Covid-19: Why patients develop dry cough and fever

an illustration of young ill woman coughing with fist in front of mouth. PHOTO | FOTOSEARCH

What you need to know:

  • Only asymptomatic patients are being tested for Covid-19 in government facilities to cut the virus transmission.
  • For fever, it’s normally about the immune system reacting to a foreign body.

From coughing and shortness of breath to losing your sense of taste and smell, the list of Covid-19 symptoms keeps growing.

The pandemic started off with a short list of symptoms — most patients were developing a cough, body aches, fever and occasional sore throat.


Later, doctors added losing the ability to smell and taste along with digestive problems.

In Kenya, according to the data from the Ministry of Health, out of the 3,106 positive cases reported in so far, only 20 per cent are symptomatic. The rest do not present with any symptoms.

According to the data, cough and fever are predominantly present at 49 and 44 per cent respectively followed by shortness in breathing at 31 per cent, with 19 per cent of the patients having a headache.

“These are the people we need to monitor closely. The transmission is easier and with the symptoms, they can easily develop complications in worse scenarios,” Prof Matilu Mwau, a researcher at the Kenya Medical Research Institute told the Nation.


This is even as the government changes its narrative and is now concentrating on people with symptoms.

Only asymptomatic patients are being tested for Covid-19 in government facilities to cut the virus transmission.

The World Health Organization head, Dr Van Kerkhove, urged countries to focus on following asymptomatic patients to cut the transmission of the virus. “If we followed all the symptomatic cases because we know this is a respiratory pathogen which passes from an individual through infectious droplets, isolated those cases, followed the contacts and quarantined them, we would drastically reduce transmission,” Dr Kerkhove said.

Explaining why many patients present with the symptoms, Dr Isaac Ngere, a medical epidemiologist, said since Covid-19 is a respiratory infection, it gets through the respiratory route and causes infection to the lungs.

It binds specific receptors in the body, which are abundant in the lungs. When tissue is compromised, the patients get irritation, hence the dry cough symptom.


“Once in the lungs, it irritates the system and that’s why you find more people trying to clear the throat by a cough to remove the foreign materials,” he explained

As the disease goes on in the lungs, the body naturally tries to remove the fluids in the lungs through coughing and because the lung tissues are damaged by the virus, breathing becomes shallower and many people develop breathing problem.

“That’s why you find many patients struggling to breathe. You breathe so hard but there is no enough oxygen, hence the shortness in breath,” he said.

For fever, it’s normally about the immune system reacting to a foreign body. When one has a virus, it gets into cells and damages them while triggering a response, and this is when the body produces a chemical to raise the body temperature.

The body needs a higher temperature so that it can fight microorganisms. Further, the temperature can be a reason for an infection in the respiratory system.


“A fever can help your immune system to fight infections in two ways. A higher temperature in the body speeds up the functioning of cells, including the ones that fight illness. They can respond to invading germs faster. Also, higher body temperatures make it harder for bacteria and viruses to thrive in the body,” Dr Ngere said.

His sentiments were echoed by Dr Eric Osoro, a doctor and an epidemiologist who explained that once the virus gets through the mouth, it passes to the mucous membranes in the throat.

At this point, he said, some patients develop a cough while others get fever depending on how their body reacts to the foreign virus.

“The virus moves down your respiratory tract. That’s the airway that includes your mouth, nose, throat, and lungs. Your lower airways have more receptors than the rest of your respiratory tract. So Covid-19 is more likely to go deeper than other viruses,” he said.

These, he said, causes damage to the lungs, which leads to fluid leaking from small blood vessels in the lungs. The fluid collects in the lungs’ air sacs, making it difficult for the lungs to transfer oxygen from the air to the blood and hence the breathing difficulty. “This is when a patient develops a fever,” he said.