A surveillance system for lymphatic filariasis after its elimination in Sri Lanka.

Lymphatic filariasis (LF) has been declared eliminated in Sri Lanka in September 2016. To maintain elimination status, a surveillance system to detect hidden endemic foci or LF resurgence is of highest priority. In this paper, we have reported an investigation of LF transmission in Trincomalee district where a surveillance program was not carried out due to 30 years of civil unrest. Proposed surveillance system included, measurement of anti-filarial IgG4 in urine of schoolchildren in areas where LF transmission could exist and assessment of circulating filarial antigen (CFA) and microfilaria (mf) in all urine antibody positive schoolchildren, their family members and 10-15 neighbours of each urine antibody positive household. Spatial distribution of the anti-filarial antibody titers in urine in a high antibody suspected area was analyzed using GPS logger data. Among 2301 school children from 11 schools studied, 41 (1.8%) urine antibody positives were found. The antibody positive rates of the schools ranged between 0 and 4.0%. Nine of the 630 (1.4%) examined became positive for CFA but were negative for mf. Although there were no mf positives, positive CFA and antibody results indicated the existence of Wuchereria bancrofti in Trincomalee. Highest antibody titres in an area correlated with the prevalences of urine antibodies and CFA. Spatial analysis showed LF transmission foci. Therefore, a combination of the non-invasive methods, urine ELISA and GPS mapping, will be a new effective surveillance system to identify hidden LF transmission foci.

Chiluria in a lymphatic filariasis endemic area.

OBJECTIVE: To establish clinical and laboratory data of individuals presenting chyluria in endemic areas. RESULTS: 75 individuals were studied. The majority were females with an average age of 45 years residing in the Metropolitan Region of Recife. The mean time between the beginning of the presentation of chyluria and the first care service in the Serviço de Referencia Nacional em Filarioses was approximately 5 years. The most frequent urinalysis changes were hematuria (27.6%), leukocytes (21.9%) and proteinuria (10.5%). The Addis test showed mean values of 155.43 E/min/mL of cylinders, 52,892 E/min/mL of erythrocytes and 291,660 E/min/mL of leukocytes. Among recorded cases, proteinuria had a mean value of 1372.80 mg/dL in 24 h, and the presence of lymphocytes in the urine was positive in 68.3%. Among lymphatic filariasis tests, immunochromatography was positive in 16.7%, there was circulating filarial antigen determined by detection of OG4C3 antibodies in 7.7% and microfilaremia in only 1/55.

Two cases of spontaneous remission of non-parasitic chyluria.

OBJECTIVES: Chyluria is a medical condition with presence of chyle in urine. The disease is most prevalent in South East Asian countries mostly caused by parasitic (Wuchereria bancrofti) infections. Our objective was to investigate the spontaneous remission of non-parasitic chyluria. DESIGN AND METHODS: The spontaneous remission of non-parasitic chyluria cases were worked up with diagnostic investigations, clinical assessment and studied in detail with respect to their natural evolution. RESULTS: We present two patients who were evaluated in the nephrology clinic with symptoms of milky urine and painless hematuria. Midnight blood smear was negative for filarial parasites. Urine culture was without mycobacteria. Urine cytology and IgG western blot for cysticercus were negative. Imaging for a lymphatic leak by lymphoscintigraphy was unrevealing. Chyluria resolved spontaneously in both patients. CONCLUSIONS: In our cases, radiologic visualization via lymphoscintigraphy was unrevealing. The patients were managed conservatively and fortunately underwent spontaneous remission marked by the disappearance of chyluria within several months of her initial diagnosis. In our opinion this spontaneous remission could be due to unrevealed lymphatico-renal fistula collapse or sclerosis of lymphatics caused by contrast media.

Detection of Wuchereria bancrofti DNA in paired serum and urine samples using polymerase chain reaction-based systems

The Global Program for the Elimination of Lymphatic Filariasis (GPELF) aims to eliminate this disease by the year 2020. However, the development of more specific and sensitive tests is important for the success of the GPELF. The present study aimed to standardise polymerase chain reaction (PCR)-based systems for the diagnosis of filariasis in serum and urine. Twenty paired biological urine and serum samples from individuals already known to be positive for Wuchereria bancrofti were collected during the day. Conventional PCR and semi-nested PCR assays were optimised. The detection limit of the technique for purified W. bancrofti DNA extracted from adult worms was 10 fg for the internal systems (WbF/Wb2) and 0.1 fg by using semi-nested PCR. The specificity of the primers was confirmed experimentally by amplification of 1 ng of purified genomic DNA from other species of parasites. Evaluation of the paired urine and serum samples by the semi-nested PCR technique indicated only two of the 20 tested individuals were positive, whereas the simple internal PCR system (WbF/Wb2), which has highly promising performance, revealed that all the patients were positive using both samples. This study successfully demonstrated the possibility of using the PCR technique on urine for the diagnosis of W. bancrofti infection.

