Fusarioses B 46.5

Link, 1809 (first descriptor of Fusarium species)

Fusariosis is the term used to describe a variety of diseases caused by tubular fungi of the genus Fusarium. The term fusariosis is used for both mould infestation of plants and mould diseases of humans.

Mould genus with over 20 subspecies. Most Fusarium species are plant damaging (phytopathogenic) parasites.

Humapathogenic Fusarium species are mainly Fusarium solani (50% of all cases), Fusarium oxysporum, Fusarium verticillioides and Fusarium moniliforme. Fusaria can cause mould fungus infection with a tendency to angioinvasion, especially in immunocompromised patients. Invasive fusariosis, once a very rare event, is now a major cause of death in immunocompromised children, especially after haematopoietic stem cell transplantation (Schwartz KL et al. 2015).

Molds of the genus Fusarium live mainly in the soil or on and in plants. Fusarium solani preferentially infects potatoes, Fusarium sambucinum grows on elderberries and Fusarium poae on grasses. Many Fusarium species are found on cultivated plants such as cereals. Unlike most other moulds, which spread their spores through the air, the spores of Fusarium are mainly spread by animals. The spores of Fusarium species are formed in slimy aggregates called sporodochia, which attach themselves to the fur of animals.

Fusarium in households: Fusarium species can be found in households on food, feed, paint, wallpaper and textiles. On food, they are most commonly found on corn and wheat products.

Fusarium as a pathogen: colonisation of the skin of immunosuppressed haematological patients with Fusarium was reported to be 52% in a larger study (Varon AG et al. 2014). Clinical signs of a mycological skin infection (7.2% of patients) were intertriginous mycosis or nail mycosis. Immunocompromised patients with a localised mould disease are therefore predestined to develop invasive fusariosis.

Different clinical pictures depending on the degree of spread of the disease:

Localized disease caused by inoculation (predominantly long-term immunosuppressed patients are affected), skin (onychomycosis, intertriginous mycosis), eye (keratitis), joints, e.g. knee joints (purulent arthritis), osteomyelitis, lung, CNS, urogenital tract (Khetan S et al. 2017)

Invasive fusariosis (generalization): the clinical symptoms of generalization after fungemia are signs of a severe infectious disease with fever, myalgia, secondary skin and lung involvement and other organ manifestations.

Allergic reactions to fusarium spores: Allergic reactions to fusarium spores are also possible (mostly allergic respiratory diseases) (see below allergy to mould).

Cultural detection from blood culture or from biopsy material; serological detection by Galactomann antigen test. This test system is suitable for detecting early infection or later dissemination (Nucci M et al. 2014).

Voriconazole

Alternative: liposomal amphotericin B.

Fusarium infestation causes a variety of diseases in plants. For example, emergence and foot diseases, leaf spots, whiteness, partial deafness and shrivelled grains. Fusariosis can lead to very severe harvest reductions in various types of grain. On traditional open-air cucumber cultivation areas (approx. 4-year crop rotation, 4 - 8 crops), the occurrence of more or less severe infestation by Fusariosis is to be expected.

Mycotoxins: The genus Fusarium belongs to the 5 most frequent mycotoxin producers like Aspergillus, Penicillium, Alternaria and Claviceps. Concerning the development of mycotoxins, a distinction is made between fungal toxins which are already formed in the field before the harvest (by field fungi such as Fusarium) and those which are formed after the harvest by improper storage (Aspergillus and Penicillium).

1. Khetan S et al (2017) Urinary tract infection due to Fusarium oxysporum in an immunocompetent patient with chronic kidney disease. J Biomed Res. doi: 10.7555/JBR.32.20160128.
2. Nucci M et al (2014) Earlier diagnosis of invasive fusariosis with Aspergillus serum galactomannan testing. PLoS One 9:e87784.
3. Schwartz KL et al (2015) Invasive Fusariosis: A Single Pediatric Center 15-Year Experience. J Pediatric Infect Dis Soc 4:163-170.
4. Varon AG et al (2014) Superficial skin lesions positive for Fusarium are associated with subsequentdevelopment of invasive fusariosis. J Infect 68:85-89.