Comparative Safety Surveillance of Triple (IDA) Versus Dual Therapy (DA) in Mass Drug Administration for Elimination of Lymphatic Filariasis in Kenya: A Cohort Event Monitoring Study

INTRODUCTION

Dual diethylcarbamazine and albendazole (DA) therapy is the standard mass drug administration (MDA) regimen for lymphatic filariasis in Kenya. Following the recent World Health Organization recommendation, Kenya piloted triple therapy with ivermectin, diethylcarbamazine, and albendazole (IDA) in MDA.

OBJECTIVE

We conducted a community-based, observational, cohort event monitoring study to compare the types, frequency, severity, and predictors of adverse events following dual versus triple therapy in 20,421 eligible residents.

METHODS

Residents in Kilifi (n = 10,010) and Mombasa counties (n = 10,411) received DA and IDA through MDA campaigns, respectively. Adverse events were actively monitored through house-to-house visits on days 1, 2, and 7 after MDA. Any clinical events reported before and after MDA were cross-checked and verified to differentiate pre-existing events from MDA-associated adverse events.

RESULTS

Overall, 5807 and 3102 adverse events were reported by 2839 and 1621 individuals in the IDA and DA groups, respectively. The incidence of experiencing one or more adverse events was significantly higher (p < 0.0001) in the IDA group (27.3%; 95% confidence interval [CI] 26.4-28.2) than in the DA group (16.2%; 95% CI 15.5-16.9). Dizziness (15.9% vs 5.9%) and drowsiness (10.1% vs 2.6%) were the most common adverse events and significantly higher in the IDA group compared with the DA group (p < 0.0001). Most adverse events were mild or moderate with a few severe cases (IDA = 0.05%; 95% CI 0.35-0.78, DA = 0.03%; 95% CI 0.14-0.60). Female sex, obesity, taking three or more diethylcarbamazine or ivermectin tablets, and having pre-existing clinical symptoms were significant predictors of adverse events following IDA treatment.

CONCLUSIONS

Ivermectin, diethylcarbamazine, and albendazole as a combination is as safe and well tolerated as DA to use in MDA campaigns with no serious life-threatening adverse events. Systemic mild-to-moderate adverse events with a few severe cases and transient adverse events are more common with IDA treatment than with DA treatment. Hence, integrating pharmacovigilance into a MDA program is recommended for the timely detection and management of adverse events.

Safety and tolerability of moxidectin and ivermectin combination treatments for lymphatic filariasis in Côte d'Ivoire: A randomized controlled superiority study

BACKGROUND

Moxidectin is a macrocyclic lactone registered for the treatment of human onchocerciasis. The drug has a good safety profile, large volume of distribution and a long elimination half-life. This paper reports tolerability data from the first use of moxidectin in persons with Wuchereria bancrofti infection.

METHODS

In this randomized, open-label, masked-observer superiority trial, adults with Wuchereria bancrofti microfilaremia in Côte d'Ivoire were randomized to 1 of 4 treatment arms: ivermectin + albendazole (IA), moxidectin + albendazole (MoxA), ivermectin + diethylcarbamazine (DEC) + albendazole (IDA), or moxidectin + DEC + albendazole (MoxDA). As part of a larger efficacy trial, all participants were closely monitored for 7 days after treatment.

RESULTS

One hundred sixty-four individuals were treated, and monitored for treatment emergent adverse events (TEAE). Eighty-seven participants (53%) experienced one or more mild (grade 1) or moderate (grade 2) TEAE. Four participants had transient Grade 3 hematuria after treatment (3 after IDA and 1 after IA). There were no serious adverse events. There were no significant differences in frequency or types of TEAE between treatment groups (IA = 22/41 (53%), MoxA = 24/40 (60%), IDA = 18/41 (44%), MoxDA = 15/42 (36%), p = 0.530). Fifty-nine participants (36%) had multiple TEAE, and 8.5% had a one or more grade 2 (moderate) TEAE. Grade 2 TEAE were more frequent after triple drug treatments (IDA, 14.6%; MoxDA, 9.5%) than after two-drug treatments (IA, 7.3%; MoxA, 2.5%). There was no difference in TEAEs based on baseline Mf counts (OR 0.69 (0.33, 1.43), p-value 0.319).

CONCLUSION

All treatment regimens were well tolerated. We observed no difference in safety parameters between regimens that contained ivermectin or moxidectin.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT04410406.

Lessons from Large-Scale Tolerability and Acceptability Studies of Triple Drug Mass Drug Administration Performed to Support Policy Change and Accelerate Elimination of Lymphatic Filariasis

Early clinical trials clearly demonstrated the superior efficacy of triple drug therapy with ivermectin plus DEC and albendazole (IDA) for clearing microfilaremia (Mf) in individuals with lymphatic filariasis (LF). Although these initial pharmacokinetic and efficacy studies were necessary first steps in the clinical development of IDA, they were not sufficient to justify policy changes necessary for widespread use of this new regimen by national filariasis elimination programs. Processes and procedures that led to the World Health Organization's (WHO) endorsement of IDA as a mass drug administration (MDA) regimen for LF are reviewed elsewhere in this Supplement. However, the "guideline review process" depended heavily on preliminary results from multicenter studies that were performed to compare the safety, tolerability, and acceptability of IDA versus DA (the two-drug regimen of DEC plus albendazole that was recommended for use for filariasis elimination in countries without co-endemic onchocerciasis or loiasis). Efficacy and tolerability results from those studies have been recently published. Therefore, this paper will focus on practical aspects of the planning and conduct of the large-scale studies that were so critically important for policy change.

An open label, block randomized, community study of the safety and efficacy of co-administered ivermectin, diethylcarbamazine plus albendazole vs. diethylcarbamazine plus albendazole for lymphatic filariasis in India

Background

Better drug regimens for mass drug administration (MDA) could accelerate the Global Programme to Eliminate Lymphatic Filariasis (LF). This community study was designed to compare the safety and efficacy of MDA with IDA (ivermectin, diethylcarbamazine and albendazole) or DA (diethylcarbamazine and albendazole) in India.

Methodology/Principal findings

This two-armed, open-labelled, block randomised, community study was conducted in LF endemic villages in Yadgir district, Karnataka, India. Consenting participants ≥5 years of age were tested for circulating filarial antigenemia (CFA) and microfilaremia (Mf) before treatment with a single oral dose of IDA or DA. Adverse events (AEs) were monitored actively for two days and passively for five more days. Persons with positive CFA or Mf tests at baseline were retested 12-months post-treatment to assess treatment efficacy.

Baseline CFA and Mf-rates were 26.4% and 6.9% in IDA and 24.5% and 6.4% in DA villages respectively. 4758 and 4160 participants received IDA and DA. Most AEs were mild after both treatments; fewer than 0.1% of participants experienced AEs with severity > grade 1. No serious AEs were observed. Fever, headache and dizziness were the most common AEs. AE rates were slightly higher after IDA than DA (8.3% vs. 6.4%, P<0.01). AEs were more frequent in females and Mf-positives after either treatment, but significantly more frequent after IDA (40.5% vs 20.2%, P < 0.001).

IDA was more effective for clearing Mf than DA (84% vs. 61.8%, P < 0.001). Geometric mean Mf counts per 60μl in retested Mf-positives decreased by 96.4% from 11.8 after IDA and by 90.0% from 9.5 after DA. Neither treatment was effective for clearing CFA.

Conclusions/Significance

IDA had an acceptable safety profile and was more effective for clearing Mf than DA. With adequate compliance and medical support to manage AEs, IDA has the potential to accelerate LF elimination in India.

Trial registration

Clinical Trial Registry of India (CTRI No/2016/10/007399)

Lymphatic filariasis (LF) is a major neglected tropical disease that is caused by filarial nematode worms. The strategies of the Global Programme to Eliminate Lymphatic Filariasis, launched in 2000, are mass drug administration (MDA) of antifilarial medications to kill the parasites and reduce transmission and morbidity management and disability prevention for those who are already affected by the disease. Recent clinical trials have shown that a single co-administered dose of ivermectin, diethylcarbamazine and albendazole (IDA) is more effective for clearing microfilariae (Mf) from the blood than the traditional two-drug regimen (DA). That is important, because blood Mf are essential for mosquitoes to transmit the parasite. As part of a large multicenter study, we assessed the safety of IDA and compared the efficacy of IDA and DA for clearing parasites from the blood. We treated almost 9,000 people in Wuchereria bancrofti endemic villages with either IDA or DA. Adverse events (AE) were monitored actively for two days and passively for another five days. AE rates were slightly higher after IDA than DA, but AEs were mild and self-limited. Infected persons, adults and females had higher AE rates in both treatment areas. We retested infected persons one year after treatment. IDA was significantly more effective for clearing Mf and reducing blood Mf counts than DA. Neither treatment was effective for clearing circulating filarial antigenemia. Our large study showed that IDA was well tolerated and more effective than DA. This new treatment has the potential to hasten LF elimination in India and many other countries.

