Local doctors are on notice to pay extra attention to anyone suspected of having an mpox infection as concern builds around a deadlier and more-infectious “Clade 1” version of the virus spreading rapidly in some African countries.
The county health department advised all physicians late last week that they should take a careful travel history of anyone exhibiting mpox symptoms, asking about travel to the Democratic Republic of Congo or any adjacent countries — or close contact with anyone who visited the region — in the 21 days previous to symptoms appearing.
Last week, the World Health Organization declared Clade 1 a public health emergency of international concern, citing its increasing spread in the Congo.
Specimens collected from all who fit this travel profile are to be submitted to state laboratories for analysis, which can determine whether Clade 1 is present.
“In the event that Clade 1 ever made its way here, which we’re obviously hoping does not happen, we want to be prepared,” said Dr. Winston Tilghman, medical director of the health department’s HIV, STD and Hepatitis Branch.
Clade 2, the mpox type that caused a global outbreak in 2022, continues to pop up in San Diego County, with 51 cases suspected or confirmed so far in 2024.
It’s a massive decrease compared to the 469 cases tallied in 2022 and yet is still significantly higher than the zero to one case per year that was the norm before the global outbreak.
Mpox, formerly called monkeypox, generally spreads through intimate contact. Though anyone can become infected, recent outbreaks have most often occurred in men who have sex with men.
Though it is rarely deadly, the disease causes sores, often in and around the most sensitive and private areas of the body, that can be excruciatingly painful.
Vaccination, Tilghman added, remains the biggest missed opportunity to reduce the suffering.
According to county records, 76 percent of those who have confirmed or suspected mpox infections this year were unvaccinated.
“Not everyone who would benefit from vaccination has received the vaccine, and that’s why we have been trying to encourage people to get vaccinated or complete the (two dose) vaccine series,” Tilghman said.
“While case activity is definitely low compared to what we observed in 2022, it’s still higher than we would like it to be.”
Jynneos is the vaccine used to prevent mpox infection, though it was designed to fight the smallpox virus. In 2023, the U.S. Centers for Disease Control and Prevention published the results of an effectiveness study of Jynneos for mpox, estimating effectiveness at 66 percent for two doses and nearly 36 percent for one dose.
Those numbers mean that the number of people who received two doses and became ill was 66 percent lower than those who were unvaccinated and became ill.
Dr. David “Davey” Smith, chief of infectious diseases and global public health at UC San Diego, said during an interview earlier this month that overall effectiveness has been lower than expected.
“There are people who we have vaccinated who have gotten it again, and that’s annoying,” Smith said. “The vaccine we have, which is really a smallpox vaccine, it’s closely related enough to mpox that it generates protective antibodies, but those antibodies wane quickly compared to what we see with smallpox.
“Scientists are trying to figure that out, but we don’t have the reason yet.”
In San Diego County so far this year, 12 people who receive both doses still became infected.
However, Tilghman said that these “breakthrough” infections seem to produce less-severe symptoms than is the case for those who are unvaccinated.
“The people who end up getting diagnosed who are fully vaccinated tend to have milder illness and are less likely to have complications,” Tilghman said.
According to the CDC, mpox symptoms include fever, headache, muscle aches and backache, swollen lymph nodes, chills, exhaustion and a rash that may resemble pimples or blisters, in many different locations including the chest, hands, feet, chest and face and groin.
The CDC recommends vaccination for anyone exposed to the mpox virus and for anyone who has intimate contact with more than one partner, especially in recreational settings.