This week in outbreaks: April 17 edition
And an op-ed from last week, in case you missed it
Programming notes
Last week, I collaborated with
on a topic near and dear to both our hearts: communication as leadership. Misinformation is a serious problem, but is batting it back a winning strategy? Maybe not. ⬇️Also, as we near the end of flu season, there will be some changes to the content featured in Force of Infection. Starting in May, I plan on transitioning my "This week in outbreaks" update to a monthly schedule. I will be sharing more essays and analyses throughout the summer, with some behind a paywall. Free weekly outbreak updates will resume in October when the next flu season begins. I appreciate your continued support and look forward to mixing things up in the coming weeks.
Respiratory diseases & stomach bugs
Influenza-like illness fell again. In week ending April 8, 2.1% of visits to the doctor were for fever and cough or sore throat, down slightly from 2.3% the week prior. For comparison, peak week is often around 7%, and the summer season is more like 1%. During the last week, around half of specimens tested were flu B, but the increased prevalence does not seem to be contributing to an overall increase in activity.
Although the flu season is receding, not all age groups are experiencing the full benefits. Children ages 0-4 are still experiencing a high percentage of doctor visits for ILI at 7.3%, while the percentage for ages 5-24 is 3.4%. The older age groups were below 2%.
Most of the country is "green" on the flu activity map. That's a big relief from peak season when we saw a lot of purple, which indicated very high levels of flu activity. However, there are a couple of spots that are still in the high category, namely New York City and Washington, D.C. But I don’t see updated data from NYC, so it may be holdover from last week. ILI activity in D.C. remained stable at 4%.
Covid-19 activity also continues to improve. The number of reported cases has dropped to around 101,000 this week, down from 122,000 the week before. That's the second lowest number of cases we've seen in a while (putting aside changes in reporting practices over time). However, we can't ignore that weekly deaths are still high at 1,327. Looking ahead, there is a new variant in town. XBB.1.16, another omicron subvariant, is gaining in prevalence. Some people are calling it "arcturus" but I suspect someone on the internet just made that up. In any case, I’m not worried about XBB.1.16 right now, but it’s something to keep an eye on.
Metapneumovirus activity has finally peaked, and RSV activity is low. However, we are still seeing high levels of adenovirus and parainfluenza, both of which cause respiratory illness. While these illnesses often clear up on their own, they can be more severe in infants, older adults, and those with weakened immune systems. The trends are flattening out a bit, so hopefully these illnesses will peak soon, and we can enjoy some calm.
Norovirus activity is falling! Mostly. The trend is not totally clear in all regions, but I’m counting it. Norovirus causes the classic “stomach bug.” Activity has been very high for weeks now, but I think it may finally be on the descent.
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:
More salad products and kits. Fresh Express, Publix and Fresh from Meijer (more info, more info). See also the Revolution Farms salad recall from last week (more info).
Reported in the last month:
Raw flour (no brand identified yet). Unbaked flour is a common source of Salmonella food poisoning. Do not consume unbaked flour. (more info)
Frozen organic strawberries and tropical fruit mix sold to Costco, Trader Joe's, Aldi, KeHE, Vital Choice Seafood, and PCC Community Markets. (more info)
If you have food allergies, you may wish to review these FDA safety alerts for foods with undeclared allergens.
In other news
WHO has published an update on the Marburg virus disease outbreak in Equatorial Guinea. It is troubling. The outbreak was first recognized in February, but little data has been shared. As of April 11 there were 15 confirmed cases, 23 probable cases, and 11 laboratory-confirmed deaths, and 23 probable deaths. This is an extremely high case fatality risk, in line with what has been seen in other Marburg outbreaks. Four healthcare worker infections have been reported, and two have died.
A few other pieces of data jumped out at me. Five of the confirmed cases were registered in recent weeks, which means the outbreak has not begun to slow. Confirmed cases have been found in multiple non-contiguous provinces and not all cases have known epidemiological links, which means there are likely unrecognized chains of transmission.
Mpox (formerly monkeypox) is approaching elimination in the United States and European countries. Elimination means that domestic transmission has ended, but that the virus can be reintroduced through e.g., travelers. Right now, the U.S. is reporting around one case per day. At this level, transmission can be managed through patient and provider education, and contact tracing. Approximately 1,000 vaccines are administered per week, evenly split between first and second doses. Case counts in European countries are similarly low. Reliable surveillance data is hard to come by elsewhere.
My weekly reader Q&A in the NYT covers what public health will do better when the next epidemic comes along and how the next pandemic will start. Read more here. Coincidentally, there’s also a great essay about mpox.