COVID-19 FAQ: what is the threat of secondary bacterial infections to patients?


The threat is very real. Research proved that secondary infections (bacterial infections that develop in parallel with viral infections) can significantly increase the number of deaths in a virus outbreak. 

Currently, this can be observed with Covid-19: Chinese researchers have found that half of the patients in their study who died from the illness had secondary bacterial infections. The fact that there is a complicated relationship between viral and secondary bacterial infections is not surprising: for example, a study into the 1918 Spanish flu outbreak highlighted that most deaths in that pandemic were due to secondary bacterial pneumonia and that over 70 per cent of fatalities had the pneumococci or streptococci bacteria in their lungs. A group of researchers in a recent letter to The Lancet medical journal wrote respiratory viral infections, such as caused by SARS-CoV-2 made patients likely to develop bacterial co-infections. These, in turn, could make the disease more severe and increase the number of resulting deaths.

Why does this happen and what can we do? Well, the first thing that happens when you are attacked the SARS-CoV-2 virus is the immune system is put under strain to fight the virus back and in its weakened state allows bacteria to invade the lungs where the virus is already causing damage. Being taken to hospital with COVID-19 increases the risk of serious bacterial infections because of the resistant ‘superbugs’ circulating there. Patients can be treated with antibiotics, but this causes a problem. First, they need to be checked for what kind of bacterial infection they might have and it is a complex process (that can take a few days to identify the bacterial strain), while there is an urgency to keep the patient alive. Knowing the type of bacterial infection they have is important to chose the right antibiotics for treatment. Secondly, however, the overuse of antibiotics increases the risk of bacteria becoming resistant to drugs. Due to the existing problem of antibiotic resistance, doctors are reluctant to use the few antimicrobial drugs that can still kill superbugs. With severely ill Covid-19 patients they have little choice. All this highlights the urgent need to invest in researching new antibiotics and treatment strategies.

Here is the current state of science on a Sparrho pinboard. NB: The pinboard contains research papers that have not been peer-reviewed yet, meaning that they have not gone through the standard scientific validation process yet.


Santhni Subramaniam

by Santhni Subramaniam

PhD Candidate at The University of South Australia. Santhni's research focuses on novel drug delivery strategies for antibiotics against recalcitrant Infections.