A community survey of coverage and adverse events following country-wide triple-drug mass drug administration for lymphatic filariasis elimination, Samoa 2018

The Global Programme to Eliminate Lymphatic Filariasis has made considerable progress but is experiencing challenges in meeting targets in some countries. Recent World Health Organization guidelines have recommended two rounds of triple-drug therapy with ivermectin, diethylcarbamazine (DEC), and albendazole (IDA), in areas where mass drug administration (MDA) results with two drugs (DEC and albendazole) have been suboptimal, as is the case in Samoa. In August 2018, Samoa was the first country in the world to implement countrywide triple-drug MDA. This paper aims to describe Samoa’s experience with program coverage and adverse events (AEs) in the first round of triple-drug MDA. We conducted a large cross-sectional community survey to assess MDA awareness, reach, compliance, coverage and AEs in September/October 2018, 7–11 weeks after the first round of triple-drug MDA. In our sample of 4420 people aged ≥2 years (2.2% of the population), age-adjusted estimates indicated that 89.0% of the eligible population were offered MDA, 83.9% of the eligible population took MDA (program coverage), and 80.2% of the total population took MDA (epidemiological coverage). Overall, 83.8% (2986/3563) reported that they did not feel unwell at all after taking MDA. Mild AEs (feeling unwell but able to do normal everyday things) were reported by 13.3% (476/3563) and moderate or severe AEs (feeling unwell and being unable to do normal everyday activities such as going to work or school) by 2.9% (103/3563) of participants. This study following the 2018 triple-drug MDA in Samoa demonstrated a high reported program awareness and reach of 90.8% and 89.0%, respectively. Age-adjusted program coverage of 83.9% of the total population showed that MDA was well accepted and well tolerated by the community.

Lymphatic filariasis is a disease caused by worms and transmitted between humans by mosquitoes. A global program underway aims to eliminate lymphatic filariasis as a public health problem by distributing two deworming drugs to the whole population once a year for at least five years. In some countries, including Samoa, this strategy has not been sufficient to eliminate transmission. A new drug has been added, and in 2018, Samoa was the first country in the world to distribute country-wide triple-drug mass drug administration (MDA) using ivermectin, diethylcarbamazine, and albendazole. This study reports on the coverage achieved (percentage of people who reported taking the drugs) and adverse events after taking the drugs. The study was a large community survey of over 4000 people, done 7–11 weeks after the distribution of the first round of triple-drug MDA. We found that the program reached and offered MDA to approximately 90% of the whole population, and approximately 80% of the whole population swallowed the drugs. We also collected data on whether people felt unwell after taking the pills, and found that 84% of people taking the pills did not feel unwell at all, while 13% reported feeling unwell afterwards but were able to do normal everyday activities, and 3% reported that they had felt unwell and that it stopped them doing normal everyday activities, such as going to school or work.

The safety of combined triple drug therapy with ivermectin, diethylcarbamazine and albendazole in the neglected tropical diseases co-endemic setting of Fiji: A cluster randomised trial

Lymphatic filariasis has remained endemic in Fiji despite repeated mass drug administration using the well-established and safe combination of diethylcarbamazine and albendazole (DA) since 2002. In certain settings the addition of ivermectin to this combination (IDA) remains a safe strategy and is more efficacious. However, the safety has yet to be described in scabies and soil-transmitted helminth endemic settings like Fiji. Villages of Rotuma and Gau islands were randomised to either DA or IDA. Residents received weight-based treatment unblinded with standard exclusions. Participants were actively found and asked by a nurse about their health daily for the first two days and then asked to seek review for the next five days if unwell. Anyone with severe symptoms were reviewed by a doctor and any serious adverse event was reported to the Medical Monitor and Data Safety Monitoring Board. Of 3612 enrolled and eligible participants, 1216 were randomised to DA and 2396 to IDA. Age and sex in both groups were representative of the population. Over 99% (3598) of participants completed 7 days follow-up. Adverse events were reported by 600 participants (16.7%), distributed equally between treatment groups, with most graded as mild (93.2%). There were three serious adverse events, all judged not attributable to treatment by an independent medical monitor. Fatigue was the most common symptom reported by 8.5%, with headache, dizziness, nausea and arthralgia being the next four most common symptoms. Adverse events were more likely in participants with microfilaremia (43.2% versus 15.7%), but adverse event frequency was not related to the presence of scabies or soil-transmitted helminth infection. IDA has comparable safety to DA with the same frequency of adverse events experienced following community mass drug administration. The presence of co-endemic infections did not increase adverse events. IDA can be used in community programs where preventative chemotherapy is needed for control of lymphatic filariasis and other neglected tropical diseases.

Systems analysis-based assessment of post-treatment adverse events in lymphatic filariasis

Background

Lymphatic filariasis (LF) is a neglected tropical disease, and the Global Program to Eliminate LF delivers mass drug administration (MDA) to 500 million people every year. Adverse events (AEs) are common after LF treatment.

Methodology/Principal findings

To better understand the pathogenesis of AEs, we studied LF-patients from a treatment trial. Plasma levels of many filarial antigens increased post-treatment in individuals with AEs, and this is consistent with parasite death. Circulating immune complexes were not elevated in these participants, and the classical complement cascade was not activated. Multiple cytokines increased after treatment in persons with AEs. A transcriptomic analysis was performed for nine individuals with moderate systemic AEs and nine matched controls. Differential gene expression analysis identified a significant transcriptional signature associated with post-treatment AEs; 744 genes were upregulated. The transcriptional signature was enriched for TLR and NF-κB signaling. Increased expression of seven out of the top eight genes upregulated in persons with AEs were validated by qRT-PCR, including TLR2.

Conclusions/Significance

This is the first global study of changes in gene expression associated with AEs after treatment of lymphatic filariasis. Changes in cytokines were consistent with prior studies and with the RNAseq data. These results suggest that Wolbachia lipoprotein is involved in AE development, because it activates TLR2-TLR6 and downstream NF-κB. Additionally, LPS Binding Protein (LBP, which shuttles lipoproteins to TLR2) increased post-treatment in individuals with AEs. Improved understanding of the pathogenesis of AEs may lead to improved management, increased MDA compliance, and accelerated LF elimination.

Lymphatic filariasis (LF) is a disabling parasitic disease that affects millions of people in the developing world. The Global Programme to Eliminate Lymphatic Filariasis (coordinated by the World Health Organization) uses mass administration of antifilarial medications to cure infections, prevent disease, and reduce transmission. Some individuals develop adverse events (AEs) after treatment, and this can reduce willingness of persons in endemic areas to accept treatment. The purpose of this study was to improve understanding of the cause of AEs following treatment. We hypothesized that parasite antigens released into the blood following treatment trigger inflammatory responses that lead to AEs. To test this hypothesis we collected blood from LF-infected individuals before and after treatment and clinically assessed them for AEs. We measured parasite antigens, cytokines and other components of the immune system in blood samples and compared post-treatment changes in persons with and without AEs. We also assessed changes in transcription profiles in peripheral blood leukocytes that were associated with post-treatment AEs. Post-treatment changes in transcription profiles and in immune proteins and parasite components in plasma suggest that systemic AEs are triggered by death of the parasites following treatment with release of parasite antigens and Wolbachia bacteria into the circulation. Improved understanding of the pathogenesis of post-treatment AEs may help to improve messaging related to mass drug administration programs and lead to improved AE management.

Pharmacokinetics, safety, and efficacy of a single co-administered dose of diethylcarbamazine, albendazole and ivermectin in adults with and without Wuchereria bancrofti infection in Côte d'Ivoire

Background

A single co-administered dose of ivermectin (IVM) plus diethylcarbamazine (DEC) plus albendazole (ALB), or triple-drug therapy, was recently found to be more effective for clearing microfilariae (Mf) than standard DEC plus ALB currently used for mass drug administration programs for lymphatic filariasis (LF) outside of sub-Saharan Africa. Triple-drug therapy has not been previously tested in LF-uninfected individuals from Africa. This study evaluated the pharmacokinetics (PK), safety, and efficacy of triple-drug therapy in people with and without Wuchereria bancrofti infection in West Africa.

Methods

In this open-label cohort study, treatment-naïve microfilaremic (>50 mf/mL, n = 32) and uninfected (circulating filarial antigen negative, n = 24) adults residing in Agboville district, Côte d’Ivoire, were treated with a single dose of IVM plus DEC plus ALB, and evaluated for adverse events (AEs) until 7 days post treatment. Drug levels were assessed by liquid chromatography and mass spectrometry. Persons responsible for assessing AEs were blinded to participants’ infection status.

Findings

There was no difference in AUC_0-inf or C_max between LF-infected and uninfected participants (P>0.05 for all comparisons). All subjects experienced mild AEs; 28% and 25% of infected and uninfected participants experienced grade 2 AEs, respectively. There were no severe or serious adverse events. Only fever (16 of 32 versus 4 of 24, P<0.001) and scrotal pain/swelling in males (6 of 20 versus 0 of 12, P = 0.025) were more frequent in infected than uninfected participants. All LF positive participants were amicrofilaremic at 7 days post-treatment and 27 of 31 (87%) remained amicrofilaremic 12 months after treatment.

