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It's all about germs

We are surrounded by an incredible number of germs every day and they are also very active in our bodies. We also need them there so that our organism "runs smoothly". But there are germs that can harm us - we get sick. Most of the time, our body can defend itself quite well against infections thanks to the immune system, but as the saying goes: "Prevention is better than cure!"

Picture of a adeno virus
Adeno virus

With this article we want to give a little insight into the world and diversity of germs - bacteria, fungi, viruses. What is it that crawls and flies on surfaces or infects us through the air? How can we become infected and how long do these beasts survive?


Name: Adeno virus Species: Virus Symptoms: Adenoviruses can cause a variety of diseases, such as respiratory, gastrointestinal, or ocular conjunctiva and cornea. In most cases, the eyes are affected. Infection begins with redness of the eyes and swelling of the conjunctiva. Itching, tearing, and clouding of the cornea also usually occur. After 2 to 4 weeks, the symptoms usually subside. Mode of transmission: The hands are the most common route of transmission, as infected persons quickly have the viruses on their hands and can then pass them on via all surfaces they touch. Shaking hands should also be avoided when infected, as the viruses can also be transmitted this way. Survival: The disease usually breaks out 5 to 12 days after infection. The risk of transmission begins with the first signs of illness and usually lasts for at least 2 weeks. At room temperature, the pathogens may adhere to surfaces for several weeks and remain contagious there.


Name: Polio virus Species: Virus Symptoms: Poliomyelitis, also called polio, is caused by the poliovirus. Most people do not notice the infection at all because they do not develop any symptoms. However, since there are three variants, one is not automatically immune after contracting the disease. In the case of abortive poliomyelitis, symptoms such as fever, sore throat, headache or muscle aches, inflammation of the stomach or nausea may occur, but they go away after a few days. In the other two variants, the central nervous system (CNS) is also affected. If fever, neck stiffness, back pain and muscle spasms occur as signs of meningitis, everything points to non-paralytic poliomyelitis. If there is also uneven paralysis in the leg, arm, abdominal, chest or eye muscles, this is called paralytic poliomyelitis. In severe cases, the diaphragm, which is responsible for breathing, may also be affected and the patient could die.

Even though the virus has been virtually eradicated in our latitudes, it can be brought in from other countries. Only vaccination offers comprehensive protection against all variants.

Transmission route: The polio virus enters the body through the mouth or nose, as a smear or droplet infection. The virus can pass from a surface to one's own hand and then enter through the mouth, e.g. by ingesting food. The virus can also be passed on through contaminated food itself or by shaking hands. Transmission is also possible through the smallest droplets when speaking or breathing. From the oral cavity, the pathogen first reaches the intestine, from where it can migrate into the lymphatic and blood vessels and spread throughout the body via these. Survival: The virus can be passed on as long as it is excreted in the stool. This can be up to six weeks.


Name: Monkeypox virus Orthopoxvirus simiae (also Monkeypox virus, MPXV).

Species: Virus Symptoms: Initial symptoms of the disease include fever, headache, muscle and back pain, and swollen lymph nodes. A few days after the onset of fever, skin lesions develop, which simultaneously progress through the stages from spot to pustule, ultimately crusting and falling off. The rash is usually concentrated on the face, palms, and soles. The skin and mucous membrane lesions can also be found on the mouth, genitals, and eyes. Symptoms usually last between two and four weeks and disappear on their own without treatment. Complications in endemic countries include encephalitis, bacterial skin infections, fluid loss, conjunctivitis, corneal infections, and pneumonia. Transmission route: Human-to-human transmission is rare and only possible with close contact, but can occur through contact with body fluids, the typical skin lesions (e.g., vesicle contents, scabs) of monkeypox infected individuals. It is currently uncertain whether monkeypox can be spread through direct sexual routes of transmission (e.g., semen or vaginal secretions), but direct skin contact with lesions during sexual activity can spread the virus. Particularly high concentrations of virus are found in the typical smallpox lesions (skin lesions). Transmission is possible even when still nonspecific symptoms (such as fever, headache, and pain in the limbs) appear even before the skin lesions appear during face-to-face contact through excreted respiratory secretions. Others can also become infected through clothing, bedding, towels, or items such as eating utensils that have been contaminated with the virus through contact with an infected person. Ulcers, lesions or sores in the mouth can also be contagious, meaning the virus can then be transmitted through the saliva of such infected individuals. The entry sites are often the smallest skin lesions as well as all mucous membranes (eye, mouth, nose, genitals, anus) and possibly the respiratory tract. Infected persons are contagious as long as they have symptoms (usually for two to four weeks).

