TY - JOUR
T1 - Risk associated with asymptomatic parasitaemia occurring post-antimalarial treatment
AU - Olliaro, Piero
AU - Pinoges, Loretxu
AU - Checchi, Francesco
AU - Vaillant, Michel
AU - Guthmann, Jean Paul
PY - 2008/1
Y1 - 2008/1
N2 - Objective: Parasites may recur asymptomatically after initial clearance by antimalarial treatment. Current guidelines recommend treatment only when patients develop symptoms or at the end of follow-up. We wanted to assess prospectively the probability of becoming symptomatic and the risks of this practice. Methods: We analysed data collected in 13 trials of uncomplicated paediatric malaria conducted in eight sub-Saharan African countries. These studies followed all cases of post-treatment asymptomatic parasitaemia until they developed symptoms or to the end of the 28-day follow-up period, at which time parasite genotypes were compared to pre-treatment isolates to distinguish between recrudescences and new infections. Results: There were 425 asymptomatic recurrences after 2576 treatments with either chloroquine, sulfadoxine/ pyrimethamine or amodiaquine, of which 225 occurred by day 14 and 200 between day 15 and day 28. By day 28, 42% developed fever (median time to fever = 5 days) and 30% remained parasitaemic but afebrile, while 23% cleared their parasites (outcome unknown in 4%). Young age, parasitaemia ≥500 parasites/μl; onset of parasitaemia after day 14, and treatment with amodiaquine were the main variables associated with higher risk of developing fever. Conclusion: In areas of moderate to intense transmission, asymptomatic recurrences of malaria after treatment carry a substantial risk of becoming ill within a few days and should be treated as discovered. Young children are at higher risk. The higher risk carried by cases occurring in the second half of follow-up may be explained by falling residual drug levels.
AB - Objective: Parasites may recur asymptomatically after initial clearance by antimalarial treatment. Current guidelines recommend treatment only when patients develop symptoms or at the end of follow-up. We wanted to assess prospectively the probability of becoming symptomatic and the risks of this practice. Methods: We analysed data collected in 13 trials of uncomplicated paediatric malaria conducted in eight sub-Saharan African countries. These studies followed all cases of post-treatment asymptomatic parasitaemia until they developed symptoms or to the end of the 28-day follow-up period, at which time parasite genotypes were compared to pre-treatment isolates to distinguish between recrudescences and new infections. Results: There were 425 asymptomatic recurrences after 2576 treatments with either chloroquine, sulfadoxine/ pyrimethamine or amodiaquine, of which 225 occurred by day 14 and 200 between day 15 and day 28. By day 28, 42% developed fever (median time to fever = 5 days) and 30% remained parasitaemic but afebrile, while 23% cleared their parasites (outcome unknown in 4%). Young age, parasitaemia ≥500 parasites/μl; onset of parasitaemia after day 14, and treatment with amodiaquine were the main variables associated with higher risk of developing fever. Conclusion: In areas of moderate to intense transmission, asymptomatic recurrences of malaria after treatment carry a substantial risk of becoming ill within a few days and should be treated as discovered. Young children are at higher risk. The higher risk carried by cases occurring in the second half of follow-up may be explained by falling residual drug levels.
KW - Asymptomatic parasitaemia
KW - Malaria
KW - Malaria treatment
UR - http://www.scopus.com/inward/record.url?scp=39449104831&partnerID=8YFLogxK
U2 - 10.1111/j.1365-3156.2007.01977.x
DO - 10.1111/j.1365-3156.2007.01977.x
M3 - Article
C2 - 18291006
AN - SCOPUS:39449104831
SN - 1360-2276
VL - 13
SP - 83
EP - 90
JO - Tropical Medicine and International Health
JF - Tropical Medicine and International Health
IS - 1
ER -