Respiratory infections often cause worry, especially when symptoms overlap, making diagnosis difficult. Strep throat is a bacterial infection caused by Streptococcus pyogenes (Group A Streptococcus) that typically targets the throat and tonsils. In contrast, COVID-19 is a viral illness caused by the SARS-CoV-2 virus, affecting the respiratory system and potentially multiple organs. Simultaneous infection, known as co-infection, is biologically possible, though not common.
Why Co-infection Occurs
Co-infection is possible because both pathogens use similar routes of transmission. Both the SARS-CoV-2 virus and Streptococcus bacteria spread through respiratory droplets released when an infected person coughs or sneezes. Inhaling these droplets exposes the individual to both the viral and bacterial agents simultaneously.
A primary viral infection, such as COVID-19, can make the body more susceptible to a secondary bacterial invader. SARS-CoV-2 can damage the lining of the respiratory tract, which normally acts as a physical barrier against microbes. This damage allows bacteria like Streptococcus pyogenes to more easily colonize the area, leading to an opportunistic infection.
A significant viral load can also temporarily suppress the immune system as the body fights the primary infection. This compromised response may fail to effectively neutralize the Group A Streptococcus bacteria, allowing it to establish itself in the throat. This risk increases during seasons when multiple respiratory pathogens are actively circulating.
How Symptoms Differ
Distinguishing between Strep throat and COVID-19 is challenging because they share general symptoms like fever, headache, and malaise. However, specific characteristics can help differentiate the two infections, especially without testing. Strep throat symptoms tend to begin suddenly and are highly focused on the throat.
A hallmark sign of Strep throat is severe pain when swallowing, often accompanied by red, swollen tonsils. A physician may observe white patches, streaks of pus, or tiny red spots (petechiae) on the roof of the mouth. Strep throat is typically not accompanied by a cough, which is a major distinguishing factor.
COVID-19, in contrast, often presents with a broader range of systemic symptoms and tends to have a more gradual onset. Common manifestations include a persistent dry cough, which is rare in Strep throat. Key signs for COVID-19 are the temporary loss of taste or smell, and potential shortness of breath.
COVID-19 can also cause severe body aches, prolonged fatigue, and nasal congestion, which are less typical primary symptoms of an uncomplicated Strep infection. When co-infection occurs, the symptom presentation can be significantly more severe or prolonged than with either illness alone.
Testing and Treatment Approaches
Relying on clinical presentation alone is insufficient for diagnosis due to the symptom overlap, making specific testing for both pathogens necessary. For COVID-19, diagnosis relies on molecular tests like the Polymerase Chain Reaction (PCR) test for accuracy, or rapid antigen tests for quick results. These methods detect the presence of the SARS-CoV-2 virus.
To diagnose Strep throat, a healthcare provider performs a rapid strep test using a throat swab, which delivers results within minutes. If the rapid test is negative but suspicion remains, the sample may be sent for a throat culture, a more definitive method for identifying the Group A Streptococcus bacteria. Testing for both infections is important when symptoms are ambiguous.
Treatment protocols differ fundamentally because one infection is bacterial and the other is viral. Strep throat requires a full course of antibiotics, such as penicillin or amoxicillin, to eliminate the bacteria and prevent complications like rheumatic fever. Completing the entire prescribed course ensures eradication and prevents antibiotic resistance.
Treatment for COVID-19 focuses on supportive care, including rest, hydration, and fever-reducing medication. For high-risk individuals, specific antiviral medications, like Paxlovid, may be prescribed to reduce the risk of severe disease. In cases of co-infection, the patient requires dual treatment: antibiotics for the bacterial Strep infection and supportive care or antivirals for the viral COVID-19 infection.