Detection of Wuchereria bancrofti DNA in paired serum and urine samples using polymerase chain reaction-based systems.

The Global Program for the Elimination of Lymphatic Filariasis (GPELF) aims to eliminate this disease by the year 2020. However, the development of more specific and sensitive tests is important for the success of the GPELF. The present study aimed to standardise polymerase chain reaction (PCR)-based systems for the diagnosis of filariasis in serum and urine. Twenty paired biological urine and serum samples from individuals already known to be positive for Wuchereria bancrofti were collected during the day. Conventional PCR and semi-nested PCR assays were optimised. The detection limit of the technique for purified W. bancrofti DNA extracted from adult worms was 10 fg for the internal systems (WbF/Wb2) and 0.1 fg by using semi-nested PCR. The specificity of the primers was confirmed experimentally by amplification of 1 ng of purified genomic DNA from other species of parasites. Evaluation of the paired urine and serum samples by the semi-nested PCR technique indicated only two of the 20 tested individuals were positive, whereas the simple internal PCR system (WbF/Wb2), which has highly promising performance, revealed that all the patients were positive using both samples. This study successfully demonstrated the possibility of using the PCR technique on urine for the diagnosis of W. bancrofti infection.

Enzyme-linked immunosorbent assay for the diagnosis of Wuchereria bancrofti infection using urine samples and its application in Bangladesh.

In Sri Lanka, urine ELISA showed high sensitivity and specificity in detecting filaria-specific IgG4. It also produced much higher positive rates than antigen tests in prevalence studies with young children. In this study, we have confirmed the usefulness of urine ELISA in the field of Bangladesh. The ELISA detected 89 of 105 (85%) ICT antigen test positive subjects in endemic areas. With both ICT and microfilaria positives, the sensitivity was 97% (30/31). All of 104 ICT negative people in a non-endemic area were ELISA negative (100% specificity). In a prevalence study with 319 young children (5-10 years) from a low endemic area after five rounds of MDA, seven (2.2%) were detected by the present urine test, but only one (0.3%) by ICT (P=0.075). The satisfactorily high sensitivity, 100% specificity and effective case detection among young ages along with scope for analyzing the titers will indicate urine ELISA to be an effective tool in the post-MDA surveys to confirm elimination or to detect resurgence in Bangladesh.

Filariasis, with chyluria and nephrotic range proteinuria.

28 yr female presented with (grade III) chyluria, with nephrotic range proteinuria and Ig M mesangial deposition in immunofluorescence, secondary to filariasis which was confirmed by serology and microfilaria in glomerulus,and successfully treated by Renal Pelvic instillation sclerotherapy with 0.2% povidine and medical treatment (Diethylcarbamazine). She was asymptomatic with follow up period of 19 months.

Visual detection of filaria-specific IgG4 in urine using red-colored high density latex beads.

The use of urine for the immunodiagnosis of lymphatic filariasis has a definite advantage: the sample collection is not invasive and thus well accepted by people. Urine-based ELISA to detect filaria-specific IgG4 has been used successfully. However, ELISA requires equipment such as a microplate reader, which is often not available in most endemic areas. We have developed a new visual immunodiagnosis that detects urinary IgG4 using red-colored latex beads (bead test). The sensitivity was 87.2% when ICT antigen test positive people were regarded as the standard (136/156), and the specificity was 97.2% with the non-endemic people in Japan and Bangladesh, and the urine ELISA negatives in Sri Lanka (1264/1300). In a prevalence study, the bead test could detect filarial infection more effectively than ICT test among young children in Sri Lanka, indicating the usefulness of the visual test in epidemiological studies.

Confirmation of elimination of lymphatic filariasis by an IgG4 enzyme-linked immunosorbent assay with urine samples in Yongjia, Zhejiang Province and Gaoan, Jiangxi Province, People's Republic of China.

A sensitive and specific IgG4 enzyme-linked immunosorbent assay (ELISA) with urine samples has been reported. To confirm elimination of bancroftian filariasis, the ELISA was used in a study conducted in Yongjia County and Gaoan City, People's Republic of China, where filariasis elimination was declared, with 10,409 students 5-16 years of age. The antibody positive rates were 0.08% in Yongjia and 0.34% in Gaoan. All positive samples were re-examined and found to be negative. Our results show that this ELISA is practical and useful for confirmation of the elimination of filariasis. If similar results are obtained in different filariasis-endemic countries, this method may be useful in global filariasis elimination programs.

Comparison of open surgery versus retroperitoneoscopic approach to chyluria.

