Human Infections. infectious diseases are caused by pathogenic microorganisms such as bacteria, viruses, fungi, and parasites. They are a major public health concern and can lead to significant morbidity and mortality. Infectious diseases can spread rapidly from person to person through different modes of transmission, including direct contact, droplets, airborne transmission, and vector-borne transmission. In this blog post, we will discuss some of the most common infectious diseases that affect humans, their causes, symptoms, and treatments.

Bacterial infections:

Bacterial infections are caused by pathogenic bacteria that can invade different parts of the body, including the skin, respiratory tract, urinary tract, and gastrointestinal tract. Some of the most common bacterial infections include strep throat, urinary tract infections, and bacterial pneumonia.

Strep throat is a common bacterial infection that affects the throat and tonsils. It is caused by the Streptococcus bacteria and is highly contagious. The symptoms of strep throat include a sore throat, difficulty swallowing, fever, and swollen lymph nodes. Treatment for strep throat typically involves a course of antibiotics to kill the bacteria and alleviate symptoms.

Urinary tract infections (UTIs) are bacterial infections that affect the urinary system, including the bladder, ureters, and kidneys. UTIs are more common in women than in men and are often caused by E. coli bacteria. The symptoms of a UTI include pain or burning during urination, frequent urination, and lower abdominal pain. Treatment for UTIs typically involves a course of antibiotics.

Bacterial pneumonia is a serious bacterial infection that affects the lungs. It is caused by several different types of bacteria, including Streptococcus pneumoniae and Haemophilus influenzae. The symptoms of bacterial pneumonia include cough, fever, chest pain, and difficulty breathing. Treatment for bacterial pneumonia typically involves a course of antibiotics and supportive care, such as oxygen therapy.

Viral infections:

Viral infections are caused by pathogenic viruses that can invade different parts of the body, including the respiratory tract, digestive system, and nervous system. Some of the most common viral infections include the common cold, influenza, and hepatitis.

The common cold is a viral infection that affects the upper respiratory tract. It is caused by several different types of viruses, including rhinovirus and coronavirus. The symptoms of the common cold include a runny or stuffy nose, sore throat, cough, and fever. There is no specific treatment for the common cold, and symptoms typically resolve on their own within a week or two.

Influenza, or the flu, is a viral infection that affects the respiratory system. It is caused by the influenza virus and is highly contagious. The symptoms of the flu include fever, cough, sore throat, body aches, and fatigue. Treatment for the flu typically involves rest, fluids, and over-the-counter medications to alleviate symptoms. Antiviral medications may also be prescribed in some cases.

Hepatitis is a viral infection that affects the liver. It is caused by several different types of viruses, including hepatitis A, B, and C. The symptoms of hepatitis include fatigue, nausea, vomiting, abdominal pain, and jaundice. Treatment for hepatitis depends on the type of virus causing the infection and may involve antiviral medications, rest, and supportive care.

Fungal infections:

Fungal infections are caused by pathogenic fungi that can invade different parts of the body, including the skin, nails, and respiratory system. Some of the most common fungal infections include athlete\’s foot, ringworm, and candidiasis.

An athlete\’s foot is a fungal infection that affects the skin on the feet. It is caused by several different types of fungi and is highly contagious. The symptoms of athlete\’s foot include itching, burning, and scaling of the skin on

Infectious diseases are disorders caused by organisms — such as bacteria, viruses, fungi or parasites. Many organisms live in and on our bodies. They\’re normally harmless or even helpful, but under certain conditions, some organisms may cause disease.
Some infectious diseases can be passed from person to person. Some are transmitted by bites from insects or animals.


And others are acquired by ingesting contaminated food or water or being exposed to organisms in the environment.

Signs and symptoms vary depending on the organism causing the infection but often include fever and fatigue. Mild infections may respond to rest and home remedies, while some life-threatening infections may require hospitalization.

Early one morning, Dani woke up to find that he has a very high temperature and pains in his joints. He was also tired. Because of this, he was unable to go to school. He was unable to do any work. At the hospital, the doctor examined him.

