In a recent study published on medRxiv* preprint server, researchers explored the impact of non-pharmaceutical preventive measures associated with the coronavirus disease 2019 (COVID-19) pandemic on the transmission of 22 infectious diseases in England.
Efforts to contain the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the early days of the pandemic before the widespread availability of COVID-19 vaccines consisted of government-initiated lockdowns, the wearing of masks and social distancing measures. Public health communications also strongly encouraged handwashing.
Studies suggest that in addition to limiting the transmission of SARS-CoV-2, these measures could have affected the transmission of other airborne or fecal-oral pathogens.
About the study
In the current study, the researchers used data from three sources – the UK Health Safety Agency (UK), the Royal College of General Practitioners Center for Research and Monitoring and the Office for UK National Statistics – to analyze the transmission patterns of 22 pathogens. in England during the COVID-19 pandemic.
The study investigated the transmission of diseases that are spread by aerosolized droplets, direct contact, blood, vectors and the fecal-oral route. Airborne diseases included chickenpox, measles, mumps, rubella, tuberculosis, influenza, pneumococcal disease, whooping cough, strep throat, and scarlet fever.
Herpes simplex virus, methicillin resistant Staphylococcus aureus (MRSA), urinary tract infections, and skin and subcutaneous tissue infections were the studied diseases that are spread by direct contact. Skin and subcutaneous tissue infections include cellulitis, folliculitis, abscesses, trauma-related infections, and other necrotizing or uncomplicated conditions of the skin and subcutaneous fat that cause erythema , inflammation and pain.
Faecal-oral transmitted diseases included hepatitis E, norovirus, shigellosis, cryptosporidiosis, infectious intestinal diseases and foodborne diseases. Infectious bowel diseases generally refer to diseases of the small intestine, stomach or intestines, such as gastroenteritis, typhoid and cholera, which cause diarrhea, abdominal pain and vomiting. The vector-borne disease examined in the study was Lyme disease, while the blood-borne disease was hepatitis C.
The transmission patterns of these pathogens were examined in association with the COVID-19 preventative measures implemented between March 2020 and February 2022 in the UK. Key measures include the first and second lockdowns, which started on March 23 and November 5, 2020, respectively. The first vaccination administration and the third confinement, which took place on the following days (January 4 and 5, 2021), were also included in the study.
The results showed a decrease in cases of all infectious diseases except MRSA, Lyme disease and hepatitis E after the first lockdown. The authors believe that since MRSA primarily occurs in hospitals, the increase in MRSA cases during increased hospitalizations during COVID-19 made sense.
While Lyme disease cases did not show a marked decrease during the first lockdown, the number of cases decreased during the COVID-19 pandemic. Nine out of 10 airborne diseases and four out of six faecal-oral transmitted diseases showed a significant reduction in cases from the time preventive measures against COVID-19 were implemented. Tuberculosis was the exception in airborne diseases, which the authors believe could be explained by delayed diagnoses during shutdowns or co-infections of tuberculosis with COVID-19.
Despite concerns that interrupting routine vaccinations would lead to a resurgence of vaccine-preventable infections, diseases such as mumps, measles, rubella, pneumococcal disease, influenza and whooping cough remained suppressed even after the lifting of restrictions. However, non-vaccine preventable diseases such as scarlet fever, strep throat and chickenpox (vaccination not routinely provided in the UK) showed an increase after preventive measures against COVID-19 were stopped.
With decreased human interactions and lockdowns leading to reduced exposure to the environment and common pathogens, concerns have been raised about increasing disease outbreaks due to reduced overall immunity. However, the study reported that only four of the 22 diseases examined showed an increase in transmission beyond pre-COVID-19 levels. These were chickenpox, skin and subcutaneous infections, herpes simplex and infectious intestinal diseases.
Overall, the study indicated that non-pharmaceutical COVID-19 mitigation strategies such as lockdowns, social distancing, and hand washing significantly reduced the spread of other infectious pathogens, especially those transmitted via aerosol droplets and the fecal-oral route.
Lack of exposure to common pathogens during lockdowns and other social distancing measures did not reduce overall immunity or lead to outbreaks after these measures were stopped, exception of chickenpox, herpes simplex and skin and intestinal infections. However, whether the increased incidence of these four diseases is related to COVID-19 measures has not been investigated.
Vaccine-preventable diseases remained suppressed even after COVID-19 restrictions were lifted. Yet diseases such as chicken pox have increased, underscoring the need to integrate varicella vaccines into the routine immunization program in the UK.
medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be considered conclusive, guide clinical practice/health-related behaviors, or treated as established information.