PURPOSE: We compared the clinical effectiveness of renal pedicle lymphatic disconnection for chyluria performed by retroperitoneoscopy and by open surgery. MATERIALS AND METHODS: Three male and 4 female patients 33 to 68 years old (mean age 49) with chyluria underwent retroperitoneoscopic renal pedicle lymphatic disconnection. Chyluria was on the left side in 5 cases and on the right side in 2. Open renal pedicle lymphatic disconnection was performed in 4 men and 2 women 33 to 61 years old (mean age 45.8). Chyluria was on the left and right sides in 3 cases each. Mean operative time, intraoperative blood loss, postoperative intestinal function recovery time, intraoperative and postoperative complications, postoperative hospital delay and operative outcome were compared in these 2 groups. RESULTS: Compared with the open surgery group results in the retroperitoneoscopic group were superior in terms of operative time (42 to 90 minutes, mean +/- SD 65.0 +/- 18.8 versus 120 to 220, mean 156.7 +/- 38.8), intraoperative blood loss (20 to 50 ml., mean 29.3 +/- 10.2 versus 60 to 250, mean 171.7 +/- 76.5), postoperative intestinal function recovery time (24 to 48 hours, mean 36.0 +/- 6.9 versus 24 to 72, mean 54.0 +/- 21.1), intraoperative and postoperative complications, and postoperative hospital stay (3 to 6 days, mean 4.7 +/- 0.7 versus 7 to 9 days, mean 7.8 +/- 1.0). In the open surgery group primary anastomosis was performed in 1 case due to injury to a renal artery branch during the operation. Chyluria resolved the day after surgery in the 2 groups. No obvious complications developed postoperatively. The followup of 2 to 12 months (mean 6.7 +/- 4.0) showed no recurrence of chyluria. CONCLUSIONS: Retroperitoneoscopic renal pedicle lymphatic disconnection completely ligates the lymphatic vessels with minimal invasion, less blood loss, rapid recovery and a good short-term outcome.

Sensitive and specific enzyme-linked immunosorbent assay for the diagnosis of Wuchereria bancrofti infection in urine samples.

We developed an enzyme-linked immunosorbent assay (ELISA) that detects filaria-specific immunoglobulin G4 antibodies in unconcentrated urine. The ELISA was positive in 87 of 91 (95.6%) urine samples collected from people with Wuchereria bancrofti microfilariae, antigen, or both. Of 298 urine samples collected in Thailand, Lao People's Democratic Republic, and Japan, where no human filariasis is known, 295 (99.0%) were negative by ELISA. Various intestinal nematode and fluke infections did not interfere with the ELISA. Urine samples with sodium azide could be kept at 37 degrees C for 4 weeks, and the time of urine collection did not influence ELISA results. This ELISA can be used to identify endemic foci of filariasis.

Renal abnormalities in microfilaremic patients with Bancroftian filariasis.

To determine the frequency of renal abnormalities occurring with Bancroftian filarial infections and to assess the effects of treatment on such abnormalities, we initiated a prospective, hospital-based study of 20 microfilaremic and five amicrofilaremic patients with Wuchereria bancrofti infections. Thorough clinical evaluations and detailed renal assessments were made prior to treatment and at multiple time points for 60 days following a standard twelve-day course of treatment with diethylcarbamazine (DEC). There were two important findings. First, even prior to DEC treatment, almost half of the microfilaremic patients had hematuria and/or proteinuria. Second, treatment with DEC induced these same abnormalities in almost all of the remaining microfilaremic patients. However, this DEC-induced hematuria and/or proteinuria was transient, and the long-term response to DEC in all of the microfilaremic patients was resolution of the abnormal renal findings during the two-month followup period. In the amicrofilaremic study patients, no hematuria or proteinuria was detected before, during, or after treatment with DEC.

Fractionation and characterization of urinary filarial antigen in bancroftian filariasis.

Urine samples from microfilaraemic patients were concentrated and fractionated by gel chromatography on Ultrogel AcA 44. Four protein fractions labelled as UFA C1, UFA C2, UFA C3 and UFA C4 were tested for filarial antigenicity by sandwich ELISA. UFA C1 and UFA C2 showed antigenic activity. On further analysis by SDS-PAGE, UFA C1 and UFA C2 showed antigenic components with MW ranging from 10.4 K to 123 K. UFA C1-1 and UFA C2-2 showed high antigen titre in ELISA. Urinary albumin was observed as a major component in UFA C2. Absorption of albumin from UFA C2 enhanced its antigenic activity considerably. As little as 0.01 pg antigenic protein per test was found to be sufficient for the detection of filarial antibody in ELISA. Biochemical characterization indicated a glycoprotein nature of UFA C2.