What are the characteristics of Brugia malayi?

Long and threadlike, B. malayi and other nematode possess only longitudinal muscles and move in an S-shape motion. Adults are typically smaller than adult W. bancrofti, though few adults have been isolated. Female adult worms (50 mm) are larger than male worms (25 mm).

How do you identify Brugia malayi?

Microfilariae of Brugia malayi are sheathed and in stained blood smears measure 175—230 µm. In 2% formalin they are longer, measuring 240—300 µm. The tail is tapered, with a significant gap between the terminal and subterminal nuclei. Microfilaria circulate in the blood.

What are the three types of filariasis?

There are 3 types of these thread-like filarial worms: Wuchereria bancrofti, which is responsible for 90% of the cases. Brugia malayi, which causes most of the remainder of the cases. Brugia timori, which also causes the disease.

What is the difference between W bancrofti and B. malayi microfilariae?

bancrofti are more protruding while in B. malayi they are flattened. The lateral caudal papillae in B. malayi have an indentation around their bases which is absent in W.

What is morphology of Brugia malayi?

They lie folded with head close to tail. Each microfilaria measures 177-230 µm in length and 5-6 µm in diameter. They possess secondary kinks, instead of smooth curves. The presence of two distinct nuclei at the tip of the tail is the distinguishing feature of microfilaria.

Which disease is caused by Brugia malayi?

The typical vector for Brugia malayi filariasis are mosquito species from the genera Mansonia and Aedes. During a blood meal, an infected mosquito introduces third-stage filarial larvae onto the skin of the human host, where they penetrate into the bite wound .

What is the difference between Brugia malayi and Brugia timori?

timori has greater numbers of single row nuclei in the terminal column of body cells and a lesser bulge of the cuticle surrounding nuclei in the distal portion of the tail than does B. malayi. About 60% of B. timori microfilariae were exsheathed in haemalum-stained thick blood films.

What is the morphology of loa loa?

Loa loa is cylindrical, has a cuticle with three main outer layers made of collagen and other compounds. The outer layers are non-cellular and are secreted by the epidermis. The cuticle layer protects the nematodes so they can invade the digestive tracts of animals.

What is the definitive host of Brugia malayi?

malayi migrate to the proboscis of the mosquito. During the mosquito’s blood meal the larvae enter the wound of the definitive host, which consist of humans, monkeys, domestic cats, and forest carnivores. The larvae then migrate through the subcutaneous tissue to the lymphatic vessels of the definitive host.

Is Brugia malayi diurnal?

Wuchereria bancrofti, Brugia malayi and B.

bancrofti found in some Pacific Islands produce microfilariae that appear in the blood in the daytime (diurnal periodicity). Mosquitoes obtain blood at night and the larvae develop into the infective stage in 10–14 days.

What is the causative agent of Loa loa?

Loiasis, called African eye worm by most people, is caused by the parasitic worm Loa loa. It is passed on to humans through the repeated bites of deerflies (also known as mango flies or mangrove flies) of the genus Chrysops. The flies that pass on the parasite breed in certain rain forests of West and Central Africa.

What is the pathology of Loa loa?

Loa loa is only mildly pathogenic. Adult worms wander throughout the body, moving through the tissues at a maximum rate of about 1.5 cm/minute. The most troublesome infection sites are the conjunctiva (Fig. 17-5) and the bridge of the nose, where impaired vision, irritation, and pain may result.

What is the vector of Loa loa?

Background. Loiasis is a filarial disease caused Loa loa. The main vectors are Chrysops silacea and C. dimidiata which are confined to the tropical rainforests of Central and West Africa.

Which organ is Loa loa found?

Loa loa actually means “worm worm”, but is commonly known as the “eye worm”, as it localizes to the conjunctiva of the eye.

How is Loa loa diagnosis?

Loa loa is usually diagnosed by the finding of microfilaria in peripheral blood smears or adults in the subconjunctiva. The blood films may be thick or thin and stained with Giemsa or hematoxylin-and-eosin. For increased sensitivity, concentration techniques can be used.

How do you test for Loa loa?

In general the diagnosis of L. loa infection should be made with blood smear. However, when blood smears are negative and clinical suspicion of infection is high, the general antibody test could be used in an attempt to exclude infection.

What is river blindness caused by?

Parasites – Onchocerciasis (also known as River Blindness)

Onchocerciasis, or river blindness, is a neglected tropical disease (NTD) caused by the parasitic worm Onchocerca volvulus. It is transmitted through repeated bites by blackflies of the genus Simulium.

What is the incubation period of Loa loa?

L loa microfilariae mature into their infective third-stage larval forms in their Chrysops hosts, a process that typically takes 10-12 days to complete. These larvae make their way into humans when female flies take blood meals and migrate from the proboscis of an infected fly to the bite wound it creates.