What is the meaning of asymptomatic?
The term asymptomatic refers to the absence of symptoms. It can apply to an individual, a disease, or even a stage of the disease. Symptoms such as fever, shivering, pain, bloating, diarrhea, and coughing are signs that help us diagnose diseases. Therefore one might think that asymptomatic people are not sick: this is not true. An asymptomatic person is a patient who does not know that he or she is sick. Therefore, an asymptomatic person can often transmit a disease, even if he or she does not suffer the consequences – at least not immediately! Some diseases have a long asymptomatic phase, which slows down their detection before they become symptomatic a few years later.
The term asymptomatic can sometimes be confused with “healthy carrier”, which refers to a person carrying a virus or other micro-organism without symptoms. This phrase is sometimes used in former patients, who still carry bacteria or viruses, but with sufficient control over their population so that they do not pose any risk. This is the case for former patients with typhoid or, more recently, for asymptomatic persons with SARS-Cov-2.
There are different types of asymptomatic patients
Presymptomatic Transmitters: It is the sick who carry a germ inside them and transmit it before they themselves are affected by the symptoms. This is the case with Covid 19 disease, where the disease can be transmitted before the disease develops.
Convalescent Transmitters: This time the infection occurs after the disease. In fact, shortly after the disease, the bacteria or virus can still be present in our body and thus be transmitted to others.
Asymptomatic transmitters: This is the purest version of the asymptomatic, linked to the term “healthy carrier”. This time the infectious patient will never show symptoms.
What are asymptomatic diseases?
There are several diseases where asymptomatic patients make up a large chunk. Often these diseases have an asymptomatic first phase. Here is an example of such diseases:
- The Zika virus
- Coronaviruses (such as Sars-Cov2, which has been on the rise since the end of 2019)
- Cancer (hence the importance of screening, especially for breast cancer)
- HIV (AIDS virus)
- Typhoid fever
- STDs such as Chlamydia, HPV, gonorrhea, Herpes and Trichomoniasis
- Epstein-Barr virus
- Hepatitis B and C
A famous example: Typhoid Mary
Between 1900 and 1907 Mary Mallon, originally from Ireland, worked as a cook in the United States. Without knowing it, she was asymptomatically ill with typhoid, a contagious disease caused by the presence of a bacterium resembling salmonella. The cook infected more than 50 people during the preparation of her dishes and created mini clusters everywhere she worked. It was only after 1907 that the doctors realized that she was a “healthy carrier” of the disease since she had never shown symptoms of typhoid fever herself. She denied this accusation and resumed her work as a cook under a different name! After two deaths from her new infections, she was forced to remain in quarantine for the rest of her life. From that moment on, she was remembered as “Typhoid Mary “.
What are the risks?
You might think that being asymptomatic is a good thing; who would really want to suffer from the symptoms of a disease? However, this is misleading, a bit like people who do not feel pain due to sensory issues: without pain, one exposes oneself to more serious dangers. Therefore, there are several possible risks:
Late Diagnosis: An asymptomatic patient may develop symptoms that are more severe later on that could have been mitigated had he felt symptoms earlier. Hence the importance of screening tests, to be able to make a diagnosis even without symptoms. Catching cancer early before it shows symptoms could increase the chances of survival dramatically.
Risks during pregnancy: Pregnant women are also tested during pregnancy for signs of asymptomatic diseases. Because if the mother is not showing symptoms, the fetus may develop symptoms at birth. This is, for example, the case with the Zika virus, which can reduce the development of the skull and the brain capacity of children.
Diagnosis of asymptomatic diseases
Diagnosis of diseases that are not causing visible symptoms usually require urine or blood tests to immediately check for the presence of bacteria or viruses in the individual.
When the symptoms are still in their infancy, it is important to be able to detect more subtle signs. This is the case during breast cancer screenings for example, where we look for the presence of abnormal lumps, even without the patient feeling any discomfort or pain.