Infectious Diseases: Symptoms, Causes, Diagnosis & Preventions | Narayana Health
Infectious Diseases

Infectious Diseases

Our team of Experts diagnose and provide treatment for wide range of Complicated Infections.

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Infectious Diseases

Infectious diseases are disorders caused by microorganisms. Germs or microbes are found everywhere - in the air, water or soil; many microorganisms live in and on the human body, which are normally harmless, helpful, and they aid in necessary bodily functions. But under some circumstances, certain microbes can cause an infection.

Microorganisms such as Virus, Bacteria, Fungi or Parasites can lead to infectious diseases. Organisms that cause Infections are collectively called pathogens. These pathogens can disrupt normal bodily processes and stimulate the immune system to produce a defensive response, resulting in various symptoms.

Why Narayana Health for treatment of Infectious Diseases?

The doctors at Narayana Health can treat various complicated infectious diseases, ranging from parasitic infections to rare complexities. Our team comprised skilled physician assistants, nurse practitioners, dieticians to provide the highest quality comprehensive care to both inpatients and outpatients suffering from various infectious diseases.

Infectious Diseases (ID) is a sub-speciality of General/Internal Medicine, which helps in the management of patients with complicated infections. Traditionally simple, short-term infections are considered under General Medicine but the more complicated infections are referred to the sub-speciality of ID. ID specialists are relatively few in India at this point. Unlike many other specialities, training programs in India for this field are very few. Good and appropriate laboratory back-up is crucial in the infectious diseases treatment speciality.

At NH, ID specialists manage referred patients from other specialists in the hospital and help out in the management of complicated infections. We also see referred patients within the OPD with complex infectious disease conditions.

Symptoms of Infectious Diseases

Each type of infection has its own specific sign and symptom. Few common symptoms include:

  • Fever
  • Diarrhoea
  • Fatigue
  • Muscle aches
  • Coughing

When to see a Doctor?

You may need medical attention if you:

  • Have been bitten by an animal
  • Are having trouble breathing
  • Have been coughing for more than a week
  • Have a severe headache with fever
  • Experience a rash or swelling
  • Have unexplained or prolonged fever
  • Experience sudden vision problems

Causes of Infectious Diseases:

There are primarily four kinds of germs which cause clinical infectious diseases.

Virus - Much smaller than a Bacteria, these tiny infectious agents replicate only in the living cells of other organisms. They invade the cells in the human body and multiply. This can change, damage, or even kill a cell. Viral infections include the common cold and HIV/AIDS.

Different viruses spread through various mediums. An Influenza virus spreads through aerosols (sneezing and coughing), a Norovirus or Rotavirus spreads by not washing hands after going to the toilet, whereas HIV spreads through sexual contact. The virus SARS-CoV 2 is the main reason behind the COVID-19 pandemic of 2020.

Bacteria - Though most types of bacteria in a human body are not harmful and are rather beneficial, a harmful bacterium can grow and spread in the body leading to infectious diseases. These single-celled microorganisms can multiply quickly, hence early infectious symptoms should not be ignored. They produce toxins which can make one very sick. Often antibiotics are prescribed to help prevent a bacterial infectious disease.

Bacteria are spread in various ways, including:

  • Aerosols (through coughing and sneezing). For example, Streptococcus.
  • Surface and skin contact. For example, Staphylococcus aureus, including MRSA.
  • Body fluids, such as blood and saliva. For example, Meningococcal Disease (Meningitis).

Fungi - Most fungi are harmless to humans and some are edible too, like mushrooms, truffles, matsutake, porcini, and yeasts, etc. There are few fungi which can be infectious and cause life-threatening diseases. Fungal infections often affect the nails, skin and lungs. Some infections may also penetrate the body and affect organs. Few fungal infections include Thrush, Ringworm, and Athlete’s foot.

Parasites - Organisms which live in or on another organism and extracts the required nutrients from their host. Such parasites in the human body can be found in the eyes, blood, liver, digestive system, and the brain. Whipworm (ingested), hookworms (directly penetrate the skin), Wuchereria bancrofti (transmitted by mosquitoes), Giardia (ingested), Plasmodium falciparum (causes malaria and is transmitted by mosquitoes), Trichomonas (sexually transmitted), Pork tapeworm and Schistosomes (blood flukes) are few commonly found parasites in a human body.

How Infectious Disease spreads?

There are many ways that you can contract an infectious disease.

Person to Person

Most common way of spreading an infection is the direct transfer of germs from one person to another. For example, an infected person kissing, touching, sneezing, coughing on a healthy person.

Animal to Person

Being scratched or bitten by an infected animal can make you sick. Infection can also spread through animal waste.

Mother to unborn Child

A pregnant woman can pass infectious germs to her unborn baby. The germs can pass through breast milk or the placenta.

