Incidence, clinical spectrum, diagnostic features, treatment and predictors of paradoxical reactions during antibiotic treatment of Mycobacterium ulcerans infections

Background: Paradoxical reactions from antibiotic treatment of Mycobacterium ulcerans have recently been recognized. Data is lacking regarding their incidence, clinical and diagnostic features, treatment, outcomes and risk factors in an Australian population.

Methods: Data was collected prospectively on all confirmed cases of M. ulcerans infection managed at Barwon Health Services, Australia, from 1/1/1998-31/12/2011. Paradoxical reactions were defined on clinical and histological criteria and cases were determined by retrospectively reviewing the clinical history and histology of excised lesions. A Poisson regression model was used to examine associations with paradoxical reactions.

Results: Thirty-two of 156 (21%) patients developed paradoxical reactions a median 39 days (IQR 20-73 days) from antibiotic initiation. Forty-two paradoxical episodes occurred with 26 (81%) patients experiencing one and 6 (19%) multiple episodes. Thirty-two (76%) episodes occurred during antibiotic treatment and 10 (24%) episodes occurred a median 37 days after antibiotic treatment. The reaction site involved the original lesion (wound) in 23 (55%), was separate to but within 3 cm of the original lesion (local) in 11 (26%) and was more than 3 cm from the original lesion (distant) in 8 (19%) episodes. Mycobacterial cultures were negative in 33/33 (100%) paradoxical episodes. Post-February 2009 treatment involved more cases with no antibiotic modifications (12/15 compared with 11/27, OR 5.82, 95% CI 1.12-34.07, p = 0.02) and no further surgery (9/15 compared with 2/27, OR 18.75, 95% CI 2.62-172.73, p < 0.001). Six severe cases received prednisone with marked clinical improvement. On multivariable analysis, age ≥ 60 years (RR 2.84, 95% CI 1.12-7.17, p = 0.03), an oedematous lesion (RR 3.44, 95% CI 1.11-10.70, p=0.03) and use of amikacin in the initial antibiotic regimen (RR 6.33, 95% CI 2.09-19.18, p < 0.01) were associated with an increased incidence of paradoxical reactions.

Conclusions: Paradoxical reactions occur frequently during or after antibiotic treatment of M. ulcerans infections in an Australian population and may be increased in older adults, oedematous disease forms, and in those treated with amikacin. Recognition of paradoxical reactions led to changes in management with less surgery, fewer antibiotic modifications and use of prednisolone for severe reactions.

FRAX provides robust fracture prediction regardless of socioeconomic status

The authors investigated the fracture risk assessment tool (FRAX) Canada calibration and discrimination according to income quintile in 51,327 Canadian women, with and without a competing mortality framework. The data shows that, under a competing mortality framework, FRAX provides robust fracture prediction and calibration regardless of socioeconomic status (SES).

Impact of HIV-associated conditions on mortality in people commencing anti-retroviral therapy in resource limited settings

Objectives: To identify associations between specific WHO stage 3 and 4 conditions diagnosed after ART initiation and all cause mortality for patients in resource-limited settings (RLS).

Design, Setting: Analysis of routine program data collected prospectively from 25 programs in eight countries between 2002 and 2010.

Subjects, Participants: 36,664 study participants with median ART follow-up of 1.26 years (IQR 0.55–2.27).

Outcome Measures: Using a proportional hazards model we identified factors associated with mortality, including the occurrence of specific WHO clinical stage 3 and 4 conditions during the 6-months following ART initiation.

Results: There were 2922 deaths during follow-up (8.0%). The crude mortality rate was 5.41 deaths per 100 person-years (95% CI: 5.21–5.61). The diagnosis of any WHO stage 3 or 4 condition during the first 6 months of ART was associated with
increased mortality (HR: 2.21; 95% CI: 1.97–2.47). After adjustment for age, sex, region and pre-ART CD4 count, a diagnosis of extrapulmonary cryptococcosis (aHR: 3.54; 95% CI: 2.74–4.56), HIV wasting syndrome (aHR: 2.92; 95%CI: 2.21 -3.85), nontuberculous mycobacterial infection (aHR: 2.43; 95% CI: 1.80–3.28) and Pneumocystis pneumonia (aHR: 2.17; 95% CI 1.80–3.28) were associated with the greatest increased mortality. Cerebral toxoplasmosis, pulmonary and extra-pulmonary
tuberculosis, Kaposi’s sarcoma and oral and oesophageal candidiasis were associated with increased mortality, though at lower rates.

Conclusions: A diagnosis of certain WHO stage 3 and 4 conditions is associated with an increased risk of mortality in those initiating ART in RLS. This information will assist initiatives to reduce excess mortality, including prioritization of resources for
diagnostics, therapeutic interventions and research.

