Rapid decrease of malaria morbidity following the introduction of community-based monitoring in a rural area of central Vietnam.
BACKGROUND
Despite a successful control programme, malaria has not completely disappeared in Vietnam; it remains endemic in remote areas of central Vietnam, where standard control activities seem to be less effective. The evolution of malaria prevalence and incidence over two and half years in a rural area of central Vietnam, after the introduction of community-based monitoring of malaria cases, is presented.


METHODS
After a complete census, six cross-sectional surveys and passive detection of malaria cases (by village and commune health workers using rapid diagnostic tests) were carried out between March 2004 and December 2006 in Ninh-Thuan province, in a population of about 10,000 individuals. The prevalence of malaria infection and the incidence of clinical cases were estimated.


RESULTS
Malaria prevalence significantly decreased from 13.6% (281/2,068) in December 2004 to 4.0% (80/2,019) in December 2006. Plasmodium falciparum and Plasmodium vivax were the most common infections with few Plasmodium malariae mono-infections and some mixed infections. During the study period, malaria incidence decreased by more than 50%, from 25.7/1,000 population at risk in the second half of 2004 to 12.3/1,000 in the second half of 2006. The incidence showed seasonal variations, with a yearly peak between June and December, except in 2006 when the peak observed in the previous years did not occur.


CONCLUSIONS
Over a 2.5-year follow-up period, malaria prevalence and incidence decreased by more than 70% and 50%, respectively. Possibly, this could be attributed to the setting up of a passive case detection system based on village health workers, indicating that a major impact on the malaria burden can be obtained whenever prompt diagnosis and adequate treatment are available.
Thang
Ngo Duc
ND
National Institute of Malariology, Parasitology and Entomology, Tu Liem district, Hanoi, Vietnam. thangnimpevn@yahoo.com
Erhart
Annette
A
Hung
Le Xuan
le X
Thuan
Le Khanh
le K
Xa
Nguyen Xuan
NX
Thanh
Nguyen Ngoc
NN
Ky
Pham Van
PV
Coosemans
Marc
M
Speybroeck
Nico
N
D'Alessandro
Umberto
U
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000818:Animals; D000962:Antimalarials / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003150:Community Health Workers / Q000458:organization & administration*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008288:Malaria / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology* / Q000469:parasitology; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D010961:Plasmodium / Q000145:classification / Q000302:isolation & purification*; D011159:Population Surveillance / Q000379:methods; D012307:Risk Factors; D012424:Rural Population; D012621:Seasons; D011795:Surveys and Questionnaires; D014744:Vietnam / Q000453:epidemiology; D055815:Young Adult
D000962:Antimalarials