Wuchereria bancrofti & Brugia malayi Ashley Skellie & Karissa Jensen.
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Transcript of Wuchereria bancrofti & Brugia malayi Ashley Skellie & Karissa Jensen.
Wuchereria bancrofti & Brugia malayi
Ashley Skellie & Karissa Jensen
Background Lymphatic filariasis and
elephantiasis Leading cause of permanent
disability worldwide120 million people affected
More than 30% have severe cases
One billion people are at risk in over 80 countries
BackgroundElephatiasis
Was confused with leprosy Nonsense word
WWII soldiers feared the disease
Wuchereria bancrofti Responsible for 90% of lymphatic filariasis. Likely brought to New World by slave trade Lingered near Charleston, NC until 1920s
Brugia malayi Microfilariae first discovered in 1927 In 1940, adult form discovered
Hosts
Definitive Host:Humans
Intermediate Host:Mosquito
77 species Anopheles, Aedes,
Culex, and Mansonia
Geographical Range
Wuchereria bancrofti
Asia Subtropical and tropical Mostly India
Africa
The Pacific
Americas Brazil Haiti Guyana Dominican Republic
Brugia malayi
Asia
South and South East
South China
Indonesia
Thailand
Vietnam
Malaysia
Philippines
South Korea
Geographical Range
Morphology
Microfilariae
Larvae
Adults
MicrofilariaeConsidered advanced embryosRetain egg membrane sheathWhen stained, can see nuclei and organs
Nuclei are diagnostic
Maximum number in peripheral blood occurs between 10pm and 2am
During the day, found in tissues
Larvae
Stage found in mosquito
Microfilariae ingested and turns into L1 for 8 days
Molts into L2ShortSausage-shapedLack anus
2 to 4 days later, molt to L3 Become elongated, gut development completed
Juveniles 1.4 to 2.0 mm
Adults
Wuchereria bancroftiFemales
6-10 cm Vuvla is near the
level of the middle of their esophagus
Ovoviviparous, producing thousands of microfilariae
Males 40 mm Finger-like tail
No nuclei in end of tail
Brugia malayiFemales
80-100 mm Vuvla is near the level
of the middle of their esophagus
Males 13.5-20.5 mm Tail
Curved ventrally Bears 3 to 4 pairs
of both adanal and postanal papillae.
Spicules are unequal and dissimilar
Left papillae more complex
Nuclei in end of tail
AdultsLong and slender
Smooth cuticle and bluntly rounded ends
Head is slightly swollen and bears two circles of papillae
Mouth is small, buccal capsule is lacking
Live in lymphatic ducts Afferent lymph channels near
major lymph glands of lower body
Take 6 to 12 months to mature
Life Cycle
Symptoms
Lymphatic filariasisAsymptomatic Phase, Inflammatory
Phase, Obstructive Phase
IgE mediated allergic response which brings on asthma-like symptoms
Elephantiasis Swelling in legs, arms, genitalia, breasts Thickening of skin and underlying tissues
Elephantiasis is more common with Wuchereria bancrofti infections
Diagnosis
Blood Sample Nighttime draw to ensure microfilariae in sample Presence of antibodies
Antifilarial IgG4
Finger-prick Detects antigens Taken anytime during the day
Polymerase Chain Reaction (PCR) Molecular level Detects as little as 1 picogram of microfilariae DNA to
determine which species is present
X-ray and ultrasonography
Treatment
Diethylcarbamazine (DEC) Many side effects Kills microfilariae and usually adults with careful administration
Ivermectin Only kills microfilariae Best when combined with DEC or albendazole
Clean infected areas daily Prevents bacterial infections
Exercise or use pressure bandages Allows movement of bodily fluids
No vaccines are available
WolbachiaWolbachia bacteria in symbiosis with Wuchereria
bancrofti
Bacteria lives inside worm
Antibiotics used to kill bacteria, and kill the W. bancrofti at the same time
Control
Mosquito control and preventative measures
Repellant applied to skin and bed nets
Wear pants and long sleeves near reservoirs and vectors, especially at night
Mass treatments to entire communities
Education
Review
What are the definitive and intermediate hosts?
What are the 3 morphological forms?
Name one difference between Wuchereria bancrofti and Brugia malayi.
What is the infective stage in the life cycle?
Is elephantiasis more common in Wuchereria bancrofti or Brugia malayi?
Name two treatments.