Dirofilariasis

Dirofilariosis is a disease caused by Dirofilaria repens or Dirofilaria immitis. They are thin white worms and belong to the filariae. Commonly beasts, especially canine and feline, attack. Man is a random host, in man the larva does not grow. The source of the infection is a mosquito (vector).

Dirophilariasis is one of the so-called emerging infectious diseases. It is an infectious disease that is spreading worldwide and is often known to be closely linked to human travel, animal movements and global climate change, in particular global warming.

Life cycle
The larvae develop in mosquitoes for 15-18 days. As soon as a mosquito bites a human, the larvae enter the skin and from it into the blood. The larvae in humans do not mature in the adult, but nest in some organ, where they form nodules. They most often affect the subcutaneous tissue, lungs, heart or eyes. They can also become trapped in the lymph nodes and in the abdomen.

Dirofilaria repens

 * In the Czech Republic it is more common than Dirofilaria immitis (in the Czech Republic only 5 cases, but it is still expanding and is approaching the Czech Republic from the classic places of occurrence).
 * The most common cause of symptomatic heartworm disease.
 * When infected, a person forms nodules in the skin, orbit, vitreous, conjunctiva, and eyelid.

Dirofilaria immitis

 * Czech hairy dog.
 * It is often called a heart worm because it likes to settle in the heart and causes cardiopulmonary damage (in dogs).
 * However, it most often causes asymptomatic infections in humans and dogs.
 * In humans, the larva is most often trapped in the subcutaneous tissue, eye, or lungs, where it forms nodules.

Heartworm infections can elicit a relatively strong immune response, which may be related to some other symptoms located outside the affected area.

Diagnostics

 * Microscopic examination of collected tissues (biopsy, excision).
 * Detection of specific antibodies (serum, vitreous) or DNA parasite.

Therapy

 * Anthelmintics (ivermectin, diethylcarbamazine) that damage worm muscle.
 * Surgical removal of the worm.

Prevention
Cases of heartworm disease are likely to increase due to the spread of the parasite itself and the ever-increasing travel of people with pets (dogs and cats). Travelers should also protect themselves from mosquitoes in non-malarial areas.

Related articles

 * Filaria
 * Loa loa
 * Onchocerciasis

Literature
CHANOVÁ, Marta. Diseases caused by nematodes III (Filaria) [lecture on the subject Parasitology, General Medicine, 1st Medical Faculty, Charles University]. Prague. 11/23/2015