What are other Names for this Condition? (Also known as/Synonyms)
- Bancroftian Elephantiasis
- Bancroftian Filariasis
- Infection due to Wuchereria Bancrofti
What is Wuchereria Bancrofti Infection? (Definition/Background Information)
- Wuchereria Bancrofti Infection describes an infection of the lymphatic vessels and lymph nodes. It is caused by the filarial worm Wuchereria bancrofti. The larval forms of the worm, or microfilariae, are distributed from one individual to another through mosquito bites
- Wuchereria bancrofti is commonly found in tropical areas of the world. It can be found in parts of Africa, South America, Central America, Southern China, and the Pacific Islands.
- The larval worms circulate in the bloodstream of infected individuals and mature within the lymph nodes. This may cause obstruction and can lead to a condition known as elephantiasis, or swelling of the limbs, as well as hydrocele, or swelling of the testicles
- Wuchereria Bancrofti Infection is commonly treated using medications to kill the parasitic worms. In addition, therapy to deal with the swelling of the limbs may be necessary. In more severe cases of lymphatic obstruction, a surgical intervention may be required
- Prevention of Wuchereria Bancrofti infection is largely dependent on reducing the number of bites from mosquitos. This may include measures such as insect repellents, bed netting, and elimination of mosquito breeding areas
Who gets Wuchereria Bancrofti Infection? (Age and Sex Distribution)
- Wuchereria Bancroft Infection does not show an age or sex preference due to the fact that it is propagated through mosquito bites. However, the disease may present differently among males and females
- There is no ethnic or racial preference for contracting Wuchereria Bancrofti Infection. Any individuals staying in areas endemic to the disease may develop the infection, if bitten by mosquitoes carrying the parasite
- Infection due to Wuchereria Bancrofti is contained within the regions it is endemic to - including Central Africa, the Nile Delta region of Africa, South and Central America, Southern China, and the Pacific Islands
What are the Risk Factors for Wuchereria Bancrofti Infection? (Predisposing Factors)
The Risk factors for Wuchereria Bancrofti Infection include:
- Living in areas endemic to the parasitic worms; being exposed to areas in which mosquitos thrive
- Having a compromised immune system
- Being exposed to unsanitary conditions: The infection has a notable socioeconomic distribution as well. The worms thrive in unsanitary conditions and as such affect individuals living in impoverished areas with poor living situations
- The infection is endemic to tropical and sub-tropical areas
It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.
Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.
What are the Causes of Wuchereria Bancrofti Infection? (Etiology)
Wuchereria Bancrofti Infection is caused by an infection of the parasitic nematode (worm), Wuchereria bancrofti. The worms are transmitted from an infected individual to an uninfected individual through mosquito bites.
- Several species of mosquito contribute to transmittance and can be found throughout the equatorial regions of the world
- Adult worms produce offspring known as microfilariae
- While the adult worms are localized to the lymphatic system, microfilariae are present in the blood circulation
- Mosquitoes bite infected individuals and pass on the microfilariae to uninfected individuals
- The microfilariae then mature into adult worms in the individual’s lymph nodes
What are the Signs and Symptoms of Wuchereria Bancrofti Infection?
The signs and symptoms of Wuchereria Bancrofti Infection are variable. Some individuals are asymptomatic while other individuals may present with the following signs and symptoms:
- Fever and chills
- Inflammation of the lymph nodes or lymphadenopathy
- Inflammation of the lymphatic vessels
- Males may develop swelling in the testicles (hydrocele) and females may develop swelling in the breasts. This is due to obstruction of the lymph nodes near the aforementioned areas by adult worms
- Elephantiasis (swelling of the limbs)
- Hardening of the skin
- Pain in the swollen areas
- Asthma-like symptoms resulting from microfilariae traveling through blood to the lungs and triggering an allergic response
- Chyluria (milky-white urine) resulting from lymphatic fluid emptying into the urinary tract. If this condition persists, it may lead to nutrient deficiency
How is Wuchereria Bancrofti Infection Diagnosed?
