Microscopic spore image

them may give rise to problems through infections,

production of toxins or hyperstimulation of the im-

mune system. Fungal infections can range from re-

latively benign to other dangerous diseases, such

as lung histoplasmosis or infections of the species

Aspergillus in people with impaired immune system.

Fungi can produce hypersensitivity reactions invol-

ving the immune system, such as allergies, asthma

and al-three diseases. All these reactions follow the

inhalation of fungi or related antigens. Especially in

children there was an increase in these reactions,

such as asthma, in many countries.

Viruses

Viruses are extremely small microorganisms, visi-

ble only under the electron microscope, consisting

of genetic material (DNA or RNA) enclosed in a

protein envelope (capsid) and, often, even in an

outer membrane made of phospholipides (a type of

fats) and proteins, called pericapside.

Viruses and health risks

Viruses are not able to reproduce (replicate) in-

dependently, but exclusively within the cells of the

tissues of the organism, causing their destruction

or, for some particular viruses, transformation into

cancer cells.

The resistance of viruses in the environment is ex-

tremely low, although some viruses (for example,

some respiratory viruses) can survive for a long

time. Viruses can infect people by air, food, throu-

gh sexual intercourse or through vectors (especial-

ly insects); they can cause local symptoms borne

by different systems (e.g. respiratory, digestive or

uro-genital system) or general (systemic) if it spre-

ads throughout the body. Some types of viruses

can be fought with effective drugs or prevented due

to specific vaccination.

Focus on Covid-19

Coronaviruses (CoV) are a wide family of respira-

tory viruses that can cause mild to moderate dise-

ases, from the common cold to respiratory syndro-

mes such as MERS (Middle Eastern Respiratory

Syndrome, Middle East respiratory syndrome) and

SARS (severe acute respiratory syndrome, Seve-

re acute respiratory syndrome) They are called so

due to the crown shaped tips that are present on

their surface. A new coronavirus is a new strain of

coronavirus that has never been previously identi-

fied in humans. The human coronaviruses known to

date, common around the world, are seven, some

Strain of influenza H3M2 showing Glycoprotein on surface,

with spikes of Hemagglutinin and Neuraminidase.

identified several years ago (the first in the mid-six-

ties) and some identified in the new millennium. On

January 9, 2020, WHO stated that Chinese health

authorities identified a new strain of coronavirus ne-

ver first identified in humans, officially classified un-

der the name SARS-CoV-2. The virus is associated

with an outbreak of cases of pneumonia registered

starting December 31, 2019 in the city of Wuhan,

Central China.

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