Easily Remember by this Story
Once upon a time, deep in the tropical countries of the world, there lived a small, but powerful creature known as Wuchereria bancrofti. This tiny worm was responsible for causing a terrible disease known as Bancroftian filariasis, which affected the lymphatic system of the human body.
Wuchereria bancrofti had a very unique life cycle. It would first begin its journey as a small larva, living inside the body of a mosquito. But as it matured, it would make its way into the human body, where it would take up residence in the lymphatic vessels and sinuses of the lymph nodes.
The adult worms were thin and thread-like, with females measuring 8-10cm and males measuring 4-5cm. They would spend their entire lives coiled up inside the lymphatic system, reproducing and producing tiny offspring known as microfilaria.
These microfilaria were small and slender, measuring only 210x310µm, and they would make their home in the blood vessels, mainly in the pulmonary capillaries. But they also had a sneaky habit of escaping into the peripheral blood, where they could be detected during certain hours of the day.
The people living in the tropical countries where Wuchereria bancrofti thrived, were at risk of being bitten by the vectors of this worm such as Culex quinquefasciatus, Anopheles, Aedes and Mansonia mosquitoes. These mosquitoes would suck the blood of the infected person and transfer the worm to the next person.
Despite the efforts of the medical community to combat this disease, Wuchereria bancrofti continued to spread its reach, causing severe symptoms such as lymphoedema, elephantiasis, and hydrocoele. But with the help of medication and education on prophylactic measures, the people of these tropical countries could protect themselves and their communities from the spread of this terrible disease.
1.What disease does Wuchereria bancrofti cause?
Bancroftian (urban) filariasis
2. What is the main lymphatic filariasis infection in Sri Lanka?
Bancroftian filariasis
3. What is the life cycle and habitat of Wuchereria bancrofti?
The worm has a biphasic life cycle, with the larval stages in the mosquito (intermediate host) and the larval and adult development in the human (definitive host). The adult worms are found coiled inside the lymphatics and mainly in the lymph nodes of the inguinal region and in the lymphatic system of male/female genitalia, less commonly they may be found in the axilliary and epitrochlear region.
4.What is the morphology of adult Wuchereria bancrofti?
Adult worms are thread-like, with female 8-10cm and male 4-5cm in length. They are found coiled inside the lymphatics and have a well-developed and paired coiled uterus.
5.What is the reproductive system of Wuchereria bancrofti?
The worms have 2 ovaries, which lead to the uterine zone with 2 oviducts. Eggs are produced in ovaries and fertilized eggs develop in uteri and produce the first stage larva (microfilaria).
6.What is the habitat and periodicity of Wuchereria bancrofti microfilaria?
Microfilaria are found in blood, mainly in the pulmonary capillaries. They have a periodicity in their 24-hour cycle, where they are found in peripheral blood only during a certain period of the day, mainly nocturnal.
7.What is the vector for filariasis caused by Wuchereria bancrofti?
Answer: The main vector is Culex quinquefasciatus (formerly C. pipens fatigans), a night-biting mosquito found abundantly in urban areas. Other vectors include Anopheles, Aedes and Mansonia mosquitoes.