Which Cave Disease is the Worst? Top 4 to Avoid

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Beware: You should never explore wild caves alone or without proper gear. Consider getting in touch with a Grotto of the National Speleological Society at www.caves.org or a qualified cave club. These groups are skilled and will train you. Without sufficient knowledge, preparation, and equipment, cave exploring can lead to serious injury or death.

Want to know the quickest way to ruin your caving experience? Succumbing to an unexpected illness or infection due to a cave disease you had never heard of before. Experienced cavers understand the health risks of caves. There is a total absence of light at lower levels that gives distinct characteristics to a cave environment and influences the composition and distribution of the cave fauna that cause and spread infectious disease.

This doesn’t mean that you are at risk of getting deathly ill with every caving expedition. But you ought to be prepared for the worst in all cases. Below are some of the diseases you hope to never catch inside a cave.

1 – Cave Fever

Cave fever is a vector-borne cave disease caused by the Borrelia bacteria. This fever or disease is transmitted to humans through the bite of black-legged ticks. Usually, this disease is found in the Middle Eastern and Central Asian countries, and it is not common in the USA.

Ticks are extremely tiny and you may not even notice them.

In most English speaking countries, we call it Lyme disease. Of course, we can’t associate it with the caves alone, but under humid climate conditions, caves become an ideal place for ticks; they breed and spread disease much easier in these conditions.

The symptoms of this disease start with chills, headaches, and stomach pain. You develop these symptoms between 5 and 15 days after visiting the cave and coming into contact with the tick.

Fortunately, a 1-2 week course of antibiotics can help you fight off cave fever. There are almost no complications or deaths due to this fever. Most physicians recommend tetracycline-class antibiotics that often improve a patient’s condition within 24 hours.

Now the key question here is: how to avoid cave fever?

Use insect repellents that work for ticks. This is the simplest thing you can do while visiting a cave to prevent cave fever. This discourages ticks from landing and climbing on your bod and doesn’t allow them to transmit disease.  Consider products with the active ingredients DEET, Picaridin, Oil of Lemon Eucalyptus (OLE)*, or Permethrin for tick bite prevention.

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2 – Histoplasmosis

The second cave disease is Histoplasmosis, a lung infection caused by inhaling fungal spores.

These spores of the fungus are often found in bird and bat droppings. Experienced cavers note that this is why it is better to avoid a dirty cave that contains a large amount of bird or bat droppings in its soil. Although most people who breathe in these spores don’t get sick, there are chances of having cough, fever, and fatigue. People with a weaker immune system can experience severe problems and the disease can spread into other parts of the body; however, 95% of people never develop symptoms. They don’t even notice the infection; their immune systems kill Histoplasmosis automatically.

There is no specific vaccine available to prevent Histoplasmosis. Physicians often count on Amphotericin B to treat its effects.

After speaking to a professional spelunker, you might learn that some get Histoplasmosis more than once. However, only the first infection of this disease is severe. After that, the immune system starts handling it rather well. In most cases, you don’t even need to consult your doctor.

But because its symptoms occasionally become chronic and spread throughout the body, you do have to prepare to treat it quickly. Our bodies are ultimately vulnerable and letting a disease run rampant through it is never worth the risk. Dangerous complications associated with this disease are Acute Respiratory Distress Syndrome, Meningitis, and Adrenal Glands, and Hormone Problems.

A graphic shows the definition and symptoms of Histoplasmosis, a cave disease caused by fungal spores.

3 – Leptospirosis

This cave disease is caused by Leptospira, which is a kind of bacteria; it was first observed in 1907 in kidney tissues and divided into 20 species by DNA hybridization studies.

Experts call it a rare infection that we only get through contact with animals.

We particularly get it through their urine. It lives in their kidneys and ends up in soil and water. For that reason, if some cave provides shelter to animals, birds, and bats, you should assume the surfaces are not clean. The infected animals have peed on it and the germs can invade in your body anytime and cause a wide range of symptoms.

The most common symptoms associated with Leptospirosis are high-fever, abdominal pain, vomiting, muscle aches, and diarrhea. Remember that these symptoms overlap with other diseases too. It is pertinent to investigate your condition thoroughly.

A colony of bats in Bear Gulch Cave at Pinnacles National Park.

Leptospirosis happens in two main phases.

  • The first phase causes headache, fever, and chills. It happens after 2 days to 4 weeks. Mostly, the patient recovers naturally and quickly but become ill again after a few days.
  • The second phase is critical and causes kidney or liver failure.

There are a few important things you can do inside the cave to avoid it, such as avoid swimming in contaminated water, stay away from bats and wild rats, and use disinfectants.

Learn more about bats here.

4 – Rabies

Do you know in 1956 two men died because of rabies after exploring a Frio Cave in Texas? Okay, probably not. But you should know that rabies is not an uncommon occurrence.

This disease afflicts people in almost 150 countries. It affects a wide range of domestic and wild animals. Cave bats are less likely to get rabies, but there is a possibility, and they can infect you too. Luckily, very few people get rabies from bats in caves. When they do, they catch it from a bat’s saliva or from a wound. It is not necessary to be bitten by the bat.

The initial signs of rabies include headache, fever, and sensory changes. In some cases, you get hallucinations, aerophobia (fear of flying), and hydrophobia (fear of water).

Surprisingly, many cavers don’t take this disease seriously and think the risk is less as human rabies has become exceedingly rare in the United States. But something to keep in mind is that 2% of rabies patients have a history of direct physical contact with bats.

That’s why it is imperative to be careful when caving. Know what to expect inside each cave before you go in.

We have many rabies vaccinations today that identify and fight rabies and prevent the virus from affecting you, but you have to get them as soon as possible after the bite. So stay prepared, be aware of potential illnesses or other dangers, and keep yourself safe during your trip!


There is much we don’t know and there are still some details that we may never learn about caves. Bats might be the origin of the current pandemic, and certain diseases can infect livestock on a massive scale. 60-75 percent of infectious and dangerous diseases in humans come from animals.

Because of the increasing amount of travelers visiting the caves, it is your responsibility to stay safe, have the proper equipment like a suit or mask, and to follow the local guides. They know which areas and pockets of the caves contain pathogens and dangerous creatures like cave bats, and can help you avoid catching any diseases. Nobody needs to fall ill during their first time caving!

Did you suffer from one or more of the above diseases during your spelunking adventure? What happened? We’d love to hear about how you managed it in the comment section below.

Click here to read up on other dangers of caving.

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