W. bancrofti

Diethylcarbama2iae has limited antimicrofilarial activity against Onchocerca volvulus. Adults of W. bancrofti the filarial worm causiag elephantiasis, coil in the lymph system. Here females can attain a length of 10 cm. Over the years, tissue reactions result in obstmction to lymph return. Lymph nodes, lymph vessels, and the spleen become enlarged. The condition of elephantiasis is a late and unusual complication of filariasis, where the lower extremities of the body become edematous, enlarge, and over a period of time harden with a rough nodular skin. 

VT—ventricular tachycardia W. bancrofti—Wuchereria bancrofti Zn—zinc... 

It is the drug of choice for filariasis. It is effective against W. malayi, W. bancrofti, Loa... 

Diethylcarbamazine is the drug of choice for treatment of infections with these parasites because of its efficacy and lack of serious toxicity. Microfilariae of all species are rapidly killed adult parasites are killed more slowly, often requiring several courses of treatment. The drug is highly effective against adult L loa. The extent to which W bancrofti and malayi adults are killed is not known, but after appropriate therapy microfilariae do not reappear in the majority of patients. 

Between the third and twelfth days of treatment, local reactions may occur in the vicinity of dying adult or immature worms. These include lymphangitis with localized swellings in W bancrofti and malayi, small wheals in the skin in L loa, and flat papules in M streptocerca infections. Patients with attacks of lymphangitis due to W bancrofti or malayi should be treated during a quiescent period between attacks. 

W. bancrofti and B. malayi. Both of these species affect mainly the lymphatic systems or connective tissues, causing elephantiasis or hydrocele. Geographically, W. bancrofti is found in Central Africa, Southeast Asia, Central and South America, while B. malayi is more prevalent in Southeast Asia. The microfilariae of both of these species are detectable at night and circulate in the peripheral blood. 

Mosquitoes, are the most notorious carriers, or vectors, of disease and parasites. Female mosquitoes rely on warm-blooded hosts to serve as a blood meal to nourish their eggs. During the process of penetrating a host s skin with their long, sucking mouth parts, saliva from the mosquito is transferred into the bite area. Any viral, protozoan, or helminth infections carried in the biting mosquito can be transferred directly into the blood stream of its host. Among these are malaria, yellow fever, W. bancrofti (filariasis and elephantiasis), and D. immitis (heartworm). 

Brugia malayi is more susceptible to diethylcarbamazine than W. bancrofti. A study of the former, undertaken to explain the very severe effects often associated with diethylcarbamazine treatment of Ijmiphatic filariasis, provided evidence of the involvement of the cytokine mterleukin-6 (IL-6), concentrations of which were raised during treatment (12). 

Recently it has been shown that ivermectin prevents moulting of L3 larvae of W. bancrofti to L4 in vitro at the concentrations ranging from 0.1-1000 mg/ml. The inhibition of moulting of L3 to L4 of W. bancrofti is 20 times higher for ivermectin than DEC [193]. Ivermectin also appears to inhibit the intrinsic exsheathing process of the microfilariae of B. nrnlayi in mosquito hosts thereby blocking the transmission of filariasis [194]. 

The action of DEC on adult filarial worms is species dependent. The drug shows only poor or no activity on the macrofilariae of L.carinii and D. viteae in rodents and Dirofilaria immitis and D.repens in dogs. The adult worms of O. volvulus are also not susceptible to DEC. However, DEC has been found to kill the adult worms of Brugia pahangi, B.malayi, W.bancrofti, L loa, Dipetalonema streptocerca and Setaria digitata in different animals [7,62]. 

In case of loasis, the drug may provoke ocular problems and meningoencephalitis, especially in patients with heavy infections [55,99,102]. The occurrence of encephalitis due to the presence of microfilariae of Lloa in the central nervous system and cerebrospinal fluid may be fatal. The patient first falls in coma and then dies. A few cases of collapse and death have also been reported during treatment of W. bancrofti or O. volvulus infections [7]. The use of DEC should be avoided during pregnancy and in patients with renal and cardiac diseases [65]. 

Suramin exerts a selective action on the adult female worms of O. volvulus, which die within 4-5 weeks of treatment. The adult male worms and microfilariae are killed rather slowly. The drug has no action on W. bancrofti, L. loa or D. perstaris. 

W. bancrofti, the efficacy of a single dose of albendazole 600 mg alone or in combination with ivermectin 400 pg/kg or diethylcarbamazine 6 mg/kg was compared with a single dose of the combination diethylcarbamazine 6 mg/kg and ivermectin 400 pg/kg over a period of 15 months after treatment. Albendazole plus ivermectin was the most effective regimen for clearing microfilariae. Nine of 13 subjects (69%) were amicrofilaremic 15 months after treatment compared... 

This drug is effective against w. bancrofti and w. malayi, unlike other antihelmintic agents. 

DIETHYLCARBAMAZINE Diethylcarbamazine is a first-hne agent for control and treatment of lymphatic filariasis and for therapy of tropical pulmonary eosinophilia caused by W. bancrofti and Brugia malayi. Although partially effective against onchocerciasis and loiasis, it can cause serious reactions to affected microfilariae. For this reason, ivermectin has replaced diethylcarbamazine for onchocerciasis. Despite its toxicity diethylcarbamazine remains the best drug available to treat loiasis. 

Microfilarial forms of susceptible species are most affected by diethylcarbamazine, which elicits rapid disappearance from blood for W. bancrofti, B. malayi, and L. loa. The drug kills microfilariae of O. volvulus in skin but not in nodules that contain the adult (female) worms. It does not affect the microfilariae of W. bancrofti in a hydrocele. Diethylcarbamazine appears to exert a direct toxic effect on W. bancrofti microfilariae it also kills worms of adult L. loa and probably adult W. bancrofti and B. malayi. Diethylcarbamazine may impair intracellular processing and transport of certain macromolecules to the helminth plasma membrane. The drug also may affect specific immune responses of the host. 

W. Bancrofti, B. Malayi, and B. Timori The standard regimen for LF has been a 12-day, 72-mg/kg (6 mg/kg/day) course of diethylcarbamazine. A single dose of 6 mg/kg had comparable macrofilaricidal and microfilaricidal efficacy to previous regimens. Single-dose therapy may be repeated every 6-12 months, as necessary. 

Ivermectin also is effective against microfilaria but not adult worms of W. bancrofti, B. malayi, L. loa, and M. ozzardi. It exhibits excellent efficacy against A. lumbricoides, S. sterco-ralis, and cutaneous larva migrans. 

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