Enlarge / An entomologist for the Louisville Metro Department of Public Health and Wellness in a swampland area on August 25, 2021, in Louisville, Kentucky, collecting various mosquito species and testing the samples for mosquito-borne diseases, such as EEE. (credit: Getty |)

New York is facing an unusual boom in mosquitoes toting the deadly eastern equine encephalitis (EEE) virus, which has already led to one rare death in the state and a declaration of an "imminent threat" by officials.

While the state's surveillance system typically picks up EEE-positive mosquitoes in two or three counties each year, this year there have been 15 affected counties, which are scattered all across New York, State Health Commissioner James McDonald said this week.

"Eastern equine encephalitis is different this year," McDonald said, noting the deadly nature of the infection, which has a mortality rate of between 30 and 50 percent. "Mosquitoes, once a nuisance, are now a threat," McDonald added. "I urge all New Yorkers to prevent mosquito bites by using insect repellents, wearing long-sleeved clothing, and removing free-standing water near their homes. Fall is officially here, but mosquitoes will be around until we see multiple nights of below-freezing temperatures."

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.