Case of the Month - February 2012

Victoria Howell1, Candice Royal2, Mary Morgan2

1. Department of Microbiology, National Health Laboratory Services, Greys Hospital, Pietermaritzburg.
2. Department of Paediatrics, Greys Hospital, Pietermaritzburg

A 6-week old female infant presented to Greytown Hospital with a 1-week history of progressive respiratory distress. She was treated for 3 days with ampicillin and gentamicin but was subsequently changed to piperacillin-tazobactam and amikacin. One week after admission she was referred to Greys Hospital Paediatric ICU (PICU) because of her deteriorating condition and her need for ventilatory support.

Her mother was known to be HIV-infected and had been commenced on HAART during her pregnancy because her CD4 count was found to be 99 cells/mm3. Her routine antenatal bloods were normal and she had an uncomplicated pregnancy. She was delivered at 34 weeks gestation by normal vaginal delivery due to unexplained pre-term labour. Her birth weight was 2.42kg with Apgar scores of 9/10 and 10/10 at 1 and 5 minutes respectively. She was given nevirapine as per the PMTCT protocol. There were no complications noted during the period prior to admission. She was exclusively formula fed from birth and was growing well according to her road-to-health chart.

On admission to Greys Hospital PICU she was in respiratory distress. Her oxygen saturation was 77% and respiratory rate was 50 breaths per minute. She had bilateral crepitations and scattered wheezes. Chest X-ray showed bilateral infiltrates. She was diagnosed with bilateral bronchopneumonia complicated by ARDS and was commenced on high dose cotrimoxazole, dexamethasone, ganciclovir and meropenem on admission. On day 2 after admission it was decided that she needed to be intubated and ventilated. She was also commenced on erythromycin for a possible atypical pneumonia and fluconazole for a possible fungal infection. On day 4 her HIV PCR result was positive and she was commenced on HAART consisting of a regimen of abacavir, lamivudine and kaletra (lopinavir/ritonavir). On day 6 a repeat chest X-ray showed areas of breakdown and right lung collapse. In view of these findings it was decided to treat her with vancomycin for a possible Staphylococcus aureus infection. Her endotracheal aspirates up to this point had not yielded a positive culture.

She had no identifiable Mycobacterium tuberculosis contacts and a mantoux skin test was negative. 3 early morning gastric washings were negative for acid-fast bacilli on microscopy. On day 16 of admission superimposed nosocomial pneumonia was suspected based on her worsening clinical condition and Acinetobacter baumannii was cultured on an endotracheal aspirate. The patient was treated with ceftazidime and tobramycin based on sensitivities of the organism.

On day 18 of admission multiple abscess were noted on the patient’s left ankle, shoulder and right forearm. The lesions started as small erythematous papules that rapidly became fluctuant and then produced purulent exudates. Within 3 days of their appearance they showed necrotic ulcerative changes. X-rays of the areas were taken to exclude underlying osteomyelitis. The patient was started on intravenous cloxacillin and recommenced on meropenem but she showed no response to these antibiotics. A swab was taken from each of these sites and was sent to the microbiology laboratory. All 3 of these swabs grew an Aspergillus species that was later identified as Aspergillus flavus. The pus from all 3 lesions was negative for acid-fast bacilli on microscopy. The patient was commenced on amphotericin B. Two days later the patient was extubated and coping comfortably on nasal prong oxygen. The rest of the infant’s course in hospital was uneventful. The lesions healed slowly over the course of the next few days and no further lesions developed after the antifungal therapy was commenced. She was changed to oral voriconazole for the last 3 weeks of therapy and was discharged home on the treatment.

A urine specimen taken during the time of the manifestation of the skin lesions showed growth of Aspergillus flavus. Repeated blood cultures were negative. A 6-week culture of her endotracheal aspirate taken a week after admission was positive for Mycobacterium tuberculosis (TB). It was sensitive to isoniazid and rifampicin and first line intensive phase TB treatment was commenced.

In summary, this was an unusual case of invasive/ disseminated Aspergillus flavus in an HIV positive infant presenting with multiple cutaneous lesions with pulmonary M. tuberculosis co-infection.

Figures 1 and 2 showing the necrotic skin lesions

Figures 3 and 4 showing the mould growing on Sabouraud Dextrose + Chloramphenicol agar

Figure 5 showing sporulating heads of Aspergillus flavus using lactophenol cotton blue stain.

ACKNOWLEDGEMENTS: Dianne Naidu from the Inkosi Albert Luthuli Hospital Mycology Reference Laboratory, Durban and the staff of Greys Hospital NHLS Microbiology Laboratory, Pietermaritzburg.

Question 1: What are the clinical features of Aspergillus infection?

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