Impact of azole antifungal treatment on outcome in acute invasive fungal rhinosinusitis with orbitocranial involvement: a surgical perspective

PURPOSE

To provide real-life data on azole treatment outcomes and the role of surgery in the current management of invasive fungal rhinosinusitis complicated by orbitocranial fungal infection (OCFI).

METHODS

Data was collected retrospectively from a chart review from four participating centers and a systematic literature review. The study group included patients with OCFI treated with azole antifungals. The control cases were treated with other antifungal agents. The cranial and orbital involvement degree was staged based on the imaging. The extent of the surgical resection was also classified to allow for inter-group comparison.

RESULTS

There were 125 patients in the azole-treated group and 153 in the control group. Among the patients with OCFI cranial extension, 23% were operated on in the azole-treated group and 18% in the control group. However, meninges and brain resection were performed only in the controls (11% of patients) and never in the azole antifungals group. Orbital involvement required surgery in 26% of azole-treated cases and 39% of controls. Despite a more aggressive cranial involvement, azole-treated patients' mortality was significantly lower than in controls, with an OCFI-specific mortality rate of 21% vs. 52%. A similar, though not statistically significant, trend was found for the extent of the orbital disease and surgery.

CONCLUSION

Despite less aggressive surgical intervention for cranial involvement, OCFI patients treated with azoles had a higher survival rate. This finding suggests we may improve morbidity with a more conservative surgical approach in conjunction with azole treatment. The same trend is emerging for orbital involvement.

Candidaemia with uncommon Candida species: predisposing factors, outcome, antifungal susceptibility, and implications for management

The risk factors for and clinical features of bloodstream infection with uncommon Candida spp. (species other than C. albicans, C. glabrata, C. parapsilosis, C. tropicals and C. krusei) are incompletely defined. To identify clinical variables associated with these species that might guide management, 57 cases of candidaemia resulting from uncommon Candida spp. were analysed in comparison with 517 episodes of Candida albicans candidaemia (2001-2004). Infection with uncommon Candida spp. (5.3% of candidaemia cases), as compared with C. albicans candidaemia, was significantly more likely to be outpatient-acquired than inpatient-acquired (15 of 57 vs. 65 of 517 episodes, p 0.01). Prior exposure to fluconazole was uncommon (n=1). Candida dubliniensis was the commonest species (n=22, 39%), followed by Candida guilliermondii (n=11, 19%) and Candida lusitaniae (n=7, 12%).C. dubliniensis candidaemia was independently associated with recent intravenous drug use (p 0.01) and chronic liver disease (p 0.03), and infection with species other than C. dubliniensis was independently associated with age<65 years (p 0.02), male sex (p 0.03) and human immunodeficiency virus infection (p 0.05). Presence of sepsis at diagnosis and crude 30-day mortality rates were similar for C. dubliniensis-related, non-C. dubliniensis-related and C. albicans-related candidaemia. Haematological malignancy was the commonest predisposing factor in C. guilliermondii (n=3, 27%) and C. lusitaniae (n=3, 43%) candidaemia. The 30-day mortality rate of C. lusitaniae candidaemia was higher than the overall death rate for all uncommon Candida spp. (42.9% vs. 25%, p not significant). All isolates were susceptible to amphotericin B, voriconazole, posaconazole, and caspofungin; five strains (9%) had fluconazole MIC values of 16-32 mg/L. Candidaemia due to uncommon Candida spp. is emerging among hospital outpatients; certain clinical variables may assist in recognition of this entity.

Candidemia following solid organ transplantation in the era of antifungal prophylaxis: the Australian experience

Solid organ transplant (SOT) recipients have high rates of invasive fungal infections, with Candida species the most commonly isolated fungi. The aim of this study was to identify differences between incidence rates, risk factors, clinical presentations, and outcomes of candidemia in SOT recipients and non-SOT patients. Data from the multicenter prospective Australian Candidaemia Study were examined. From August 2001 to July 2004, 24 episodes (2.2%; 24/1068) of candidemia were identified in SOT recipients. During this period, the numbers of transplanted organs included liver (n=455), kidney (n=1605), single lung (n=57), bilateral lung (n=183), heart and lung (n=18), heart (n=157), and pancreas (n=62). The overall annual estimated incidence of candidemia in SOT recipients was higher (3 per 1000 transplant admissions) than in non-SOT patients (incidence 0.21 per 1000 admissions; P<0.001). The incidence and timing of candidemia post transplant was influenced by the transplanted organ type, with the majority of episodes (n=14, 54%) occurring >6 months after renal transplantation. Risk factors for candidemia in the month preceding diagnosis were similar to non-SOT recipients except for corticosteroid therapy (P<0.001). Antifungal prophylaxis did not select for more resistant or non-albicans Candida species in the SOT group. The 30-day all-cause mortality was similar to non-SOT patients with candidemia and remains high at 21%. All deaths in SOT recipients occurred early (within 5 days of diagnosis), underlining a need for better diagnostic tests, targeted prevention, and early treatment strategies.