Survival: Monkeypox viruses can survive and be infectious for long periods of time (days to months) on surfaces (e.g., glasses, silverware, bedside tables) or fabrics (e.g., bedding or towels).


Name: Measles Type: Virus Symptoms: A measles infection usually starts like a flu with a cold, cough, fever and inflammation of the nose, throat or conjunctiva. Typical of measles is a rash with white to blue-white spots on the mucous membrane of the mouth and the pinkish-brownish spots on the skin of the body that appear after three to seven days and persist for up to a week. The most persistent symptom, however, is an immune deficiency that lasts up to six weeks and can promote further illnesses. Transmission route: The measles viruses are transmitted from person to person and via surfaces. Particularly tricky, the highly contagious viruses can also be passed on over several metres by droplet infection. For this reason, there is also a reporting obligation and infected persons should also be isolated if possible. Survival: 2 hours in the air


Name: Herpes simplex virus Species: Bacterium

Symptoms: The most common forms of the enveloped virus are herpes labialis (lip herpes), and herpes genitalis (genital herpes). In the most common variant, herpes labialis, it usually starts with a slight tingling sensation. Those affected know the unpleasant feeling and immediately know what to do - get the right cream or patches at the pharmacy. Within a very short time, sore, sensitive areas with small blisters appear around the mouth. The blisters fill with clear liquid and burst after a few days. What remains is a small wound that quickly crusts over and heals after 8 to 14 days. Affected persons often feel ill and exhausted. Genital herpes is also manifested by fluid-filled blisters, which, however, occur in the genital area. In this disease, too, they burst after 1-2 days and then heal. Other symptoms may include pain in the genital area, headaches, aching limbs and fever. These symptoms also subside within a few days. Transmission route: Transmission of both variants occurs via smear infection through saliva or genital secretions, mucous membranes, or simple skin contact. Survival: 4.5 hours to 8 weeks


Name: Pseudomonas aeruginosa Species: Bacterium

Symptoms: The tricky thing about the bacteria is that most strains have developed a resistance to antibiotics. Thus, pneumonia, wound or urinary tract infections or, in the worst case, sepsis (blood poisoning), which can be caused by the bacteria, are now very difficult to treat. Those with previous illnesses, such as cystic fibrosis patients, hospital patients, the elderly or infants are particularly at risk. Transmission route: The pathogens often enter the body via tiny droplets in the air (so-called aerosols). By coughing or sneezing, the bacteria can "fly" several metres and then be inhaled by another person. Researchers have shown that the tiny particles can remain suspended in the air for more than 45 minutes. However, pseudomonads are also ingested with food or spread through direct contact via hands and objects. Careful hand hygiene is therefore very important. Survival: 6 hours to 16 months; on dry floors: 5 weeks


Name: Listeria Species: Bacterium

Symptoms: If the immune system is intact, the course of the disease remains asymptomatic in most people. A mild feeling of illness and fever may occasionally occur. People with a weakened immune system may develop severe flu-like conditions. Listeria can have serious consequences on unborn and newborn babies. Premature births and stillbirths can occur, or neonatal listeriosis, which is associated with severe and often fatal meningitis.

Transmission route: The bacteria are found in the environment and in agricultural areas, but food can also be contaminated through processing. Transmission occurs through consumption of these foods, but can also occur faecal-orally through healthy excretors or through direct contact with infected humans, animals or soil.

Survival: 1 day to several months on surfaces


Name: Legionella

Species: Bacterium

Symptoms: Legionella cause various disease patterns in humans, ranging from flu-like symptoms, called Pontiac fever, to severe pneumonia, known as Legionnaires' disease.

Transmission route: Legionella are environmental germs that are widespread worldwide and are a natural component of surface water and groundwater in small numbers. Legionella proliferate best at temperatures between 25 °C and 45 °C. Above 60 °C they are usually killed and below 20 °C they hardly reproduce. Especially in artificial water systems such as water pipes in buildings, the pathogens find good growth conditions at corresponding temperatures. Legionella can multiply particularly well in deposits and coatings in the pipe system.

