RANJAN BANERJEE

BIOL 062

NOVEMBER 20TH 2008

Lymphatic Filariasis

What is Lymphatic Filariasis?

Parasitic disease of lymphatic system

What is Lymphatic Filariasis?

Parasitic disease of lymphatic system Circulates in blood

What is Lymphatic Filariasis?

Parasitic disease of lymphatic system Circulates in bloodAlmost exclusively in humans

What is Lymphatic Filariasis?

Parasitic disease of lymphatic system Circulates in bloodAlmost exclusively in humansAmong world's leading causes of disability

What is Lymphatic Filariasis?

Parasitic disease of lymphatic system Circulates in bloodAlmost exclusively in humansAmong world's leading causes of disabilityIncreasing due to unchecked urbanization

Prevalence

Endemic in tropical regions Asia, Africa, Central/South America

Prevalence

>120 million people infected1 billion at risk for infection

Cause

Three worms Wuchereria bancrofti - 90% of cases Brugia malayi  Brugia timori

Transmission cycle is complicated

CDC Public Image Library

Risk Group

People in tropical/subtropical regions

www.groovythemes.com/nature/tropics.shtml

Repeated mosquito bites over many years

dvice.com/archives/2008/07/sk_telecom_offe.php

Symptoms

Most due to dysfunctional lymphatic system

The Physiotherapist Pte Ltd. 

Symptoms

Lymphedema Gangrene

Symptoms

Genital damage - hydrocele 10-50% men

http://img.tfd.com/dorland/hydrocele.jpg

Filarial antigens provoke immune responses

Increasing levels of IgE and IgG4

Symptoms (cont’d)

pulmonary tropical eosinophilia syndrome Inflammation of the lung Cough, shortness of breath

myweb.lsbu.ac.uk/dirt/museum/p6-633.html

Symptoms

Manifestation may take years

Diagnosis

Giemsa stain – differential stain

But doing smear is complicated..

Nocturnally periodic

Nuchprayoon et al. Filaria Journal 2007 6:6   doi:10.1186/1475-2883-6-6

Serology is another method

Immunoglobulin test - antifiliarial IgGs

Treatment

diethylcarbamazine (DEC) Kills microfilarae Prevents transmission

Albendazole Kills adults and microfilarae

Slightly different in Africa

Ivermectin instead of DEC Side effects with other diseases River blindness

Secondary Treatment

Good hygiene is important

http://www.a-wol.net/images/on_legs.jpg

Socio-economic Impact

Disease of the poor Incapacitates cycle

http://www.bbc.co.uk/radio4/today/gallery/media/poverty2.jpg

Social stigma

“Her husband left her when he realized that her legs would not shrink, she said. As her new boyfriend, a handsome out-of-work carpenter, sold goods nearby, she said, "I don't know if he will leave me, too.”

- Antoinette St. Fab

Efforts

In 1993 identified as one of six eliminable infectious diseases

In 1997, World Health Assembly called for elimination of LF worldwide

WHO: Global Programme to Eliminate LF

Goal 1: break cycle of transmission

MDA Combination therapy Donated Drugs

WHO: Global Programme to Eliminate LF

Goal 2: Alleviate suffering in infected persons Community education programs Community care

© Global Alliance to Eliminate Lymphatic Filariasis

© Global Alliance to Eliminate Lymphatic Filariasis

Future

September 20th, 2007 – genome of Brugia malayi mapped Vaccine?

http://wishart.biology.ualberta.ca/BacMap/cgview_linked_maps/NC_006833/png/1_1.png