Clinical and parasitological characteristics of puerperal malaria.
BACKGROUND
Women with semi-immunity to malaria who live in regions where the disease is endemic are at increased risk for more frequent and severe episodes of malaria during pregnancy. Recent findings indicate that this increased risk might persist beyond delivery, but the underlying mechanisms for this change in risk are poorly understood.


METHODS
One hundred fifty women were included in a cohort study in Lambaréné, Gabon, and were actively followed up weekly for 10 weeks after delivery, as were nonpregnant control women who had been matched to them by location and age. Parasites in samples of placenta and blood were genotyped by use of polymerase chain reaction amplification of the merozoite surface antigen 2 gene and the subtelomeric variable open reading frame gene of Plasmodium falciparum.


RESULTS
Eleven puerperal women had cases of clinical malaria, compared with 1 control woman (rate ratio, 9.8; P=.006). Eighteen puerperal women had P. falciparum parasitemia, compared with 6 control women (rate ratio, 2.7; P=.03). Five of 16 puerperal women (31%) with parasitemia on follow-up had identical parasites in their placentas and blood, and 11 of these cases (69%) were the result of reinfection. Puerperal women remained at equal risk for the development of parasitemia throughout the first 10 weeks after delivery. Use of bed nets, use of chloroquine prophylaxis during pregnancy, presence of malaria episodes during pregnancy, gravidity, and age were not associated with the acquisition of parasitemia during follow-up.


CONCLUSIONS
Compared with nonpregnant women, puerperal women have a considerably increased risk for the development of malaria and/or parasitemia. This increased risk is caused both by the recurrence of P. falciparum parasitemia and by the increased susceptibility to new infections, although the latter plays a more significant role.
Ramharter
Michael
M
Medical Research Unit, Albert Schweitzer Hospital, Lambaréné, Gabon, Germany. michael.ramharter@meduniwien.ac.at
Grobusch
Martin P
MP
Kiessling
Georg
G
Adegnika
Ayola A
AA
Möller
Ulrike
U
Agnandji
Selidji T M
ST
Kramer
Martin
M
Schwarz
Norbert
N
Kun
Jürgen F J
JF
Oyakhirome
Sunny
S
Issifou
Saadou
S
Borrmann
Steffen
S
Lell
Bertrand
B
Mordmüller
Benjamin
B
Kremsner
Peter G
PG
D000328:Adult; D000818:Animals; D001769:Blood / Q000469:parasitology; D015331:Cohort Studies; D005260:Female; D005681:Gabon / Q000453:epidemiology; D005838:Genotype; D006801:Humans; D015994:Incidence; D016778:Malaria, Falciparum / Q000453:epidemiology* / Q000469:parasitology / Q000503:physiopathology*; D018512:Parasitemia / Q000453:epidemiology / Q000469:parasitology; D010920:Placenta / Q000469:parasitology; D010963:Plasmodium falciparum / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D049590:Postpartum Period; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000453:epidemiology; D011446:Prospective Studies; D011645:Puerperal Infection / Q000453:epidemiology* / Q000469:parasitology / Q000503:physiopathology*; D012307:Risk Factors