Enlarge / Parents with children who are suffering from respiratory diseases are lining up at a children's hospital in Chongqing, China, on November 23, 2023. (credit: Getty | Costfoto/NurPhoto )

Last week, news stories and a posting on an infectious disease surveillance system raised fears that another novel respiratory pathogen with pandemic potential was mushrooming in northern areas of China—namely Beijing and Liaoning province. The reports referenced " undiagnosed pneumonia " in " clusters " of children, hospitals that were "overwhelmed," and parents who were questioning whether "authorities were covering up the epidemic."

But, rather than a sequel to the COVID-19 pandemic, the situation appears to be merely a side effect of it. According to independent experts and the World Health Organization, it's most likely that China is now experiencing a roaring comeback of a mix of common respiratory infections that were muted during the global health crisis. Many other countries experienced the same surges in the past year or two, including the US. As with the other countries, the wave of infection in China is mostly affecting children, who were less exposed to all sorts of pathogens amid the health restrictions, leaving them more vulnerable to infections now.

The global explosion of COVID-19 transmission and subsequent pandemic health measures severely disrupted common cycles of many infectious diseases worldwide, knocking seasonal respiratory infections like adenoviruses and RSV (respiratory syncytial virus) off their annual cycles. In the US, the 2020-2021 flu season was virtually nonexistent, for instance. But, as the novel coronavirus abated and restrictions lifted, those pathogens vigorously returned. (The US also experienced early and intense peaks of RSV and flu last year.)

Enlarge / Travelers walk through Union Station as they travel ahead of the Thanksgiving holiday in Washington, DC, November 21, 2023. (credit: Getty | Saul Loeb )

As Americans prepare for the Thanksgiving holiday this week, respiratory viruses are ramping up, creating hazardously infectious conditions for mass travel and multi-generational family gatherings.

Flu is on the rise in most of the country, with six Southern states and the District of Columbia already seeing high levels of influenza-like illnesses (ILI) activity. Louisiana has reached "very high" ILI activity, the Centers for Disease Control and Prevention reported in the latest flu surveillance update . The percentage of flu tests coming back positive is also increasing nationwide, with only one region, the Mid-Atlantic region, showing a stable week-over-week positivity rate. But the CDC noted that its rate overall is trending upward.

This year's flu season is again starting early; the current flu activity levels are about four to six weeks ahead of when we usually see them. And with activity already at highs in many states, there's a good chance that we'll once again see extremely high levels in some places—moving from red to the dreaded deep purple on CDC's scale, which we saw last year.

Enlarge / A baby with measles. (credit: CDC )

The World Health Organization and the US Centers for Disease Control and Prevention are sounding the alarm over the global rise of measles cases, deaths, and outbreaks as vaccination rates struggle to recover from a crash during the COVID-19 pandemic.

Between 2000 and 2019, estimated worldwide coverage of the first dose of a measles-containing vaccine rose from 72 percent to 86 percent. But amid the global public health crisis in 2020, the vaccination rate fell to 83 percent, and then to 81 percent in 2021—the lowest since 2008.

According to a new joint report by WHO and the CDC published this week, coverage of first-dose measles vaccines recovered slightly in 2022, rising to 83 percent. But of 194 WHO countries, only 65 (34 percent) reached a target vaccination rate of 95 percent or above for the first measles vaccine. Further, two doses are needed to stop the disease, and the estimated coverage rate for two doses was only 74 percent in 2022, up from 71 percent in 2021. Overall, the gains in vaccination weren't enough to prevent a comeback from the highly contagious and sometimes deadly virus.

Enlarge / Histoplasma capsulatum is a species of parasitic, yeast-like dimorphic fungus that can, if inhaled, cause a type of lung infection called histoplasmosis. (credit: Nanoclustering/Science Photo Library )

Back at the turn of the 21st century, Valley fever was an obscure fungal disease in the United States, with fewer than 3,000 reported cases per year, mostly in California and Arizona. Two decades later, cases of Valley fever are exploding, increasing more than sevenfold and expanding to other states.

And Valley fever isn’t alone. Fungal diseases in general are appearing in places they have never been seen before, and previously harmless or mildly harmful fungi are turning deadly for people. One likely reason for this worsening fungal situation, scientists say, is climate change. Shifts in temperature and rainfall patterns are expanding where disease-causing fungi occur; climate-triggered calamities can help fungi disperse and reach more people; and warmer temperatures create opportunities for fungi to evolve into more dangerous agents of disease.

For a long time, fungi have been a neglected group of pathogens. By the early 2000s, researchers were already warning that climate change would make bacterial and viral infectious diseases like cholera and dengue more widespread. “But people were not focused at all on the fungi,” says Arturo Casadevall , a microbiologist and immunologist at the Johns Hopkins Bloomberg School of Public Health. That’s because, until recently, fungi haven’t troubled humans much.

