Enlarge / A US child infected with measles during a 2024 outbreak. The child’s cheek shows the characteristic rash associated with this viral infection. (credit: CDC)

With one of the highest vaccine exemption rates in the country, Oregon is experiencing its largest measles outbreak in decades. This year's count is now higher than anything seen since 2000, when the Centers for Disease Control and Prevention declared the highly contagious virus eliminated from the US.

Since the start of the year, Oregon has tallied 31 cases of measles, all in unvaccinated people. The cases have been accumulating in sustained waves of transmission since mid-June.

Last month, when the outbreak tally was still in the 20s, health officials noted that it was nearing a state record set in 2019. There were 28 cases that year, which were linked to a large outbreak across the border in Washington state. But, with that record now surpassed, the state is in pre-elimination territory.

Enlarge / Listeria monocytogenes. (credit: Getty | BSIP)

Five more people have died in a nationwide outbreak of Listeria infections linked to contaminated Boar's Head brand meats, the Centers for Disease Control and Prevention reported Wednesday.

To date, 57 people across 18 states have been sickened, all of whom required hospitalization. A total of eight have died. The latest tally makes this the largest listeriosis outbreak in the US since 2011, when cantaloupe processed in an unsanitary facility led to 147 Listeria infections in 28 states, causing 33 deaths, the CDC notes.

The new cases and deaths come after a massive recall of more than 7 million pounds of Boar's Head meat products, which encompassed 71 of the company's products. That recall was announced on July 30, which itself was an expansion of a July 26 recall of an additional 207,528 pounds of Boar's Head products. By August 8, when the CDC last provided an update on the outbreak, the number of cases had hit 43, with 43 hospitalizations and three deaths.

Enlarge / A 13-year-old celebrates getting the Pfizer-BioNTech COVID-19 vaccine in Hartford, Connecticut, on May 13, 2021. (credit: Getty | JOSEPH PREZIOSO )

With the impending arrival of the 2024–2025 COVID-19 vaccines approved yesterday, some Americans are now gaming out when to get their dose—right away while the summer wave is peaking, a bit later in the fall to maximize protection for the coming winter wave, or maybe a few weeks before a big family event at the end of the year? Of course, the group pondering such a question is just a small portion of the US.

Only 22.5 percent of adults and 14 percent of children in the country are estimated to have gotten the 2023–2024 vaccine. By contrast, 48.5 percent of adults and 54 percent of children were estimated to have gotten a flu shot. The stark difference is despite the fact that COVID-19 is deadlier than the flu, and the SARS-CoV-2 virus is evolving faster than seasonal influenza viruses.

In a press briefing Friday, federal health officials were quick to redirect focus when reporters raised questions about the timing of COVID-19 vaccination in the coming months and the possibility of updating the vaccines twice a year, instead of just once, to keep up with an evolving virus that has been producing both summer and winter waves.

Enlarge / A mosquito collected to test for mosquito-borne diseases. (credit: Getty | Jon Cherry)

A small town in Massachusetts is urging residents to stay indoors in the evenings after the spread of a dangerous mosquito-spread virus reached "critical risk level."

The virus causes Eastern equine encephalitis (EEE), which kills between 30 and 50 percent of people who are stricken—who are often children under the age of 15 and the elderly. Around half who survive are left permanently disabled, and some die within a few years due to complications. There is no treatment for EEE. So far, one person in the town—an elderly resident of Oxford—has already become seriously ill with neuroinvasive EEE.

EEE virus is spread by mosquitoes in certain swampy areas of the country, particularly in Atlantic and Gulf Coast states and the Great Lakes region. Mosquitoes shuttle the virus between wild birds and animals, including horses and humans. In humans, the virus causes very few cases in the US each year—an average of 11, according to the Centers for Disease Control and Prevention. But given the extreme risk of EEE, health officials take any spread seriously.

Enlarge (credit: Getty | Thomas Trutschel)

With the country experiencing a relatively large summer wave of COVID-19, the Food and Drug Administration is considering signing off on this year's strain-matched COVID-19 vaccines as soon as this week, according to a report by CNN that cited unnamed officials familiar with the matter.

Last year, the FDA gave the green light for the 2023–2024 COVID shots on September 11, close to the peak of SARS-CoV-2 transmission in that year's summer wave. This year, the summer wave began earlier and, by some metrics, is peaking at much higher levels than in previous years.

Currently, wastewater detection of SARS-CoV-2 shows "very high" virus levels in 32 states and the District of Columbia. An additional 11 states are listed as having "high" levels. Looking at trends, the southern and western regions of the country are currently reporting SARS-CoV-2 levels in wastewater that rival the 2022–2023 and 2023–2024 winter waves, which both peaked at the very end of December.

