COVID-19 Pandemic Precautions Have Profound Impact on Other Respiratory Tract Infections

By: Garrett Coleman

Figure 1: Andrew Weynand, MHS

It’s a story we know all too well, at the start of 2020, SARS-CoV-2, the culprit of COVID-19, quickly spread across the world. Within months, countries began implementing health and safety measures including social distancing, quarantine, isolation, sanitation, and mask wearing to reduce the spread of COVID-19. All of these measures were implemented to reduce transmission of COVID-19, but how did these measures affect the transmission of other respiratory viruses?

Austin Weynand, MHS is a second-year medical student and One Health Collaborator at UTMB. Prior to starting his medical degree at UTMB, Austin received his Master of Health Science in Epidemiology at Johns Hopkins School of Public Health in 2021. Part of his research included a study on the transmission of respiratory viruses in rural Zambia before and during the COVID-19 pandemic which was recently published in Tropical Medicine & International Health.

In 2018, researchers from John Hopkins partnered with Zambian healthcare workers and established surveillance for respiratory infections at the Macha Hospital in Southern Province, Zambia. Patients were tested for respiratory pathogens if they presented with influenza like symptoms. Prior to COVID-19 the most prevalent infections included influenza A, respiratory syncytial virus (RSV) and rhinovirus/enterovirus. After the introduction of COVID-19 into Zambia, the most prevalent infections included parainfluenza virus, human metapneumovirus, and rhinovirus/enterovirus. Interestingly, in 2020, there were no positive cases of influenza A, RSV, or SARS-CoV-2.

Several reasons were hypothesized for the decline in seasonal flu cases in 2020. At the start of the COVID-19 pandemic, the Zambian government combatted the SARS-CoV-2 virus using mask mandates, limiting travel, and banning social gatherings. These social distancing measures and increased mask mandates likely halted the spread of influenza viruses which have a similar route of transmission. While cases of SARS-CoV-2 were prevalent in the urban capital, Lusaka, few cases were likely to be imported from the capital due to travel restrictions as well as the rural nature of the region where the current study took place.

Structural and transmission-related properties of enteroviruses/rhinoviruses could result in continued circulation of these viruses despite public health measures. These viruses are non-enveloped allowing them to be more stable in the environment and resistant to disinfectants. Moreover, these viruses are effectively transmitted via fomites, which are less preventable with masking. These factors can be enhanced in the rural setting since hygiene-related interventions are more difficult to implement and travel restrictions are more effective in preventing introductions of seasonal viruses in remote areas.

Next, the team hopes to conduct a longitudinal study to understand the differences in clinical presentation between influenza A virus and SARS-CoV-2.

The full article can be found here.

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