A randomized, parallel study of the safety and efficacy of 45 mg primaquine versus 75 mg bulaquine as gametocytocidal agents in adults with blood schizonticide-responsive uncomplicated falciparum malaria [ISCRTN50134587]

BACKGROUND

The WHO recommends that adults with uncomplicated P. falciparum successfully treated with a blood schizonticide receive a single dose of primaquine (PQ) 45 mg as a gametocytocidal agent. An earlier pilot study suggested that 75 mg of bulaquine (BQ), of which PQ is a major metabolite, may be a useful alternate to PQ.

METHODS

In a randomized, partial blind study, 90 hospitalized adults with Plasmodium falciparum malaria that was blood schizonticide-responsive and a gametocytemia of > 55/microl within 3 days of diagnosis were randomized to receive single doses of either PQ 45 mg or BQ 75 mg on day 4. We assessed gametocytemia on days 8, 15, 22 and 29 and gametocyte viability as determined by exflagellation (2 degrees end point) on day 8.

RESULTS

On day 8, 20/31 (65%) primaquine recipients versus 19/59 (32%) bulaquine recipients showed persistence of gametocytes (P = 0.002). At day 15 and beyond, all patients were gametocyte free. On day 8, 16/31 PQ and 7/59 BQ volunteers showed gametocyte viability (p = 0.000065).

CONCLUSION

BQ is a safe, useful alternate to PQ as a Plasmodium falciparum gametocytocidal agent and may clear gametocytemia faster than PQ.

A prospective study evaluating the efficacy of a single, 45-mg dose of primaquine, as a gametocytocidal agent, in patients with Plasmodium falciparum malaria in Mumbai, India

The efficacy of a single dose of 45 mg primaquine, as a gametocytocidal agent, was assessed in Mumbai, India, among adults with uncomplicated or severe Plasmodium falciparum malaria. All the patients investigated had been found gametocytaemic, with at least 56 gametocytes/microl blood, within the first 72 h of their illness. Those with uncomplicated malaria, like those with severe malaria, were randomized to receive or not receive primaquine. All the patients were followed up for 29 days post-admission, for gametocytaemia and gametocyte viability (as determined by exflagellation). Among those with uncomplicated malaria, six (27.3%) of the 22 who did not receive primaquine but only one (4.2%) of the 24 who did receive the drug, on day 4, remained gametocytaemic on day 29 (P < 0.05). Similarly, seven (31.8%) of the 22 severe cases who did not receive primaquine but only two (9.5%) of the 21 severe cases who received the drug, on day 8, were found gametocytaemic on day 15 (P < 0.05). While the single, 45-mg dose of primaquine recommended by the World Health Organization was effective in clearing gametocytes from the blood of > 90% of the present cases of malaria, > 4% of the patients with uncomplicated malaria and > 9% of those with the severe disease continued to harbour gametocytes in their peripheral blood 29 and 15 days after taking the primaquine, respectively.

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.

Diagnostic and prognostic utility of rapid strip (OptiMal and Paracheck) versus conventional smear microscopy in adult patients of acute, uncomplicated P. falciparum malaria in Mumbai, India

OBJECTIVES

The present study compared the diagnostic and prognostic utility of two rapid tests the (Paracheck and OptiMal) versus conventional smear microscopy.

METHODS

Using two independent microscopists we carried out the three tests in 31 adult cases of smear positive, acute, uncomplicated Plasmodium falciparum malaria. All three tests were done pretreatment, and on Days 8, 15 and 29.

RESULTS

Compared to microscopy, the Paracheck had a sensitivity of 100%, while the OptiMal had a sensitivity of 83.7%. The lower sensitivity of OptiMal resulted from misidentification by both microscopists of 6/31 cases as Plasmodium vivax. As a follow up tool, the OptiMal was better than Paracheck, due to the earlier disappearance of the parasite LDH. Also in the Paracheck, between microscopists, there was a significant difference in reading the tests, on Days 8 and 15.

CONCLUSION

Our study reiterates, the continued utility of conventional smear microscopy.

Seroprevalence of human immunodeficiency virus infection in an infectious disease hospital

AIMS AND OBJECTIVES

To analyse clinicopathological features of HIV infected patients admitted in an infectious disease hospital in Mumbai.

MATERIAL AND METHODS

Retrospective study of 501 patients admitted from 1st September, 1996 to 28th February, 1998 and screened for HIV status out of clinical suspicion was carried out. HIV seropositivity was established by double confirmation of spot test results with microwell Elisa test.

RESULTS

HIV seropositivity was seen in 39.92%. Out of these 94% were adults with male preponderance and 96.5% had only HIV-1 infection. The significant clinical features in HIV positive patients were chronic diarrhea (51.5%), prolonged fever (41.5%) and history of exposure (34%). Pulmonary tuberculosis could be diagnosed in 19.5% of HIV positive patients. In patients with prolonged/recurrent jaundice HBsAg and HIV was noted as a coinfection within 10/42 cases tested.

CONCLUSIONS

Increasing prevalence of HIV seropositivity was noted in patients admitted to an infectious disease hospital. Association of HIV infection with tuberculosis and in icteric cases with HBsAg was significant. The HIV screening should be carried out in patients with prolonged illness resistant to usual mode of treatment.