Enlarge / An intensive care nurse cares for a patient suffering from respiratory syncytial virus (RSV), who is being ventilated in the children's intensive care unit of the Olga Hospital of the Stuttgart Clinic in Germany. (credit: Getty | picture alliance )

A Pfizer vaccine designed to protect newborns and infants from severe RSV illness won a recommendation from the Centers for Disease Control and Prevention Friday—but only for seasonal use.

The vaccine is Pfizer’s bivalent RSVpreF vaccine, called Abrysvo, and is administered to pregnant people late in gestation, between 32 and 36 weeks.

RSV, or respiratory syncytial (sin-SISH-uhl) virus, is the leading cause of hospitalization for infants in the US. Each year, 1.5 million children seek out-patient care for RSV, with 58,000 to 80,000 ending up in the hospital and 100 to 300 tragically dying from the infection.

Adult female worm of Angiostrongylus cantonensis recovered from rat lungs with characteristic barber-pole appearance (anterior end of worm is to the top). Scale bar = 1 mm. (credit: Lindo et al. )

The dreaded rat lungworm—a parasite with a penchant for rats and slugs that occasionally finds itself rambling and writhing in human brains—has firmly established itself in the Southeast US and will likely continue its rapid invasion, a study published this week suggests.

The study involved small-scale surveillance of dead rats in the Atlanta zoo. Between 2019 and 2022, researchers continually turned up evidence of the worm. In all, the study identified seven out of 33 collected rats (21 percent) with evidence of a rat lungworm infection. The infected animals were spread throughout the study's time frame, all in different months, with one in 2019, three in 2021, and three in 2022, indicating sustained transmission.

Although small, the study "suggests that the zoonotic parasite was introduced to and has become established in a new area of the southeastern United States," the study's authors, led by researchers at the University of Georgia College of Veterinary Medicine, concluded. The study was published Wednesday in the journal Emerging Infectious Diseases.

Enlarge (credit: Getty | picture alliance )

Americans will again have an opportunity to receive free at-home COVID-19 rapid tests from the US government, with orders beginning next Monday, September 25, the Biden administration announced Wednesday.

Households will be eligible to receive four free rapid tests that will "detect the currently circulating COVID-19 variant," the Department of Health and Human Services said in an announcement. The tests, available next week via COVIDTests.gov and expected to start shipping on October 2, are meant to help Americans detect COVID-19 and keep from spreading it for the rest of the year—especially during holiday gatherings.

"At this point, our focus is getting through the holidays and making sure folks can take a test if they’re going to see Grandma for Thanksgiving ,” Dawn O’Connell, assistant secretary for preparedness and response at the HHS, told the Associated Press.

Enlarge / The Centers for Disease Control and Prevention (CDC) headquarters stands in Atlanta, Georgia, on Saturday, March 14, 2020. (credit: Getty | Bloomberg )

The Centers for Disease Control and Prevention on Tuesday recommended that everyone ages six months and older get an updated COVID-19 vaccine booster shot this fall or winter.

The recommendation came quickly on the heels of a meeting of CDC advisors who voted 13-to-1 strongly in favor of making the updated versions of mRNA COVID-19 vaccines available to everyone ages 6 months and older.

"The virus that causes COVID-19 is always changing, and protection from COVID-19 vaccines declines over time," the CDC said in an announcement. "Receiving an updated COVID-19 vaccine can restore protection and provide enhanced protection against the variants currently responsible for most infections and hospitalizations in the United States."

Enlarge / Competitors take part in "Tough Mudder" at the Glen Helen Raceway in San Bernardino, California, United States on April 2, 2023. (credit: Getty | Tayfun CoÅkun )

Hundreds of people who participated in a recent Tough Mudder event—a very muddy obstacle course race—held in Sonoma, California, have fallen ill with pustular rashes, lesions, fever, flu-like symptoms, nerve pain, and other symptoms, local health officials and media outlets report.

The cases could be caused by various infectious agents, including Staphylococcus bacteria, but the leading culprit is the relatively obscure Aeromonas bacteria— specifically A. hydrophila , according to the Sonoma County health department. In a statewide alert this week, the California Department of Public Health said it is considering it an Aeromonas outbreak, noting that multiple wound cultures have yielded the hardy bacterium.

A spokesperson for the Sonoma County health department told the Los Angeles Times on Thursday that, based on calls and emails the department had received, health officials estimate that the outbreak involves around 300 cases . Tough Mudder participants, meanwhile, have tallied as many as 489 cases in online forums.