What are the other Names for this Condition? (Also known as/Synonyms)

• Chigoe Flea Infection
• Pio and Bicho de Pie
• Sand Flea Disease

What is Tungiasis? (Definition/Background Information)

• Tungiasis is an infection of a parasitic flea that is common in many developing countries with tropical climates. The flea, which is often known as the chigoe flea, seeks a warm-blooded host, frequently humans, to feed, reach fertility, and produce offspring
• The fleas responsible for Tungiasis reside in areas that contain sand and pebbles, typically beaches or homes without a concrete foundation. Human infection occurs when individuals walk through sand without shoes on, or sleep outside their homes. The infection occurs when the parasitic flea attaches and burrows itself into the skin
• Tungiasis is highly-endemic to many Central African countries. Elderly individuals and children bear a higher risk for infection. The risk factors include being in an area of Tungiasis infection and exposing bare skin, to sandy surfaces in the endemic regions
• The signs and symptoms of Tungiasis infection include the presence of black-spotted lesions and skin rashes, severe itching at or around the lesions, including pain and inflammation
• The unique lesions caused by the flea forms the basis of diagnosing Tungiasis, following which the flea is removed with a sterile needle. Once all fleas are removed, the infection is considered resolved
• Tungiasis can be prevented by wearing shoes while stepping outside/outdoors, removing sand and pebbles from around the houses, and limiting contact with infected individuals and environments

Who gets Tungiasis? (Age and Sex Distribution)

• Tungiasis is common in some developing nations in the tropics. Such geographic locations include Central Africa, Southern Mexico, through South America, and West Indies
• Nevertheless, Tungiasis is most endemic to Central Africa, where in some areas, up to 50% of the individuals have been reported to be infected
• Children and the elderly are more likely to become infected, when compared to other age groups. The infection affects both males and females equally
• All races and ethnicities are equally susceptible to Tungiasis

An infected host cannot directly pass the parasite to another individual. However, being around infected individuals is an increased risk as chigoe fleas may be residing in the nearby environment.

What are the Risk Factors for Tungiasis? (Predisposing Factors)

The following are the risk factors for Tungiasis:

• Coming in contact with infected livestock, specifically pigs, which may be also infected. Trading or moving infected livestock can introduce Tungiasis to new areas and lead to human infection
• Residing in the vicinity of an infected individual: Although, Tungiasis is not transmissible from one host to another host, the presence of an infected individual may indicate that the environment harbors chigoe flea eggs that can infect others
• Walking through sand with bare feet: Fleas in contaminated sand can attach itself to exposed skin
• Sleeping outside, in areas of high-risk
• Having extensive sand or pebbles in or around homes (within the endemic regions)

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. 

Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Tungiasis? (Etiology)

• Tungiasis is caused by a burrowing parasitic flea known as the chigoe flea. The flea attaches to, and digs into the skin of humans
• Once enclosed, the flea feeds on the blood supply of the host and sheds eggs externally into the environment
• The eggs become buried in sand and pebbles near the host. In 3-4 days, the eggs hatch and larvae develop. The larvae reach maturity in 3-4 weeks
• Once the parasite is fully-developed, female chigoe fleas need to find a host to produce eggs, via a blood meal, and the life cycle repeats itself

It is important to remember that infected hosts, such as humans, cannot directly transfer the disease to another host. Infection only occurs through contact with fleas in the environment.

What are the Signs and Symptoms of Tungiasis?

The signs and symptoms of Tungiasis include the following:

• Yellow/brown lesions (bumps) with central black spots
• Severe itching and rash formation around the lesions
• Inflammation and swelling around lesions; pain at lesion sites
• Extensive infection can lead to necrosis, or the death of skin tissue (skin appears black)

It is important to note that the presence of a sign or symptom does not confer infection. Additionally, infection could be experienced without any of the above signs or symptoms.

How is Tungiasis Diagnosed?

The diagnosis of Tungiasis is made by the following tests and exams:

• A physical examination and an evaluation of the patient’s medical history and travel history to the endemic areas
• An assessment of symptoms:
  • Tungiasis is diagnosed by the unique lesions it presents on the skin surface
  • The lesion is most common on the feet, hands, and elbows
  • Typically, multiple parasites are burrowed in an infected individual, resulting in multiple lesions in a specific bodily area
  • The presence of multiple lesions is a general sign of Tungiasis
• No other tests, such as blood tests or imaging studies, are generally necessary

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Tungiasis?

Complications from Tungiasis may include:

• Viral and bacterial superinfections: This occurs owing to the parasite rupturing the outer skin (endothelium), facilitating the development of additional infections. Bacteremia, tetanus, and gangrene are some of the most common superinfections noted
• Severe Tungiasis on the lower part of the body (or legs) can make it difficult or impossible to walk due to severe pain
• Sometimes, the infections can lead to severe inflammation and necrosis (death) of nearby tissue, resulting in permanent loss of the affected tissue

How is Tungiasis Treated?

The treatment for Tungiasis requires extraction of the parasitic flea, via a fine sterile needle.

• There is no medication currently available that can kill the parasite, nor is there a vaccine available to prevent infection from taking place
• If bacterial infection occurs, antibiotics may be prescribed
• Other symptoms are treated suitably

How can Tungiasis be Prevented?

The following preventive measures may be helpful in preventing Tungiasis (in the endemic regions): 

• Limiting exposure to and movement of infected livestock
• Wearing shoes when walking outside and avoiding direct contact with sand and pebbles 
• Removing sand and pebbles from inside or around homes and establishing a concrete foundation (if possible)
• Sleeping indoors and not on the bare ground/soil

What is the Prognosis of Tungiasis? (Outcomes/Resolutions)

• Without treatment, the parasite may cause a lesion with itching, rash, and inflammation for approximately two weeks. The parasite will then die and the lesion will clear
• Re-infection is highly likely in such cases. Precautions should be taken to reduce the chances for reinfection
• With treatment, the parasite can be removed and the symptoms will usually resolve within a few days. Re-infection is likely, if there are parasites still present in the environment

Additional and Relevant Useful Information for Tungiasis:

• Only mature female fleas burrow into the skin of the host and feed on the blood supply. This is because only females need host blood to develop the eggs
• The flea digs into the skin of the host, with only the posterior end of the flea visible. The flea sheds approximately 100-200 eggs into the environment and consequently dies. It is then shed from the host’s skin approximately two weeks after the initial infection
• In most cases, the flea can latch onto skin and burrow itself without the host realizing the same
• Almost any warm-blooded animal can be a host for chigoe fleas. This means that transmission of the parasite to a new area could be facilitated by pets, livestock, and wild animals