Microfilariae obtained from in vitro culture of adult Dirofilaria immitis were inoculated into naive dogs and used to test the in vivo efficacy of the antimicrofilarial drug Dizan. Injection of 33 million microfilariae into a 3-month-old male beagle pup over a 5-day period resulted in a microfilaremia that peaked at 863 microfilariae per ml on day 30. Treatment with Dizan resulted in a rapid cl...

Onchocerciasis is a major cause of blindness worldwide, and much of the blindness is caused by onchocercal chorioretinitis. In an experimental animal model for ocular onchocerciasis, intravitreal injections of 10,000 live Onchocerca volvulus microfilariae isolated from infected humans into the eyes of cynomolgus monkeys (Macaca fascicularis) resulted in patchy, progressive loss of retinal pigme...

The binding of 10 different lectins to the surface of microfilariae of Wuchereria bancrofti has been investigated. Wheat germ agglutinin (WGA) and Helix pomatia lectin (HPA) bound specifically to the sheathed microfilariae indicating the presence of N-acetyl-D-glucosamine and N-acetyl-D-galactosamine respectively on the surface. Exsheathed microfilariae did not react with any of the lectins. Tr...

Heartworm prevention: Major factors of resistance First, heartworm preventives were designed and marketed at doses intended to prevent infection by killing third-stage and young fourth-stage larvae, not microfilariae. Thus, microfilariae may persist despite exposure to a macrocyclic lactone (ML); these drug-selected microfilariae can be transmitted between dogs by mosquitoes. This seems an unwi...

Loa loa is a filarial nematode that infects humans. The adults live in subcutaneous tissues and produce microfilariae that live for several weeks in the blood circulation in order to be transmitted to another person via blood meals of a dipterian vector. As microfilariae live in continuous contact with plasma, it is obvious that they evade the complement system. We studied markers of complement...

The aim of this study was to determine the prevalence and distribution of canine dirofilariosis from different districts of the Mazovian Province in central-eastern Poland. 462 dogs aged from 1.5-14 years were examined for dirofilariosis. Blood samples were examined for the presence of microfilariae using the Knott method, as well as the method of Kingston and Morton, after centrifugation in ha...

Four techniques for the detection and quantification of Dirofilaria immitis microfilariae in peripheral blood were compared, namely the conventional thick smear, thick films prepared by cytocentrifugation, filtration of blood through polycarbonate membranes, and density gradient centrifugation followed by membrane filtration. The efficiency of the methods and their sensitivity was assessed by d...

A fluoresceinated lectin binding assay was employed to detect carbohydrates on the sheath and cuticle of mature in vivo-derived, and immature in utero-derived Brugia pahangi microfilariae. The sheath of mature microfilariae bound concanavalin A and wheat germ agglutinin, indicating the presence of N-acetylglucosamine and glucose or mannose. In addition to binding concanavalin A and wheat germ a...

The distribution of living and dead microfilariae in 160 cases of ocular onchocerciasis has been studied. A model for coding the densities in 9 different areas of the cornea has been used. The average numbers of microfilariae and onchocercal punctate opacities per square millimetre were assessed. The highest densities were found in the superficial one-third of the corneal stroma at the peripher...

The distribution of living and dead microfilariae in 160 cases of ocular onchocerciasis has been studied. A model for coding the densities in 9 different areas of the cornea has been used. The average numbers of microfilariae and onchocercal punctate opacities per square millimetre were assessed. The highest densities were found in the superficial one-third of the corneal stroma at the peripher...