Even in endemic zones, congenital malaria, first described in 1876, is
rarely encountered. The incidence has greatly increased however over
the last 10 years suggesting several diagnostic problems. We observed
a case of infected twins born to an asymptomatic mother which would th
row some light on the pathophysiology involved in congenital transmiss
ion. A 2-month old infant was hospitalized for surgical cure of an omb
ilical hernia. Haemolytic anaemia (6.3 g/dl) and fever (39 degrees C)
were observed during the postoperative period. A wide spectrum antibio
therapy was prescribed but the temperature remained at 39 degrees C, A
blood swab cultured one week after the operation revealed Plasmodium
falciparum. The infant's twin sister was in apparently good health but
was also found to be anaemic (6.1 mg/dl Hg) and a blood sample was po
sitive for P. falciparum. For the mother, the search for parasites was
negative. Serology tests performed at diagnosis revealed anti-P. falc
iparum antibodies at 1/1600, 1/3200 and 1/6400 in the infant, his twin
sister and the mother. Outcome was favourable. The mother had arrived
in France from Togo 14 months earlier and had not returned to an ende
mic zone. She had had frequent episodes of fever in Togo and had taken
quinine, but no episode of fever had occurred during the pregnancy or
delivery. This twin case of vertical mother-infant transmission is th
e equivalent to transfusional malaria since red cells pass the placent
al barrier near the end of pregnancy, even when no placental lesion ex
ists. Congenital transfusional malaria must however be dissociated fro
m congenital infective malaria resulting from early primoinfection in
endemic areas.