Andrew Fuller

Treatment Outcomes for Serious Infections Caused by Methicillin-Resistant Staphylococcus aureus with Reduced Vancomycin Susceptibility

Although infections caused by methicillin-resistant Staphylococcus aureus with reduced vancomycin susceptibility (SA-RVS) have been reported from a number of countries, including Australia, the optimal therapy is unknown. We reviewed the clinical features, therapy, and outcome of 25 patients with serious infections due to SA-RVS in Australia and New Zealand. Eight patients had endocarditis, 9 had bacteremia associated with deep-seated infection, 6 had osteomyelitis or septic arthritis, and 2 had empyema. All patients had received vancomycin before the isolation of SA-RVS, and glycopeptide treatment had failed for 19 patients (76%). Twenty-one patients subsequently received active treatment, which was effective for 16 patients (76%). Eighteen patients received linezolid, which was effective in 14 (78%), including 4 patients with endocarditis. Twelve patients received a combination of rifampicin and fusidic acid. Surgical intervention was required for 15 patients (60%). Antibiotic therapy, especially linezolid with or without rifampicin and fusidic acid, in conjunction with surgical debulking is effective therapy for the majority of patients with serious infections (including endocarditis) caused by SA-RVS.

SMART-COP: A Tool for Predicting the Need for Intensive Respiratory or Vasopressor Support in Community-Acquired Pneumonia

BACKGROUND Existing severity assessment tools, such as the pneumonia severity index (PSI) and CURB-65 (tool based on confusion, urea level, respiratory rate, blood pressure, and age >or=65 years), predict 30-day mortality in community-acquired pneumonia (CAP) and have limited ability to predict which patients will require intensive respiratory or vasopressor support (IRVS). METHODS The Australian CAP Study (ACAPS) was a prospective study of 882 episodes in which each patient had a detailed assessment of severity features, etiology, and treatment outcomes. Multivariate logistic regression was performed to identify features at initial assessment that were associated with receipt of IRVS. These results were converted into a simple points-based severity tool that was validated in 5 external databases, totaling 7464 patients. RESULTS In ACAPS, 10.3% of patients received IRVS, and the 30-day mortality rate was 5.7%. The features statistically significantly associated with receipt of IRVS were low systolic blood pressure (2 points), multilobar chest radiography involvement (1 point), low albumin level (1 point), high respiratory rate (1 point), tachycardia (1 point), confusion (1 point), poor oxygenation (2 points), and low arterial pH (2 points): SMART-COP. A SMART-COP score of >or=3 points identified 92% of patients who received IRVS, including 84% of patients who did not need immediate admission to the intensive care unit. Accuracy was also high in the 5 validation databases. Sensitivities of PSI and CURB-65 for identifying the need for IRVS were 74% and 39%, respectively. CONCLUSIONS SMART-COP is a simple, practical clinical tool for accurately predicting the need for IRVS that is likely to assist clinicians in determining CAP severity.

The Etiology of Community-Acquired Pneumonia in Australia: Why Penicillin plus Doxycycline or a Macrolide Is the Most Appropriate Therapy

BACKGROUND Available data on the etiology of community-acquired pneumonia (CAP) in Australia are very limited. Local treatment guidelines promote the use of combination therapy with agents such as penicillin or amoxycillin combined with either doxycycline or a macrolide. METHODS The Australian CAP Study (ACAPS) was a prospective, multicenter study of 885 episodes of CAP in which all patients underwent detailed assessment for bacterial and viral pathogens (cultures, urinary antigen testing, serological methods, and polymerase chain reaction). Antibiotic agents and relevant clinical outcomes were recorded. RESULTS The etiology was identified in 404 (45.6%) of 885 episodes, with the most frequent causes being Streptococcus pneumoniae (14%), Mycoplasma pneumoniae (9%), and respiratory viruses (15%; influenza, picornavirus, respiratory syncytial virus, parainfluenza virus, and adenovirus). Antibiotic-resistant pathogens were rare: only 5.4% of patients had an infection for which therapy with penicillin plus doxycycline would potentially fail. Concordance with local antibiotic recommendations was high (82.4%), with the most commonly prescribed regimens being a penicillin plus either doxycycline or a macrolide (55.8%) or ceftriaxone plus either doxycycline or a macrolide (36.8%). The 30-day mortality rate was 5.6% (50 of 885 episodes), and mechanical ventilation or vasopressor support were required in 94 episodes (10.6%). Outcomes were not compromised by receipt of narrower-spectrum beta-lactams, and they did not differ on the basis of whether a pathogen was identified. CONCLUSIONS The vast majority of patients with CAP can be treated successfully with narrow-spectrum beta-lactam treatment, such as penicillin combined with doxycycline or a macrolide. Greater use of such therapy could potentially reduce the emergence of antibiotic resistance among common bacterial pathogens.

