Severe morbidity and mortality risk from malaria in the United States, 1985-2011.
BACKGROUND
Recent reports of Plasmodium vivax associated with severe syndromes and mortality from malaria endemic areas questions the "benign" course of non-falciparum malarias.


METHODS
We retrospectively analyzed data from patients reported to the US Centers for Disease Control and Prevention with a diagnosis of malaria parasite single-species infection between 1985 and 2011. Patients classified as having severe illness were further classified according to outcome (survival versus death) and clinical syndrome.


RESULTS
Among all cases, .9% of Plasmodium falciparum cases resulted in death and 9.3% were classified as severe, whereas .09% of P. vivax cases resulted in death and 1.3% were classified as severe. The odds ratios for severe illness among 15 272 diagnoses of P. falciparum relative to patients diagnosed with P. vivax (n = 12 152), Plasmodium malariae (n = 1254), or Plasmodium ovale (n = 903) was 7.5, 5.7, and 5.0, respectively (P < .0001 for all); in contrast, the corresponding odds ratios for death among those severely ill was 1.6, 1.1, and .8 (P > .1 for all), respectively. Compared with P. vivax (n = 163), the odds of P. falciparum cases classified as severely ill (n = 1416) were 1.9 (P = .0006), .5 (P = .001), and 1.3 times (P = .1) as likely to present as cerebral, acute respiratory distress, and renal syndromes, respectively.


CONCLUSIONS
Although less common, patients presenting with non-falciparum even in the United States can develop severe illness, and severe illness in patients having malaria of any species threatens life.
Malaria Branch , Centers for Disease Control and Prevention , Atlanta , Georgia ; Global Health Group , University of California , San Francisco , California.
Jimee
J
Hwang
Malaria Branch , Centers for Disease Control and Prevention , Atlanta , Georgia.
Karen A
KA
Cullen
Malaria Branch , Centers for Disease Control and Prevention , Atlanta , Georgia.
S Patrick
SP
Kachur
Malaria Branch , Centers for Disease Control and Prevention , Atlanta , Georgia.
Paul M
PM
Arguin
Eijkman-Oxford Clinical Research Unit , Jakarta , Indonesia ; Centre for Tropical Medicine, Nuffield Department of Medicine , University of Oxford , United Kingdom.
J Kevin
JK
Baird
Plasmodium; USA; morbidity; mortality; species