Conclusions

Moderate to heavy W. bancrofti infection did not affect PK parameters for IVM, DEC or ALB following a single co-administered dose of these drugs compared to uninfected individuals. The drugs were well tolerated. This study confirmed the efficacy of the triple-drug therapy for clearing W. bancrofti Mf and has added important information to support the use of this regimen in LF elimination programs in areas of Africa without co-endemic onchocerciasis or loiasis.

Trial registration

ClinicalTrials.gov NCT02845713.

Lymphatic filariasis is a mosquito-borne infection that causes disability in the form of lymphedema, hydroceles, and elephantiasis. It has been targeted for global elimination based on mass drug administration in the total population at risk including many people uninfected with LF. Recently, a single co-administered dose of IVM + DEC + ALB has been shown to be much more effective than the standard treatment with DEC + ALB for sustained clearance of Mf for 3 years based on studies in Papua New Guinea. This study confirms the efficacy and safety of triple-drug therapy for clearing of Wuchereria bancrofti Mf in an African population. The presence of LF did not affect drug levels and the medicines were well tolerated, with 28% and 25% rate of moderate AEs in infected and uninfected individuals respectively, and no severe or serious AEs, supporting the use of triple-drug therapy for mass drug administration. This study shows for the first time that triple-drug therapy also has a potent macrofilaricidal effect, as determined by the reduction in circulating filarial antigen and inactivation of worm nests one year following treatment.

A Trial of a Triple-Drug Treatment for Lymphatic Filariasis

BACKGROUND

The World Health Organization has targeted lymphatic filariasis for global elimination by 2020 with a strategy of mass drug administration. This trial tested whether a single dose of a three-drug regimen of ivermectin plus diethylcarbamazine plus albendazole results in a greater sustained clearance of microfilariae than a single dose of a two-drug regimen of diethylcarbamazine plus albendazole and is noninferior to the two-drug regimen administered once a year for 3 years.

METHODS

In a randomized, controlled trial involving adults from Papua New Guinea with Wuchereria bancrofti microfilaremia, we assigned 182 participants to receive a single dose of the three-drug regimen (60 participants), a single dose of the two-drug regimen (61 participants), or the two-drug regimen once a year for 3 years (61 participants). Clearance of microfilariae from the blood was measured at 12, 24, and 36 months after trial initiation.

RESULTS

The three-drug regimen cleared microfilaremia in 55 of 57 participants (96%) at 12 months, in 52 of 54 participants (96%) at 24 months, and in 55 of 57 participants (96%) at 36 months. A single dose of the two-drug regimen cleared microfilaremia in 18 of 56 participants (32%) at 12 months, in 31 of 55 participants (56%) at 24 months, and in 43 of 52 participants (83%) at 36 months (P=0.02 for the three-drug regimen vs. a single dose of the two-drug regimen at 36 months). The two-drug regimen administered once a year for 3 years cleared microfilaremia in 20 of 59 participants (34%) at 12 months, in 42 of 56 participants (75%) at 24 months, and in 51 of 52 participants (98%) at 36 months (P=0.004 for noninferiority of the three-drug regimen vs. the two-drug regimen administered once a year for 3 years at 36 months). Moderate adverse events were more common in the group that received the three-drug regimen than in the combined two-drug-regimen groups (27% vs. 5%, P<0.001). There were no serious adverse events.

CONCLUSIONS

The three-drug regimen induced clearance of microfilariae from the blood for 3 years in almost all participants who received the treatment and was superior to the two-drug regimen administered once and noninferior to the two-drug regimen administered once a year for 3 years. (Funded by the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT01975441 .).

Adverse events following single dose treatment of lymphatic filariasis: Observations from a review of the literature

Background

WHO’s Global Programme to Eliminate Lymphatic Filariasis (LF) uses mass drug administration (MDA) of anthelmintic medications to interrupt LF transmission in endemic areas. Recently, a single dose combination of ivermectin (IVM), diethylcarbamazine (DEC), and albendazole (ALB) was shown to be markedly more effective than the standard two-drug regimens (DEC or IVM, plus ALB) for achieving long-term clearance of microfilaremia.

Objective and methods

To provide context for the results of a large-scale, international safety trial of MDA using triple drug therapy, we searched Ovid Medline for studies published from 1985–2017 that reported adverse events (AEs) following treatment of LF with IVM, DEC, ALB, or any combination of these medications. Studies that reported AE rates by treatment group were included.

Findings

We reviewed 162 published manuscripts, 55 of which met inclusion criteria. Among these, 34 were clinic or hospital-based clinical trials, and 21 were community-based studies. Reported AE rates varied widely. The median AE rate following DEC or IVM treatment was greater than 60% among microfilaremic participants and less than 10% in persons without microfilaremia. The most common AEs reported were fever, headache, myalgia or arthralgia, fatigue, and malaise.

Interpretation

Mild to moderate systemic AEs related to death of microfilariae are common following LF treatment. Post-treatment AEs are transient and rarely severe or serious. Comparison of AE rates from different community studies is difficult due to inconsistent AE reporting, varied infection rates, and varied intensity of follow-up. A more uniform approach for assessing and reporting AEs in LF community treatment studies would be helpful.

WHO’s Global Programme to Eliminate Lymphatic Filariais (LF) supports annual mass drug administration to over 400 million people in LF-endemic areas each year. Two drug combinations (either DEC or ivermectin, given with albendazole) have been recommended in most endemic areas. With the exception of well-described serious adverse events (AEs) occurring in patients with high level loiasis, severe AEs due to these medications are extremely rare. Mild to moderate AEs, however, are common, particularly in patients with active filarial infection. In this manuscript we synthesize published data on AEs following single-dose treatment of LF with ivermectin, DEC, or albendazole. This provides a background against which to compare the safety of triple drug therapy (ivermectin, DEC, and albendazole) recently endorsed by WHO, and provides a useful context for evaluating safety of new treatments for LF. The compiled data illustrate that transient, mild to moderate AEs following single-dose LF treatment are common in microfilaremic patients and are much less common in amicrofilaremic patients. They also show that passive surveillance for post-treatment AEs underestimates AE incidence and suggest that adherence to common reporting standards would improve the usefulness of AE reporting in filariasis studies.

Children and adolescents infected withWuchereria bancroftiin Greater Recife, Brazil: a randomized, year-long clinical trial of single treatments with diethylcarbamazine or diethylcarbamazine–albendazole

In filariasis-endemic areas beyond sub-Saharan Africa, the World Health Organization's recommended strategy for interrupting transmission of the causative parasites is annual, single-dose, mass treatment with a combination of diethylcarbamazine (DEC; given at 6 mg/kg) and albendazole (ALB; given at 400 mg) for 4-6 years (the minimum estimated life-span of the adult parasites). In an open, hospital-based, randomized and controlled trial, with a blinded evaluation of outcome, 82 children and adolescents from Recife, all with Wuchereria bancrofti microfilaraemias, were given either DEC alone (6 mg/kg) or the same dose of DEC combined with ALB (at 400 mg/patient). Every 90 days for 1 year after the single treatment, each patient was checked for microfilaraemia by the filtration of up to 5 ml of venous blood collected at night. One year post-treatment, 16 (39%) of the 41 patients given DEC alone and 20 (49%) of the 41 given DEC-ALB were found microfilaraemic (relative risk=0.8, with a 95% confidence interval of 0.49-1.31) and the corresponding geometric mean levels of microfilaraemia were 2.0% and 1.8% of the levels recorded immediately pre-treatment, respectively (P>0.05). In terms of the prevalences and intensities of microfilaraemia, therefore, the addition of ALB to the DEC appeared to offer no significant benefit.

[Loa loa filariasis in Italy: review of the literature with a clinical report]

We present the case of an asymptomatic Loa loa disease in a 28-year-old Nigerian man living in Italy for 5 years. The man was admitted to our clinic for an occasional identification of hypereosinophilia (white blood cell count 5440/mmc, eosinophil 42%) and the presence of microfilaria at an hemoscopic evaluation. The diagnosis was made by testing the diurnal peripheral blood that showed a parasitaemia of 7000 microfilia/mL. The patient was treated with ivermectin 12 mg on the first day followed by albendazole 400 mg every 12 hours for 21 days with a reduction but no negativization of the parasitaemia and no collateral effect. Filariasis should be considered in all patients who come from or have stayed in endemic areas or who present alterations in the leukocyte formula, including hypereosinophilia, or some unexplainable allergic disorders. The lab diagnosis can be conducted through a hemoscopic test or directly with the identification of the adult worm, whereas the parasitaemia can be evaluated only through a hemoscopic test. The therapy can be non-conclusive or carried out with difficulty as finding diethylcarbamazine may be a hard task or potentially fatal anaphylactic reactions may occur.