Enlarge / A negative stain electron micrograph of an mpox virus virion in human vesicular fluid. (credit: Getty | BSIP)

The World Health Organization on Wednesday declared an international health emergency over a large and rapidly expanding outbreak of mpox that is spilling out of the Democratic Republic of the Congo.

It is the second time in about two years that mpox's spread has spurred the WHO to declare a public health emergency of international concern (PHEIC), the highest level of alarm for the United Nations health agency. In July 2022, the WHO declared a PHEIC after mpox cases had spread across the globe, with the epicenter of the outbreak in Europe, primarily in men who have sex with men. The outbreak was caused by clade II mpox viruses, which, between the two mpox clades that exist, is the relatively mild one, causing far fewer deaths. As awareness, precautions, and vaccination increased, the outbreak subsided and was declared over in May 2023.

Unlike the 2022–2023 outbreak, the current mpox outbreak is driven by the clade I virus, the more dangerous version that causes more severe disease and more deaths. Also, while the clade II virus in the previous outbreak unexpectedly spread via sexual contact in adults, this clade I outbreak is spreading in more classic contact patterns, mostly through skin contact of household members and health care workers. A large proportion of those infected have been children.

Enlarge / A child with a "slapped cheek" rash. (credit: CDC)

A common seasonal respiratory virus that typically infects school-age children is causing an unusually large spike in cases across Europe and the US this summer. The surge in transmission is a significant danger to certain vulnerable populations, including pregnant people, according to a health alert released by the Centers for Disease Control and Prevention on Tuesday.

The virus is parvovirus B19, aka B19V, which spreads via respiratory droplets and typically causes a mild, two-phased illness in children. The first phase is marked by flu-like symptoms that can include fever, headache, malaise, muscle aches, cough, sore throat, and joint pain. In the second phase, a characteristic "slapped cheek" rash develops, which is also called Fifth Disease or Erythema Infectiosum. By age 20, about 50 percent of people have been infected and have antibodies that can help fight reinfection. And by age 40, the figure rises to 70 percent.

But, for those who have compromised immune systems, are pregnant, or have certain conditions, such as sickle-cell anemia, the virus can cause severe complications, such as severe anemia, myocarditis, hepatitis, or encephalitis. In pregnancy, the virus can infect the fetus and cause dangerous complications and miscarriage.

Enlarge / A recall notice is posted next to Boar's Head meats that are displayed at a Safeway store on July 31, 2024, in San Rafael, California. (credit: Getty | Justin Sullivan)

A third person has died in a nationwide bacterial outbreak linked to Boar's Head brand deli meats. Last week, the company recalled more than 7 million pounds of its meats, which was in addition to a recall of over 200,000 pounds of meat from July 26. In all, 71 types of products made between May 10, 2024, and July 29, 2024, and sold nationwide have been recalled.

According to an update Thursday from the Centers for Disease Control and Prevention, the outbreak has now sickened a total of 43 people, an increase from 34 last week. There have been 43 hospitalizations, up from 33 last week. The illnesses are reported from 13 states. The three deaths in the outbreak include one from Illinois and one from New Jersey, and the newly reported death is from Virginia. The CDC expects the tally of illnesses so far to be a significant undercount of actual cases, and additional states may be affected.

The illnesses in the outbreak are caused by Listeria monocytogenes, a foodborne bacterium that is particularly dangerous to people who are pregnant, people age 65 years or older, and people who have weakened immune systems. In these high-risk groups, the bacteria are more likely to move beyond the gastrointestinal system to cause an invasive infection called listeriosis. During pregnancy, listeriosis can cause miscarriage, stillbirth, premature delivery, or a life-threatening infection in newborns. For non-pregnant people who develop listeriosis, nearly 90 percent require hospitalization, and 1 in 6 die.

Enlarge / A 2003 photo of the arms and legs of a 4-year-old girl infected with mpox in Liberia. (credit: Getty | BSIP)

A deadly outbreak of mpox (previously called monkeypox) is spilling out of the Democratic Republic of the Congo, raising alarm among global health experts.

The DRC has reported more than 22,000 suspected cases since the start of 2023, including 1,200 suspected deaths, according to the US Centers for Disease Control and Prevention. A high proportion of the cases are in children younger than 15 years old.

On Wednesday, the CDC released a health advisory noting that although mpox is endemic to the DRC, the current outbreak is larger and more widespread than any outbreak the country has previously seen. The virus has also spilled over to several neighboring countries in recent months, including the Republic of the Congo, the Central African Republic, Burundi, Rwanda, and Uganda. The World Health Organization reported that cases have also been detected in Kenya.

Enlarge (credit: Tony C. French/Getty)

A small study in Texas suggests that human bird flu cases are being missed on dairy farms where the H5N1 virus has taken off in cows, sparking an unprecedented nationwide outbreak.

