Culture-positive mould infections in patients with haemato-oncological diseases

Abstract

Background: Moulds are increasingly recognised as important pathogens carrying a high morbidity and mortality in critically ill and immune-compromised patients, including those with haematological neoplasms (HNs) and aplastic anaemia (AA). Our understanding of these diseases remains incomplete, largely due to the lack of surveillance data.

Aim: This study aimed to describe the distribution, patient characteristics, risk factors, therapy and treatment outcome in culture-positive mould infections in patients with haematological conditions.

Setting: The study was conducted at Universitas Academic Hospital (UAH), Bloemfontein, South Africa.

Methods: All mould isolates cultured from sterile and selected respiratory specimens were identified retrospectively from 01 July 2014 to 30 June 2017. Laboratory and clinical data were reviewed for patients meeting the inclusion criteria.

Results: Eleven patients with underlying HNs (n = 9/11; 81.8%) or AA (n = 2/11; 18.2%) were identified. Acute myeloid leukaemia was the most common HN. Aspergillus species were most frequently isolated, followed by mucoraceous moulds. Histological examination proved a useful adjunct in the diagnosis of these infections. Risk factors for invasive mould infections (IMIs) included chemotherapy and antimicrobial exposure. Most patients had prolonged severe neutropenia. Seven (63.6%) patients received antifungal therapy. Only two patients underwent surgery. The mortality rate was 45.5% (n = 5/11).

Conclusion: Invasive mould infections are a major cause of morbidity and mortality in patients with HNs or AA, especially in the setting of severe neutropenia.

Contribution: The findings complement current evidence on IMIs, especially in patients with HNs and AA in the province, and will stimulate future research in this field.