Relapse pattern of Plasmodium vivax in Kheda district, Gujarat

A study on relapse pattern of P. vivax in Kheda district of Gujarat revealed that the relapse rate in P. vivax within 8 months of primary attack was around 40% in untreated cases. It was 2.6% within one year in patients treated with 5-day course of primaquine. Relapses occurred more frequently from April to October and 82% relapses occurred within one year of the primary attack. Relapses occurred up to 4 years after primary attack but they were less frequent in 3rd and 4th year.