How endemic countries can accelerate lymphatic filariasis elimination? An analytical review to identify strategic and programmatic interventions

Lymphatic filariasis (LF) is endemic in 81 countries in the world, and a number of these countries have targeted for LF elimination. This review of literature and analysis was conducted to identify additional and sustainable strategies to accelerate LF elimination from endemic countries. This review noted that adverse events due to mass drug administration (MDA) of diethyl carbamazine (DEC) tablets, poor knowledge and information about LF amongst health workers & community members, and limited focus on information, education & communication (IEC) activities and interpersonal communication are the major barriers in LF elimination. The new approaches to increase compliance with DEC tablets (including exploring the possibility for DEC fortification of salt), targeted education programmes for physicians and health workers, and IEC material and inter personal communication to improve the knowledge of community are immediately required. There is a renewed and pressing need to conduct operational research, evolve sustainable and institutional mechanisms for education of physicians and health workers, ensure quality of trainings on MDA, strengthen IEC delivery mechanisms, implement internal and external monitoring of MDA activities, sufficient funding in timely manner, and to improve political and programmatic leadership. It is also time that lessons from other elimination programmes are utilized to accelerate targeted LF elimination from the endemic countries.

A single dose of doxycycline in combination with diethylcarbamazine for treatment of bancroftian filariasis

Standard treatment of lymphatic filariasis with diethylcarbamazine (DEC) is associated with systemic adverse reactions, thought to be due to the release of microfilariae material and Wolbachia endosymbiotic bacteria into the blood. Combination treatments with doxycycline for 3-8 weeks are more effective than standard treatment. However, long-term use of antibiotics may contribute to drug resistance and are not practical for use in remote areas. We assessed whether a single dose of doxycycline combined with the standard DEC regimen would reduce the incidence and severity of adverse reactions and increase the efficacy of standard treatment. Forty-four subjects from Tak Province were recruited into the randomized double-blind clinical trial study: 25 received DEC (300 mg) combined with a placebo, and 19 received DEC (300 mg) combined with doxycycline (200 mg). The incidences of adverse reactions to standard treatment were lower in the doxycycline group (45.5%) than in the placebo group (58.8%). Severe reactions occurred only in the placebo group (3 of 25 subjects). The severity of adverse reactions was significantly lower in the doxycycline group (mean score 0.45) than in the placebo group (mean score 1.17). The levels of IL-6 and Wolbachia DNA in the plasma were significantly lower in the doxycycline group. The filarial antigen levels were significantly lower in the doxycycline group at months 6 after treatment.

Role of community empowerment in the elimination of lymphatic filariasis in south India

The World Health Assembly in 1997 has targeted the elimination of lymphatic filariasis (LF) by 2020, and in India the goal has been set for the year 2015 by annual single dose mass drug administration (MDA). The role of community empowerment in enhancing the drug compliance and bringing out the function of various methods used to disseminate the information on MDA to the villagers is focused. A longitudinal survey was carried out in nine villages in Tirukoilur block of Villupuram district, Tamil Nadu for filarial infection variables like microfilaraemia, antigenaemia, transmission indices before and after each MDA, to determine the drug impact. Prior to each MDA, health education campaigns with different approaches were carried out with community as the leading player. These IEC approaches were assessed after 4 MDAs for its perception in the community. After four rounds of MDA, there was a significant decline in the filarial infection variables. The microfilaraemia and antigenaemia declined by 59% and 67% respectively. The transmission indices lowered by 89% and 94% (in resting and landing catch of mosquitoes respectively). The decline in these variables, with a drug consumption rate of >80% was achieved due to the effective IEC campaigns prior to each MDA. After 4 MDAs almost 97% of the respondents were aware of lymphatic filariasis. The KAP survey in the rural villages revealed that the dissemination of MDA message through autorickshaw was the most effective, followed by school students' rally. Empowerment of community through the members of women self help groups and school students were observed to be integral to mass drug administration campaigns for the enhancement of drug compliance, thus leading to LF elimination.

Strengthening of mass drug administration implementation is required to eliminate lymphatic filariasis from India: an evaluation study

BACKGROUND & OBJECTIVES

The mass drug administration (MDA) is one of the strategies to eliminate lymphatic filariasis in India. Eleven districts are endemic for the disease in Madhya Pradesh state of India, which conduct MDA activities annually. A mid-term evaluation was conducted with the objectives to review the progress of the single dose of di-ethyl-carbamazine (DEC) administration, and to understand the functioning of the programme to recommend mid-term amendments.

METHODS

A qualitative cross-sectional study was conducted in three endemic districts of Madhya Pradesh between July and October 2007. The teams of faculty members from medical college visited the study districts and collected data by desk review, indepth interviews, on site observations, and from the community.

RESULTS

The filaria units in these districts were understaffed. There were no night clinics in two out of the three districts. The sufficient number of trainings for MDA were conducted without any mechanism for quality assurance. There was erratic and inadequate supply of DEC tablets, leading to the postponement of MDA activity, twice. The evaluated coverage with DEC tablets was much lower than that reported by the district officials. The tablet intake was not ensured by the distributors and the compliance rate was in the range of 60-70%. The IEC activities were conducted in limited areas, and there were prevailing myths and misconceptions, contributing to low compliance rate. There was no proper recording of the data on filariasis with gross mismatch at district headquarters and peripheral health facilities. A proportion of community members developed side effects following DEC tablet intake and had to visit private health facilities for treatment.

INTERPRETATION & CONCLUSION

This evaluation study noted that MDA is restricted to tablet distribution only and the major issues of implementation in compliance, health education, side effect and morbidity management, and the logistics were not being given due attention. The implementation should be strengthened immediately in the MDA programme in India to achieve the goal of LF elimination by 2015.

Lymphatic filariasis

(1) Lymphatic filariasis is a set of parasitic diseases that are endemic in tropical and subtropical regions and can be disabling in the long term. (2) The standard antiparasitic drug for adults is oral diethylcarbamazine. Ivermectin is an alternative, especially for patients with intercurrent onchocercosis or loasis.

Description, mechanisms and control of reactions to treatment in the human filariases

Since diethylcarbamazine at the dosages used to treat filarial infections has little direct toxicity, most of the post-treatment reactions (termed Mazzotti reactions in onchocerciasis) result from the immunological inflammatory mechanisms activated in the process of clearing and killing the skin-swelling or blood-borne microfilariae. These reactions may be either localized to the skin, eyes or lymphatics or generalized systemically (e.g. headache, fever, adenopathy, arthralgia, tachypnoea, tachycardia, hypotension and even death). The occurrence and intensity of such reactions can be shown to be related to the intensity of infection. It had previously been speculated that the best candidates for triggering these post-treatment reactions were activation of complement, immediate hypersensitivity responses mediated by immunoglobulin E, and degranulation of eosinophils with resultant inflammatory reactivity. Recent detailed studies have given little support to the primacy of either complement or immediate hypersensitivity responses in triggering such reactions, but eosinophil degranulation with the release of inflammatory mediators into the tissues and peripheral blood is extremely prominent in all patients undergoing post-treatment reactions and develops with a time course generally consistent with what would be required of an initiator of such reactions. Other inflammatory mediators and pathways may be involved (e.g. kinins, prostaglandins, immune complexes, leukotrienes, platelets and parasite-derived inflammatory molecules), but there is currently no evidence to implicate any of these mechanisms as initiators of the response. Symptomatic treatment of these post-treatment reactions with analgesics, antipyretics, antihypotensive agents etc. has been successful, but their prevention has been achieved only with the broadly anti-inflammatory corticosteroids.

Endpoints for lymphatic filariasis programs

In 2000, annual mass administration of diethlycarbamazine and albendazole began in Leogane Commune, Haiti, to interrupt transmission of lymphatic filariasis (LF). After 5 years of treatment, microfilaremia, antigenemia, and mosquito infection rates were significantly reduced, but LF transmission was not interrupted. These finding have implications for other LF elimination programs.

Adverse reactions of 300 MG diethylcarbamazine, and in a combination of 400 MG albendazole, for a mass annual single dose treatment, in migrant workers in Phang Nga province

BACKGROUND

Foreign migrant workers with work permits in Thailand are given once a year 300 mg diethyl-carbamazine (DEC) for bancroftian filariasis, and 400 mg albendazole (ABZ) for helminthiasis. Treatment effectiveness, tolerability, and safety of two treatment arms, DEC + ABZ and DEC alone, had never been fully documented.

OBJECTIVE

Evaluate the tolerability of the two treatment arms and analyze the effects of adverse reaction, prevalence, and intensity of both common and uncommon adverse drug reactions (ADR) in relation to the reaction time (2 hours = acute, > 2 to 24 hours = subacute, and > 24 to 72 hours = latent).

