Relevance of anti-BmR1 IgG4 antibodies in children from an area endemic for Brugia malayi infection in Kerala, India.

Brugian filariasis prevalent mostly in South-East Asian countries including India contributes to a small but significant proportion of the socioeconomic burden due to lymphatic filariasis. Along with bancroftian filariasis, brugian filariasis has been targeted for elimination globally. The lack of a reliable daytime diagnostic test has been seen as an important barrier to the successful implementation and monitoring of elimination programmes in brugia endemic areas. We evaluated an anti-BmRI-IgG4 antibody test namely, 'Brugia Rapid' in a large study meant to understand the clinical and pathological manifestations of brugian filariasis in children. We found the test superior to traditional night blood screening for microfilaraemia. Although an antibody detection test, we found it to be a reliable indicator of brugian infection. Among the 100 children studied extensively, 94% of the microfilaraemics, 86% of those showing filarial dance sign indicating presence of, live adult worms and 78% having abnormal lymphatics on lymphoscintigraphy were IgG4 positive. Coupled with its advantages like ease of use any time of the day, high sensitivity and specificity, this test may be the ideal tool to assist programme managers in their efforts to eliminate lymphatic filariasis where brugian infections are found.

Lymphoscintigraphic evidence of lymph vessel dilation in the limbs of children with Brugia malayi infection.

Lymphatic filariasis (LF) is targeted for global elimination by the year 2020. It was earlier believed that LF is mostly a disease of adults. Recent studies indicate that in endemic countries filarial infection starts mostly in childhood even though the disease manifestations occur much later in life. The initial damage to the lymph vessels where the adult worms are lodged is dilation, thought to be irreversible even with treatment. Most of these studies relate to bancroftian filariasis. Studies that address this early pathology in brugian filariasis in humans are scarce. We report here for the first time, the lymphatic abnormalities seen on lymphoscintigraphy (LSG) in children with Brugia malayi filariasis. LSG was performed in 100 children aged between 3-15 years, who were enrolled in the study either because they were microfilaremic; had present or past filarial disease or were positive for antifilarial IgG4 antibodies. Inguinal and axillary lymph nodes were imaged in most children. Dilated lymph vessels were visualized in 80 children and this pathology was evenly distributed in all the three study groups. Lymph vessels dilation was seen even in three year old children. The implications of these findings for management of LF and control programmes are discussed.

Synthesis of isonicotinoylhydrazones from anacardic acid and their in vitro activity against Mycobacterium smegmatis.

Isonicotinoylhydrazones were synthesized from a natural product anacardic acid, a major constituent of cashew nut shell liquid. The unsaturated side chain in anacardic acid and its 5-nitro derivative were converted into C(8')-aldehydes by oxidative cleavage. C(8')-aldehydes are then coupled with isoniazid (an anti-TB drug) to obtain N-isonicotinoyl-N'-8-[(2'-carbohydroxy-3'-hydroxy) phenyl] octanal hydrazone (5) and N-isonicotinoyl-N'-8-[(2'-carbohydroxy-3'-hydroxy-6-nitro) phenyl] octanal hydrazone (6). These isonicotinoylhydrazones of anacardic aldehydes showed potent antimycobacterial activity against Mycobacterium smegmatis mc(2)155. The synergistic studies of 5 and 6 with isoniazid showed more inhibitory activities than isoniazid alone. Compounds 5 and 6 also showed activity against Mycobacterium tuberculosis H(37)Rv.

A preliminary study of filariasis related acute adenolymphangitis with special reference to precipitating factors and treatment modalities.