PCR studies of feline leprosy cases

16S rRNA gene sequence analysis provided evidence for two different mycobacterial species, Mycobacterium lepraemurium and a potentially novel species, as causative agents of 'feline leprosy'. Comparison of 16S rRNA gene sequence data obtained for M. lepraemurium and the potentially novel species indicated 12 nucleotide differences over a 446 bp region encompassing the V2 and V3 hypervariable regions. From available 16S rRNA gene sequence data, M. lepraemurium shared greatest nucleotide identity with M. avium subsp paratuberculosis and M. avium. The novel species had a long helix 18 in the V3 region and shared greatest nucleotide identity with M. leprae, M. haemophilum and M. malmoense. The novel species had an additional 'A' nucleotide at position 105 of the aligned 16S rRNA gene sequence, the only other mycobacterial database sequence having this same extra nucleotide being M. leprae. This nucleotide variation was exploited to develop specific PCR assays for the two species. These were found to be effective and specific when tested against a panel of mycobacteria including species found in feline leprosy lesions and closely related mycobacteria and also when applied directly to formalin-fixed, paraffin-embedded tissues from feline leprosy cases.

Feline leprosy: two different clinical syndromes

Feline leprosy refers to a condition in which cats develop granulomas of the subcutis and skin in association with intracellular acid-fast bacilli that do not grow on routine laboratory media. In this study, the definition was extended to include cases not cultured, but in which the polymerase chain reaction (PCR) identified amplicons characteristic of mycobacteria. Tissue specimens from 13 such cases from eastern Australia were obtained between 1988 and 2000. This cohort of cats could be divided into two groups on the basis of the patients' age, histology of lesions, clinical course and the sequence of 16S rRNA PCR amplicons. One group consisted of four young cats (less than 4 years) which initially developed localised nodular disease affecting the limbs. Lesions progressed rapidly and sometimes ulcerated. Sparse to moderate numbers of acid-fast bacilli were identified using cytology and/or histology, typically in areas of caseous necrosis and surrounded by pyogranulomatous inflammation. Organisms did not stain with haematoxylin and ranged from 2 to 6 microm (usually 2 to 4 microm). Mycobacterium lepraemurium was diagnosed in two cases based on the sequence of a 446 bp fragment encompassing the V2 and V3 hypervariable regions of the 16S rRNA gene a different sequence was obtained from one additional case, while no PCR product could be obtained from the remaining case. The clinical course was considered aggressive, with a tendency towards local spread, recurrence following surgery and development of widespread lesions over several weeks. The cats resided in suburban or rural environments. A second group consisted of nine old cats (greater than 9 years) with generalised skin involvement, multibacillary histology and a slowly progressive clinical course. Seven cats initially had localised disease which subsequently became widespread, while two cats allegedly had generalised disease from the outset. Disease progression was protracted (compared to the first group of cats), typically taking months to years, and skin nodules did not ulcerate. Microscopically, lesions consisted of sheets of epithelioid cells containing large to enormous numbers of acid-fast bacilli 2 to 8 microm (mostly 4 to 6 microm) which stained also with haematoxylin. A single unique sequence spanning a 557 bp fragment of the 16S rRNA gene was identified in six of seven cases in which it was attempted. Formalin-fixed paraffin-embedded material was utilised by one laboratory, while fresh tissue was used in another. The same unique sequence was identified despite the use of different primers and PCR methodologies in the two laboratories. A very slow, pure growth of a mycobacteria species was observed on Lowenstein-Jensen medium (supplemented with iron) and semi-solid agar in one of three cases in which culture was attempted at a reference laboratory. Affected cats were domicile in rural or semi-rural environments. These infections could generally be cured using two or three of rifampicin (10-15 mg/kg once a day), clofazimine (25 to 50 mg once a day or 50 mg every other day) and clarithromycin (62.5 mg per cat every 12 h). These findings suggest that feline leprosy comprises two different clinical syndromes, one tending to occur in young cats and caused typically by M lepraemurium and another in old cats caused by a single novel mycobacterial species.