MATERIAL AND METHOD

A hospital-based clinical study of on-hour-2 treatment with both treatment arms in 280 Myanmar male migrant volunteers (DEC + ABZ = 150, DEC = 130) was conducted in Phang Nga province, southern Thailand Of these, ADR evaluation at three reaction times was performed using antigenemic (WbAg+) and non-antigenemic (WbAg-) volunteer groups (DEC + ABZ/WbAg+ = 14, DEC/WbAg+ = 12, DEC + ABZ/ WbAg- = 8, andDEC/WbAg- = 16).

RESULTS

Both drug groups had similarly overall ADR prevalence [5.2%for DEC + ABZ and 5. 1% for DEC (p > 0. 05)], as well as mean ADRacute scores (p > 0. 05) on hour 2 post-treatment. The four groups had maximum overall prevalence (10% to 40%for ADRsubacute). It was more likely to show no relationship between treatment arms and WbAg (neither WbAg+ nor WbAg-) with adverse reaction intensity for ADRacute, ADRsubacute, Or ADRlatent Three major specific ADR were fatigue, dizziness, and headache.

CONCLUSION

Adverse reaction prevalence and intensity were independent for WbAg and treatment arm. The DEC + ABZ have no greater effects on ADR development as the DEC does. The common ADR after treatment are not required for symptomatic treatment. The study confirms DEC + ABZ regime can be safe and not toxic for use in mass treatment of those migrants in Thailand and, its value, in a mass annual single dose treatment, is beneficial for the Global Alliance to Eliminate of Lymphatic Filariasis (GAELF).

Using knowledge, attitudes and practice (KAP) surveys on lymphatic filariasis to prepare a health promotion campaign for mass drug administration in Alor District, Indonesia

We report the results of two surveys of people's knowledge, attitudes and practices (KAP) regarding lymphatic filariasis (LF) in Alor District, eastern Indonesia. The results of the surveys were used to prepare and evaluate the social mobilization component of a pilot mass drug administration (MDA) in five villages. In the study area, the filarial parasites Brugia timori and Wuchereria bancrofti are highly endemic. Frequent and severe adverse reactions after MDA may occur especially in areas endemic for B. timori and therefore, a special communication strategy was designed to inform and to educate communities about LF and its control. The first KAP survey was conducted as a baseline pre-MDA with diethylcarbamazine and albendazole and the second as a post-intervention evaluation in order to obtain information on the impact of the communication campaign. Before the information campaign and the subsequent MDA, 54% of the study population had heard of one of the three main terms for LF, whereas after health education and MDA, 89% had heard of at least one of the three terms. Similarly, pre-MDA, 21% reported having had previously taken the treatment for filariasis, while post-MDA, 88% reported having taken the treatment during the pilot treatment period. The historical fears and traumatic experiences associated with past LF treatment campaigns in Indonesia were averted since both the communication campaign and the MDA were designed appropriately for and together with the community. As a result, compliance was sufficient in the first round to successfully begin the elimination process.

Mass drug administration against lymphatic filariasis: experiences from Kozhikode district of Kerala State

The mass DEC drug administration to eliminate lymphatic filariasis in Kozhikode district was monitored from 2001 to 2003 to assess the drug distribution coverage, compliance, reasons for non-compliance, side reactions, mf prevalence and intensity, infection and infectivity rates in the vector. The drug distribution coverage and compliance were much below the required level. "No disease so not necessary" (42.5%) and "fear of side reactions" (25.2%) were the two major reasons for non-compliance. The adverse reactions were minimal. No appreciable changes were found in the mf prevalence and intensity. For the successful implementation of the MDA programme, proper planning, intense and timely efforts to motivate the community and innovative drug delivery strategies are required.

Implication of diethylcarbamazine induced morbidity and the role of cellular responses associated with bancroftian filariasis pathologies

Pre and post-diethylcarbamazine treatment clinical expression, microfilaraemia prevalence and cellular responses were investigated in individuals in Tanga, Tanzania. Fifty-seven male individuals (aged = 15 years old) were identified for further studies on IL-4, IL-6, IL-8. IFN-gamma, IL-beta, TNF-alpha and nitric oxide in plasma and hydrocoele fluid. Microfilarial prevalence in the examined individuals was 12% with a geometric mean intensity (GMI) of 838 mff/ml in a community with a population of 1018 individuals. Microfilaraemic hydrocoele stage II and III were the most frequent pathologies observed with prevalence of 17.5% and 42. 1 %, respectively. All study individuals treated with diethylcarbamazine (DEC) standard dose of 6 mg/kg experienced post-treatment adverse events. There was no direct relationship between elevated IL-6 and the occurrence and severity of clinical adverse effects post-treatment. The findings from this study suggests that, blood elevated cytokine profile is not the main etiological factor in the inflammatory responses developing after treatment of bancroftian filariasis infections and pathology with DEC. Plasma levels of cellular (cytokines) responses during treatment revealed a proportion of symptomatic patients. Prior to treatment, patients with hydroecoele had high levels of IL-6 than those without the pathology. In conclusion these findings do not support the hypothesis that pro-inflammatory cytokines are directly responsible for adverse events to DEC chemotherapy in bancroftian filariasis infections and pathologies such as hydrocoele, lymphoedema and elephantiasis.

Adverse reactions following mass drug administration during the Programme to Eliminate Lymphatic Filariasis in Orissa State, India

The frequency and severity of adverse reactions are the main reasons for low compliance of mass drug administration (MDA) under the Programme to Eliminate Lymphatic Filariasis (PELF). This paper reports the frequency and types of adverse reactions during two MDAs during January 2002 and September 2004 in the State of Orissa, India. Of the people who consumed the drugs, 15.5% in the 2002 MDA and 16.5% in the 2004 MDA reported one or more adverse reactions. This rate is higher (49.7%) in a group of individuals who were monitored for 6 days from the day of consumption of drugs during the 2002 MDA. However, many of these reactions were mild. No significant difference was found in the frequency of adverse reactions between MDA with diethylcarbamazine (DEC) alone and with DEC and albendazole. Significant gender differences were found in the 2004 MDA but no such differences were found in the 2002 MDA; however, the frequency of adverse reactions increased with age. Of all the adverse reactions, systemic adverse reactions typically associated with microfilarial death were more frequent. The frequency of adverse reactions was higher in microfilaraemics compared with amicrofilaraemic controls. The present study warrants developing an active adverse reaction surveillance system to minimise the impact of adverse reactions on MDA compliance.

Lethal LPS-independent side effects after microfilaricidal treatment in Acanthocheilonema viteae-infected rodents

Mastomys coucha and jirds infected with Acanthocheilonema viteae, a filarial species free of endosymbiontic bacteria of the genus Wolbachia, suffer lethal side effects after effective microfilaricidal therapy with diethylcarbamazine and levamisole, whereas, M. coucha infected with the Wolbachia-infested species Brugia malayi or Litomosoides carinii tolerate corresponding treatment. Mortality in A. viteae infected, treated animals varied with microfilariae density in the blood. It was up to 100% in highly microfilaraemic M. coucha and jirds, but low or absent in animals with low microfilariae counts. Deaths occurred in most cases 5-24 h after treatment. Characteristic symptoms in animals, which died subsequently were a rapid drop in body temperature by 4-7 degrees C, an increase in hematokrit values by up to 10% and a moderate blood acidosis. Lethal effects in A. viteae infections did not depend on a particular status of hypersensitivity of the animals since desensitization procedures, which protected infected M. coucha against an otherwise lethal intravenous challenge with A. viteae homogenate did not protect against adverse reactions to a subsequent microfilaricidal treatment. The animals were protected from treatment induced death by injection of N-LMMA. Thus the final morbific agent seems NO. The data show that adverse effects after effective microfilaricidal therapy may be caused by microfilariae derived components different from Wolbachia-released LPS.

Pattern of community compliance with spaced, single-dose, mass administrations of diethylcarbamazine or ivermectin, for the elimination of lymphatic filariasis from rural areas of southern India

Current programmes to eliminate lymphatic filariasis (LF) are largely based on annual mass administrations of single doses of antifilarial drugs. The level and pattern of compliance by the target population are important determinants of the success of such mass drug administrations (MDA). Community compliance was therefore investigated during a study in southern India of the effects, on Wuchereria bancrofti microfilaraemia and transmission, of spaced MDA based on diethylcarbamazine (DEC) or ivermectin (IVM). During six rounds of MDA, the frequency of compliance in the target populations, in the five study villages given DEC and the five given IVM, ranged from 55%-77%. Analysis of the relevant cohort data indicated that about 30% of the villagers had complied with treatment during all six rounds, but 3.5% of those in the DEC arm and 4.0% of those in the IVM arm had never complied with treatment. Most of the villagers (>90%) had received treatment at least once, however, and >60% had each received treatment in at least four of the six rounds. Overall, there was a significant negative correlation (r=-0.78; P=0.008) between the size of the village, in terms of the number of villagers, and the mean frequency of compliance over the six rounds of MDA. The pattern of community compliance was found to be 'semi-systematic', laying between random and systematic. In terms of the elimination of LF, a semi-systematic pattern of compliance is worse than random compliance but better than systematic. The relevance of the levels and patterns of compliance to LF control or elimination is discussed.