Episodic adenolymphangitis (ADL) is one of the important clinical manifestations of lymphatic filariasis. Recurrent ADLs contribute to the progress of the disease and also have important socioeconomic implications since they cause significant loss of man days. The present study was conducted in order to identify the precipitating factors responsible for ADL attacks and also to examine the different modalities of treatment. Sixty-five individuals with filariasis related ADL attacks, who are residents of Alleppey district (endemic for Brugia malayi) were studied. All efforts were taken to identify the precipitating factors for ADLs in these individuals. They were hospitalized for a period of five days or more. All of them received symptomatic antipyretic/antiinflammatory therapy and topical antibiotic/antifungal treatment of the affected limbs. They were then randomly allocated to one of the following four regimens: group I - symptomatic alone; group II - symptomatic plus antibiotics; group III - symptomatic followed by diethylcarbamazine citrate (DEC) and group IV - symptomatic plus antibiotic followed by DEC. Patients in groups III and IV received DEC every three months up to one year. There was a significant relationship between the number of ADL attacks and the grade of edema. Presence of focus of infection in the affected limb could be identified in 28 of the 65 patients. In the majority of patients (48) response to treatment was rapid (resolution in less than five days). Neither antibiotics nor DEC (given at intervals of three months) appeared to alter the frequency of ADL attacks. On the otherhand simple hygienic measures combined with good foot care and local antibiotic/antifungal cream application (where required), were effective in reducing the number of ADL attacks.

Estimation of ASO titer as an indicator of streptococcal infection precipitating acute adenolymphangitis in brugian lymphatic filariasis.

Recurrent episodes of acute adenolymphangitis (ADL) are important clinical manifestations of lymphatic filariasis which contribute significantly to the progression of lymphedema. It is increasingly being recognized that secondary bacterial infections play an important role in the etiology of ADL. We examined the role of streptococcal infection as a precipitating factor of ADL in brugian filariasis, by determining the anti-streptolysin O (ASO) titers and by isolating the causative organism wherever possible. The study population consisted of 30 patients with filariasis related ADL (Group A), 30 patients with chronic filarial edema (Group B) and 60 age and sex matched healthy adults (Group C). ASO titer was estimated by the latex agglutination method at the time of entry into the study, at the 15th day and at 3, 6 and 12 months. ASO titers were persistently elevated in 90% of patients in Group A and a portal of entry for bacterial infection was detected in all of these patients. In Group B only six patients had persistently elevated ASO titers. These patients had grade III lymphedema and three of them had monilial infections in the affected limb. In the control group none had persistently elevated ASO titers. The elevated ASO titers and the detection of a site of entry for bacteria in patients with ADL supports a streptococcal etiology for this condition.

A qualitative study on the feasibility and benefits of foot hygiene measures practiced by patients with brugian filariasis.

Disability alleviation is an important component of 'Global Programme for Elimination of Lymphatic Filariasis'. In Brugia malayi infection the disability is largely due to acute attacks of adenolymphangitis (ADL), which frequently prevent patients from attending their normal activities, causing much suffering and economic loss. The foot care programme has been shown to reduce the frequency and severity of these episodes. In the present study we used semi-structured interviews to evaluate the impact of the foot care in 127 patients with brugian filariasis. They were previously trained in this procedure and were advised to practice it regularly, unsupervised. All except one could recollect the various components of foot hygiene and were practicing it regularly. They were aware of the factors causing ADL attacks and were able to avoid them. Majority (95.2%) expressed their happiness with the relief provided by foot care, which prevented or reduced the ADL episodes. The motivation was such that they transmitted this knowledge to others suffering in the community and even physically helped them to carry out foot care. This study fully endorses the advocacy of foot care programme as an easy to carry out, effective, sustainable and economically feasible procedure to prevent acute ADL attacks.

Antifilarial drugs, in the doses employed in mass drug administrations by the Global Programme to Eliminate Lymphatic Filariasis, reverse lymphatic pathology in children with Brugia malayi infection.

