title: Rapid decrease of malaria morbidity following the introduction of community-based monitoring in a rural area of central Vietnam.
abstract: 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.
authors.affiliation: National Institute of Malariology, Parasitology and Entomology, Tu Liem district, Hanoi, Vietnam. thangnimpevn@yahoo.com
authors.forename: Ngo Duc
authors.initials: ND
authors.lastname: Thang
authors.forename: Annette
authors.initials: A
authors.lastname: Erhart
authors.forename: Le Xuan
authors.initials: le X
authors.lastname: Hung
authors.forename: Le Khanh
authors.initials: le K
authors.lastname: Thuan
authors.forename: Nguyen Xuan
authors.initials: NX
authors.lastname: Xa
authors.forename: Nguyen Ngoc
authors.initials: NN
authors.lastname: Thanh
authors.forename: Pham Van
authors.initials: PV
authors.lastname: Ky
authors.forename: Marc
authors.initials: M
authors.lastname: Coosemans
authors.forename: Nico
authors.initials: N
authors.lastname: Speybroeck
authors.forename: Umberto
authors.initials: U
authors.lastname: D'Alessandro
mesh_terms: 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
chemical_list: D000962:Antimalarials