Wuchereria Bancrofti Infection is generally diagnosed by a healthcare professional. The following methods may be used to diagnose the infection due to Wuchereria Bancrofti:
- A full physical examination performed by a healthcare professional complete with a full medical history
- Often times, a blood test will be performed to determine the presence of microfilariae (larval worms) in blood
- Microfilariae can be detected in blood or in the lymphatic fluid
- Blood tests will be done between 10pm and 2am – Wuchereria Bancrofti microfilariae tend to be active in blood during the night
- An individual’s serum will be tested for antifilarial antibodies as well as increased amounts of eosinophils (a type of white blood cell). The presence of these 2 factors may support the diagnosis of Wuchereria Bancrofti Infection
- An ultrasound test can be performed to observe adult worms present in the lymph nodes or lymphatic vessels
If the blood test returns negative for circulating microfilariae, other methods may be used to test for proteins produced by adult Wuchereria bancrofti. These are commonly known as circulating filarial antigen (CFA) tests.
- The immunochromatographic card test (ICT) requires a drop of blood (usually collected from a finger prick) to test for the presence of filarial antigens (proteins)
- The IgG4 ELISA test will screen for a type of antibody that is produced by individuals that have Wuchereria Bancrofti Infection
Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.
What are the Possible Complications of Wuchereria Bancrofti Infection?
Severe cases of Wuchereria Bancrofti Infection may lead to a number of possible complications for the individual:
- Repeated infections of Wuchereria bancrofti may result in hardening of tissues that surround the lymphatic vessels. This, in addition to obstruction of lymph nodes by adult worms, may eventually lead to elephantiasis, or the severe swelling and enlargement of the affected limbs
- In some cases, the breasts or testicles may become swollen
- In cases where W. bancrofti microfilariae travel to the lungs, an allergic response may result. This response generally will manifest itself in asthma-like symptoms
How is Wuchereria Bancrofti Infection Treated?
A qualified healthcare professional may consider the following treatment options for Wuchereria Bancrofti Infection:
- The main drug used to treat Wuchereria Bancrofti Infection is diethylcarbamazine (DEC). DEC kills microfilariae that circulate in blood and may also be effective against adult W. bancrofti worms as well
- If the lymph nodes are severely blocked and limbs are enlarged, surgery may be needed to relieve the obstruction
- Antihistamines and pain medication may be given to help with inflammation and pain associated with swelling
- Measures should be taken to keep infected limbs clean, as they are prone to bacterial infection
- Exercising and massaging of an infected limb may improve lymph flow and the condition of the limb
How can Wuchereria Bancrofti Infection be Prevented?
Wuchereria Bancrofti Infection is best prevented through reducing exposure to mosquito bites.
- The disease is transmitted from one individual to another through mosquitoes; so taking steps to avoid their bites is crucial
- For those travelling to the endemic areas, insect repellents and wearing clothing that cover the arms and legs are good protective measures
- Sleeping with bed netting will help prevent bites, especially at dusk and dawn, when mosquitoes are most active
- The use of chemicals to kill mosquitos and other methods to eliminate breeding sites are also effective methods to prevent Wuchereria Bancrofti Infection
What is the Prognosis of Wuchereria Bancrofti Infection? (Outcomes/Resolutions)
- The prognosis for individuals with Wuchereria Bancrofti Infection is generally good for those that have access to the appropriate treatment and preventative measures
- If treatment and preventive steps are not taken, the infection may result in a worse prognosis. Complications such as elephantiasis, hydrocele, tropical eosinophilia (asthma-like symptoms), or chyluria may develop
- It is important to consult a healthcare professional before starting the use of DEC; in certain cases, it may lead to encephalitis (inflammation and swelling of the brain)
Additional and Relevant Information for Wuchereria Bancrofti Infection:
- Wuchereria Bancrofti Infection is part of a larger classification of diseases known as filariasis
- Wuchereria bancrofti is responsible for up to 90% of the cases of Lymphatic Filariasis. In addition, Brugia malayi and Brugia timori may cause Lymphatic Filariasis
- Adult W. bancrofti worms may lodge in an infected individual’s lymph nodes for up to 8 years
The World Health Organization has set a goal to eliminate Lymphatic Filariasis (and, subsequently, Wuchereria Bancrofti Infection) by 2020.