Lymphatic filariasis is increasingly viewed as the result of an infection that is often acquired in childhood. The lymphatic pathology that occurs in the disease is generally believed to be irreversible. In a recent study in India, Doppler ultrasonography and lymphoscintigraphy were used to explore subclinical pathology in 100 children from an area endemic for Brugia malayi infection. All the children investigated showed some evidence of current or previous filarial infection. Some were microfilaraemic but asymptomatic, some were amicrofilaraemic but had filarial disease or a past history of microfilaraemia and/or filarial disease, and the rest, though amicrofilaraemic, asymptomatic and without any history of microfilaraemia or filarial disease, were seropositive for antifilarial IgG(4) antibodies. All the children were treated every 6 months, with a single combined dose of diethylcarbamazine (6 mg/kg) and albendazole (400 mg), and followed up for 24 months. By the end of this period all but one of the children were amicrofilaraemic and the 'filarial dance sign' could not be detected in any of the 14 children who had initially been found positive for this sign. Although lymphoscintigraphy revealed lymph-node and lymph-vessel damage in 82% of the children at enrolment, in about 67% of the children this pathology was markedly reduced by the 24-month follow-up. These results indicate that the drug regimens used in the mass drug administrations run by the Global Programme to Eliminate Lymphatic Filariasis are capable of reversing subclinical lymphatic damage and can provide benefits other than interruption of transmission in endemic areas. The implications of these findings are presented and discussed.

Doppler ultrasonography reveals adult-worm nests in the lymph vessels of children with brugian filariasis.

Although ultrasonography has allowed 'nests' of live adult worms and dilated lymphatics to be detected in the early stages of infection with Wuchereria bancrofti, previous attempts to locate such adult-worm nests in brugian filariasis have been unsuccessful. In this study, the successful location of live adult Brugia malayi parasites, in the lymphatics of the axilla, thigh, epitrochlear region and/or popliteal fossa of children aged 3-15 years, is described for the first time. The 'filarial dance sign' (FDS), which indicates the presence of live adult worms, was observed in six children with microfilaraemia and in eight children who, though amicrofilaraemic, either had experienced an episode of lymphoedema (one) or were only positive for antifilarial IgG4 antibodies (seven). In bancroftian infection, the adult-worm nests have mostly been seen in asymptomatic but microfilaraemic subjects. The suspected worm nests, 18 in the 14 children, were all confirmed using colour-power and pulse-wave Doppler examinations. The worm nests were distinctly smaller and the wriggling movements were less rapid and less conspicuous than those seen in bancroftian filariasis. The importance of these findings in the management and control of lymphatic filariasis is discussed.

Preliminary findings from a cross-sectional study on lymphatic filariasis in children, in an area of India endemic for Brugia malayi infection.

As the more obvious clinical manifestations of the disease are very uncommon in children, lymphatic filariasis has been considered to be primarily a disease of adults. In many recent reports, however, there is evidence indicating not only that filarial infection is commonly acquired in childhood but also that many infected children already have irreversible damage to their lymphatics. The preliminary results of a cross-sectional study on the patterns of Brugia-attributable pathology in 7934 children (aged 3-15 years) who live in an area of India with endemic B. malayi infection confirm these trends. The children were screened for microfilaraemia, evidence of filarial disease, and the presence of antifilarial IgG(4) antibodies. One hundred children who were microfilaraemic but asymptomatic (32), with filarial disease or an history of such disease or microfilaraemia (29) or amicrofilaraemic and asymptomatic but seropositive for antifilarial IgG(4) (39) were investigated further. They were given detailed clinical examinations, their levels of microfilaraemia were evaluated (by counting microfilariae filtered out of blood samples), their lymphatics were explored by Doppler sonography, and their limbs were checked by lymphoscintigraphy. The 'filarial dance sign', which indicates the presence of live adult worms, was detected by sonography in 14 children (apparently the first time this sign has been observed in brugian filariasis). Lymphoscintigraphy revealed dilated lymphatic channels in the limbs of 80 of the children. At the end of the study, each of the 100 hospitalized children was treated with a single combined dose of diethylcarbamazine and albendazole; the aim is to follow-up the treated children every 6 months for 3 years. Even these preliminary results have important implications for filariasis-control programmes and emphasise the need for disability-alleviation efforts among children as well as adults.

Efficacy and sustainability of a footcare programme in preventing acute attacks of adenolymphangitis in Brugian filariasis.

