditis. Blood cultures and an L3-4 aspirate grew Enterococcus faecalis, and transthoracic echocardiography revealed a large vegetation on the posterior mitral valve leaflet. The osteoarticular infection resolved with antimicrobial treatment, but worsening heart failure necessitated valve replacement surgery. The patient had an uneventful recovery with no evidence of recurrence or complications. A review of the medical literature from 1966 through 1998 identified 13 additional cases, only 8 of which provided clinical and treatment data. We present the clinical and laboratory findings reported in these cases, along with data from our patient. This report highlights the rare occurrence of osteoarticular infection in the setting of enterococcal endocarditis and emphasizes early recognition and treatment.

Assessment, investigation, and management of acute monoarthritis

Trauma is the commonest cause of acute monoarticular joint pain and swelling in patients attending an accident and emergency (A&E) department. However, in a significant minority of patients there will be no history of trauma and consequently a different approach to assessment and investigation is required. Our aim is to offer an outline of how to assess, investigate, and manage a patient with monoarthritis. Despite advances in antibiotic treatment diagnostic delay partly explains why septic arthritis is still associated with considerable morbidity and mortality. It is therefore imperative that joint infection is considered above all other diagnoses. Arthrocentesis is a relatively safe procedure and doctors in A&E medicine are encouraged to develop the skills required to aspirate large joints. In the same way that the A&E department is often portrayed as the shop window of a hospital, the joint can reflect a wide variety of internal diseases. Connective tissue disease, inflammatory bowel disease, sarcoidosis, and vasculitis can all present with a monoarthritis. A non-specific reactive monoarthritis may be a feature of a wide variety of common and uncommon infections including, brucellosis, Lyme disease, and leptospirosis. Drugs are also associated with acute arthritis either through their metabolic consequences or as idiosyncratic drug reactions. The ability for the joint to reflect multisystem disease necessitates close liaison with specialists from other fields. A multidisciplinary approach to the management of these patients is strongly encouraged as some will have unusual diseases that require specialist advice. It is not difficult to appreciate how the patient with monoarthritis can present the clinician with a fascinating diagnostic and therapeutic challenge, which we hope this article will help to unravel.

Arthritis and meningitis--the first manifestations of bacterial endocarditis in 2 patients

We have encountered 2 patients in whom the first manifestations of bacterial endocarditis were arthritis (in 1 case septic arthritis and in the other nonseptic arthritis) and bacterial meningitis. These presentations were followed by acute heart failure due to aortic valve destruction, although the patients showed no significant cardiovascular manifestations on admission. Aortic valve replacement was performed in each case and the patients' postoperative course was comfortable. We would like to emphasize the following points. (1) Arthritis and meningitis are uncommon in patients with bacterial endocarditis. However, it is necessary to consider the possibility of bacterial endocarditis when these clinical manifestations present together. Such a combination can cause rapid valve destruction. When more than 2 rare complications of bacterial endocarditis coexist, surgery should be considered as soon as the definite diagnosis of bacterial endocarditis is established, even if congestive heart failure has not yet developed. (2) Arthritis associated with bacterial endocarditis might be truly septic rather than mediated by circulating immune complexes as is commonly believed.