The finding adds some data to what many experts have suspected amid the outbreak. But the authors of the study, led by researchers at the University of Texas Medical Branch in Galveston, went further, stating bluntly why the US is failing to fully surveil, let alone contain, a virus with pandemic potential.

"Due to fears that research might damage dairy businesses, studies like this one have been few," the authors write in the topline summary of their study, which was posted online as a pre-print and had not been peer-reviewed.

Enlarge / Shelves sit empty where Boar's Head meats are usually displayed at a Safeway store on July 31, 2024, in San Anselmo, California. (credit: Getty | )

Over 7 million pounds of Boar's Head brand deli meats are being recalled amid a bacterial outbreak that has killed two people. The outbreak, which began in late May, has sickened a total of 34 people across 13 states, leading to 33 hospitalizations, according to the US Department of Agriculture.

On June 26, Boar's Head recalled 207,528 pounds of products, including liverwurst, beef bologna, ham, salami, and "heat and eat" bacon. On Tuesday, the Jarratt, Virginia-based company expanded the recall to include about 7 million additional pounds of meat, including 71 different products sold on the Boar's Head and Old Country brand labels. The products were sold nationwide.

The meats may be contaminated with Listeria monocytogenes, a foodborne pathogen that is particularly dangerous to pregnant people, people over the age of 65, and people with compromised immune systems. Infections during pregnancy can cause miscarriage, stillbirth, premature delivery, or a life-threatening infection in newborns. For others who develop invasive illness, the fatality rate is nearly 16 percent. Symptoms of listeriosis can include fever, muscle aches, headache, stiff neck, confusion, loss of balance, and convulsions that are sometimes preceded by diarrhea or other gastrointestinal symptoms.

Enlarge (credit: Getty | David Paul Morris)

A second Colorado poultry farm has reported a case of bird flu in a worker, marking the state's seventh human case this month amid the ongoing outbreak among dairy cows.

Colorado health officials said the seventh case is, for now, a presumptive positive. That means that the person has tested positive at the state level while confirmatory testing is being carried out at the Centers for Disease Control and Prevention.

The presumptive positive worker was at a poultry facility in the state's northeastern Weld County. In recent weeks, six workers at another poultry farm in Weld also tested positive for bird flu. In that facility, a commercial egg layer operation with about 1.8 million birds, workers were infected as they culled chickens known to be infected with the highly pathogenic avian influenza. Genetic testing of the virus in the birds and the workers indicated that they were infected with a strain of H5N1 closely related to the virus found spreading in dairy cattle and to dairy farm workers.

Enlarge (credit: Getty | Yui Mok)

The strain of H5N1 bird flu isolated from a dairy worker in Texas was 100 percent fatal in ferrets used to model influenza illnesses in humans. However, the virus appeared inefficient at spreading via respiratory droplets, according to newly released study results from the Centers for Disease Control and Prevention.

The data confirms that H5N1 infections are significantly different from seasonal influenza viruses that circulate in humans. Those annual viruses make ferrets sick but are not deadly. They have also shown to be highly efficient at spreading via respiratory droplets, with 100 percent transmission rates in laboratory settings. In contrast, the strain from the Texas man (A/Texas/37/2024) appeared to have only a 33 percent transmission rate via respiratory droplets among ferrets.

"This suggests that A/Texas/37/2024-like viruses would need to undergo changes to spread efficiently by droplets through the air, such as from coughs and sneezes," the CDC said in its data summary. The agency went on to note that "efficient respiratory droplet spread, like what is seen with seasonal influenza viruses, is needed for sustained person-to-person spread to happen."

Enlarge / Fresh raw milk being poured into a container on a dairy farm on July 29, 2023, in De Lutte, Netherlands. (credit: Getty | Pierre Crom)

Despite the delusions of the raw milk crowd, drinking unpasteurized milk brimming with infectious avian H5N1 influenza virus is a very bad idea, according to freshly squeezed data published Friday in the New England Journal of Medicine.

Researchers at the University of Wisconsin-Madison squirted raw H5N1-containing milk from infected cows into the throats of anesthetized laboratory mice, finding that the virus caused systemic infections after the mice were observed swallowing the dose. The illnesses began quickly, with symptoms of lethargy and ruffled fur starting on day 1. On day 4, the animals were euthanized to prevent extended suffering. Subsequent analysis found that the mice had high levels of H5N1 bird flu virus in their respiratory tracts, as well their hearts, kidneys, spleens, livers, mammary glands, and brains.

"Collectively, our data indicate that HPAI [Highly Pathogenic Avian Influenza] A(H5N1) virus in untreated milk can infect susceptible animals that consume it," the researchers concluded. The researchers also found that raw milk containing H5N1 can remain infectious for weeks when stored at refrigerator temperatures.