Everybody knows you usually don’t get a cold in the summer. Fall, winter and spring are much more likely seasons for respiratory viruses to thrive in.
Except that the COVID-19 pandemic has disrupted historic cycles, meaning now you can expect respiratory viruses to flare up in the warmer summer months, health care experts say.
“A lot of these nonspecific respiratory illnesses going around are likely due to coronavirus,” said Dr. Robert Atmar, professor of infectious diseases at Baylor College of Medicine.
Those currently detected by local Houston-area hospitals include Rhinovirus, the most frequent case of the common cold; Respiratory Syncytial Virus or RSV; Human Metapneumovirus or hMPV; and Parainfluenza Type 1 through Type 4.
According to Atmar, during the pandemic when people were engaging in protective practices such as washing their hands or remaining socially distant – at least five feet away from each other – these viruses virtually went away.
Then as people moved away from these preventative measures, they altered the way these viruses were transmitted from person to person. Illnesses that were expected in November and December, came as early as June or July.
Dr. Michael Chang, pediatric infectious disease specialist at UTHealth Houston affiliated with Children’s Memorial Hermann Hospital said this was the case especially with RSV – an upper respiratory illness that causes mild, cold-like symptoms.
RSV is usually most common in the fall and mid-to-late winter; however, these last two years, this disease has infected primarily children younger than three years old and older adults during the summer time.
“Over the last few summers, there have been pretty big spikes of RSV, which is not typical,” Chang said. “This was completely turned upside down by COVID-19; it is definitely something to keep an eye on in the next few weeks to see if we have a spike this year.”
According to Chang, RSV was not the only virus to show up then, as hMPV an upper and lower respiratory tract disease also randomly spiked last summer – despite tending to peak in late winter or spring.
This largely had to do with the world “opening up the floodgates” for the first time since the pandemic began. Almost everything was back in operation by then, which led to a significant increase in all kinds of exposures, Chang said.
However, unlike RSV – which he said was still unpredictable – hMPV seems to have returned to its normal pattern a bit faster as cases remain relatively low.
And this year’s peak occurred in March when 11 percent of tests were positive, which is 36 percent higher than the average pre-pandemic peak of 7 percent, according to the Centers for Disease Control and Prevention.
Despite the higher than average number of infections, the timing of the spread of the virus was during its regular season.
And although some physicians are treating more cases recently than they had seen a few weeks ago, Atmar said it is unlikely cases will increase that much this summer as they have since decreased.
As for COVID-19 cases, numbers remain low, as do hospitalizations and deaths; with 1,761 new confirmed cases reported last week, down from the 3,170 new confirmed cases from the week before, according to the Texas Department of State Health Services.
Unlike RSV and hMPV, Chang said COVID-19 does not appear to have a season yet, which makes it difficult to determine when or if cases will increase.
Due to the number of people who have either had the virus or are immunized for it, he does not anticipate an increase in the number of cases this summer – but instead a slow plateau.
Which Atmar said would be different from past summers, as COVID-19 tended to peak during these warmer months.
Atmar said there is a slight chance for the virus to peak again this summer; but the impact of the waves of COVID-19 have decreased over the course of the last three years – so even if it did cases would likely be a lot lower when compared to past summers.
According to Atmar, as people move further and further away from pandemic behaviors, the likelier it will be that people will see more typical seasonality of these viruses, he said.
“The way the pandemic disrupted a lot of different respiratory viruses circulate makes it a little bit hard to know what is going to happen and whether we’ll see some of the viruses that typically are fall-winter or spring viruses in this summer – like we have these last few years,” he said.
This article appears in Jan 1 – Dec 31, 2023.
