Efficacy and tolerability of treatment with single doses of diethylcarbamazine (DEC) and DEC plus albendazole (ABZ) for three consecutive years in lymphatic filariasis: a field study in India

Lymphatic filariasis (LF) affects 73 countries, causes morbidity and impedes socioeconomic development. We had found no difference in safety and micro (Mf) and macro filarial action of single-dose diethylcarbamazine (DEC) and DEC + albendazole (ABZ) in an F01 study done in India (year 2000). There was a programmatic need to evaluate safety and efficacy of multiple annual treatments (F02). Subjects (155) from the F01 study, meeting inclusion-exclusion criteria, were enrolled in F02 and treated with further two annual doses of DEC or DEC + ABZ. Efficacy was evaluated for Mf positivity by peripheral smear (PS) and nucleopore (NP) filter, circulating filarial antigen (CFA) and filarial dance sign (FDS) positivity and Mf count at yearly follow-up. Safety was assessed for 5 days after drug administration. Total of 139 subjects evaluated for efficacy (69 DEC and 70 DEC + ABZ group). Mf positivity prevalence declined progressively by 95% (PS), 66% (NP), and 95% (PS) and 86% (NP); CFA positivity prevalence declined by 15% and 9%; FDS by 100% each; Mf count declined by 75.5 and 76.9% with three annual treatment of DEC and DEC + ABZ, respectively. Addition of ABZ did not show any advantage over DEC given as three annual rounds for LF. DEC and DEC + ABZ were well tolerated. There was no correlation between result of CFA and FDS, (both claimed to be indicative of adult worm). Analysis of published studies and our data indicate that macrofilaricidal effect of DEC/DEC + ABZ may be seen in children and not adults, with three or more annual dosing.

Studies on facile synthesis of polyaniline/cadmium sulfide composites and their morphology

A composite of polyaniline (PANI) and cadmium sulfide (CdS) has been prepared via chemical bath deposition with crystalline structures which is confirmed from the X-ray diffraction (XRD) studies. Scanning electron microscopic studies and XRD have shown that the morphology and crystallinity of the materials in the composite have apparently changed after the formation of composite. The transmission electron microscopic study has revealed that there is an increase in the crystallite size of CdS and its impregnation into the granular pillar-like structure of PANI. The absorption edge of the composite red shifted as compared to that of CdS and blue shifted with respect to that of PANI. Fourier transform infrared spectroscopic studies show a clear shifting of wave numbers indicating the interaction between CdS and PANI due to the strengthening of the C=C bond in PANI.

Efficacy of a 14-day primaquine regimen in preventing relapses in patients with Plasmodium vivax malaria in Mumbai, India

We studied the antirelapse efficacy of a supervised 14-d 15 mg/d regimen of primaquine therapy (n = 131) compared with no antirelapse therapy (n = 142) in 273 patients with confirmed Plasmodium vivax malaria in Mumbai, India, between July 1998 and April 2000. There were 6/131 (4.6%) recurrences in patients given primaquine compared with 13/142 (9.2%) in those not given antirelapse therapy. In the 14-d primaquine group, polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) genotyping analysis of pre- and post-treatment blood samples was done for the 6 patients who had a recurrence of parasitaemia and the results gave a true relapse rate of 2.29% (3/131), 2 samples were classified as reinfections and 1 sample did not amplify. Our results indicate probable resistance to the 14-d regimen of primaquine for the first time in India and illustrate the need to (i) monitor patients given this regimen and (ii) carry out comparative studies between primaquine and new drugs such as tafenoquine and bulaquine for preventing relapses.

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 cost-effectiveness analysis of three antimalarial treatments for acute, uncomplicated Plasmodium falciparum malaria in Mumbai, India

BACKGROUND

Malaria is a major public health problem representing 2.3% of the overall global disease burden. The cost of treatment of malaria continues to rise as older drugs and insecticides become less effective and are replaced by more effective, but also more expensive products.

METHODS

A post-hoc pharmacoeconomic analysis (direct and indirect costs only) of three antimalarials, chloroquine, mefloquine and co-artemether, was carried out to address the problem of switch to a more expensive first-line antimalarial in the face of growing chloroquine resistance.

RESULTS

From the perspective of a large public hospital, it was seen that in an area of high grade chloroquine resistance, the total expenditure on patients who fail chloroquine would exceed the excess expenditure on mefloquine when the RII + RIII resistance exceeded 9%.

CONCLUSIONS

Switch to a more expensive drug like mefloquine as a first-line option would be cost-effective when the moderate-severe chloroquine resistance exceeded 9%.

Relapse pattern of Plasmodium vivax in Mumbai: a study of 283 cases of vivax malaria

OBJECTIVES

To analyze the relapse pattern of Plasmodium vivax in the city of Mumbai.

METHODS

283 cases of smear positive vivax malaria were treated with full dose (25 mg/kg) chloroquine and were asked to follow up for at least one year. None of the patients received primaquine.

RESULTS

Of the 150 cases who followed up for at least one year, 19 relapsed, 17/19 relapsed within the first 6 months; indicating that the relapse pattern in the city is predominantly of the tropical or Chesson strain type.

CONCLUSIONS

Vivax malaria patients should be monitored for at least six months. Those who do relapse should receive treatment with full dose chloroquine and 14 days of primaquine treatment.

A randomized, parallel-group study in Mumbai (Bombay), comparing chloroquine with chloroquine plus sulfadoxine-pyrimethamine in the treatment of adults with acute, uncomplicated, Plasmodium falciparum malaria

A major problem in the control of malaria is the development of resistance, of the parasites to the existing drugs and of the vectors to insecticides. With few new drugs in the pipeline, in an era of declining resources, it is imperative to make judicious use of the existing antimalarials. In the city of Mumbai, resistance exists to chloroquine (CQ) and to sulfadoxine-pyrimethamine (SP). Use of a combination of CQ with SP would theoretically slow down the development of resistance to each of the drugs and increase their useful lives. The effectiveness of this combination in the treatment of adults from Mumbai, who had acute, uncomplicated Plasmodium falciparum malaria, was compared with that of CQ alone. The combination was found to be significantly more effective, in terms of 28- or 42-day cure rates, and to be more cost-effective.

Efficacies of 5- and 14-day primaquine regimens in the prevention of relapses in Plasmodium vivax infections

Vivax malaria accounts for 80% of malaria cases in Mumbai (Bombay) and has high morbidity. In India, the standard treatment to prevent relapses of vivax malaria is a 5-day regimen of primaquine. However, between 1977 and 1997, the efficacy of this treatment declined from approximately 99% to 87%. The efficacy of the 5-day regimen was therefore compared with that of the 14-day regimen currently recommended by the World Health Organization, in Mumbai. The relapse rates observed, over a 6-month period of follow-up, were 0% with the 14-day regimen, 26.7% with the 5-day, and 11.7% when no primaquine treatment was given. The expenditure incurred on the door-to-door dispensing of the 5-day regimen appears to be without benefit. There is an urgent need to review the present strategy for controlling relapses in vivax malaria, at least for the city of Mumbai, and similar studies need to be carried out in other parts of India, to make all anti-relapse strategies more appropriate.