Cause, symptoms, complications, treatment, differential diagnosis of COVID-19

1. What is Coronavirus?
Coronaviruses are a family of viruses that can cause respiratory illness in humans. They are called
“corona” because of crown-like spikes on the surface of the virus
CAUSES
COVID-19 is caused by the Severe Acute Respiratory Syndrome Cov-2 Virus abbreviated as SARS-CoV-2
virus.
SYMPTOMS
COVID-19 symptoms vary from person to person. In fact, some infected people don’t develop any
symptoms (asymptomatic). In general, people with COVID-19 report some of the following symptoms:
Fever or chills.
Cough.
Shortness of breath or difficulty breathing.
Tiredness.
Muscle or body aches.
Headaches.
New loss of taste or smell.
Sore throat.
Congestion or runny nose.
Nausea or vomiting.
Diarrhea.
Additional symptoms are possible
MODE OF TRANSMISSION
Current evidence suggests that the virus spreads mainly between people who are in close contact with
each other, for example at a conversational distance.
The virus can spread from an infected person’s mouth or nose in small liquid particles when they:
cough, sneeze or breathe.

2. Another person can then contract the virus when infectious particles that pass through the air are
inhaled at short range (this is often called short-range aerosol or short-range airborne transmission).
When infectious particles come into direct contact with the eyes, nose, or mouth.
The virus can also spread in poorly ventilated and/or crowded indoor settings, where people tend to
spend longer periods of time.
When you touch surfaces that someone who has the virus has coughed or sneezed on. You may touch a
counter top or doorknob that is contaminated and then touch your nose, mouth, or eyes.
COMPLICATIONS
Complications of COVID-19 may include the following;
Acute Respiratory Failure: Lungs' failure to pump enough oxygen
Pneumonia: Inflammation of the lungs
Acute Respiratory Distress Syndrome (ARDS): Damage to the lungs causing fluids to leak into them
Acute Liver Injury: Sudden injury to the liver.
Heart problems such as heart failure.
Acute Kidney Injury
Septic Shock( sepsis): Released chemicals into the bloodstream to fight illness do not trigger the right
response resulting into damage to certain organs.
DIC( Disseminated Intravascular Coagulation): Failure of the body’s clotting response resulting into
abnormal clot formation leading to internal bleeding or organ failure.
Mult-system Inflammatory Syndrome in Children( MIS-C)
Chronic Fatigue: includes severe symptoms such as brain fog, dizziness, trouble thinking, pain and
severe fatigue
Treatment
Treatments for COVID-19 vary depending on the severity of your symptoms. If you’re not in the hospital
or don’t need supplemental oxygen, no specific antiviral or immunotherapy is recommended.
Depending on the severity of your COVID symptoms, you may need:
Supplemental oxygen (given through tubing inserted into your nostrils).
Some people may benefit from an infusion of monoclonal antibodies.

3. Antiviral medications may reduce the risk of hospitalization and death in certain patients with COVID-19.
Mechanical ventilation (oxygen through a tube inserted down your trachea). You are given medications
to keep you comfortable and sleepy as long as you’re receiving oxygen through a ventilator.
Extracorporeal membrane oxygenation (ECMO). You continue to receive treatment while a machine
pumps your blood outside your body. It takes over the function of your body’s lungs and heart.
DIFFERENTIAL DIAGNOSIS
The distinguishing of a disease or condition from others presenting with similar signs and symptoms.
Community-acquired pneumonia
Differentiating COVID-19 from community-acquired bacterial pneumonia is not usually possible from
signs and symptoms. However, patients with bacterial pneumonia are more likely to have rapid
development of symptoms and purulent sputum. They are less likely to have myalgia, anosmia, or
pleuritic pain
Influenza infection
SIGNS / SYMPTOMS
Differentiating COVID-19 from community-acquired respiratory tract infections is not possible from signs
and symptoms. However, fever is less common with influenza. Rhinorrhea, sore throat, myalgia,
headache, and dyspnea are more common.[644][645] New-onset smell and/or taste disorders were less
common in a case-control study.[646]
More common in children.[647] Children with COVID-19 tend to be older, and are more likely to have
comorbidities, fever, gastrointestinal symptoms, headache, and chest pain compared with those with
influenza.
Coinfection is possible, but is not significantly associated with mortality.[649] Coinfection is higher in
children and critically ill patients.[650]
Only testing can distinguish between influenza infection and COVID-19 and identify coinfection..
Differentiating COVID-19 from community-acquired respiratory tract infections is not possible from signs
and symptoms. However, fever is less common with the common cold, and headache, rhinorrhea,
myalgia, and sore throat are more common. Patients may have a greater number of general
symptoms.[645]
INVESTIGATIONS

