While the African nations that comprised around 21% of the cases showed a decrease in the trend over a period of 19 years from 2000 to 2018, studies still proved the global burden of infection to be concentrated in southeast Asia.
These are divided into three groups according to the part of the body they affect: These worms are transmitted by infected mosquitoes of the genera Aedes, Culex, Anopheles and Mansonia.
The most common mosquito vectors that aid in transmission are Anopheles in Africa, Culex in America, Aedes and Mansonia in Asia (Zulfiqar et al., 2023).
Here they travel through the dermis to the lymph organs and further mature into male and female worm forms for the next 6 to 12 months and finally reproduce to complete the cycle.
The most spectacular symptom of lymphatic filariasis is elephantiasis – edema with thickening of the skin and underlying tissues—which was the first disease discovered to be transmitted by mosquito bites.
[citation needed] Cases of acute inflammatory filariasis manifest 5 to 7 day episodes of fever along with inflammation of lymph nodes.
[citation needed] Filariasis is usually diagnosed by identifying microfilariae on Giemsa stained, thin and thick blood film smears, using the "gold standard" known as the finger prick test.
[citation needed] In past, one of the first successes in the efforts to improve sensitivity and specificity of filarial diagnostic tests was identification of the repeated sequences in the parasite genome.
The advancement in technologies like polymerase chain reaction (PCR) led to the development of various assays that made large scale surveys of parasitic prevalence much easier.
It has been found that T regulatory cells play an essential role in how filarial worms modify the host immune response by producing immunoglobulin G4 (IgG4).
[10] These commercial tests based on the above circulating antigens are also limited to successful detection of only adult bancroftian worms, making diagnosis only possible in later stages of infection when the therapeutics might no more show effect.
Wb-SXP was found to be 85 percent identical to the BmSXP polypeptide and differed along the C terminal where the former had an extra 29 amino acid long extension.
The WbSXP-1 variant, where a stop codon has been introduced at the amino acid position 153 has been shown to be widely distributed among different W.bancrofti populations.
[17] One review study found that "there is good evidence" that albendazole itself does not contribute to the elimination of microfilaraemia or adult filarial worms, and thus is likely an unnecessary component of albendazole-ivermectin treatment.
[21] Filarial parasites have symbiotic bacteria in the genus Wolbachia, which live inside the worm and seem to play a major role in both its reproduction and the development of the disease.
[22][non-primary source needed] [23] In 2015 William C. Campbell and Satoshi Ōmura were co-awarded half of that year's Nobel prize in Physiology or Medicine for the discovery of the drug avermectin, which, in the further developed form ivermectin, has decreased the occurrence of lymphatic filariasis.