Lymphatic filariasis is associated with considerable disability related to the intensity and frequency of acute adenolymphangitis (ADL) attacks. The global programme for elimination of lymphatic filariasis emphasizes the need to combine transmission control with alleviation of disability. Footcare aimed at the prevention of secondary bacterial infections is the mainstay of disability alleviation programmes. We evaluated the efficacy and sustainability of an unsupervised, personal footcare programme by examining and interviewing 127 patients who had previously participated in a trial that assessed the efficacy of diethylcarbamazine, penicillin and footcare in the prevention of ADL. During the trial period these patients had been educated in footcare and were supervised. During the unsupervised period, which lasted 1 year or longer, 47 patients developed no ADL, and ADL occurred less frequently in 72.5%. Most patients were practising footcare as originally advised, unsupervised and without cost, which proves that such a programme is sustainable and effective.

A qualitative study of the perceptions, practices and socio-psychological suffering related to chronic brugian filariasis in Kerala, southern India.

Lymphatic filariasis is a major health problem in many parts of the tropical world. Although the disease itself is rarely fatal, the disability caused by the swollen extremities, the acute attacks of adenolymphangitis and the consequent sufferings of those afflicted are considerable. The economic burden imposed by lymphatic filariasis is not fully quantified and information on the social and psychological problems caused by the disease is scanty. Semi-structured interviews were therefore used, in southern India, to assess the perceptions, practices and socio-psychological problems of 127 patients with brugian filariasis. The patients were aware of the causative factors and the precautions to be taken to prevent progression of the disease. However, depression and loss of job opportunities were common in the study population. Patients also complained that the disease eroded their standing in the community and diminished their prospects of marriage. Awareness of these factors will be of help in planning suitable disability-management packages, including the rehabilitation of those who find it difficult to carry on with their existing jobs because of the severity of their disease.

Apparent failure of ultrasonography to detect adult worms of Brugia malayi.

Adult worms of Wuchereria bancrofti, or rather their characteristic movements (the 'filarial dance'), can now be detected in the scrotal lymphatics of microfilaraemic males, using ultrasonography. This ability has been used to delineate the lymphatic pathology of bancroftian filariasis, guide the surgical removal of the adult worms and, most importantly, assess the macrofilaricidal effects of antifilarial drugs. In the present study, the first report of the use of ultrasonography in brugian filariasis, 22 men (aged 18-62 years) with 60-2972 (median = 370) Brugia malayi microfilariae/ml blood were subjected to ultrasonography using a linear, 7.5-MHz probe. In addition, four other men (aged 19-35 years), with W. bancrofti microfilaraemia [28-524 (median = 234) microfilariae/ml], were similarly examined. Adult worms were not detectable in any of the patients with B. malayi parasitaemia but were detected in the scrotal lymphatics of two of the four individuals with W. bancrofti infection. The reasons for the failure to detect adult B. malayi and the limitations of ultrasound as a screening tool are examined. The results highlight the differences between the two species that cause most lymphatic filariasis and the need for rapid development of tools that can be used for the control of brugian lymphatic filariasis.

Two-year follow-up of the microfilaraemia of asymptomatic brugian filariasis, after treatment with two, annual, single doses of ivermectin, diethylcarbamazine and albendazole, in various combinations.

Repeated, single, oral doses of combinations of ivermectin, diethylcarbamazine (DEC) or albendazole are recognized as important tools for parasite control in lymphatic filariasis. In order to assess the effects of re-treatment using these combinations in Brugia malayi infections, 40 asymptomatic microfilaraemics were re-treated at the end of the first year, with an additional, single, dose of the combination they had previously received. They were then followed-up for another year. The subjects, of both sexes and aged 14-70 years, each received a two-drug combination: ivermectin (200 micrograms/kg) with DEC (6 mg/kg); ivermectin (200 micrograms/kg) with albendazole (400 mg); or DEC (6 mg/kg) with albendazole (400 mg). The kinetics of microfilarial clearance were similar to that seen during the first treatment, the members of the two groups given DEC having less intense microfilaraemias, 1 year after the re-treatment, than those given ivermectin with albendazole (P < 0.001 for each comparison). At this time, the two DEC groups also had a higher proportion of amicrofilaraemic individuals (22 of 26) than the ivermectin + albendazole group (three of nine). There were fewer adverse reactions in all the groups after re-treatment than seen after the first treatment. In countries such as India, where there is no co-endemicity of onchocerciasis or loiasis, the options for control programmes in areas where brugian filariasis is endemic are DEC alone or DEC in combination with ivermectin or albendazole. Where there is no access to ivermectin, transmission control must be based on DEC alone or in combination with albendazole.

