title: A High Malaria Prevalence Identified by PCR among Patients with Acute Undifferentiated Fever in India.
abstract: BACKGROUND
  Approximately one million malaria cases were reported in India in 2015, based on microscopy. This study aims to assess the malaria prevalence among hospitalised fever patients in India identified by PCR, and to evaluate the performance of routine diagnostic methods.
  
  
  METHODS
  During June 2011-December 2012, patients admitted with acute undifferentiated fever to seven secondary level community hospitals in Assam (Tezpur), Bihar (Raxaul), Chhattisgarh (Mungeli), Maharashtra (Ratnagiri), Andhra Pradesh (Anantapur) and Tamil Nadu (Oddanchatram and Ambur) were included. The malaria prevalence was assessed by polymerase chain reaction (PCR), routine microscopy, and a rapid diagnostic test (RDT) with PCR as a reference method.
  
  
  RESULTS
  The malaria prevalence by PCR was 19% (268/1412) ranging from 6% (Oddanchatram, South India) to 35% (Ratnagiri, West India). Among malaria positive patients P. falciparum single infection was detected in 46%, while 38% had P. vivax, 11% mixed infections with P. falciparum and P. vivax, and 5% P. malariae. Compared to PCR, microscopy had sensitivity of 29% and specificity of 98%, while the RDT had sensitivity of 24% and specificity of 99%.
  
  
  CONCLUSIONS
  High malaria prevalence was identified by PCR in this cohort. Routine diagnostic methods had low sensitivity compared to PCR. The results suggest that malaria is underdiagnosed in rural India. However, low parasitaemia controlled by immunity may constitute a proportion of PCR positive cases, which calls for awareness of the fact that other pathogens could be responsible for the febrile disease in submicroscopic malaria.
authors.affiliation: National Centre for Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Norway.
authors.forename: Christel Gill
authors.initials: CG
authors.lastname: Haanshuus
authors.affiliation: Infectious Diseases Training and Research Center, Department of Medicine Unit-1 and Infectious Diseases, Christian Medical College, Vellore, India.
authors.forename: Sara
authors.initials: S
authors.lastname: Chandy
authors.affiliation: Infectious Diseases Training and Research Center, Department of Medicine Unit-1 and Infectious Diseases, Christian Medical College, Vellore, India.
authors.forename: Anand
authors.initials: A
authors.lastname: Manoharan
authors.affiliation: Infectious Diseases Training and Research Center, Department of Medicine Unit-1 and Infectious Diseases, Christian Medical College, Vellore, India.
authors.forename: Rosario
authors.initials: R
authors.lastname: Vivek
authors.affiliation: Infectious Diseases Training and Research Center, Department of Medicine Unit-1 and Infectious Diseases, Christian Medical College, Vellore, India.
authors.forename: Dilip
authors.initials: D
authors.lastname: Mathai
authors.affiliation: Infectious Diseases Training and Research Center, Department of Medicine Unit-1 and Infectious Diseases, Christian Medical College, Vellore, India.
authors.forename: Deepika
authors.initials: D
authors.lastname: Xena
authors.affiliation: Baptist Christian Hospital, Tezpur, Assam, India.
authors.forename: Ashita
authors.initials: A
authors.lastname: Singh
authors.affiliation: National Centre for Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Norway.|Department of Clinical Science, University of Bergen, Bergen, Norway.
authors.forename: Nina
authors.initials: N
authors.lastname: Langeland
authors.affiliation: National Centre for Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Norway.|Department of Clinical Science, University of Bergen, Bergen, Norway.
authors.forename: Bjørn
authors.initials: B
authors.lastname: Blomberg
authors.affiliation: Infectious Diseases Training and Research Center, Department of Medicine Unit-1 and Infectious Diseases, Christian Medical College, Vellore, India.
authors.forename: George
authors.initials: G
authors.lastname: Vasanthan
authors.affiliation: Infectious Diseases Training and Research Center, Department of Medicine Unit-1 and Infectious Diseases, Christian Medical College, Vellore, India.
authors.forename: Usha
authors.initials: U
authors.lastname: Sitaram
authors.affiliation: Christian Fellowship Hospital, Oddanchatram, Tamil Nadu, India.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Appasamy
authors.affiliation: Bethesda Hospital, Ambur, Tamil Nadu, India.
authors.forename: Joel
authors.initials: J
authors.lastname: Nesaraj
authors.affiliation: Christian Hospital, Mungeli, Chhattisgarh, India.
authors.forename: Anil
authors.initials: A
authors.lastname: Henry
authors.affiliation: B.K.L. Walawalkar Hospital, Ratnagiri, Maharashtra, India.
authors.forename: Suvarna
authors.initials: S
authors.lastname: Patil
authors.affiliation: Rural Development Trust Hospital, Anantapur, Andhra Pradesh, India.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Alvarez-Uria
authors.affiliation: Duncan Hospital, Raxaul, Bihar, India.
authors.forename: Lois
authors.initials: L
authors.lastname: Armstrong
authors.affiliation: National Centre for Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Norway.
authors.forename: Kristine
authors.initials: K
authors.lastname: Mørch
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003955:Diagnostic Tests, Routine; D005260:Female; D005334:Fever / Q000469:parasitology*; D005843:Geography; D006760:Hospitalization; D006801:Humans; D007194:India; D016778:Malaria, Falciparum / Q000175:diagnosis / Q000453:epidemiology*; D016780:Malaria, Vivax / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D008403:Mass Screening; D008853:Microscopy; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012680:Sensitivity and Specificity; D055815:Young Adult