4. RT-PCR: positive for causative organism; negative for SARS-CoV-2 viral RNA (coinfections are possible).
Pulmonary tuberculosis
SIGNS / SYMPTOMS
Consider diagnosis in endemic areas, especially in patients who are immunocompromised.
History of symptoms is usually longer.
Presence of night sweats and weight loss may help to differentiate.
INVESTIGATIONS
Chest x-ray: fibronodular opacities in upper lobes with or without cavitation; atypical pattern includes
opacities in middle or lower lobes, or hilar or paratracheal lymphadenopathy, and/or pleural effusion.
Sputum acid-fast bacilli smear and sputum culture: positive.
Molecular testing: positive for Mycobacterium tuberculosis
Middle East respiratory syndrome (MERS)
SIGNS / SYMPTOMS
Travel history to the Middle East or contact with a confirmed case of MERS.
Differentiating COVID-19 from MERS is not possible from signs and symptoms. However, the clinical
course of MERS is usually more severe and the case fatality rate is higher.
INVESTIGATIONS
Reverse-transcriptase polymerase chain reaction (RT-PCR): positive for MERS-CoV viral RNA.
Other viral or bacterial respiratory infections

5. SIGNS / SYMPTOMS
Differentiating COVID-19 from community-acquired respiratory tract infections is not possible from signs
and symptoms.
Adenovirus and Mycoplasma should be considered in clusters of pneumonia patients, especially in
closed settings such as military camps and schools.
INVESTIGATIONS
Blood or sputum culture of molecular testing: positive for causative organism.
RT-PCR: negative for SARS-CoV-2 viral RNA (coinfections are possible
PREVENTION AND CONTROL MEASURES
Getting tested for COVID-19 infection.
Getting vaccinated
Wear a multilayered cloth facemask that fits snugly on your face and covers your mouth, nose and chin
as recommended by the CDC.
Avoid touching your eyes, nose and mouth to prevent the spread of viruses from your hands.
Cover your mouth and nose with a tissue when sneezing and coughing or sneeze and cough into your
sleeve. Throw the tissue in the trash. Wash your hands afterward. Never cough or sneeze into your
hands!
Avoid close contact (within 6 feet) with those who have coughs, colds or are sick. Stay home if you’re
sick.
If you’re prone to sickness or have a weakened immune system, stay away from large crowds of people. .

6. Clean frequently used surfaces (such as doorknobs, phones, remote control and countertops) with a
virus-killing disinfectant.
Don't share personal items like dishes, utensils, and towels.
Use hand sanitizers that contain at least 60% alcohol if soap and water are not available.
Greet people with a friendly gesture instead of shaking hands.
Get enough sleep, eat a healthy diet, drink plenty of liquids and exercise if you are able. These steps will
strengthen your immune system and help you fight off infections more easily.
Quarantine and work from home.
REFERENCES
Centers for Disease Control and Prevention. CDC Updates and Shortens Recommended Isolation and
Quarantine Period for the General Population (https://www.cdc.gov/media/releases/2021/s1227-
isolation-quarantine-guidance.html). Accessed 3/1/2022.
Centers for Disease Control and Prevention. COVID-19 (https://www.cdc.gov/coronavirus/2019-
ncov/index.html). Accessed 3/1/2022.
Centers for Disease Control and Prevention. COVID Data Tracker. (https://covid.cdc.gov/covid-data-
tracker/?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fcoronavirus%2F2019-ncov%2Fcases-
updates%2Fcases-in-us.html#cases_casesper100klast7days) Accessed 3/1/2022.
Infectious Disease Society of America. COVID-19 (https://www.idsociety.org/). Accessed 3/1/2022.
Mallapaty S. COVID reinfections surge during Omicron onslaught
(https://pubmed.ncbi.nlm.nih.gov/35173320/). Nature. 2022 Feb 26. (Online ahead of print). Accessed
3/1/2022.
National Health Service (UK). How to look after yourself at home if you have coronavirus
(https://www.nhs.uk/conditions/coronavirus-covid-19/self-isolation-and-treatment/how-to-treat-
symptoms-at-home/). Accessed 3/1/2022.
National Institutes of Health. COVID-19 Treatment Guidelines
(https://www.covid19treatmentguidelines.nih.gov/). Accessed 3/1/2022.
Centre for Evidence-Based Medicine; Heneghan C, Pluddemann A, Mahtani KR. Differentiating viral from
bacterial pneumonia. Apr 2020 [internet publication].
World Health Organization. Coronavirus (https://www.who.int/health-topics/coronavirus). Accessed
3/1/2022.