PMID- 18648666
OWN - NLM
STAT- MEDLINE
DCOM- 20080924
LR  - 20211028
IS  - 1932-6203 (Electronic)
IS  - 1932-6203 (Linking)
VI  - 3
IP  - 7
DP  - 2008 Jul 23
TI  - Effect of transmission setting and mixed species infections on clinical measures 
      of malaria in Malawi.
PG  - e2775
LID - 10.1371/journal.pone.0002775 [doi]
LID - e2775
AB  - BACKGROUND: In malaria endemic regions people are commonly infected with multiple 
      species of malaria parasites but the clinical impact of these Plasmodium 
      co-infections is unclear. Differences in transmission seasonality and 
      transmission intensity between endemic regions have been suggested as important 
      factors in determining the effect of multiple species co-infections. PRINCIPAL 
      FINDINGS: In order to investigate the impact of multiple-species infections on 
      clinical measures of malaria we carried out a cross-sectional community survey in 
      Malawi, in 2002. We collected clinical and parasitological data from 2918 
      participants aged >6 months, and applied a questionnaire to measure malaria 
      morbidity. We examined the effect of transmission seasonality and intensity on 
      fever, history of fever, haemoglobin concentration ([Hb]) and parasite density, 
      by comparing three regions: perennial transmission (PT), high intensity seasonal 
      transmission (HIST) and low intensity seasonal transmission (LIST). These regions 
      were defined using multi-level modelling of PCR prevalence data and spatial and 
      geo-climatic measures. The three Plasmodium species (P. falciparum, P. malariae 
      and P. ovale) were randomly distributed amongst all children but not adults in 
      the LIST and PT regions. Mean parasite density in children was lower in the HIST 
      compared with the other two regions. Mixed species infections had lower mean 
      parasite density compared with single species infections in the PT region. Fever 
      rates were similar between transmission regions and were unaffected by mixed 
      species infections. A history of fever was associated with single species 
      infections but only in the HIST region. Reduced mean [Hb] and increased anaemia 
      was associated with perennial transmission compared to seasonal transmission. 
      Children with mixed species infections had higher [Hb] in the HIST region. 
      CONCLUSIONS: Our study suggests that the interaction of Plasmodium co-infecting 
      species can have protective effects against some clinical outcomes of malaria but 
      that this is dependent on the seasonality and intensity of malaria transmission.
FAU - Bruce, Marian C
AU  - Bruce MC
AD  - Division of Infection and Immunity, Institute of Biomedical and Life Sciences, 
      Glasgow Biomedical Research Centre, Glasgow University, Glasgow, United Kingdom. 
      m.bruce@bio.gla.ac.uk
FAU - Macheso, Allan
AU  - Macheso A
FAU - Kelly-Hope, Louise A
AU  - Kelly-Hope LA
FAU - Nkhoma, Standwell
AU  - Nkhoma S
FAU - McConnachie, Alex
AU  - McConnachie A
FAU - Molyneux, Malcolm E
AU  - Molyneux ME
LA  - eng
GR  - WT_/Wellcome Trust/United Kingdom
GR  - 060446/WT_/Wellcome Trust/United Kingdom
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20080723
PL  - United States
TA  - PLoS One
JT  - PloS one
JID - 101285081
RN  - 0 (Hemoglobins)
SB  - IM
MH  - Adult
MH  - Child
MH  - Child, Preschool
MH  - Female
MH  - Hemoglobins/metabolism
MH  - Humans
MH  - Infant
MH  - Malaria/diagnosis/*parasitology/*transmission
MH  - Malawi
MH  - Male
MH  - Polymerase Chain Reaction
MH  - Prevalence
MH  - Seasons
MH  - Species Specificity
MH  - Treatment Outcome
PMC - PMC2467490
COIS- Competing Interests: The authors have declared that no competing interests exist.
EDAT- 2008/07/24 09:00
MHDA- 2008/09/25 09:00
PMCR- 2008/07/23
CRDT- 2008/07/24 09:00
PHST- 2008/02/15 00:00 [received]
PHST- 2008/06/20 00:00 [accepted]
PHST- 2008/07/24 09:00 [pubmed]
PHST- 2008/09/25 09:00 [medline]
PHST- 2008/07/24 09:00 [entrez]
PHST- 2008/07/23 00:00 [pmc-release]
AID - 08-PONE-RA-03648R2 [pii]
AID - 10.1371/journal.pone.0002775 [doi]
PST - epublish
SO  - PLoS One. 2008 Jul 23;3(7):e2775. doi: 10.1371/journal.pone.0002775.