Forgotten but not gone - Scrofuloderma in a migrant student from India

A 34-year-old Indian student who immigrated to Australia five years ago presented with a four-week history of neck pain. Physical examination revealed two firm fixed cervical lymph nodes in the anterior triangle and midline region which were tender on palpation and erythematous on inspection. Cording phenomenon was found on ZN staining of FNA sample and mycobacterium tuberculosis (M.tb) PCR confirmed the diagnosis with incomplete resistance to isoniazid. Patient was treated with other three first line antituberculosis medications for nine months with an excellent outcome. Prednisolone was also used as adjunctive therapy and tapered during the course of treatment.

A case of Kingella kingae endocarditis complicated by native mitral valve rupture

We report a case of Kingella kingae endocarditis in a patient with a history of recent respiratory tract infection and dental extraction. This case is remarkable for embolic and vasculitic phenomena in association with a large valve vegetation and valve perforation. Kingella kingae is an organism known to cause endocarditis, however early major complications are uncommon. Our case of Kingella endocarditis behaved in a virulent fashion necessitating a combined approach of intravenous antibiotic therapy and a valve replacement. It highlights the importance of expedited investigation for endocarditis in patients with Kingella bacteraemia.

Clinical features and risk factors of oedematous Mycobacterium ulcerans lesions in an Australian population: beware cellulitis in an endemic area

Introduction
Oedematous lesions are a less common but more severe form of Mycobacterium ulcerans disease. Misdiagnosis as bacterial cellulitis can lead to delays in treatment. We report the first comprehensive descriptions of the clinical features and risk factors of patients with oedematous disease from the Bellarine Peninsula of south-eastern Victoria, Australia.

Methods
Data on all confirmed Mycobacterium ulcerans cases managed at Barwon Health, Victoria, were collected from 1/1/1998–31/12/2012. A multivariate logistic regression model was used to assess associations with oedematous forms of Mycobacterium ulcerans disease.

Results
Seventeen of 238 (7%) patients had oedematous Mycobacterium ulcerans lesions. Their median age was 70 years (IQR 17–82 years) and 71% were male. Twenty-one percent of lesions were WHO category one, 35% category two and 41% category three. 16 (94%) patients were initially diagnosed with cellulitis and received a median 14 days (IQR 9–17 days) of antibiotics and 65% required hospitalization prior to Mycobacterium ulcerans diagnosis. Fever was present in 50% and pain in 87% of patients. The WCC, neutrophil count and CRP were elevated in 54%, 62% and 75% of cases respectively. The median duration of antibiotic treatment was 84 days (IQR 67–96) and 94% of cases required surgical intervention. On multivariable analysis, there was an increased likelihood of a lesion being oedematous if on the hand (OR 85.62, 95% CI 13.69–535.70; P<0.001), elbow (OR 7.83, 95% CI 1.39–43.96; p<0.001) or ankle (OR 7.92, 95% CI 1.28–49.16; p<0.001), or if the patient had diabetes mellitus (OR 9.42, 95% CI 1.62–54.74; p = 0.02).

Conclusions
In an Australian population, oedematous Mycobacterium ulcerans lesions present with similar symptoms, signs and investigation results to, and are commonly mistakenly diagnosed for, bacterial limb cellulitis. There is an increased likelihood of oedematous lesions affecting the hand, elbow or ankle, and in patients with diabetes.

Community-onset Escherichia coli infection resistant to expanded- spectrum cephalosporins in low-prevalence countries

Background
By global standards the prevalence of community onset expanded-spectrum cephalosporin resistant Escherichia coli (ESC-R-EC) remains low in Australia and New Zealand. Of concern, our countries are in a unique position with high extramural resistance pressure from close population and trade links to Asia-Pacific neighbours with high ESC-R-EC rates. We aim to characterize the risks and dynamics of community onset ESC-R-EC in our low-prevalence region.

Methods
A case-control methodology was used. Patients with ESC-R-EC or susceptible E. coli isolated from blood or urine were recruited at six geographically dispersed tertiary hospitals in Australia and New Zealand. Epidemiological data was prospectively collected and bacteria were retained for analysis.

Results
In total, 182 patients (91 cases and 91 controls) were recruited. Multivariate logistic regression identified risk factors for ESC-R amongst E. coli including birth on the Indian subcontinent (OR=11.13, 2.17-56.98, p=0.003), urinary tract infection in the past year (per infection OR=1.430, 1.13-1.82, p=0.003), travel to South East Asia, China, Indian subcontinent, Africa and the Middle East (OR=3.089, 1.29-7.38, p=0.011), prior exposure to trimethoprim+/-sulfamethoxazole &/or an expanded-spectrum cephalosporin (OR=3.665, 1.30-10.35, p=0.014) and healthcare exposure in the previous six months (OR=3.16, 1.54-6.46, p=0.02).

Amongst our ESC-R-EC the blaCTX-M ESBLs was dominant (83% of ESC-R-EC), and the worldwide pandemic clone ST-131 was frequent (45% of ESC-R-EC).

Conclusion
In our low prevalence setting, ESC-R amongst community onset E. coli may be associated with both ‘export’ from healthcare facilities into the community and direct ‘import’ into the community from high-prevalence regions.