Acanthocheilonemiasis: Causes, Symptoms, Complications, And Treatment

Dipetalonema perstans or Acanthocheilonemiasis can be defined as a rare infectious disease transmitted through the bite of tropical flies called A. coliroides via parasites known as Acanthocheilonema perstans. The parasite is commonly found in Africa.

Acanthocheilonema perstans belong to a group of parasitic diseases known as filarial diseases also known as nematodes, which can be considered as one of the most numerous multicellular animals on earth. They can be found in free-living species grounds where the parasite feeds on bacteria, fungi, and other nematodes, flies like A. coliroides will feed on the open food items contaminated with the parasite which transfers to the human body when bitten.

Mansonella perstans or acanthocheilonema perstans is an arthropod-borne (filarial) nematode transmitted by tiny blood-sucking flies called midges or A. coliroides.

A midge usually gets infected when they ingest microfilariae during a blood meal of an infected animal or human. After the meal, the pesticide travels to the midge's midge and microfilariae migrate via the flies' hemocoel and lastly to the thoracic muscles of the midge. In the thoracic muscles of the insect, the parasite develops into second-stage larvae which might take 6 to 12 months. The second stage larvae are not as infectious as the next stage which is the third stage.

Third-stage (L3) filarial larvae get injected into the human flesh during a blood meal of the fly that has been carrying the parasite into their stings.

Human body heat acts as an incubator for the parasite which prompts them to leave the vector and actively penetrate the skin leaving body cavities mostly in the mesentery, perirenal spaces, retroperitoneal spaces, or the pericardium to develop themselves into adults. This parasite can live and feed onto the human body for years.

The adult parasite directly penetrates and creates body cavities that produce unsheathed and subperiodic microfilariae (multiply themselves) into the bloodstream which can further spread into the cerebrospinal fluid.

Acanthocheilonemiasis or dipetalonemiasis is an infectious disease that is caused by the third stage or adult “thread-like” worms known as Acanthocheilonema perstans or dipetalonema perstans. They belong to the group of parasitics which can describe filarial diseases or nematodes. These can be life-threatening diseases as the parasite feeds on the protein of the skin and muscles. The parasitic disease is mostly transmitted by small black insects found in the parts of Africa commonly known as a midge or A. Culicoides.

Like any general insect bite, the effects of the infections take their time to grow on the surface of the skin. This time period is known as the incubation period. So people who get infected by Acanthocheilonemiasis may show no symptoms at the start, but they gradually show symptoms that may escalate with time if not treated on time:

• Itchy skin (pruritus)
• Abdominal pain
• Chest pain
• Headache
• Localized swelling (edema)
• Muscle pains (myalgias)
• Swelling under the skin (subcutaneous)

Further complications that can be seen via medical examination are:

• Abnormal immune reactions
• Inflammation of the lining of the lungs (pleuritis)
• Enlarged liver and spleen (hepatosplenomegaly)
• High levels of granular white blood cells (eosinophilia)
• Inflammation in the muscles surrounding the heart (pericarditis)
• Inflammation in areas like the abdomen and chest is caused due to nematode invasion

Since Acanthocheilonemiasis is a rare parasitic disease and the symptoms may resemble other medical disorders, some of the diseases may show similar to some of the following disorders:

• Filariasis belongs to a group of rare infectious diseases caused by the same group of parasitic worms called nematodes. The symptoms of the parasitic infection may resemble the symptoms of Acanthocheilonemiasis like lymphadenopathy (abnormal changes or chronic obstruction of the flow with the lymph glands), mumu, loiasis (Calabar swellings), onchocerciasis (river blindness), dirofilariasis (human infection by dog heartworm) which may result in the extreme swelling in legs and/or genitalia (elephantiasis). The key difference here is the parasite enters the body by a mosquito bite while the parasite of Acanthocheilonemiasis enters the body by a midge or A. Culicoides.

Other common symptoms like abdomen and chest pain, itchy skin, and muscle cramps can also be associated with different tropical or local parasitic or non-parasitic medical disorders.

Research has shown that people who work or visit areas regularly with the presence of infected insects (endemic locations) are more likely to get attacked by the parasite than the ones who visited the place only once.

Furthermore, since the presence of parasites is in abundance in central Africa and some areas of South America, locals and natives are more prone to get infected rather than visitors or tourists.

In the case of gender or age, the parasite can infect both males and females at any stage of life.

There are no specific guidelines to diagnose Acanthocheilonemiasis, yet there are some sets of testing recommended by researchers around the globe to detect any type of parasite.

• A fecal (stool) exam or ova and parasite test (O&P):The test is generally is been conducted to identify the cause of illness associated with a digestive track like diarrhea, loose or watery stools, cramping, flatulence (gas), and abdominal pain, etc. In the case of parasite identification, they will mainly focus on the presence of ova (eggs) or the parasite in the stool.

