Types of Infectious Diseases and Microbes That Cause Them

Natural environment is filled with overwhelming numbers of microbes that may or may not be the cause of various types of infectious diseases. It is the immune system of human body that naturally resists infections. However, certain bacteria, fungi, parasites and viruses often find a way to attack the human body. The types of infections are described here according to microbes that cause them.

Bacterial Diseases

Infections caused by bacteria may localize to specific part of the body or may disseminate throughout its host. Various types of infectious diseases that are caused by Bacteria are bacterial meningitis, bacterial pneumonia, bloodstream infections, food poisoning, gonorrhea, pelvic inflammatory disease, septic arthritis, sinusitis, soft tissue and skin infections, syphilis, toxic shock syndrome, strep throat and urinary tract infections.

Bacterial Diseases

Escherichia coli, Clostridium, Bacillus anthracis, Chlamydia, Enterobacter, Klebsiella, Meningococcus, Mycobacterium tuberculosis, Pneumococcus, Proteus, Pseudomonas, Salmonella, Shigella, Staphylococcus aureus, Streptococcus group A & B and Treponemapallidum are bacterial species that are agents of various infections.

Fungal Diseases

There are different types of fungi that cause various types of infectious diseases. Unlike bacterial and viral infections, fungal infections develop progressively and get healed gradually. Athlete’s foot, fungal nail infections, Jock itches, scalp ringworms, thrush, vaginal yeast infections, etc. are some of the surface fungal infections that are reported quite frequently by people.

Fungal Diseases

On the other side, lung and sinus infections such as Aspergillosis, blast mycosis, Coccidioido mycosis, cryptococcosis and Mucor mycosis are caused due to inhalation of fungal spores. Immunity is quite considerable in case of contraction of fungal infections or resistance against it. People who have weak immune system may suffer from such infections and those with strong immune system may never contract. Pneumocystis pneumonia is common only among people who are affected by AIDS.

Parasitic Diseases

Organisms that thrive on other living beings are called Parasites. They infect other living organisms for food. Parasites range between unicellular protozoa to worms that may reach 20 feet in length. Babesiosis, Amoebic dysentery, intestinal cryptosporidiosis and giardiasis, Malaria and vaginal trichomoniasis are infections that are caused by Protozoan parasites while parasitic worms infect gastrointestinal tracts which cause illnesses such as Ancylostomiasis, Ascariasis, Cysticercosis, river blindness, etc. Intestinal tapeworms, pinworms, elephantiasis, etc. are commonly known to reside inside human or animals or both.

Parasitic Diseases

Viral Diseases

The most common of all types of infectious diseases are those caused by viruses. In fact, people suffer from viral illnesses several times throughout their life. Common cold is the most common example of viral illness that afflicts people multiple times through the span of their life. However, not all viral disorders are considered minor as common cold. AIDS, aseptic meningitis, chickenpox, dengue, fifth disease, genital herpes, infectious mononucleosis, measles, shingles, viral encephalitis, viral gastroenteritis, viral hepatitis, viral pneumonia and yellow fever are some diseases that also spread through viruses and are considered among the scariest.

Viral Diseases

Top 10 Infectious Diseases That Signify the Importance of Health

Among the following top 10 infectious diseases, some are still epidemic, some have been restricted considerably while others have been completely eradicated.

1. Anthrax

Inhalation or eating of Anthrax spores or physical contact with organisms that have ingested its spores causes the infection. Anthrax viruses multiply within the body and destroy host cells to cause cold symptoms, which leads to severe breathing issues, shock and consequent death. Strains of Anthrax that are antibiotic-resistant have prevented the disease from being completely curable.

2. Bubonic Plague

Infected fleas are the transmitters of this plague the fatality rate of which is 70%. Infected persons die within a week of contraction. Swollen lymph nodes are the characteristic symptoms of Bubonic plague.

3. Cholera

Consumption of infected food or water causes cholera. Lack of appropriate treatment can progressively cause diarrhea, shock and even death within 18 hours of infection. Rehydration in any form and hygienic sanitation are the best survival and prevention strategies respectively.

