Filariasis is one of the oldest diseases in the world. It is an endemic problem in our country. Filariasis is an important clinical problem and often encountered by the Urologists all over the country. It is a mosquito-borne parasitic disease caused by three lymphatic dwelling nematodes namely Wuchereria bancrofti, Brugia malayi and Brugia timori. W bancrofti accounts for 90% of human cases. Filariasis may cause acute lymphangitis and lymphadenopathy or chronic lymphatic dilatation with hydrocele, elephantiasis of limbs, lymphoedema of  genitalia and chyluria.

EPIDEMIOLOGY
Lymphatic filariasis affects 120 million persons living in 73 countries, with India accounting for 40% of global infections. A recent estimate has shown that in India, 22 states are endemic and 9 states (AP, Bihar, Gujarat, Kerala, Maharashtra, TN, Orissa, UP and WB) contribute to about 95% of the total burden.

FUNICULO-EPIDIDYMITIS:
Filarial funiculo-epididymitis may be isolated with remession, or repetitive and progressive. Local pain radiating to the testis or simulating ureteric colic, may be accompanied by systemic symptoms. Palpable cord like swelling may be accompanied by hydrocele. Bacterial superinfection, brings exquisite pain, high grade fever and septic thrombophlebitis.

Prognosis of the funicular filarial attack is variable. Mild cases may involute spontaneously, but more often augur  recurrences and chronic lymphedema. The disease frequently simulates malignancy. Bacterial infection and malignancy should be excluded. Filariasis should be treated by surgical decompression or excision of filarial nodules, preserving the testis and the cord. When the disease is recurrent, painful and deforming or complicated by blood vessel involvement, ipsilateral orchidectomy is warranted.

HYDROCELE:
In men, hydrocele is the most common morbidity due to W. bancrofti. In endemic areas, differentiation of filarial from idiopathic hydrocele is difficult. Milky or sediment rich hydrocele fluid suggests a filarial origin. Hydrocele accompanied by nodules in the cord or epididymis, thick fibrous tunica with cholesterol or calcium deposits and tunical calcification, should prompt a diagnosis of filariasis.

Excision of hydrocele sac is the treatment of choice. Aspiration sclerotherapy or management with diethyl carbamazine (DEC) is ineffective.

SCROTAL, PENILE ELEPHANTIASIS AND LYMPH SCROTUM:
For genital elephantiasis, the treatment is excision and reconstruction by full thickness skin graft.
As physiological derangement is uncorrected by such procedures, recurrence is common.
Lymph scrotum is profuse scrotal edema, with blistering and weeping of lymph spontaneously. The moist intercrural area gets easily super-infected  causing skin ulcers or systemic sepsis.

CHYLURIA :
Chyluria is characterized by passage of milky urine. It is a state of chronic lympho-urinary reflux via fistulous communication secondary to lymphatic stasis caused by obstruction of lymphatic flow. In endemic areas 10% population may be afflicted by filariasis, but chyluria occurs only in 2% of them.

Symptoms: Patient will pass milk like urine. It is characteristically intermittent

It may be associated with dysuria, haematuria, renal colic, urinary retention, backache, urinary tract infections, pedal edema, hypoproteinemia, weight loss and malnutrition.

Pathophysiology: Adult worms are 1-10cm long depending on the species and sex. They live inside human lymphatic vessels and cause lymphatic vessel obstruction and dysfunction. Chyluria occurs due to obstruction and rupture of retroperitoneal lymphatics, secondary to fibrosis produced by parasitic infestation. Fistulous connections occur most often near the renal calyces, though they may rupture into any part of urinary system from renal pelvis to bladder. Once there is a rupture the pressure within the lymphatic system drops and similar communications with the opposite urinary system do not form. Thus most cases of chyluria are unilateral.

