This week in outbreaks: April 3 edition
Happy April! We are starting the new month off on a good note. Influenza-like illness (ILI) has been at or below baseline for the fourth week in a row. Activity is currently at its lowest levels since the start of the 2022-2023 season back in October. According to recent data, only 2.3% of visits to the doctor were for ILI, down from a peak of 7.4%. Activity fell slightly in children ages 0-4 and remained flat in older age groups.
Almost all states and jurisdictions are reporting ILI activity at or below baseline. The two exceptions are New York City and Washington D.C, which are still classified as "high" activity areas. In NYC, the percentage of doctors’ visits that are for ILI is now at 5%, which is actually a slight increase. The city is reporting that many influenza cases are influenza B (more on that in a minute). Puerto Rico and New Mexico, two jurisdictions that were in the “high” category long after more places, have finally improved to the low and moderate categories, respectively.
As expected, there is some increased flu B activity at the national level compared to earlier in the season. In the most recent CDC update, one-third of specimens typed in public health laboratories were for flu B. Flu B often causes a small bump in cases in the spring portion of the season. In general, it is less severe than its counterpart that dominates most of the season, flu A. However, some studies have shown that children and young adults may be more susceptible to the complications of flu B. (Although the proportion of flu B cases is noteworthy, the absolute number of cases remains low.)
According to recent data, the number of reported Covid-19 cases in the United States is currently at the second lowest ever reported. Hospitalizations have dropped to around 20,400, which is the third lowest it has ever been. As before, adults aged 70 and older continue to have the highest rate of hospitalizations. Recent data on COVID-19 activity across the United States shows no clear geographic trends. Hotspots include parts of Oklahoma and Missouri, as well as some areas in North Carolina and South Carolina. Despite the improvements, the number of weekly deaths attributed to Covid-19 remains significant, with 2,060 deaths reported in the most recent data.
Activity for three of the four seasonal coronavirus activity is down. The exception is CoVNL63, which has stubbornly increased well past when the other seasonal coronaviruses peaked. The northeastern, southern and western regions all continue to see rising CoVNL63 activity. Only the midwestern region has peaked. Coronavirus NL63 (CoVNL63) is a type of coronavirus that was first identified in 2004. This virus is known to cause respiratory illnesses, with symptoms ranging from mild cold-like symptoms to more severe respiratory infections. Common symptoms of CoVNL63 can include coughing, fever, sore throat, and difficulty breathing.
RSV activity is down, and its relative metapneumovirus has also peaked in all four regions.
The two respiratory viruses that remain on my radar are adenovirus and parainfluenza. Activity for both pathogens is elevated. Adenovirus is a type of virus that can cause a range of illnesses, from mild respiratory infections to more severe illnesses such as pneumonia or gastroenteritis. This virus is highly contagious and can be spread through close contact or contaminated surfaces. Parainfluenza virus is another type of virus that can cause respiratory infections. This virus is most common in young children and can cause symptoms such as cough, runny nose, and fever. Like adenovirus, parainfluenza virus is highly contagious and can be spread through close contact or contaminated surfaces.
Norovirus is still defying gravity with continued elevated activity. It may (may!) have peaked in all but the Western regions, but that’s me hopefully scrutinizing a glimmer of data. And remember that activity can be past peak and still be high.
Food recalls:
The following foods are being recalled because they are contaminated. Please check your cupboards and throw out any of these items:
New this week:
Raw flour (no brand identified yet). Unbaked flour is a common source of Salmonella food poisoning. Do not consume unbaked flour. (more info)
Biltmore Smoked Wild Sockeye Salmon with best by dates of April 14. (more info)
Reported in the last month:
Frozen organic strawberries and tropical fruit mix sold to Costco, Trader Joe's, Aldi, KeHE, Vital Choice Seafood, and PCC Community Markets. (more info)
Boneless beef chuck packed in February and sold in many states. (more info)
The Ezricare/Delsam eye product recall has been expanded to include Artificial Eye Ointment due to contamination with a pathogen that could cause blindness. The original recall applied to Artificial Lubricant Eye Drops. (more info, more info)
There is also a multi-state outbreak of Listeria linked to deli meats and cheeses, but the specific source has not been identified. If you are pregnant, over the age of 65, or have a condition that weakens your immune system, consider avoiding meat or cheese from deli counters. (more info)
If you have food allergies, you may wish to review these FDA safety alerts for foods with undeclared allergens.
In other news
There are two active outbreaks of Marburg disease, one in Equatorial Guinea that was first recognized in February and a second in Tanzania reported late last month. Few epidemiological details are available about either event. There are also reports of an outbreak of serious illness in Burundi, with symptoms that resemble a viral hemmorhagic fever. The causative pathogen has not been identified.
I answered reader questions for the New York Times again this week. In the course of researching one question, I learned some interesting and unsettling things about fungal pathogens.