The pathogens are transmitted through atomised, nebulised water. The droplets containing the pathogen can spread in the air and be inhaled. Possible sources of infection are, for example, showers, whirlpools, humidifiers or water taps, as well as cooling towers. Infection from person to person does not occur.


Name: Staphylococcus aureus (incl. MRSA, VRSA) Species: Bacterium

Symptoms: This bacterium, which is widespread worldwide, belongs to the staphylococci species. It colonises the skin and mucous membranes in the nasopharynx - but usually without causing any symptoms. However, if the germs enter the body, e.g. through wounds, they can cause boils, abscesses, meningitis, wound infections but also pneumonia or sepsis. The tricky thing is that the strains of MRSA and VRSA, which are now known as "hospital germs", are resistant to most common antibiotics and are therefore very difficult to fight in the body.

Transmission route: The bacteria are most often transmitted from person to person via the hands, but only cause an infection in the body, e.g. in wounds. Therefore, you can also infect yourself if you touch a wound with contaminated hands. In addition the pathogen can also be transmitted via objects and medical instruments, or via contact with farm animals carrying the bacterium.

Survival: 7 days to 7 months


Name: Streptococcus Species: Bacterium

Symptoms: The most common bacterium, S. pyogenes can cause many different illnesses, including local purulent infections of the skin or throat, such as middle ear, sinus, pharyngitis or tonsillitis but also scarlet fever. If an infection is not treated, it can lead to further illnesses such as rheumatic fever, neurological abnormalities or even movement disorders.

Transmission route: Smear and droplet infection, direct contact or via surfaces.

Survival: 3 days to 6.5 months


Name: Candida albicans

Type: Yeast fungus

Symptoms: The yeast fungus normally permanently colonises mucous membranes in the mouth and intestines as well as the skin. In healthy people, however, the immune system has the fungus well under control. With a weakened immune system, skin infections occur, but infestation of the internal organs or sepsis are also possible consequences.

Transmission: Through direct or indirect contact with infected skin or surfaces.

Survival: 1 day to 4 months


Name: Influenza

Type: Virus

Symptoms: Typical symptoms are a sudden feeling of illness, fever, sore throat and dry cough, accompanied by muscle, limb, back or head pain. If the infection is uncomplicated, it usually subsides after five to seven days. However, it can also take a severe course, leading to death in the worst case. The most common complications are pneumonia and middle ear infections in children.

Transmission: Infection with the influenza virus usually occurs via droplet infection from person to person or from surfaces to person. By coughing, sneezing, even talking, others in the environment can catch it from infected people.

Survival: 1 to 2 days


Name: Escherichia coli (E. coli)

Type: Bacterium

Symptoms: There are "harmless" E. coli bacteria that are part of the normal human intestinal flora. The harmful variants can cause urinary tract infections, severe diarrhoea, wound and respiratory infections and blood poisoning. The bacteria are also the most frequent causes of infections after operations, so-called nosocomial infections.

Transmission: Transmission occurs through the ingestion of minute traces of faeces via direct or indirect contact with contaminated persons, animals or objects. Inadequately heated food or contaminated water, even when bathing, can also cause infections. The incubation period is three to five days.

Survival: 1.5 hours to 16 months


Name: Salmonella

Type: Bacterium

Symptoms: Typical food poisoning with severe diarrhoea

Transmission: Transmission occurs through direct contact with infected persons or indirectly through contaminated food or via surfaces. Classic examples of sources of infection are insufficiently heated eggs or poultry, raw meat or ice cream. However, the bacteria can also get into the food via contaminated kitchen equimpent (e.g. cutting boards).

Survival: 1 day up to 4 years


Name: Corona (COVID-19; SARS-CoV-2)

Type: Virus

Symptoms: Mild cold symptoms with cough, fever, cold, loss of smell and taste, up to severe pneumonia with lung failure, but sometimes no symptoms at all despite infection.

Transmission: High risk of infection through droplet infection or aerosols produced when breathing, coughing, speaking, singing and sneezing, as well as through surfaces.

Survival: up to 28 days


To be continued...




Published: 4. February 2021 (Last update: 4. October 2022)

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