Tolerability and efficacy of a three-age class dosage schedule of Diethylcarbamazine citrate (DEC) in the treatment of microfilaria carriers of Wuchereria bancrofti and its implications in mass drug administration (MDA) strategy for elimination of lymphatic filariasis (LF)

A six-age class dosage schedule of Diethylcarbamazine (DEC) of 50mg (1-2 years), 100mg (3-4 years), 150mg (5-8 years), 200mg (9-11 years), 250mg (12-14 years) and 300mg for above 14 years is being adopted for annual single dose MDA for LF elimination treat Wuchereria bancrofti microfilaria carriers. In order to increase the community compliance as well as to make the distribution easier during MDA, a revised 3 age class dosage schedule of 100mg (2-4 years), 200mg (5-14 years) and 300mg for above 14 years was evaluated for its tolerability and efficacy. By this change, it was observed that the 4-8 years age class is receiving 50 mg higher and 11-14 years age class is receiving 50mg lesser dose compared to the earlier class schedule. Therefore, the safety aspect in the age class of 4-8 years and efficacy component in the age class of 11-14 years were assessed. Apparently "healthy" asymptomatic microfilaraemic volunteers between the age class of 4-8 and 11-14 years were recruited for the study. The incidence of side reaction in the 4-8 years age class was 50.0% with 150mg dose and 66.7% with 200mg (P>0.05). No life threatening adverse reactions was observed in any dosage schedule. Fever, headache and myalgia, the predominant adverse reactions were mild and similar in both schedules. The mean intensity of the three major specific adverse reactions (fever, headache and myalgia) also did not differ significantly (P>0.05). For the purpose of LF elimination, efficacy in terms of reduction in mean microfilaria load is important. In the 11-14 year age class considerable reduction in the geometric mean density (GMD) was observed by day 90 and 180 post-therapy in both groups (250mg group and 200mg group) compared to pre-therapy level. By day 360 post-therapy, the difference was statistically not significant (P>0.05) (reduction of 72.2% in 250mg and 69.6% reduction in 200mg). The reductions in GMD were statistically significant when compared to pre-therapy levels in both the old (250mg) and new (200mg) doses. Thus, three- age class dosage schedule is as safe and efficacious as the six- age class schedule.

Tolerability and efficacy of single dose diethylcarbamazine (DEC) alone or co-administration with Ivermectin in the clearance of Wuchereria bancrofti microfilaraemia in Pondicherry, South India

The tolerability and efficacy of single dose DEC (12mg/kg body weight) or co-administration of DEC (6mg/kg body weight) with Ivermectin (200 or 400 mcg/kg of body weight) was studied in 60 asymptomatic W. bancrofti microfilariae (Mf) carriers following a double blind randomized design. The drugs were tolerated well. The incidence of adverse reactions of DEC (85.0%), DEC + Ivermectin 200mcg (95.0%) and DEC + Ivermectin 400mcg (100%) did not vary significantly (P>0.05). The mean score of adverse reaction intensity due to DEC + Ivermectin 200mcg (1.41) was significantly higher compared to DEC (0.61) (P<0.05). However, there was no significant difference between and DEC +Ivermectin 400mcg (0.89) and DEC + Ivermectin 200mcg (1.41) and DEC + Ivermectin 400mcg and DEC. The major adverse reactions were fever, headache and myalgia in all groups. The incidence and intensity of the adverse reactions were maximum between 24 to 48 hours of post therapy. The haematological and biochemical parameters did not vary significantly between pre and 7-day post therapy values in any of the study groups (P>0.05). Efficacy was measured in terms of proportion of cases clearing microfilaraemia completely and reduction in geometric mean parasite density in comparison to pre therapy levels. At the end of one year, DEC with Ivermectin 400mcg group showed significantly higher efficacy in complete clearance of Mf (94.4%) than that of DEC with Ivermectin 200mcg (60.0%) or DEC alone (52.6%) (P<0.05). However, no significant difference was observed in reduction of geometric mean Mf density (99.9%, 99.7%, 99.5% respectively). In all the groups, the tolerability and efficacy of the drugs were independent of host age and gender.

Coverage, compliance and some operational issues of mass drug administration during the programme to eliminate lymphatic filariasis in Orissa, India

This paper reports the coverage, compliance and other operational issues of mass drug administration (MDA) of diethylcarbamazine and albendazole under a programme to eliminate lymphatic filariasis (LF) in Orissa state of India. Both quantitative and qualitative methods were used to collect data from 90 villages and nine urban areas of four districts of Orissa, India. In Orissa, 67% of people older than 2 years had received the drugs during MDA and 42% had consumed them. About 25% of people had not taken the tablets although they received them. Urban areas recorded lower rates than rural areas. The paper discusses some policy/health system-, community- and drug-related issues that influenced coverage and compliance of MDA. It is essential to improve compliance in future rounds of MDA to achieve targets of control and eventual elimination of LF in a reasonable time frame.

Safety, tolerability, efficacy and plasma concentrations of diethylcarbamazine and albendazole co-administration in a field study in an area endemic for lymphatic filariasis in India

Filariasis control programmes are moving towards a strategy of repeated single-dose mass treatment of endemic populations. Using a combination, such as albendazole (ALB) to diethylcarbamazine (DEC) gives both macrofilaricidal and anti-helmintic activity. However, the safety of the combination versus DEC alone should be established in field studies in large populations prior to incorporation into national programmes. The present study compared the safety, tolerability, and efficacy of single doses of DEC 6 mg/kg + ALB placebo with DEC 6 mg/kg + ALB 400 mg in populations living in two filariasis endemic villages in the district of Wardha in western India. The study was double blind, parallel group, and randomized. Safety and tolerability study were studied in males and females older than 5 years. Safety was assessed by monitoring if adverse events (AEs) over 5 days affected daily acivities. Subjects in the 2 treatment groups experienced insignificantly different effects on daily activities and the combination was shown to be safe. Efficacy was evaluated by microfilaraemia (Mf), immunochromatographic test (ICT) and ultrasonography (USG) at 0, 3, 6, and 12 months of follow up. The efficacy study enrolled 103 male patients (aged 18-50 years) in microfilariae positive, clinical disease and asymptomatic, amicrofilaremic groups. There was no significant difference in efficacy between groups at 12 months. Within the Mf positive group, significant differences were seen in microfilaraemia (P < 0.001) with both treatments, and in USG (P < 0.001 and P < 0.004 respectively), at 12 months. The present field study has shown the combination of DEC + ALB to be as safe as the single drug DEC and thus the combination can be put in use in the national filariasis control programmes. Both drugs were adequately absorbed. The study at present does not provide evidence for the greater efficacy of the combination at 12 months follow up. While the safety of the combination has been ascertained, the incorporation or otherwise of ALB into national programmes for greater efficacy must await results of studies with longer follow up.

A marker for Stevens–Johnson syndrome

Stevens-Johnson syndrome and the related disease toxic epidermal necrolysis are life-threatening reactions of the skin to particular types of medication. Here we show that there is a strong association in Han Chinese between a genetic marker, the human leukocyte antigen HLA-B*1502, and Stevens-Johnson syndrome induced by carbamazepine, a drug commonly prescribed for the treatment of seizures. It should be possible to exploit this association in a highly reliable test to predict severe adverse reaction, as well as for investigation of the pathogenesis of Stevens-Johnson syndrome.

Pathogenesis of filarial hydrocele: risk associated with intrascrotal nodulescaused by death of adult Wuchereria bancrofti

Although testicular hydrocele is the most common clinical manifestation of bancroftian filariasis, its pathogenesis is poorly understood, as is its relationship to inflammatory scrotal nodules following death of adult Wuchereria bancrofti. Between 1994 and 1998, we prospectively determined the incidence and clinical evolution of nodule-associated acute hydrocele in men attending 2 outpatient clinics in Recife, Brazil who were infected with W. bancrofti, had living adult worms detectable by ultrasound in the intrascrotal lymphatic vessels, and were scheduled for treatment with 6 mg/kg diethylcarbamazine (DEC). A total of 132 men developed 173 scrotal nodules 1-7 (mean 4.2) d after DEC treatment and another 47 developed 58 spontaneous nodules before they received DEC treatment. These 179 men with a single 'nodule event' (simultaneous development of > or =1 scrotal nodules) were followed-up by serial physical and ultrasound examinations for 18 months. Overall, 40 (22.3%) men developed acute hydrocele, 3 of whom underwent biopsy and hydrocele repair. Of the remaining 37 men, 9 (24.3%) developed chronic hydrocele and 28 had acute hydrocele resolution within 14-210 (mean 60.9) d. Rate of chronic hydrocele was similar for men who received DEC and those with spontaneous nodules. Seventeen (42.5%) men with hydrocele had multiple scrotal nodules, compared with 28 (20.1%) men who did not develop hydrocele (P= 0.007). Of 134 men with single nodules, superior paratesticular nodules were found in 56.5% and 29.7% of those with and without hydrocele, respectively (P = 0.02). Acute hydrocele occurs frequently following death of adult W. bancrofti and single episodes of scrotal nodule formation. Chronic hydrocele may develop following 5.1% of these episodes.

