Clinical Presentations of
Lymphatic Filariasis has many clinical manifestations, the most severe of which is elephantiasis, pictured above. (Image 9)
Patients who show no symptoms or microfilaraemia have most likely not been exposed to the vector. However, there are patients who have had great exposure to the lymphatic filariasis vector, but still show no infection. These patients may have immunity to the disease, and could be of great use to medical researchers. They may also have an infection that is not detected by standard clinical tests, but may exhibit filarial antigens in their blood (Reference 20).
A great percentage of populations in endemic regions show no overt symptoms of lymphatic filariasis, but have levels of microfilariae in their blood (Reference 21). Due to the presence of microfilariae in their blood, these patients have an elevated risk of developing chronic symptoms such as lymphodema, hydrocoele or elephantiasis. Generally, the mere presence of microfilariae in the blood has little to no impact on the health of the patient, although some studies have shown that the lymphatic system is compromised due to the levels of microfilariae (Reference 20).
Acute manifestations of lymphatic filariasis are most commonly exhibited as fever, lymphangitis and lymphadenitis. The fever, often called "filarial" or "elephantoid" fever, is immune-mediated and generally accompanies attacks of lymphangitis. Lymphangitis is the an infection of the lymph channel, typically originating in the lymph node. Sites for lymphangitis are often limbs, but also very typically the scrotum. Clinical symptoms are tender and hot sensations along the lymphatic channel, and sometimes abscesses can develop. Lymphadenitis is the formation of firm nodules due to the collections of adult worms in the lymph vessels or nodes. In men, nodules tend to form around the scrotal area (Reference 22).
Hydrocoele is the condition associated with severe and often permanent inflammation of the spermatic cord. It can occur due to the concentration of worms in lymph vessels around the scrotal area. If the hydrocoele is an extension of the lymph vessel, microfilariae are often found in hydrocoele fluid. If a hydrocoele or other swollen lymph breaks open into the urinary tract, patients exhibit the condition known as chyluria (Reference 22). Patients who have chyluria have urine of milky appearance and consistency due to the high content of lymph in their urine. If not treated promptly and effectively, chyluria can result in loss of important nutrients (Reference 23).
The most dramatic and debilitating result of lymphatic filariasis is elephantiasis. Luckily, this condition is relatively uncommon, but still manages to affect many people. Elephantiasis is severe swelling in the limbs, scrotum, breasts and vulva due to blockage in the lymph vessels caused by nests of adult worms (Reference 22).