The efficacies of affected-limb care with penicillin, diethylcarbamazine, the combination of both drugs or antibiotic ointment, in the prevention of acute adenolymphangitis during bancroftian filariasis

Repeated attacks of adenolymphangitis (ADL) contribute significantly to the progression of chronic lymphoedema in lymphatic filariasis. They are a cause of stigma and, since they may prevent work and require treatment for which payment must be made, of economic loss. The aim of the present study was to improve the treatment of ADL attacks, which is currently mostly empirical. In a double-blind, placebo-controlled, clinical study, 150 subjects who had each suffered at least two ADL attacks in the preceding year were enrolled and randomly allocated to a programme of self-care of the affected limb (after an intensive training programme) and one of five treatments for 12 months. The subjects were supplied with tablets and ointment so that they could take oral penicillin (800 mg/ day), oral diethylcarbamazine (DEC; 1 mg/kg. day) or both of these drugs (at the same doses), or apply framycetin ointment to the affected limb, or just take placebo tablets and apply placebo (zinc-oxide) ointment. Placebo tablets and placebo ointment were used so that neither the subjects nor those assessing the responses to treatment were aware of the treatment arm to which each subject had been assigned. The subjects were requested to continue with the affected-limb care after they had stopped taking the tablets and applying the cream, and were followed-up for 24 months from the first treatment. Overall, the mean incidence of ADL attacks decreased from 2.7 episodes/person-year in the pre-treatment year to just 0.38 episode/person-year during the treatment year (P<0.01). The greatest reduction in incidence was seen in the 58 subjects who received penicillin (with or without DEC). Even in the placebo group, however, the incidence of ADL in the treatment year was significantly lower than that seen in the pre-treatment year, indicating that affected-limb care on its own helps to prevent some attacks. In all groups except the placebo, the incidence of ADL attacks in the year post-treatment exceeded that seen in the treatment year, indicating that chemoprophylaxis needs to be continued for more than a year if such attacks are to be prevented. In most (84%) of the attacks recorded, titres of anti-streptococcal antibodies were seen to be elevated (compared with those recorded during convalescence), indicating that streptococci have a role in the aetiology of ADL. It is recommended that a combination of penicillin prophylaxis and affected-limb care be incorporated into filariasis-control programmes, to decrease morbidity.