Frequency, severity, and costs of adverse reactions following mass treatment for lymphatic filariasis using diethylcarbamazine and albendazole in Leogane, Haiti, 2000

In October 2000, 71,187 persons were treated for lymphatic filariasis using albendazole and diethylcarbamazine (DEC) or DEC alone in Leogane, Haiti. We documented the frequency of adverse reactions, severity and cost of treatment. Adverse reactions were classified as minor, moderate, or severe. Overall, 24% (17,421) of the treated persons reported one or more adverse reactions. There were 15,916 (91%) minor and 1502 (9%) moderate adverse reaction reports. Men outnumbered women 2:1 in reporting moderate problems. Three patients, representing roughly one in 25,000 persons treated, were hospitalized with severe adverse reactions judged to be treatment-associated by physician review. The cost per person treated for adverse reactions was more than twice the cost per person treated for lymphatic filariasis (dollar 1.60 versus dollar 0.71). Severe adverse reactions to lymphatic filariasis treatment using DEC with or without albendazole are uncommon. Minor and moderate reactions are more commonly reported and their management represents a challenge to lymphatic filariasis elimination programs.

Carbamazepine-provoked hepatotoxicity and possible aetiopathological role of glutathione in the events. Retrospective review of old data and call for new investigation

The antiepileptic drug (AED) carbamazepine is widely used in the treatment of different kinds of seizures as well as affective and behavioural disorders. This paper presents an epidemiological study of carbamazepine-induced hepatic injuries and death, and describes the possible mechanisms of its toxicity. A retrospective analysis of clinical data revealed that the likelihood of hepatic death was comparatively higher in children, particularly when they were receiving medication with multiple AEDs, whereas reversible hepatic injuries were more likely to be seen in elderly patients. As suggested in this paper, the development of carbamazepine hepatotoxicity is rare, and unpredictable with the present state of knowledge, but it is somehow related to disturbance of glutathione metabolism, although data in this regard are imperfect. There appear to be two types of carbamazepine-initiated idiosyncratic liver injury, hypersensitivity and toxin-induced. It is feasible that both are due to the accumulation of toxic metabolite(s), and arene oxides may probably be considered as damaging derivatives of carbamazepine metabolism. Despite the lack of clear-cut underlying clinical and experimental findings in those patients in whom an inherited weakness of drug eliminating capacity is present, those conditions that may deteriorate glutathione balance, may increase the possibility of the emergence of toxic events during carbamazepine therapy. Finally, some recommendations for carbamazepine therapy are presented.

Mass treatment to eliminate filariasis in Papua New Guinea

BACKGROUND

The global initiative to eradicate bancroftian filariasis currently relies on mass treatment with four to six annual doses of antifilarial drugs. The goal is to reduce the reservoir of microfilariae in the blood to a level that is insufficient to maintain transmission by the mosquito vector.

METHODS

In nearly 2500 residents of Papua New Guinea, we prospectively assessed the effects of four annual treatments with a single dose of diethylcarbamazine plus ivermectin or diethylcarbamazine alone on the incidence of microfilariae-positive infections, the severity of lymphatic disease, and the rate of transmission of Wuchereria bancrofti by mosquitoes. Random assignment to treatment regimens was carried out according to the village of residence, and villages were categorized as having moderate or high rates of transmission.

RESULTS

The four annual treatments with either drug regimen were taken by 77 to 86 percent of the members of the population who were at least five years old; treatments were well tolerated. The proportion with microfilariae-positive infections decreased by 86 to 98 percent, with a greater reduction in areas with a moderate rate of transmission than in those with a high rate. The respective aggregate frequencies of hydrocele and leg lymphedema were 15 percent and 5 percent before the trial began, and 5 percent (P<0.001) and 4 percent (P=0.04) after five years. Hydrocele and leg lymphedema were eliminated in 87 percent and 69 percent, respectively, of those who had these conditions at the outset. The rate of transmission by mosquitoes decreased substantially, and new microfilariae-positive infections in children were almost completely prevented over the five-year study period.

CONCLUSIONS

Annual mass treatment with drugs such as diethylcarbamazine can virtually eliminate the reservoir of microfilariae and greatly reduce the frequency of clinical lymphatic abnormalities due to bancroftian filariasis. Eradication may be possible in areas with moderate rates of transmission, but longer periods of treatment or additional control measures may be necessary in areas with high rates of transmission.

Detection of Onchocerca volvulus infection in low prevalence areas: a comparison of three diagnostic methods

The standard assay for onchocerciasis diagnosis is microscopical detection of microfilariae in skin snips. Skin snipping is painful, requires appropriate sterilization of equipment, and may fail to diagnose light infections. Two alternatives are a polymerase chain reaction (PCR) test which detects parasite DNA in pieces or scrapings of skin and a test based on allergic reactions to topical application of diethylcarbamazine (DEC). We compared these 2 diagnostics with standard skin snip microscopy in 313 individuals from 2 villages in Guinea, with low prevalence after over 10 years of control by the Onchocerciasis Control Programme. Lower and upper bounds on sensitivities and specificities of these 3 tests were estimated. In addition, these parameters were estimated using 5 different statistical models. Where prevalence was low, PCR and the DEC patch test appeared to be more sensitive than skin snipping which has low sensitivity. As the DEC test is non-invasive, simple and cheap, it may provide a good alternative to skin snipping alone for surveillance in low prevalence areas.

Treatment of Brugia timori and Wuchereria bancrofti infections in Indonesia using DEC or a combination of DEC and albendazole: adverse reactions and short-term effects on microfilariae

Filariasis caused by Brugia timori and Wuchereria bancrofti is an important public health problem on Alor island, East Nusa Tenggara, Indonesia. To implement a control programme, adverse reactions and short-term effects on the microfilaria (mf) density were studied following a divided dose of diethylcarbamazine (DEC, 6 mg/kg body weight - 100 mg on day 1 and the rest on day 3) or a single dose of DEC (6 mg/kg body weight on day 3) and albendazole (Alb, 400 mg). In order to define the most appropriate regimen, 30 persons infected with B. timori were treated in the hospital and results were compared with those obtained from the treatment of 27 persons infected with W. bancrofti. Adverse reactions consisted of systemic reactions such as fever, headache, myalgia, itching and local reactions such as adenolymphangitis. Fever experienced by a number of patients in both treatment groups generally occurred 12-24 h after drug administration and lasted up to 2 days. Adenolymphangitis tended to occur later and was resolved within 4 days. The number of W. bancrofti patients suffering from adverse reactions was lower and the reactions were milder than those of the B. timori patients. There was no difference in adverse reactions between DEC alone and DEC-Alb treatment for either infection. The geometric mean mf count decreased on day 7 in the B. timori infected patients from 234 mf/ml in the DEC group and from 257 mf/ml in the DEC-Alb group to 7 and 8 mf/ml, respectively. The mf densities of the W. bancrofti infected patients decreased on day 7 from 214 mf/ml in the DEC group and from 559 mf/ml in the DEC-Alb group to 15 and 14 mf/ml, respectively. Our data indicate that the microfilaricidal effect of the drugs is achieved more rapidly for B. timori, which is associated with more adverse reactions than W. bancrofti. In addition, 111 B. timori infected persons were treated in the community with DEC-Alb in one selected village. The adverse reactions and the reduction of mf density was similar to the findings of the hospital-based study. In this group, there was a strong correlation of mf density with the frequency and severity of adverse reactions. The addition of Alb resulted in no additional adverse reactions compared with DEC treatment alone and can also be used for the treatment of B. timori infection. In Indonesia, where the prevalence of intestinal helminths is high, the use of a combination of DEC and Alb to control lymphatic filariasis may also have impact on the control of intestinal helminths.

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.

Bacterial endosymbionts of Onchocerca volvulus in the pathogenesis of posttreatment reactions

Treatment of onchocerciasis with diethylcarbamazine (DEC) or ivermectin is associated with a posttreatment reaction characterized by fever, tachycardia, hypotension, lymphadenopathy, and pruritus. To investigate the role of the Wolbachia bacterial endosymbiont of Onchocerca volvulus in these reactions, serum samples collected before and after treatment with either anthelmintic were assessed for evidence of Wolbachia DNA. By use of real-time quantitative polymerase chain reaction, Wolbachia DNA was detected in both groups-with significantly higher levels in those who received DEC (P <.0001). In the ivermectin group, there was a significant correlation between levels of bacterial DNA and serum tumor necrosis factor-alpha (P =.013). Peak DNA levels correlated with reaction scores (P =.048). Significant correlations were also seen between Wolbachia DNA and the antibacterial peptides calprotectin (P =.021) and calgranulin B (P <.0001). These findings support a role for Wolbachia products in mediating the inflammatory responses seen following treatment of onchocerciasis and suggest new targets for modulating these reactions.