Treatment of microfilaraemia in asymptomatic brugian filariasis: the efficacy and safety of the combination of single doses of ivermectin and diethylcarbamazine.

Although combinations of ivermectin and diethylcarbamazine (DEC) have been shown to be superior to either drug alone in the suppression of bancroftian microfilariae, their efficacy against infections with Brugia malayi has never been investigated. The present, open trial is the first on the efficacy and safety of a combination of single doses of ivermectin and DEC when used against microfilaraemias of brugian filariasis. Twenty-one, asymptomatic but microfilaraemic (109-6934 microfilariae/ml blood, with a median of 841/ml) men, aged 18-48 years, each received oral doses of ivermectin (400 micrograms/kg) and DEC (6 mg/kg) as a single treatment. Twelve hours post-treatment, 96.5%-100% of the microfilariae in each subject had been cleared and 12 of the subjects were amicrofilaraemic. A further reduction in microfilarial counts was evident 1 month post-treatment (mean clearance = 99.0%) and the counts continued to fall at least until the last follow-up, at 1 year post-treatment, when the mean clearance was 99.9% and 13 (68.4%) of the 19 subjects then investigated were amicrofilaraemic. All subjects experienced adverse reactions of one form or another, lasting for up to 48 h post-treatment; these included fever, myalgia, headache, and lethargy. Postural hypotension was recorded in two subjects and dilated, inflamed lymphatic channels were seen in another two. The combination of ivermectin and DEC demonstrated a microfilaricidal effect superior to that of either drug used alone, both in the initial rapid clearance of microfilariae and in sustaining the effect for 1 year. This finding has important implications for the control of lymphatic filariasis.

Prevention of acute adenolymphangitis in brugian filariasis: comparison of the efficacy of ivermectin and diethylcarbamazine, each combined with local treatment of the affected limb.

Acute attacks of adenolymphangitis (ADL) not only force patients with lymphatic filariasis to seek medical attention but also hasten the progression of filarial oedema. Patients with filariasis-associated ADL are currently treated with repeated courses of the antifilarial drug diethylcarbamazine (DEC), with or without antibiotics and anti-inflammatory agents. In this double-blind, placebo-controlled study, the efficacy of local treatment of the affected limb combined with repeated doses of ivermectin or DEC, in preventing the occurrence of ADL in Brugia malayi lymphatic filariasis, was examined. Overall, 120 patients who had each had at least two ADL attacks in the previous year were each admitted to the study at the time of an ongoing episode of ADL. The patients were randomly allocated to receive 12, monthly treatments of ivermectin (400 micrograms/kg), DEC (10 mg/kg) or placebo, in addition to local care of the affected limbs. There was a significant reduction in the frequency of ADL attacks in each of the three groups during the 2-year study period (P < 0.001 for each comparison). Most importantly, there were no significant differences in frequency of attacks between the three groups, either at the end of the treatment phase or at the end of the post-treatment phase (P > 0.15 for each comparison), suggesting that foot care combined with appropriate use of local antibiotics or antifungals is adequate to reduce the number of ADL attacks. The implications of these observations for planning morbidity control in lymphatic filariasis are discussed.

A double-blind, placebo-controlled study of the efficacy of oral penicillin, diethylcarbamazine or local treatment of the affected limb in preventing acute adenolymphangitis in lymphoedema caused by brugian filariasis.