The report shows he has a disease which made his body not work properly. From the above, we can say that a disease is anything or sickness that prevents the body from working properly.


Diseases are caused by many agents. The most important of these agents is the germs. These germs are very tiny substances that we cannot see with our naked eyes. We can, however, see them with the help of an instrument known as the microscope. Another agent that can cause diseases is called a parasite. A parasite lives and feeds on other animals.

Feeding on other animals, injures them thus causing diseases. Tiredness and overwork can also cause diseases. In some cases, exposure to cold can cause diseases. Starvation or lack of good food can cause some diseases. Accidents can be the beginning of a number of diseases such as tetanus (lock-jaw).


Diseases are spread by air, contaminated food, water, insects and other small animals and by contact between affected and other unaffected persons.

Examples of air-borne diseases


:small-pox, measles, mumps, common cold,
Cough, pneumonia and tuberculosis.


Examples of disease contaminated food are:

dysentery, food poisoning, typhoid and worms.

Examples of water-borne diseases are:

dysentery, typhoid and liver flukes.

Examples of diseases spread by insects and other small animals:

malaria, yellow fever, dengue fever, sleeping sickness and filariasis.

Examples of diseases spread by contact:

ringworm, yaws, leprosy and scabies.

Examples of broken skin diseases:

tetanus (lock-jaw).


Except for a few cases, germs must enter the body before they can cause diseases. There are a number of ways through which they can do this.


disease germs can easily enter the body through damaged skin. For example, when we fall or have accidents, the skin is damaged. If by carelessness, we do not cover or bandage the wound, in a short while, germs will go into the body. Germs that cause tetanus or lock-jaw enter the body in this way.

(b) When a mosquito pierces the skin, it may inject germs of malaria or yellow fever into the body. The hookworm enters the body by piercing through the skin.


germs that enter the body through the mouth and nose are mainly those that are spread by air. Examples of diseases caused by germs entering the body in this way are common colds, measles, chicken pox, smallpox, pneumonia, tuberculosis and mumps.


dirty food and water contain disease germs. When such food and water are taken, the germs are sent into the stomach and intestines. From these places, the germs pass into the body. In some cases, the germs damage the walls of the stomach and intestines thus giving rise to stomach ache and pains. The diseases caused in this way are dysentery, worms and cholera


If one is to remain healthy, he must at all times eat good food and remain clean. In addition, he must carry out the following:

  1. Keep his hands and objects from his mouth. Food that is dirty or infected should not be taken. Food that has been drooped on the floor should not be eaten. Dirty and contaminated water should never be taken. Where there is no tap water, all drinking water should be boiled.
  2. Before eating the hands should be washed with soap and water, especially immediately after using the toilet. All raw food and fruits must be thoroughly washed before being eaten since they are likely to be contaminated on the farm. Do not eat uncooked or half-cooked food. Always cover your food to keep away flies and other disease-carrying insects.
  3. Have good toilets or latrines. These should be located a good distance from the house. It should always be kept clean and well-covered. Excreta should never be placed in unauthorized places.
  4. The feet are the most likely places to be wounded than other parts of the body. One should always wear shoes. The practice of removing shoes when one is walking through water or over dirty places is not good. Shoes should always be put on to protect the feet from cuts and from the entry of worms. In case of cuts, immediate treatment with antiseptics should be given. The wound should be covered with a bandage.
  5. Destroy all stagnant water. Some disease-carrying insects live and breed there. Spray the house with flit, shell to, etc. regularly to kill all dangerous insects.
  6. It is dangerous to sneeze, cough and spit about. Where there is a cough always cover it up.
  7. Certain diseases such as smallpox, cholera, tetanus, yellow fever, etc. can be prevented by immunization. Go to the health centres to do so. When this is done then you cannot be attacked by these diseases.
  8. Always stay away from people who have infectious diseases such as colds. All infected persons should see a doctor. After receiving treatment they should always stay in bed, and avoid crowded places such as cinemas

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