Infectious Disease

Infectious Diseases – An Overview

Infectious ailments arise due to the detrimental micro-organisms that infiltrate the body from external sources. Such micro-organisms consist of viruses, bacteria, fungi, parasites, and in uncommon scenarios, prions. The spread of infectious diseases can occur through contact with polluted water or food, insect bites, and human-to-human interaction. Although certain infectious diseases are not serious, others can be severe.

Difference Between Infectious Diseases and Non-infectious Diseases

According to the continuous medical research and evidence-based findings of Institute of public health, infectious diseases arise from harmful micro-organisms, including bacteria and viruses, that infiltrate the body from external sources. Conversely, non-infectious diseases stem not from external organisms but from genetic predispositions, aging process, anatomical variations, and environmental influences.

Unlike infectious diseases, non-infectious diseases cannot be transmitted from one person to another through insect bites or contaminated food. Illustrative examples of infectious diseases encompass measles, HIV, strep throat, influenza, COVID-19, and salmonella. In contrast, non-infectious diseases comprise cancer, diabetes, heart failure, and Alzheimer’s disease.

Types of Infectious Diseases

Contagious afflictions can be triggered by different microscopic organisms. These include viruses, bacteria, parasites, and fungi. 

  • TSEs, or transmissible spongiform encephalopathies, are an exceptionally uncommon contagious disease. 
  • Viruses are petite compartments of genetic material, including DNA and RNA, that can only reproduce by taking an advantage of a host cell’s tools. 
  • Bacteria are individual-celled creatures located both within and on our bodies, which can result in sickness through the secretion of toxic substances. 
  • Fungi, found in and on our bodies, may cause health problems if there is an exaggerated growth or invasion of hazardous fungi. 
  • Parasites use other organisms as hosts to live and replicate. It comprises helminths (worms) and protozoa (single-celled beings).

Common Infectious Diseases

Infections are detected globally. Yet some infections are prone to occurring more frequently than others. In many countries, one in five persons comes in contact with the influenza virus per year. On the other hand, very few contract prion diseases. The most common types of contagious diseases are below.

Common Diseases Caused by Bacteria 

  • Tuberculosis
  • Salmonella
  • Whooping cough (pertussis)
  • Strep throat.
  • E. coli
  • Sexually transmitted infections, including Chlamydia, gonorrhoea 
  • Urinary tract infections
  • Chloridoids difficile

Common Diseases Caused by Viruses

  • Common cold
  • The flu (influenza)
  • Hepatitis
  • Stomach flu (gastroenteritis)
  • Respiratory syncytial virus
  • COVID-19

Common Diseases Caused by Fungi

  • Ringworm, For example, athlete’s foot
  • Fungal nail infections
  • Thrush
  • Vaginal candidiasis (vaginal yeast infection)

Common Diseases Caused by Parasites

  • Hookworms
  • Pinworms
  • Giardiasis
  • Toxoplasmosis

Risks and Complications of Infectious Diseases 

Individuals from several groups are at a greater risk of developing an infection. These groups include people receiving cancer treatments, those living with HIV, infants, expectant mothers, elderly persons, those who have not been vaccinated, healthcare workers, and people exposed to mosquitos that spread disease. Depending on the infection, long-term repercussions can range from dehydration, pneumonia, sepsis, meningitis, AIDS, and liver cancer, to HPV and cervical cancer.

Symptoms and causes of infectious diseases 

The manifestations of contagious diseases can differ depending on the sickness. In many cases, sicknesses caused by fungi show minimal signs, such as itching and irritation. Additionally, viral, and bacterial illnesses may trigger various effects, including fever, chills, chest tightness, coughing, exhaustion, body aches, and gastrointestinal difficulties like vomiting, nausea, and loose bowels. If your indications persist or worsen, it is essential to consult a doctor.

Different types of illnesses are contracted in multiple ways. Fortunately, most of the time, it is simple to protect oneself from contagion. These pathways include: inhaling germs, kissing, or having sexual intercourse with an infected person, drinking from shared items, touching surfaces that are carrying the disease, coming in contact with faeces from infected animals or people, being bitten by an insect or animal, eating/drinking from unclean sources, gardening or interacting with infected soil or sand, or a mother passing it onto their foetus, or medical practices such as organ transplantation or blood transfusions.

How to Diagnose And Test Infectious Diseases?

Your healthcare provider will identify infectious diseases after conducting one or several laboratory tests. They will assess the health condition by:

  • Taking nose or throat swabs
  • Collecting urine, stool, blood, or saliva specimens.
  • Conducting a biopsy or scraping a small portion of skin tissue 
  • Using X-rays, CT scans, and MRIs to scan body parts.

While certain test results, like nasal swabs, can be obtained quickly, other results take more time. For example, many times, bacteria need to be cultured from a sample in the Lab before the test outcome.

