Features and prognosis of severe malaria caused by Plasmodium falciparum, Plasmodium vivax and mixed Plasmodium species in Papua New Guinean children.
BACKGROUND
Mortality from severe pediatric falciparum malaria appears low in Oceania but Plasmodium vivax is increasingly recognized as a cause of complications and death. The features and prognosis of mixed Plasmodium species infections are poorly characterized. Detailed prospective studies that include accurate malaria diagnosis and detection of co-morbidities are lacking.


RESULTS
We followed 340 Papua New Guinean (PNG) children with PCR-confirmed severe malaria (77.1% P. falciparum, 7.9% P. vivax, 14.7% P. falciparum/vivax) hospitalized over a 3-year period. Bacterial cultures were performed to identify co-incident sepsis. Clinical management was under national guidelines. Of 262 children with severe falciparum malaria, 30.9%, 24.8% and 23.2% had impaired consciousness, severe anemia, and metabolic acidosis/hyperlactatemia, respectively. Two (0.8%) presented with hypoglycemia, seven (2.7%) were discharged with neurologic impairment, and one child died (0.4%). The 27 severe vivax malaria cases presented with similar phenotypic features to the falciparum malaria cases but respiratory distress was five times more common (P=0.001); one child died (3.7%). The 50 children with P. falciparum/vivax infections shared phenotypic features of mono-species infections, but were more likely to present in deep coma and had the highest mortality (8.0%; P=0.003 vs falciparum malaria). Overall, bacterial cultures were positive in only two non-fatal cases. 83.6% of the children had alpha-thalassemia trait and seven with coma/impaired consciousness had South Asian ovalocytosis (SAO).


CONCLUSIONS
The low mortality from severe falciparum malaria in PNG children may reflect protective genetic factors other than alpha-thalassemia trait/SAO, good nutrition, and/or infrequent co-incident sepsis. Severe vivax malaria had similar features but severe P. falciparum/vivax infections were associated with the most severe phenotype and worst prognosis.
School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, Fremantle, Western Australia, Australia.
Laurens
L
Manning
Moses
M
Laman
Irwin
I
Law
Cathy
C
Bona
Susan
S
Aipit
David
D
Teine
Jonathan
J
Warrell
Anna
A
Rosanas-Urgell
Enmoore
E
Lin
Benson
B
Kiniboro
John
J
Vince
Ilomo
I
Hwaiwhanje
Harin
H
Karunajeewa
Pascal
P
Michon
Peter
P
Siba
Ivo
I
Mueller
Timothy M E
TM
Davis
D000818:Animals; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008288:Malaria / Q000469:parasitology / Q000473:pathology*; D008297:Male; D010219:Papua New Guinea; D010963:Plasmodium falciparum / Q000472:pathogenicity*; D010966:Plasmodium vivax / Q000472:pathogenicity*; D011379:Prognosis; D011446:Prospective Studies