Insect Bites

This is an indirect contagion, where the infectious microorganisms can spread through insects like mosquitoes, lice, ticks or fleas. Malaria and the West Nile Virus are the most commonly spread infectious diseases through mosquitoes.

Food Contamination

Contaminated food and water can infect you by transferring disease causing germs. Escherichia coli (E. coli) is one such bacterium that often spreads infectious disease through undercooked food or unpasteurized fruit juice.

Diagnosis of Infectious Diseases

As most infections have common signs and symptoms, doctors often prescribe lab work or imaging scans to help determine what's causing your symptoms. Few tests to determine the tailor treatment are:

  • Blood Tests
  • Urine Tests
  • Throat Swabs
  • Stool Sample
  • Spinal Tap (Lumbar Puncture)
  • Imaging Scans like X-rays, Tomography, MRI (Magnetic Resonance Imaging) scan
  • Biopsy

Treatment of Infectious Diseases

Treatment depends on which microorganism causes the infection.


For bacterial infections, antibiotics usually kill the bacteria and puts an end to the infection. Antibiotic drugs are known to be ineffective for viral infections. Sometimes it is difficult to figure out which germ has caused a disease. For example, pneumonia can be caused by a bacterium, a virus, a fungus or a parasite. It becomes difficult to diagnose the cause and figure out the treatment required. At Narayana Health, our team of expert Doctors have a great record of curing such difficult conditions.


Antiviral drugs treat several viral infections including influenza, HIV, herpes, and hepatitis B and hepatitis C. Like bacteria, viruses also mutate over time and develop resistance to antiviral drugs.


Antifungal medications are used to treat skin or nail infections caused by fungi. Some fungal infections can be treated with oral medications. People with weakened immune systems may require intravenous antifungal medications for severe internal organ fungal infections.

Infectious Diseases FAQ's

What are the different types of infectious diseases?

There are 5 common types of infectious diseases:

  • Viral infections - One of the most common clinical infectious diseases is viral infections. They are caused by viruses, organisms smaller than bacteria, that grow by finding a host cell and reproducing. Some of the common examples of viral infections are influenza, common cold, polio, chickenpox, rabies, ebola, and coronavirus.
  • Bacterial infections - These are infections caused by bacteria, a single-celled microorganism. They grow in all environments including, soil, water, and human bodies. Some of the common forms of bacterial infections are strep throat, bacterial food poisonings such as E.coli, salmonella, or shigella, gonorrhoea, and syphilis.
  • Fungal infections - These are infections caused by microorganisms such as yeast and moulds. Some examples of fungi infections are vaginal yeast infections, ringworm, athlete’s foot, and fungal meningitis.
  • Parasitic infections - These infections are caused by parasites which live in a host organism, extracting all the nutrients from the host. The three types of parasites are protozoa, helminths, and ectoparasites. Some parasitic infections are malaria, toxoplasmosis, tapeworm and roundworm infections, and scabies.
  • Prions - These are caused by a protein and not a microorganism. These affect the normal body proteins and contort them into abnormal shapes. Diseases caused by prions are rare. They are responsible for disorders such as dementia.

How do you know if you have an infectious disease?

Different kinds of infections can manifest themselves in different symptoms. Some of the general symptoms which can help you to understand that you may have an infection are:

  • Fever
  • Body pain
  • Tiredness or fatigue
  • Coughing or sneezing
  • Vomiting

How do you get diagnosed with infectious diseases?

Some infectious diseases can be easily diagnosed since they have characteristic symptoms. If you visit a doctor, they can diagnose based on your symptoms, medical history, and a physical examination. Since symptoms of some infections such as a viral and a bacterial may be similar, so it's important to find out the source of the infection. Depending on your illness and the type of organism causing it, your doctor may ask you to provide some samples. These can include blood, urine, stool, or sputum samples.

What are your treatment options for infectious diseases?

Knowing what’s causing the infection can go a long way in helping you with the right infectious diseases treatment. Some of the common treatment options are:

  • Antibiotics - These mostly work for bacterial infections. Certain antibiotics work especially well with certain classes of bacteria. However, overuse of antibiotics can make the bacteria resistant to the antibiotics.
  • Antivirals - Some antivirals have been discovered for certain viruses like HIV/AIDS, Hepatitis B and C, and influenza
  • Antifungals - Some of the common antifungal medicines help treat skin and nail infections. In case of severe fungal infections and people with weakened immune systems, intravenous antifungal medications are the way out.
  • Antiparasitics - Some antiparasitics are developed like malaria, while some others don’t work since the parasites have developed an immunity.
  • Lifestyle changes - In cases of some infectious diseases such as cold, some home remedies work such as having plenty of fluids and getting lots of rest.
  • Alternative medicine - Some common illnesses can be fended off with some alternative medicine options such as cranberry, garlic, ginseng, Vitamin C and Vitamin D, and zinc.