Treatment and Management Protocol for Infectious Diseases

Treating an infection varies according to its cause. In some scenarios, symptom tracking may be more appropriate than taking medication. In the event of a bacterial infection, the best antibiotic is identified by determining the bacterium that triggered it. The management of viral infections usually involves the usage of over-the-counter medicines until the body recovers, though antiviral medications can be prescribed for influenza, and special medicines can be administered for HIV. Fungal infections can be dealt with through anti-fungal medications- oral and topical. Antiparasitic drugs, however, are necessary to treat parasitic infections. Regrettably, prion diseases are not treatable.

Why Antibiotic Resistance occurs?

Over-utilization of antibiotics is creating a rising concern of antibiotic resistance, especially in cases like Methicillin-resistant Staphylococcus aureus (MRSA). To help counter this, medical professionals are exploring various solutions, and individuals can play their part by taking the entire dosage of antibiotics recommended by a physician. Doing so will lessen the chance of bacterial evolution and dissemination.

So how does one ensure infection prevention and control? 

By applying James Reason’s Swiss Cheese Model to infectious diseases, one can minimize the risk of getting and spreading them. There is no single solution to prevent certain illnesses, but there are multiple simple methods to reduce the chance of becoming sick. The approach is comparable to a line of slices of Swiss cheese, where certain pieces may have gaps in them while other slices offer protection. The recommended vaccinations, combined with responsible habits such as food handling safety and frequent handwashing, can give a significant amount of security.

Vaccines bolster the immune system. So, it can recognize and protect against malicious diseases that can cause harm to one’s health. Though one may still contract a virus even after a vaccine, the symptoms are typically much less severe. Vaccines are delivered as a series of shots or occasionally, as a nasal spray.

Biomedical medical science is a significant area as far as public health is concerned. At I3TK, we aim to build a better public healthcare system through innovative means. Our institution provides the best platform for exploring ways to treat diseases concerning human lives.


Vaccines exist for diseases such as Chickenpox, Whooping Cough, Covid-19, Hepatitis A and B, Malaria, Influenza, Human Papillomavirus, polio, Measles, Mumps, Rabies, and Tuberculosis. Travelers should ensure that all the relevant vaccinations for their chosen destination have been administered before their journey begins.

Food Safety 

Food safety should never be underestimated, and there are various measures one can take to minimize the chances of getting infected. Firstly, washing hands with soap and water before, during, and after cooking is an absolute must. Additionally, it is advised to scrub and wash fruits and vegetables before consuming them. Additionally, one should always freeze meat at least -18°C before defrosting and ensure it is cooked thoroughly before being eaten. It is also important to remember to sanitize cooking equipment and cutlery after each use. Furthermore, it is suggested to abstain from consuming raw seafood and avoid untreated water and unpasteurized milk.

Alternate ways for infection prevention and control

Vaccination and correct food-handling techniques are two significant steps for preventing the transmission of contagious illnesses, but there are other everyday practices you can follow. To protect yourself and others from infections, make sure to lather up with soap and water before meals or when you come in contact with animal or human waste or dirt from gardening or manual labor. When sneezing and coughing, remember to cover your nose and mouth. Also, clean often-used surfaces and abstain from contact with people who are ill. Moreover, do not drink or swim in water that may be polluted, and wear a face covering around others if you have a contagious disease. During any sexual intercourse, use a condom for additional safety. Finally, to prevent bug bites, apply an appropriate repellent and cover the skin when outside, and check for ticks afterward.

Outcomes and Prognosis for Infectious Diseases 

Medical attention can facilitate complete healing for those infected by contagious sicknesses; however, in some cases, unfavorable after-effects can still arise, even for those with robust immune systems. HIV and hepatitis B, though not fully curable, can be managed by medications that reduce severe manifestations. Undiagnosed sexually transmitted infections can have disastrous effects, like infertility or cancer, so preventive measures are essential. Fortunately, prion diseases, the most hazardous contagious maladies, are exceedingly rare.

When to call for a Healthcare Provider? 

If there are any ongoing or unusual symptoms of an infectious illness, it is significant to inform the healthcare provider or Institute of public health immediately. Continuous communication with the health provider during a prolonged illness can help to prevent the condition from worsening. Moreover, if you are planning to travel to a foreign country, it is crucial you notify your Health Provider. They can advise appropriate vaccinations for the common infections in the country you are visiting. 


There are various micro-organisms, such as bacteria, viruses, parasites, and fungi found in human surroundings, and they play a crucial role in their survival since they outnumber our human cells. Although certain micro-organisms can be detrimental, there are measures we can take to guarantee good health. It is crucial to note that specific people may have a higher chance of catching an infection. Simple actions like washing our hands and covering our mouths when coughing or sneezing can have a significant impact and could even save lives.


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