Acute attacks of adenolymphangitis (ADL) contribute significantly to the morbidity seen in cases of filarial lymphoedema. Such cases are now being treated with multiple courses of the antifilarial drug diethylcarbamazine (DEC), either alone or in combination with antibiotics or anti-inflammatory drugs, based on anecdotal experience. In this, the first double-blind, placebo-controlled study, 150 patients with lymphoedema caused by brugian filariasis, each of whom recalled two or more ADL attacks in the previous year, were enrolled on a comprehensive foot-care programme. Each was also randomly allocated to one of the following five daily regimens (30 patients/regimen) for 1 year: 800 mg oral penicillin; 1 mg DEC/kg; 800 mg oral penicillin plus 1 mg DEC/kg; local antibiotics; or placebo. Each patient was followed up for another year. For each regimen group (including the placebo group), the number of ADL attacks in the treatment year was significantly less than that in the year prior to treatment (P < 0.001). Although, in all but the placebo group, there was a slight increase in the number of episodes in the follow-up year compared with the treatment year, the increase was only significant in the two groups given penicillin. Of all the treatments tested therefore, foot care seems to play the most important role in the prevention of ADL attacks. Additional benefit may accrue from local or systemic antibiotic use in those with high grades of oedema, but antifilarials have no place in the prevention of ADL attacks in an individual patient. These observations should help in the rational management and prevention of ADL attacks in filarial lymphoedema, so that the progression of the disease may be halted and morbidity reduced.

Treatment of the microfilaraemia of asymptomatic brugian filariasis with single doses of ivermectin, diethylcarbamazine or albendazole, in various combinations.

Several new chemotherapeutic tools are now available for the control of lymphatic filariasis. Combinations of single doses of antifilarial drugs are generally superior to single drugs. The efficacy and safety of albendazole in combination with diethylcarbamazine (DEC) or ivermectin, for the treatment of Brugia malayi infection, were investigated, for the first time, in an open, hospital-based study. Fifty-one asymptomatic microfilaraemics (with 108-4034 microfilariae/ml; median = 531) of both sexes and aged 14-70 years were randomly allocated to receive single-dose treatments of ivermectin (200 micrograms/kg) with diethylcarbamazine (DEC; 6 mg/kg), ivermectin (200 micrograms/kg) with albendazole (400 mg), DEC (6 mg/kg) with albendazole (400 mg), or albendazole (400 mg) alone. Albendazole alone had no effect on the microfilarial levels at the 1-year follow-up but both groups given DEC had significantly lower microfilaraemias (P < 0.015 and P < 0.02) than that given ivermectin with albendazole. Overall, 47%-64% of those given DEC but only 14% of those given ivermectin with albendazole appeared to be amicrofilaraemic 1 year post-treatment. The adverse reactions seen in the study were mild, transient and qualitatively similar to those seen earlier with ivermectin and DEC. The combination of DEC and albendazole, both well tested drugs, offers a new option for countries such as India where there is no onchocerciasis or loiasis and where ivermectin may not be immediately available. The direct and indirect effects of albendazole on intestinal helminths would be additional benefits.

The pharmacokinetics, safety and tolerability of the co-administration of diethylcarbamazine and albendazole.

The pharmacokinetics, safety and tolerability of single, oral doses of diethylcarbamazine (DEC) and albendazole, given alone or in combination, were investigated in a double-blind, randomized and placebo-controlled trial involving 42 amicrofilaraemic subjects living in an area of India where lymphatic filariasis is endemic. The subjects (34 males and eight females, aged 18-52 years and weighing 46-66.5 kg) were randomly allocated to one of the three drug groups. Fourteen were given just DEC (6 mg/kg), another 14 were given just albendazole (400 mg) and the remaining 14 were given both DEC (6 mg/kg) and albendazole (400 mg). Blood samples for pharmacokinetic study were collected at specified intervals before and after drug administration. Plasma concentrations of DEC and albendazole/albendazole sulphoxide were estimated using gas chromatography and HPLC, respectively. The safety and tolerability of the treatments were evaluated through clinical and laboratory assessments. Both the DEC and albendazole were well tolerated when given alone or in combination, no adverse events being observed. In all three treatment groups, the drugs were rapidly absorbed from the gastro-intestinal tract although there was marked inter-individual#10; variation. The pharmacokinetics of DEC, albendazole and albendazole sulphoxide were similar, whether each drug was given alone or in combination. These results indicate that there is no adverse pharmacokinetic or pharmacodynamic reason why DEC and albendazole should not be co-administered to control lymphatic filariasis.