Zygomycosis is a frequently lethal invasive
infection in high-risk patients such as the immunocompromised [especially haematopoietic stem cell transplant (HSCT) recipients] and patients with
type 2 diabetes mellitus. However,
zygomycosis has also been reported in individuals without known risk factors. The causative fungi are members of the order Mucorales and individual species within this group require a high level of laboratory skill for their identification. These organisms are resistant to
voriconazole and also to the
echinocandins, and although
zygomycosis is less commonly documented than invasive
aspergillosis in leukaemic and HSCT patients, there are recent reports suggesting that it has increased in incidence since the introduction of
voriconazole.
Zygomycosis can present clinically as rhinocerebral, pulmonary or disseminated disease which progresses rapidly. The management of cases is based on early diagnosis, surgical
debridement when possible and aggressive antifungal
therapy. Based on clinical experience, but without the benefit of comparative studies,
liposomal amphotericin B has become the therapeutic agent of choice.
Posaconazole is a new orally administered
triazole antifungal and the first member of this class to have comparable in vitro activity to
amphotericin B against most zygomycetes. Studies of
salvage therapy of
zygomycosis with
posaconazole have yielded promising results and there are additional case reports of successful outcomes using these and other antifungal drugs as combination
therapy. Adjunctive approaches that are showing promise but with limited clinical experience are
iron chelation and
immunotherapy.