The parasite L. loa germinates frombites from deer flies. The deer fly will make a meal of the blood, the infectedfly presents third-stage larvae against the skin of a human host. The larvae thenenters the wound and matures into adults that generally reside is hypodermictissues. The female parasites are generally larger than males, gauging 40-70 mmin length.
Microfilariae lose their sheaths and bore through the wall of the gut,then larvae journey to the fat of the body where it will experience two sheds.Them the larvae become infectious after roughly 10 to 12 days, in thesubcutaneous tissue larvae take between 6 months to 4 years to mature intoadults. The parasites reach adulthood in 1 to 4 years and can live for as longas 17 years. Throughout this time they move without restrictions in the subcutaneoustissues of the host, this also includes the sclera of the eyes hence the commonname of eye worm. The worm tends to reside in the bloodstream in the hours ofdaylight and migrate into the lungs during the night.At this time it is estimated that about13 million people are infested with this parasite. Loiasis is one of the mostcommon reasons for medical appointments in some hyperendemic districts.
Cameroon, Central African Republic, Chad,Congo Republic, Equatorial Guinea, Gabon, Nigeria, and North Angola are themain areas linked with this parasite. In endemic zones there is advanced dangerof getting this infection in someone who is increasing in age. It is also themore common for filarial infection to be developed by tourists. Generally, ittakes months or even years of contact with this parasite to contract thisinfection. In some cases, infection can commence after a brief quantity of timewere a person is exposed. This disease infects as much as 30% of visitors whoare in this area for extended amounts of time.A great number of people who areinfected with L.
loa will not show symptoms. For those who do start to show symptomsthe main indications of this infection include, subcutaneous swellings, alsoknown as Calabar swellings, and movement of the adult worm across the conjunctivaof the eye. People who do not have immunity might have allergic-type signs thatinclude pruritus, asthma and urticaria.
The calabar swellings are a sort ofpainless swelling, this swelling is customarily triggered by an allergy topollen, medications, animal dander, venom, and food. However, when swellingsarise because of L. Loa it is due to sensitivity to the release of themicrofilariae or the migrating of the adult worm.
Calabar swellings are morecommon on the extremities and the face, they typically are non-erythematous anddie out after a few days. Recognizing the adult worm in the subcutaneoustissue will ultimately diagnosis this parasite. Another way to identify thisparasite would be to complete a blood smear to recognize the microfilariae,this would be done by preforming the Knott or the saponine test.
Serologic testsare more beneficial in diagnosing loiasis among travelers. In endemic dwellersserology is not helpful, this is because their antibodies stay positive for lengthyquantities of time after interaction with the parasite. Antibody tests have moderatelygood sensitivity but poor specificity because of a cross reaction with filarialinfections. The choices about what treatment should be used when handlingloiasis can be hard and often might require guidance from an expert. Surgery canbe a possibility for the abstraction of adult worms beneath the skin or in theeye.
Loiasis can not be cured with surgical procedure alone, however eliminatingthe worm might decrease anxiety in the host. There are two medications that canbe used to manage symptom and treat the infection. Diethylcarbamazine is one ofthe medications that can treat this parasite, it kills the microfilariae andadult worms. Albendazole can be used as well if numerous diethylcarbamazinetreatments still do not cure the infection. If infection worsens there is a dangerof brain inflammation if treated with diethylcarbamazine,this can cause a coma and rarely death. Thewellbeing of a person will determine if treatment can be completed.