Severe reactions to filarial chemotherapy and release of Wolbachia endosymbionts into blood

Wolbachia bacteria seem to have evolved as essential endosymbionts of their filarial nematode hosts. Studies in mice have suggested that these bacteria are associated with systemic inflammatory reactions to filarial chemotherapy. We took blood samples from 15 Indonesian patients before and after treatment with diethylcarbamazine for Brugia malayi infection, and recorded the severity of any post-treatment inflammatory reactions. Blood from all three patients with severe adverse reactions and from one of six with moderate reactions was positive for Wolbachia DNA 4-48 h after diethylcarbamazine treatment. We suggest that these severe inflammatory reactions are associated with the release of endosymbionts into the blood after treatment for filariasis.

Anthelmintics: a review

Helminths infect 25% of the world's population. In the last 50 years specific, safe and effective anthelminitic drug therapy for various parasitic infestations have been developed. The population of the developing countries across the globe suffers not only as a direct result of these infections but due also to co-morbidity such as anemia, malnutrition and reduced immunity status. Earlier anthelmintic drugs suffered from serious drawbacks such as hepatotoxicity and required specific preparation of the patient before treatment such as 12-hour fasting and pre-post purging caused considerable inconvenience to the patient. However, successive discoveries were born out of rationale approach that contributed to the effective, more specific and more easily tolerated drugs i.e. benzimidazoles, piperazine derivatives, avermectins, pyrazinoquinoline, etc. The present approach is to identify the causative parasite on the basis of stool examination and as a result of this approach, different drugs are prescribed for different parasitic infections. Examples include thiabendazole for cutaneous larva migrans, mebendazole for ascariasis, trichiuriasis and hookworm, albendazole for inoperable cases of cystic hydatid disease, DEC for Toxocara induced visceral larva migrans and loiasis, ivermectin for onchocerciasis, praziquantel for schistosomiasis and niridazole for Dracunculus medinensis. The cure rates with these drugs is also high e.g. thiabendazole produces a cure-rate of 98% in cutaneous larva migrans while mebendazole gives cure rate of 76-95% in ascariasis, trichiuriasis and hookworm infestations. A cure rate of 96% is produced by praziquantel in schistosomiasis. Most of these drugs have broad-spectrum anthelmentic effect. The present review aims at evaluating the currently available anthelmintics with respect to their efficacy and adverse effects. Steps to prevent impending helminthic drug resistance are also discussed.

Mass DEC campaign for filariasis in a hyper endemic district of West Bengal

As a part of the on-going National Filaria Control Programme, National Filaria Day was observed in Purulia district of West Bengal on 26th Nov 2000 with an extensively organized mass DEC consumption campaign preceded by IEC activities and followed by mopping up operations. In all 81.07% of the targeted population was covered, females (84.3%) being more available than males (78.3%). Percentage of coverage declines with increase in age. Municipalities and notified areas had less coverage as well as supervised consumption than in other areas. Consumption was highest in Balarampur block (88.6%). Supervised consumption among surveyed population was highest in Bandwan (56.0%). Overall patient compliance was very good, with side effects of vomiting, dizziness, headache and fever being 2.12% only among surveyed population. Disease prevalence among population covered showed 0.1% hand swelling, 0.6 to 0.8% leg swelling, while 1.1% of males had hydrocele.

Wolbachia in filarial nematodes: evolutionary aspects and implications for the pathogenesis and treatment of filarial diseases

The presence of intracellular bacteria in the body of various species of filarial nematodes, including important parasites such as Brugia malayi, Dirofilaria immitis, and Onchocerca volvulus, was observed as early as the mid-1970s. These bacteria were shown to be transovarially transmitted (from the female worm to the offspring) and to be present in significant amounts in the body of the nematode. As highlighted by their discoverers, the potential importance of these bacteria is fairly obvious: (1) bacteria-derived molecules should be considered as having an immunological and pathological role in filarial diseases; (2) the interaction between the bacteria and the filarial host deserves investigation, in view of the possibility that the bacteria are needed by the host nematode and could thus represent a target for therapy. Other authors, independently from the discovery of these intracellular bacteria, showed that the antibiotic tetracycline (which is well known for its efficacy on intracellular bacteria) had detrimental effects on two species of filarial nematodes (Brugia pahangi and Litomosoides sigmodontis). It is therefore surprising that for more than 20 years, no further investigations focused on the bacteria of filarial nematodes, nor on the anti-filarial properties of tetracycline. Recently, the bacteria of filarial nematodes have been independently "rediscovered" by research groups from the schools of Hamburg, Liverpool and Milan. These bacteria are now classified as Wolbachia, and the basic aspects of their phylogenetic history and relationship with the Wolbachia of arthropods have been reconstructed. In addition, their implications for the pathogenesis and treatment of filarial diseases have started to be uncovered. This paper, which is authored by representatives of the three European schools who reopened this research area, reviews our present knowledge of these fascinating microorganisms, highlighting the complexity of a symbiotic system which involves, in addition to the nematode and its bacterium, the vertebrate host.

Annual single-dose diethylcarbamazine plus ivermectin for control of bancroftian filariasis: comparative efficacy with and without vector control

Two intervention strategies for the control of bancroftian filariasis were compared in rural villages of southern India: annual mass treatment with single-dose diethylcarbamazine plus ivermectin, either on its own or combined with vector control. Vector control, based on the use of polystyrene beads and larvivorous fishes in the major breeding sites of Culex quinquefasciatus, brought about a drastic and sustained reduction in vector density and man-biting rates. After the first round of treatment, chemotherapy alone brought about a 60% drop in the annual transmission potential (ATP) whereas the integrated strategy reduced ATP by 96% (P < 0.05). After two annual rounds of treatment, the reduction in ATP was similar for both strategies (91%-96%), with the prevalences of microfilaraemia reduced by 88%-92%. However, when drug pressure was removed in the third and final year of the study, transmission was resumed in the absence of vector control whereas no infective female mosquitoes were detected in the villages with vector control. Vector control, though obviously not cost-effective in the short term, could play an important role in an integrated programme, by preventing re-establishment of transmission after chemotherapy is completed.

Antiepileptic hypersensitivity syndrome in children

OBJECTIVE

To assess clinical features and outcomes of childhood antiepileptic hypersensitivity syndrome (AHS). AHS is an idiosyncratic reaction to aromatic anticonvulsants that can result in severe multiorgan dysfunction and death.

METHODS

Children with suspected AHS (fever, rash, lymphadenopathy, liver dysfunction) were identified by an in-house computerized adverse drug event reporting system. The medical charts of children with suspected AHS were reviewed. A MEDLINE search (from 1966 to October 1999) was performed using the term antiepileptic hypersensitivity syndrome.

RESULTS

Fourteen of 36 children who experienced a rash, urticaria, pruritus, fever, or hepatotoxicity associated with aromatic anticonvulsants met the criteria for AHS (mean age 10.4 +/- 6.5 y; males to females 8:6, white to African-American to biracial 10:3:1). Eight patients were receiving phenytoin, six carbamazepine, and four phenobarbital alone or in combination. The mean time from exposure to development of symptoms was 23.0 +/- 14.8 days. In addition to rash and fever (present in all patients by definition), other common features of AHS were lymphocytosis (71.4%), elevated erythrocyte sedimentation rate (64.3%), elevated aminotransferases (64.3%), lymphadenopathy (57.1%), eosinophilia (42.8%, coagulopathy (42.8%), leukocytosis (35.7%), leukopenia (35.7%), hyperbilirubinemia (35.7%), and nephritis (7.1%). All children recovered except one, who died from complications of liver failure. Clinical outcome was simimlar between children who received systemic steroid therapy (n=5) and those who did not. Antiepileptics producing AHS were discontinued in all patients.

CONCLUSIONS

AHS can be fatal in children if not promptly recognized. Fever, rash, and hepatotoxicity should serve as presumptive evidence for AHS, which requires immediate discontinuation of an offending anticonvulsant.

Possible atypical cross-sensitivity between phenytoin and carbamazepine in the anticonvulsant hypersensitivity syndrome

Anticonvulsant hypersensitivity syndrome (AHS) is a rare but potentially life-threatening reaction that occurs in response to common anticonvulsants in predisposed individuals. It is often characterized by fever, rash, lymphadenopathy, hepatitis, and laboratory abnormalities. Consequently, it often is overlooked or even misdiagnosed by practitioners unfamiliar with AHS. Cross-sensitivity manifests frequently between phenytoin, phenobarbital, and carbamazepine as an exacerbation of presenting signs and symptoms. We report a case of AHS in a patient whose clinical features changed significantly when switching from phenytoin to carbamazepine. Physicians and pharmacists must become aware of the extreme variability in AHS manifestation so that the offending anticonvulsant regimen can be discontinued in a timely manner.