A sapronosis is an

infectious disease An infection is the invasion of tissue (biology), tissues by pathogens, their multiplication, and the reaction of host (biology), host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmis ...

caused by an organism that is able to live and reproduce in the

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

or an other

abiotic In biology and ecology, abiotic components or abiotic factors are non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems. Abiotic factors and the phenomena associated with them und ...

environment, and infects a living host directly from that environment. One widely-known example of a sapronosis is Legionnaire's disease. Approximately a third of all known disease organisms are sapronoses. Almost all

fungal infection Fungal infection, also known as mycosis, is a disease caused by fungi. Different types are traditionally divided according to the part of the body affected: superficial, subcutaneous, and systemic. Superficial fungal infections include common ...

s are sapronoses, but there are no known sapronotic viruses. Occupation often plays a role in sapronoses: people working with the soil, such as farmers or gardeners, are often at particularly high risk. Sporotrichosis, a fungal sapronosis, is for example sometimes known as "rose handler's disease". Sapronoses pose unique public health challenges. Because they can persist in the environment outside of any living host, they are difficult to control or eradicate. Their spread is also not subject to threshold host density. Sapronotic outbreaks are typically caused by a common source material, can be stopped by removing that material. For example, an outbreak of sporotrichosis that affected more than 3000 South African miners was stopped by removing wood in which the fungus was living.

Terminology and classification

The term "sapronosis" was coined by the Russian microbiologist Vasiliy Ilyich Terskikh in 1958, who contested the then-widespread idea that pathogenic bacteria could not persist in the environment outside of a host. Sapronoses sometimes serve as one part of the three-part classification of infectious diseases; the other two parts are anthroponoses (spread mostly from human to human) and

zoonoses A zoonosis (; plural zoonoses) or zoonotic disease is an infectious disease of humans caused by a pathogen (an infectious agent, such as a virus, bacterium, parasite, fungi, or prion) that can jump from a non-human vertebrate to a human. When h ...

(spread mostly from animals to humans). In contrast to those, the primary

reservoir A reservoir (; ) is an enlarged lake behind a dam, usually built to water storage, store fresh water, often doubling for hydroelectric power generation. Reservoirs are created by controlling a watercourse that drains an existing body of wa ...

of a sapronosis is in the soil. Sapronoses are therefore sometimes distinguished from environmental pathogens, also called "saprozoonoses", which have one part of their life cycle in the soil and one part in an animal host. Typical examples of sapronotic agents are fungal such as

coccidioidomycosis Coccidioidomycosis (, ) is a mammalian mycosis, fungal disease caused by ''Coccidioides immitis'' or ''Coccidioides posadasii''. It is commonly known as cocci, Valley fever, California fever, desert rheumatism, or San Joaquin Valley fever. Cocci ...

histoplasmosis Histoplasmosis is a fungal infection caused by ''Histoplasma capsulatum''. Symptoms of this infection vary greatly, but the disease affects primarily the lungs. Occasionally, other organs are affected; called disseminated histoplasmosis, it can ...

aspergillosis Aspergillosis is a fungal infection of usually the lungs, caused by the genus ''Aspergillus'', a common mold that is breathed in frequently from the air, but does not usually affect most people. It generally occurs in people with lung diseases su ...

cryptococcosis Cryptococcosis is a potentially fatal fungal infection of mainly the lungs, presenting as a pneumonia, and in the brain, where it appears as a meningitis. Coughing, difficulty breathing, chest pain and fever are seen when the lungs are infect ...

, ''Microsporum gypseum''. Some can be bacterial from the sporulating

clostridium ''Clostridium'' is a genus of anaerobic, Gram-positive bacteria. Species of ''Clostridium'' inhabit soils and the intestinal tracts of animals, including humans. This genus includes several significant human pathogens, including the causative ...

and bacillus to ''Rhodococcus equi, Burkholderia pseudomallei, Listeria'', ''Erysipelothrix'', ''Yersinia pseudotuberculosis,'' legionellosis, Pontiac fever, ''and'' nontuberculous mycobacterioses. Other sapronotic agents are amebic as in primary amebic meningoencephalitis. Yet again, difficulties in classification arise in the case of sporulating bacteria whose infectious spores are only produced after a significant period of inactive vegetative growth within an abiotic environment, yet this is still considered a case of sapronoses.

References

{{Authority control Disease ecology Infectious diseases

Terminology and classification

See also

References