  It has been recommended to collect three stool samples that need to be collected on separate days, which need to be preserved in a preservative fluid that should be stored in a refrigerator but should be kept under 0 degrees or frozen until delivered to the lab for testing.

• Endoscopy/Colonoscopy:this test is used in case the stool test does not show any accurate results. It is conducted with the tube-like structure known as colonoscopy which was inserted into the rectum. The colonoscope has a tiny video camera that has been attracted to its tip which allows the examiner ( gastroenterologist) to view the inside of the entire colon.

  The test is usually performed to look for parasites that cause abdominal illness like loose or watery stools, cramping, flatulence (gas), etc.

• Blood tests:Not all parasites will travel through the blood, but in the case of Acanthocheilonemiasis, the blood test is one of the most perfected tests to conduct as the nature of the parasite is to penetrate your skin and travel through your bloodstream. Here are some of the blood tests that are generally used to detect any signs of parasite into your bloodstream:
  • Serology:This is research used to diagnose the presence of antibodies or parasite antigens produced by your body's immune system under parasitic attack. The test is conducted by the examiner by taking your sample and sending it to the lab where they use centrifugation to separate the different fluids that are combined with red blood cells. The presence of specific antibodies will determine the infection caused by parasite invasion.
  • Blood smear:The test is conducted to detect the presence of parasites in the blood through microscopic examination. Your blood sample will be smeared onto a glass slide with a special stain and put under the microscope to look for parasitic diseases.
• Imagine testing:Testing like Magnetic Resonance Imaging (MRI) scan, X-ray, or Computerized Axial Tomography scan (CAT) to identify the root cause of the symptoms like chest pain and inflation in the heart muscles by detecting the presence of parasites into different organs.

Even though no single drug is proven effective against all kinds of parasite infections, and for some there is no treatment available, in the case of Acanthocheilonemiasis antiparasitic drugs and surgeries are quite effective. For cases where there is only the presence of eggs and larvae, antiparasitic drugs like Ivermectin or diethyl-carbamazine (DEC) are designed particularly to eliminate and reduce the number of worms and their associated symptoms.

In cases where the size and the number of worms are life-threatening and cannot be controlled with antiparasitic drugs, surgeries may be recommended to remove the parasite from the body followed by the drugs to eliminate any presence of the parasite in the body.

An infectious bite can create swelling at the initial stages and later escalate into serious medical conditions. Here are the steps that one needs to follow if the site of infection converts into a red swollen wound:

• Clean the wounded area with wound wash and pat dry with a clean cloth.
• Use an elasto-crepe bandage or tailor-made stockings.
• Take the patient to the emergency room to control the swelling.
• Keep massaging the limb especially in early edema, to stimulate the lymphatics and to promote the flow of lymph towards larger patent vessels while taking the patient to the nearest care center.
• Keeping the limb elevated most of the time especially at night to improves the flow of fluid and lymph.
• Intermittent pneumatic compression using single or multicell jackets on the affected limb supports the lymphatic system.
• Exercising regularly to support the lymphatic system, as directed by a doctor.
• Use heat therapy to ease out the swelling.
• Keep the wound clean, moisturized, and disinfected to prevent secondary infections.

• Avoid insect bites: The first and the foremost prevention method to avoid any parasitic attack is to prevent oneself from any insect bite. Avoid places with open grounds and places with a high population of insects. Also, the time between the hours of dusk and dawn is meal time for the insects so it's better to be more precautious for any insect bite.
• Insect control: Things like insect nets, indoor residual spraying, or personal protection measures like full covered clothes and insect repent ointments can be used to protect oneself from an insect bite. Also, proper hygiene and sanitization in living and working spaces and their surroundings may eliminate any possibility of insect growth.
• Apart from general prevention: It is important to prevent oneself from infection if the person is already infected to avoid any further complications. Here are some of the methods that one can adopt to avoid any further infection:
  • Sleep under an insect repellent net.
  • Wear long sleeves and trousers the entire day and night.
  • Maintain personal and environmental hygiene.
  • Clear leaves and other rubbish from roof gutters and from around the house.
  • Don’t leave empty buckets, tins, bottles, or drums around, turn upside down to prevent stagnant water from forming.
  • Remove old tires.
  • Cover stored water drums securely.
  • Remove potential indoor breeding habitats including vases, water try under the fridge, empty bottles and cans, stored water.
  • Work with your village or neighborhood to remove common breeding habitats from shared areas.
  • Cut long grass.
  • Remove coconut shells and husks as they accumulate water for mosquitoes to breed in.
  • Use mosquito repellent on exposed skin indoors and outdoors, especially between dusk and dawn.
  • Maintain physical exercise.
  • Take care of the wound, keep it dry and well dressed.
  • Install flywire on your windows and doors.

Summary: Acanthocheilonemiasis is a rare infectious disease that transmits through the bite of tropical flies which is infected by acanthocheilonema perstans called A. coliroides. They are mostly found in parts of Africa. It can be detected by general symptoms like headache, swelling on site of infection, chest and abdomen pain, etc.