title: The impact of low erythrocyte density in human blood on the fitness and energetic reserves of the African malaria vector Anopheles gambiae.
abstract: BACKGROUND
  Anaemia is a common health problem in the developing world. This condition is characterized by a reduction in erythrocyte density, primarily from malnutrition and/or infectious diseases such as malaria. As red blood cells are the primary source of protein for haematophagous mosquitoes, any reduction could impede the ability of mosquito vectors to transmit malaria by influencing their fitness or that of the parasites they transmit. The aim of this study was to determine the impact of differences in the density of red blood cells in human blood on malaria vector (Anopheles gambiae sensu stricto) fitness. The hypotheses tested are that mosquito vector energetic reserves and fitness are negatively influenced by reductions in the red cell density of host human blood meals commensurate with those expected from severe anaemia.
  
  
  METHODS
  Mosquitoes (An. gambiae s.s.) were offered blood meals of different packed cell volume (PCV) of human blood consistent with those arising from severe anaemia (15%) and normal PCV (50%). Associations between mosquito energetic reserves (lipid, glucose and glycogen) and fitness measures (reproduction and survival) and blood meal PCV were investigated.
  
  
  RESULTS
  The amount of protein that malaria vectors acquired from blood feeding (indexed by haematin excretion) was significantly reduced at low blood PCV. However, mosquitoes feeding on blood of low PCV had the same oviposition rates as those feeding on blood of normal PCV, and showed an increase in egg production of around 15%. The long-term survival of An. gambiae s.s was reduced after feeding on low PCV blood, but PCV had no significant impact on the proportion of mosquitoes surviving through the minimal period required to develop and transmit malaria parasites (estimated as 14 days post-blood feeding). The impact of blood PCV on the energetic reserves of mosquitoes was relatively minor.
  
  
  CONCLUSIONS
  These results suggest that feeding on human hosts whose PCV has been depleted due to severe anaemia does not significantly reduce the fitness or transmission potential of malaria vectors, and indicates that mosquitoes may be able exploit resources for reproduction more efficiently from blood of low rather than normal PCV.
authors: Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary & Life Sciences, University of Glasgow, Sir Graeme Davies Building, 120 University Place, Glasgow, UK. Noushin.Emami@glasgow.ac.uk
authors: S Noushin
authors: SN
authors: Emami
authors: Lisa C
authors: LC
authors: Ranford-Cartwright
authors: Heather M
authors: HM
authors: Ferguson
mesh_terms: D000740:Anemia; D000818:Animals; D000852:Anopheles / Q000737:chemistry / Q000502:physiology*; D004912:Erythrocytes / Q000378:metabolism*; D005247:Feeding Behavior; D005947:Glucose / Q000032:analysis; D006003:Glycogen / Q000032:analysis; D008055:Lipids / Q000032:analysis; D012726:Sexual Behavior, Animal; D016019:Survival Analysis
chemical_list: D008055:Lipids; D006003:Glycogen; D005947:Glucose
references: J Am Mosq Control Assoc. 1986 Mar;2(1):61-2
references: 3507471
references: J Med Entomol. 2003 Sep;40(5):657-63
references: 14596279
references: Med Vet Entomol. 1995 Apr;9(2):176-80
references: 7787226
references: Annu Rev Entomol. 1998;43:519-43
references: 9444756
references: Anim Behav. 2011 Apr 1;81(4):765-774
references: 21499504
references: Trans R Soc Trop Med Hyg. 2009 May;103(5):493-6
references: 19027130
references: Br Med J. 1898 Feb 26;1(1939):550-1
references: 20757668
references: J Med Entomol. 1975 Jun 30;12(2):220-5
references: 240030
references: Trends Parasitol. 2005 Dec;21(12):573-80
references: 16236552
references: Insect Biochem Mol Biol. 2011 Jun;41(6):349-55
references: 21320598
references: J Am Mosq Control Assoc. 1988 Dec;4(4):549-50
references: 3225576
references: Exp Gerontol. 2011 May;46(5):369-75
references: 20970491
references: Aging Cell. 2008 Aug;7(4):470-7
references: 18346215
references: Malar J. 2007 Aug 21;6:113
references: 17711580
references: J Med Entomol. 1990 Sep;27(5):839-50
references: 2231621
references: Med Vet Entomol. 1993 Oct;7(4):328-32
references: 8268486
references: Exp Parasitol. 1977 Apr;41(2):397-404
references: 403087
references: Lifetime Data Anal. 1995;1(3):255-73
references: 9385105
references: Malar J. 2010 Aug 26;9:243
references: 20796288
references: J Theor Biol. 1983 Dec 21;105(4):661-77
references: 6672475
references: J Obstet Gynaecol. 2008 Nov;28(8):775-8
references: 19085542
references: Methods Mol Biol. 1993;21:67-88
references: 8220736
references: Proc Biol Sci. 2003 Jul 7;270(1522):1365-71
references: 12965027
references: Parasitology. 1992 Oct;105 ( Pt 2):159-63
references: 1454415
references: Trans R Soc Trop Med Hyg. 1979;73(4):418-23
references: 555069
references: Trends Parasitol. 2001 Aug;17(8):363-8
references: 11685895
references: J Am Mosq Control Assoc. 1985 Sep;1(3):302-4
references: 2906672
references: J Med Entomol. 2010 Sep;47(5):769-77
references: 20939369
references: Nature. 1964 Dec 19;204:1173-5
references: 14268587
references: Br J Haematol. 1998 Dec;103(3):817-24
references: 9858238
references: East Afr Med J. 1995 Jan;72(1):10-4
references: 7781547
references: J Am Mosq Control Assoc. 1985 Sep;1(3):299-301
references: 2906671
references: J Parasitol. 2006 Dec;92(6):1191-5
references: 17304793
references: Malar J. 2010 Aug 07;9:225
references: 20691104
references: Eur J Haematol. 2000 Nov;65(5):285-96
references: 11092458
references: Annu Rev Entomol. 1995;40:443-74
references: 7810991
references: Parasitol Today. 1987 Jul;3(7):216-8
references: 15462959
references: Exp Gerontol. 1999 Apr;34(2):173-84
references: 10363785
references: Parasitology. 2001 May;122(Pt 5):491-6
references: 11393821
references: Parasitology. 2003 Jul;127(Pt 1):9-19
references: 12885184
references: J Insect Physiol. 2011 Jan;57(1):1-11
references: 20920508
references: Med Vet Entomol. 2004 Jun;18(2):108-15
references: 15189235