Isolation of a Novel Orientia Species ( O. chuto sp. nov.) from a Patient Infected in Dubai

ABSTRACT In July 2006, an Australian tourist returning from Dubai, in the United Arab Emirates (UAE), developed acute scrub typhus. Her signs and symptoms included fever, myalgia, headache, rash, and eschar. Orientia tsutsugamushi serology demonstrated a 4-fold rise in antibody titers in paired serum collections (1:512 to 1:8,192), with the sera reacting strongest against the Gilliam strain antigen. An Orientia species was isolated by the in vitro culture of the patients acute blood taken prior to antibiotic treatment. The gene sequencing of the 16S rRNA gene (rrs), partial 56-kDa gene, and the full open reading frame 47-kDa gene was performed, and comparisons of this new Orientia sp. isolate to previously characterized strains demonstrated significant sequence diversity. The closest homology to the rrs sequence of the new Orientia sp. isolate was with three strains of O. tsutsugamushi (Ikeda, Kato, and Karp), with a nucleotide sequence similarity of 98.5%. The closest homology to the 47-kDa gene sequence was with O. tsutsugamushi strain Gilliam, with a nucleotide similarity of 82.3%, while the closest homology to the 56-kDa gene sequence was with O. tsutsugamushi strain TA686, with a nucleotide similarity of 53.1%. The molecular divergence and geographically unique origin lead us to believe that this organism should be considered a novel species. Therefore, we have proposed the name “Orientia chuto,” and the prototype strain of this species is strain Dubai, named after the location in which the patient was infected.

Tuberculous Pancreatic Abscess in an HIV Antibody-negative Patient: Case Report and Review

Tuberculosis (TB) is most commonly diagnosed as a pulmonary disease; however, haematogenous spread of the organism can cause disease in any organ system. We report the case of a 30-y-old woman, Human Immunodeficiency Virus (HIV) antibody-negative, who was diagnosed as having a pancreatic mass on computed tomographic (CT) scans. She underwent a laparotomy and the fluid drained from the mass was culture-positive for Mycobacterium tuberculosis. We review the clinical details of 37 similar cases of pancreatic TB in the literature, where each patients HIV antibody status is negative or unknown. In this series 3 patients died (1 of these had commenced anti-TB therapy, the others had not) but the remaining 34 responded well to radiological-guided drainage and/or surgical intervention and anti-TB therapy. TB should be considered in the differential diagnosis of a pancreatic mass, especially when associated with epigastric pain or discomfort and weight loss.

Balamuthia mandrillaris brain abscess successfully treated with complete surgical excision and prolonged combination antimicrobial therapy

Amoebic encephalitis is an uncommon and usually fatal condition. This case describes successful treatment of a Balamuthia mandrillaris brain abscess using prolonged antimicrobial agents with complete excision. It illustrates the risk of dissemination from cutaneous to cerebral amoebic lesions, potential progression with corticosteroid therapy, and the prospect for curative excision.

Parvovirus B19 in HIV infection: A treatable cause of anemia

&NA; We describe the case of an adult male patient with AIDS who presented with severe anemia and on investigation was found to have red cell aplasia due to parvovirus B19 infection. Bone marrow examination revealed absence of erythroid development and rare giant pronormoblasts. Repeated serological examinations revealed a low level of parvovirus IgM but no IgG. Viremia was demonstrated by electron microscopy and by the polymerase chain reaction (PCR). The patients initial hemoglobin was 45 g/l and over a four month period he required twenty units of blood. He was treated with intravenous immunoglobulin (Intragam, CSL) at a dose of 400 mg/kg/day for five days. This led to an increase in this hemoglobin to 135 g/l. Parvovirus remained detectable by PCR but not by electron microscopy. Six months later the patient relapsed (Hb 65 g/l). Again he was transfused and treated with intravenous immunoglobulin for five days. His hemoglobin rose to 153 g/l and remained stable. He subsequently received maintenance treatment with 30 g of intagram once a month. We recommend that parvovirus be considered in any HIV infected patient with recurrent anemia.

FatalLegionella longbeachae infection following heart transplantation

A case of fatalLegionella longbeachae infection following heart transplantation is described. Gram stains of respiratory secretions on day 17 posttransplant revealed leucocytes and gram-negative bacilli, but there was no growth on routine bacterial culture.Legionella longbeachae serogroup 1 was isolated from respiratory specimens, blood, and postmortem lung tissue.Legionella longbeachae is a common cause of legionellosis in Australia, and infection has been associated with exposure to potting mixes. Specific culture forLegionella spp. should be performed for any patient who develops pneumonia following organ transplantation.

Bilateral conjunctivitis in a returned traveller.

A 30-year-old female presented to a tertiary hospital with two weeks of fevers and left upper quadrant abdominal pain after returning from the Gili Islands, Indonesia. She was immunised against hepatitis B, hepatitis A, and typhoid. She did not take malaria prophylaxis and recalls being bitten by insects. Laboratory investigations revealed an elevated C-reactive protein level (158 mg/L), mild thrombocytopenia (148 10̂9/L), and deranged liver functions tests. Her malaria smear and blood and urine cultures were negative. Serology for dengue fever, chikungunya, human immunodeficiency virus, hepatitis B, hepatitis C, hepatitis A, leptospirosis, and rickettsia were sent. Two days into the admission, she subsequently developed significant bilateral conjunctivitis and was reviewed by the ophthalmology unit (Fig. 1). Ophthalmoscopy revealed a small, pale, inactive spot on the retina. The lens, macula, and retina otherwise appeared normal. Without antibiotic treatment, the patient’s fevers and abdominal pain resolved, although the conjunctivitis worsened (Fig. 1). The patient in this manuscript has given written informed consent to publication of her case details.