A family vacation to Costa Rica turned into a trip from hell after 12 of 13 relatives were diagnosed with a potentially fatal fungal infection.
The family, who traveled from Texas, Washington and Georgia, had been exploring the Venado Caves in the north of the country, which involved crawling through tight spaces to see scores of live bats.
After returning to the US the following week, 12 family members had started to fall sick with a fever, headache, muscle pain, night sweats, breathing problems and indigestion.
Five sought help from doctors, while one was hospitalized after scans showed changes in the lungs that looked like lung cancer.
The family was eventually diagnosed with histoplasmosis — a bat-linked infection caused by the fungus Histoplasma capsulatum.
People become infected after inhaling spores of the fungus that thrive in bat feces.
Doctors say up to 40 percent of people with serious cases die from the disease, which infects the lungs and in serious cases spreads to other organs including the brain and spinal cord.
No family members died from the infection, and within 28 days of the cave visit — and following treatment — all were making a recovery.
The family had visited the Venado cave in Costa Rica, where they crawled through bat feces for two hours and saw scores of living bats (stock image)
But the CDC, which investigated the cases, said it underscored the dangers of visiting bat-infested caves and crawling through feces.
The news comes on the eve of the finale of The Last of Us season two, a hit HBO series where the modern world is turned on its head after whole cities are infected with a fungus that turns them into rabid zombies.
Histoplasmosis is often misdiagnosed or diagnosed late because it symptoms, which are similar to pneumonia, can be mistaken for a bacteria or fungus.
The fungus behind the infection is spread in bird and bat droppings, and also lives in the soil — including in the central and eastern US.
It does not spread between people, and also does not spread between animals if they become infected with the fungus.
Revealing the cases in its Morbidity and Mortality Weekly Reports, the CDC said only one family member did not get sick — the individual who did not go on the cave tour.
The family visited the caves on Christmas Eve 2024. They were in Costa Rica for a week, from December 21 to 28.
Of the sick patients, six family members were adults aged between 42 and 49 years old and six were children, aged between eight and 16 years old.
Only two family members tested positive for the fungus out of the four tested using a swab for fungus-fighting antibodies in the blood.
Researchers said more family members were likely infected, however, adding that in more mild cases it can be difficult to detect the antibodies in tests.
The caves were also linked to 51 cases of histoplasmosis diagnosed in 1998 and 1999
The other 11 patients were suspected to have the disease, given the trip and their links to the patient who tested positive.
The caves were also linked to a histoplasmosis outbreak between 1998 and 1999 that sickened 51 people, including tourists and Costa Rican residents.
Tests carried out on bat feces samples from the cave revealed they contained the fungus that causes the disease.
Symptoms appeared within eight to 19 days of visiting the caves, with no family members reporting other sources of infection since the trip.
Doctors are recommended to prescribe the antifungal itraconazole to treat the infection, but only in more serious cases. In mild cases of the fungal infection, the disease normally goes away on its own.
Some family members were initially prescribed antibiotics, which is not recommended because these could worsen the infection. The prescriptions suggest that the fungal infection was not initially suspected.
The CDC says the fungus that causes histoplasmosis lives along the Ohio and Mississippi river deltas. It has been detected in states in eastern, southern and midwestern areas of the country.
The American Thoracic Society estimates that up to 250,000 people suffer from histoplasmosis in the US every year.
Few of these cases are formally diagnosed and reported, however, with only about 4,600 cases recorded annually according to CDC data.
About 120 people die from the disease every year.
