Today, the term infectious disease is often spoken and heard, and is used with almost careless abandon in casual conversation. Other familiar terms are used equally often with the same broad meaning, such as transmissible disease and communicable disease.
All too often the term is used with very little understanding of the term’s full meaning. In reality, the term “infectious disease”, is a broad, widely encompassing, multi-faceted term. So, what does the term really mean?
An infectious disease is a health disorder whose source is that of another living organism that is hostile to the human being. Within the human body there are millions of living organisms, collectively, they are referred to as the human microbiota. Living microbes and bacteria are constant in the nose, mouth and gut, whilst also existing on the entire surface of the skin.
These organisms take the form of fungi, viruses, protozoa, multicellular parasites or aberrant proteins, which are referred to as prions. For the most part, these millions of hosted organisms coexist with the human body as its host. In fact, many of them are of great benefit to the overall health and wellbeing of the human body.
However, some organisms are pathogenic. That is to say that they invade the body, multiply and attack the host. In humans, that can lead to sickness and disease. The transmission of these biologic organisms happens via several differing conduits.
Inhalation of Pathogens
One of the most common ways of contracting an infectious disease is via the inhalation of airborne agents. People that are carrying a disease are very likely to spread it, albeit unwittingly. Sneezing, coughing and even talking can cause throat and nasal secretions to spew into the air.
These airborne particles are incredibly small and are easily inhaled by others. Topically, we are well aware of this by the way in which the Covid 19 virus spread throughout the world. Other common diseases that can spread in this way include, influenza, mumps, chicken pox, measles, whooping cough, tuberculosis and of course the common cold. It should be noted however that these conditions are not solely transferred by airborne particles.
Infection by Direct Contact
Direct contact, literally touching, an infected person is another sure-fire way of disease transmission. Through touch, pathogens can be transferred from the skin’s surface of an infected person to that of another. Although unable to multiply on the skin, they are easily transferred to the inner body by then touching the person touching their mouth, nose or rubbing their eyes.
The previously mentioned diseases can all be transferred in this way, plus many more. Hepatitis A and B are commonly contracted this way, as is herpes simplex, otherwise known as cold sores. Conjunctivitis, pertussis, adeno/rhino viruses, neisseria meningitidis and mycoplasma pneumoniae can all be transferred through direct contact with an infected person.
Genetic, or inherited, disease is an immensely complex area of medicine, and may diseases can be inherent. A sufferer may inherit a gene change from a single parent. This is known as an autosomal dominant single-gene disorder. Typical examples of this include: Huntington disease, Marfan syndrome, and Neurofibromatosis type 1.
Others may suffer because both parents contribute to a change in the gen order. Medically, this is referred to as an autosomal recessive single-gene disorder. Some typical disorders include: congenital deafness, cystic fibrosis, beta thalassemia, sickle-cell anemia, Tay Sachs disease and spinal muscular atrophy, or SMA.
It must be pointed out that some diseases that are said to “Run in the family”, are somewhat more complex. These are diseases that develop due to genetic changes and additional influencing factors, such as lifestyle, diet and the environment.
Diseases and disorders with these complex inheritance patterns may include: cancers, in their many and varied forms, arthritis, dementia, diabetes, Alzheimer’s, multiple sclerosis, Parkinson’s disease, high blood pressure, heart disease. spina bifida, and various thyroid disorders.
Infectious Disease Diagnosis
As with any disease, early diagnosis is vital to ensure the best possible chances of cure or control. From an early age testing can be carried out for all manner of diseases, and the Samitivej Hospital Infectious Disease Clinic is the leader in this field of medical science.
There are of course an almost incalculable number of infectious diseases. As such, in many cases, diagnosis is not simple and straight forward. In many cases, extracting body fluids for sample analysis can determine the presence of disease. It maybe that blood and urine tests are sufficient. In other cases, it might be a throat swab, stool sample or a spinal tap. Al of which are carried out by Samitivej Hospital’s highly trained personnel.
Imaging scans are another valuable tool in diagnosing infectious diseases. These include more hi-tech approaches, such as modern X-raying techniques, magnetic resonance imaging and computerized tomography. These diagnostic procedures help the specialized practitioners build a visual picture of any abnormalities that may exist.
Biopsies are an accurate method by which doctors can pin point and diagnose a broad spectrum of diseases. A biopsy is where a small sample of tissue is taken from an organ which can then undergo lab testing for precise diagnosis. An example might be the extraction of a small piece of lung tissue which can then be tested for fungi that can cause pneumonia.
Infectious Disease Treatment
Following an accurate diagnosis at Samitivej Hospital’s Infectious Disease Clinic a tailored treatment plan will then be drawn up by the specialist teams. By far, antibiotics remain the main weapon in fighting infectious diseases.
Antibiotics, just like bacteria, are grouped into “Families”, with all those of a similar type being grouped together. Although there are literally hundreds of different antibiotics, the majority of them fall into one of six groups. They being, penicillin’s, cephalosporins, fluoroquinolones, macrolides, aminoglycosides, and tetracyclines.
Antivirals have been developed, and continue to be, for many viral diseases, but not all. The most commonly used antiviral is for influenza. But, at the Infectious Disease Clinic, other antivirals are regularly used to treat: HIV/AIDS, hepatitis B & C, and herpes.
Antifungals are likely to be prescribed for fungal infections. These might be topical, to treat skin of nail diseases, or administered orally to treat infections that are affecting the lungs or mucus membranes. In more severe cases, or in cases where the patient has a weakened immune system, they can introduced intravenously.
There are also antiparasitic medications for diseases caused by parasites. The parasitic disease that most people are probably familiar with is malaria. Development into antiparasitic drugs continues, as it is known that many parasites quickly develop immunity to antiparasitic medication.
Samitivej Hospital’s Infectious Disease Clinic is, and will remain, at the forefront of infectious disease diagnostics and control. Lead by internationally trained physicians, the facility continues to push the boundaries of knowledge in this ever evolving, specialized area of the medical profession.