title: Severe Plasmodium vivax infection in Korea.
abstract: Although severe malaria by Plasmodium vivax has been increasingly reported, there are marked variations in the type and rate of the complications by geographic area. This is possibly because of the presence of concurrent falciparum malaria or bacteraemia, and of differences in underlying immune status among the infected subjects. Furthermore, published studies on P. vivax in temperate regions are limited. The present study investigated severe vivax malaria in Korea, where only vivax malaria occurs. Hence, other compounding factors are rare. Additionally, most of the patients are possibly non-immune to this malarial disease.
  
  
  
  Adults with vivax malaria observed in one 860-bed university hospital from January 2006 to December 2012 were retrospectively evaluated. Seventeen patients who had travelled overseas within 6 months before the presentation of malaria were excluded. Severe vivax malaria was diagnosed according to World Health Organization criteria. Other complications were also investigated.
  
  
  
  Two-hundred and ten patients were enrolled, of which 88 (41.9%) were treated as inpatients and the remainder as outpatients. Eleven patients were treated in an intensive care unit; among them, five patients received mechanical ventilation, and one needed extracorporeal membrane oxygenation therapy (ECMO) additionally. Severe vivax malaria was identified in 44 patients (21.0%), and the most common severe complication was pulmonary manifestation (40/188, 21.9%), which was followed by cerebral malaria (5/210, 2.4%), shock (4/210, 1.9%), spontaneous bleeding (3/210, 1.4%), metabolic acidosis (3/210, 3.5%) and acute kidney injury (2/210, 1.0%). Unusual complications, such as splenic infarction (ten patients) and retinal haemorrhage (two patients) were sometimes observed. There were no deaths, but the case involving ECMO was potentially fatal.
  
  
  
  Plasmodium vivax infection can be severe to be fatal and is frequently associated with various complications in non-immune adults. The frequency of each complication seems to differ from other countries. Hence, further investigation is needed to elucidate the causes and mechanisms responsible for these differences.
authors.affiliation: Department of Internal Medicine, Inha University School of Medicine, Incheon, 400-711, South Korea. dylife83@naver.com.
authors.forename: Jae Hyoung
authors.initials: JH
authors.lastname: Im
authors.affiliation: Department of Internal Medicine, Inha University School of Medicine, Incheon, 400-711, South Korea.
authors.forename: Hea Yoon
authors.initials: HY
authors.lastname: Kwon
authors.affiliation: Department of Internal Medicine, Inha University School of Medicine, Incheon, 400-711, South Korea.
authors.forename: JiHyeon
authors.initials: J
authors.lastname: Baek
authors.affiliation: Department of Internal Medicine, Inha University School of Medicine, Incheon, 400-711, South Korea.
authors.forename: Seong Wook
authors.initials: SW
authors.lastname: Park
authors.affiliation: Department of Emergency Medicine, Incheon, 400-711, South Korea.
authors.forename: Areum
authors.initials: A
authors.lastname: Durey
authors.affiliation: Department of Radiology, Inha University School of Medicine, 7-206, Shinheung-Dong, Jung-Gu, Incheon, 400-711, South Korea.
authors.forename: Kyung Hee
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Jeju University Hospital, Jeju, South Korea.
authors.forename: Moon-Hyun
authors.initials: MH
authors.lastname: Chung
authors.affiliation: Department of Internal Medicine, Inha University School of Medicine, Incheon, 400-711, South Korea. ljinsoo@inha.ac.kr.
authors.forename: Jin-Soo
authors.initials: JS
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006785:Hospitals, University; D006801:Humans; D015994:Incidence; D016780:Malaria, Vivax / Q000150:complications / Q000453:epidemiology* / Q000469:parasitology; D008297:Male; D008875:Middle Aged; D010966:Plasmodium vivax / Q000502:physiology*; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D055815:Young Adult
keywords: Acute kidney injury; Malaria; Mortality; Plasmodium vivax; Pulmonary oedema