CAUSES OF CHYLURIA
Parasitic causes:
1. Filariasis
2. Non filarial infections
     Ascariasis
     Malaria
     Echinococcus
     Cysticercuscellulose
     Tineavera

Non parasitic causes:
1. Infections       
     Tuberculosis
2. Iactrogenic
    Post PCNL
     Post traumatic
3.Medical- Nephrotic Syndrome                                                                                                                      
    Hypertriglyceridaemia
4. Congenital-Primary intestinal lymphangiectasia
5. Post Surgical - Thoracic and abdominal aortic aneurysms
6. Neoplastic - Malignancies of the retroperitoneum                                                                                  
    Lymphangiomyomatosis

Diagnosis: Diagnosis can be confirmed by evaluating a sample of a post prandial urine for chylomicrons and triglycerides. The intermittent passage  of milky urine should be differentiated from phosphaturia (clears on adding 10% acetic acid), amorphous urates, severe pyuria, lipiduria secondary to fat embolism and caseousuria due to renal tuberculosis. Chylous urine is best studied immediately after it has been voided. On gross inspection, classic chylous urine is like milk, frequently containing semisolid gel. When equal part of milky urine and ether are vigorously shaken for a few minutes, there is almost complete clearing of opacity. Under the microscope the sediment is found to contain variable number of erythrocytes and lymphocytes. Fat droplets of varying sizes can be seen. Casts are usually absent. Urine albumin has been found in varying ranges from mild to nephrotic range and immuno-electrophoresis has shown globulins of various types.

All patients should be screened with a peripheral blood smear, total and differential counts (eosinophilia), serum creatinine and urine for acid fast bacilli. Intravenous urogram is usually normal. Cystoscopy shows milky efflux from ureteric orifices. Retrograde pyelography (RGP) may demonstrate the fistulous connection and dilated lymphatics in about half the cases.
 
Lymphangiography has sensitivity of 90%, but being invasive, time consuming, technically cumbersome and prone to complications it has now been largely replaced by Tc99m-DTPA radionuclide lymphoscintigraphy. Lymphographic evidence of perihilar lymphatics is pathognomonic of chyluria.

Detection of filarial antigens in serum and urine can be done routinely with ELISA sandwich assay, but for rapid and accurate diagnosis, Immunochromatographic test (ICT) is best because of its high sensitivity of 96.7%.

Management
Medical Management:
If the initial general condition is good, chyluria is mild and there is absence of microfilaria, no therapy may be necessary.

The conservative measures include dietary manipulations with omission of long chain triglycerides, use of coconut oil, drug therapy with diethyl carbamazine, bed rest and use of abdominal binders (to decrease lympho-urinary reflux through higher intra abdominal pressure). Medium chain triglycerides have been advocated since these are directly absorbed via the portal vein bypassing the lacteals and lymphatic channels.

Diethyl Carbamazine (DEC) (Hetrazan, Benocide) kills microfilaria and some but not all adults of Wuchereria and Brugia. The standard dose is 6mg/kg, to be given in three divided doses after food for 10-14 days, which reduces microfilaremia by 80-90%.

Ivermectin, in a single dose of 200-400 µg/kg, has a microfilaricidal effect comparable to DEC. However it has no effect on adult filariae. Albendazole kills both adults and microfilariae

Surgical Management:
Surgical management of chyluria is indicated in patients with refractory severe chyluria associated with recurrent colics, urinary retention, progressive weight loss, ill health due to immunosuppression and failed medical therapy.

A) Endoscopic Sclerotherapy:  Instillation of silver nitrate (AgNO3) into renal pelvis is a safe, effective and minimally invasive procedure with an initial success rate of 70-80%. Chylous reflux is identified after a fatty meal by cystoscopy and a ureteric catheter is passed up to the renal pelvis on affected side. 1% silver nitrate is instilled into the pelvis. Silver Nitrate induces an intense aseptic sclerosing obliterative inflammatory reaction in the lymphatic channels leading to immediate relief. The subsequent healing by fibrosis leads to permanent remission.

B) Surgical Lymphatic disconnection About 20% of chylurics have unrelenting course requiring surgery. Various procedures include lympho-venous disconnection, uretero-lympholysis, hilar vessel stripping,

C) Microsurgery Recurrent intractable chyluria that has failed sclerotherapy and surgical disconnection may be cured by trans-inguinal spermatic lymphangiovenous done via laparoscopic approach.

Anastomosis or inguinal lymphnode-saphenous vein anastomosis. Due to spontaneous emergence of collateral lymphatic channels even these lymphatic shunts tend to fail after 6 months.

General guidelines for dietary modifications:

1. Use minimal amount of oil in daily cooking.
2. Use coconut oil containing medium chain fatty acids as cooking medium.
3. Skimmed milk is better, cow milk is better than buffalo milk.
4. If non-vegetarian do not have a whole egg more than 1 or 2 days in a week. Avoid having mutton. Fish and chicken are better
5. Exclusion of salt and / or sugar is only restricted in case of any other concurrent disease related to its use.