4. Hemorrhagic Fever

Ebola is one of the viruses that cause Hemorrhagic fever in which any or most of the vital organs start to ooze blood. These viruses destroy cells that line the blood vessels. The affected person dies within a fortnight due to consequent internal bleeding.


Acquired Immune Deficiency Syndrome (AIDS) is caused due to the infection of Human Immunodeficiency Virus (HIV). HIV attacks T-cells that regulate immune response in humans. AIDS is developed when much of the T-cells are killed, which leads the body without any defensive mechanism. A person actually dies of other diseases that become incurable due to loss of immunity.

HIV Infectious Diseases

6. Leprosy

Mycobacterium Leprae are bacteria that infect peripheral nerves and cause leprosy. Nerves stop function due to infection and patients inadvertently inflict injury or infections that may lead to death of flesh. In severe cases, limbs fall off the body due to deadened nerves.

7. Malaria

Although it is completely treatable, malaria still infects more than 500 million people every year, of which 1-3 million people die of it. It is spread by the saliva of female Anopheles mosquitoes.

8. Polio

Paralysis of limbs is the general outcome of Polio infection. It infects nervous system and causes permanent paralysis or deformity of body-parts. Paralyzed respiratory muscles have been one of the major causes of deaths due to polio.

9. Rabies

Saliva of animals such as dogs, raccoons, etc. spreads Rabies. However, pets who are regularly vaccinated following the health norms of the country do not carry the virus. These viruses attack the brain leading to overall insanity. Thousands of people still die of this disease.

10. SARS

Severe Acute Respiratory Syndrome (SARS) affects respiratory system in humans and 70% of the cases are fatal. Most of its victims are people aged above 65years.

Some Common Types of Infectious Diseases in Children

Infections are known as one of the major threats or reason behind diseases among children. Children being less strong to deal with germs and other tiny living organisms hold the highest possibility to acquire infectious diseases. Infectious diseases in children are usually caused due to germs and other similar organisms which are capable of infinitely getting transferred to fresh bodies. The 4 major germs which pose a threat to infectious diseases among children are:

  • Fungi
  • Viruses
  • Bacteria
  • Parasites

Each of the above germs poses different kinds of threats to cause infections in children. While some are less harmful it should be noted that any infection should never be neglected. Neglecting some infections could lead to deadly diseases and may leave a lifelong impact. They can be found everywhere, which includes the air, water or soil. Infectious diseases in children might evolve due to eating, drinking, touching, breathing, sexual contact, etc. There are several organisms which are known to reside on or inside the skin, upper airways, genitals or even the mouth. The nature of the microorganism and the state of the immune system of a particular child decides the possibility of the microorganism to cause a disease or live as a harmless companion.

Infectious Diseases in Children

There are different kinds of infectious diseases which might affect a child.

  • Communicable diseases: These kinds of diseases are transmitted through a single source. Infectious bacteria or the viral organisms are said to be the carriers of the diseases.
  • Contagious diseases: They spread rapidly from one person to another which is said to be highly communicable in nature. It may be of the other type as well where the disease spreads from food as well.
  • Non Communicable diseases: While this is not transmitted from one person to the other it is equally harmful to children.

Whether it is the communicable, contagious or the non-communicable infectious diseases in children, all of them pose a health risk. In order to control the spread for the contagious infections the exposure to its threats should be limited. It involves two steps namely:

  • Isolation: This is applicable to the children who are already affected or are ill due to an infection.
  • Quarantine: This is applicable to all those who have already been exposed to some form of infections or infection carrying environment.

There are several infectious diseases which may not pose any risk to anyone but it’s better to be on the safer side. Protecting from infectious diseases in children is highly essential and precautions and right medication could help them be protected. Proper hygiene could help in prevention from certain diseases, but it should be noted that children are at a very high risk for certain conditions due to the fact that their immune system is still under the development stage.