Identification of hot spots of malaria transmission for targeted malaria control.
BACKGROUND
Variation in the risk of malaria within populations is a frequently described but poorly understood phenomenon. This heterogeneity creates opportunities for targeted interventions but only if hot spots of malaria transmission can be easily identified.


METHODS
We determined spatial patterns in malaria transmission in a district in northeastern Tanzania, using malaria incidence data from a cohort study involving infants and household-level mosquito sampling data. The parasite prevalence rates and age-specific seroconversion rates (SCRs) of antibodies against Plasmodium falciparum antigens were determined in samples obtained from people attending health care facilities.


RESULTS
Five clusters of higher malaria incidence were detected and interpreted as hot spots of transmission. These hot spots partially overlapped with clusters of higher mosquito exposure but could not be satisfactorily predicted by a probability model based on environmental factors. Small-scale local variation in malaria exposure was detected by parasite prevalence rates and SCR estimates for samples of health care facility attendees. SCR estimates were strongly associated with local malaria incidence rates and predicted hot spots of malaria transmission with 95% sensitivity and 85% specificity.


CONCLUSIONS
Serological markers were able to detect spatial variation in malaria transmission at the microepidemiological level, and they have the potential to form an effective method for spatial targeting of malaria control efforts.
Bousema
Teun
T
Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom. teun.bousema@lshtm.ac.uk
Drakeley
Chris
C
Gesase
Samwel
S
Hashim
Ramadhan
R
Magesa
Stephen
S
Mosha
Frank
F
Otieno
Silas
S
Carneiro
Ilona
I
Cox
Jonathan
J
Msuya
Eliapendavyo
E
Kleinschmidt
Immo
I
Maxwell
Caroline
C
Greenwood
Brian
B
Riley
Eleanor
E
Sauerwein
Robert
R
Chandramohan
Daniel
D
Gosling
Roly
R
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D005260:Female; D005843:Geography; D006801:Humans; D015994:Incidence; D007223:Infant; D016778:Malaria, Falciparum / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission*; D010963:Plasmodium falciparum / Q000276:immunology / Q000302:isolation & purification*; D013636:Tanzania / Q000453:epidemiology
D000913:Antibodies, Protozoan