Immune responses after single-dose sulphadoxine-pyrimethamine indicate underestimation of protective efficacy of intermittent preventive treatment in infants.
OBJECTIVE
To assess how intermittent preventive treatment in infants (IPTi) with sulphadoxine-pyrimethamine (SP) affects Immunoglobulin (IgG) immune responses against Plasmodium falciparum in infants from rural Ghana.


METHODS
Randomized, placebo-controlled and double-blinded clinical trial with participants randomized in blocks of 10 to receive either 250 mg sulphadoxine/2.5 mg pyrimethamine or placebo at the age of 3 (IPTi-1), 9 (IPTi-2) and 15 (IPTi-3) months and followed-up for 21 months. (i) Anti-P. falciparum IgG levels were measured in 180 children at the age of 9 months. (ii) Longitudinal study of the relationship between IgG levels and P. falciparum infections and/or clinical malaria in 17 naive children until they reached the age of 2 years.


RESULTS
IgG antibody levels against crude P. falciparum lysate were dependent on the frequency of preceding infections and significantly lower in children treated with SP.


CONCLUSIONS
Placebo-treated children had an indifferentially higher incidence of P. falciparum infections than clinically observed, which implicates an underestimation of the protective efficacy of IPTi. IgG profiles in 17 children followed up until the age of 2 years provided no evidence for impaired immune responses after a single dose of SP within the framework of IPTi.
Schreiber
Nadine
N
Infectious Disease Epidemiology Group, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
Kobbe
Robin
R
Adjei
Samuel
S
Adjei
Ohene
O
Klinkert
Mo-Quen
MQ
May
Jürgen
J
D000818:Animals; D000962:Antimalarials / Q000627:therapeutic use*; D002648:Child; D004311:Double-Blind Method; D004338:Drug Combinations; D005869:Ghana / Q000453:epidemiology; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D015994:Incidence; D007223:Infant; D016778:Malaria, Falciparum / Q000453:epidemiology / Q000276:immunology* / Q000517:prevention & control; D010963:Plasmodium falciparum; D011739:Pyrimethamine / Q000627:therapeutic use*; D013413:Sulfadoxine / Q000627:therapeutic use*
D000962:Antimalarials; D004338:Drug Combinations; D007074:Immunoglobulin G; C001205:fanasil, pyrimethamine drug combination; D013413:Sulfadoxine; D011739:Pyrimethamine