title: Joint malaria surveys lead towards improved cross-border cooperation between Savannakhet province, Laos and Quang Tri province, Vietnam.
abstract: BACKGROUND
  In Savannakhet province, Laos and Quang Tri province, Vietnam, malaria is still an important health problem and most cases are found in the mountainous, forested border areas where ethnic minority groups live. The objectives of this study were to obtain a better joint understanding of the malaria situation along the border and, on the basis of that, improve malaria control methods through better cooperation between the two countries.
  
  
  METHODS
  Fourteen villages in Savannakhet and 22 villages in Quang Tri were randomly selected within 5 km from the border where a blood survey for microscopic diagnosis (n = 1256 and n = 1803, respectively), household interviews (n = 400, both sides) and vector surveys were conducted between August and October 2010. Satellite images were used to examine the forest density around the study villages.
  
  
  RESULTS
  Malaria prevalence was significantly higher in Laos (5.2%) than in Vietnam (1.8%) and many other differences were found over the short distance across the border. Bed net coverage was high (> 90%) in both Laos and Vietnam but, while in Laos more than 60% of the nets were long-lasting insecticide-treated, Vietnam used indoor residual spraying in this area and the nets were untreated. Anopheles mosquitoes were more abundant in Laos than in Vietnam, especially many Anopheles dirus were captured in indoor light traps while none were collected in Vietnam. The forest cover was higher around the Lao than the Vietnamese villages. After this study routine exchange of malaria surveillance data was institutionalized and for the first time indoor residual spraying was applied in some Lao villages.
  
  
  CONCLUSIONS
  The abundance of indoor-collected An. dirus on the Laos side raises doubts about the effectiveness of a sole reliance on long-lasting insecticide-treated nets in this area. Next to strengthening the early detection, correct diagnosis and prompt, adequate treatment of malaria infections, it is recommended to test focal indoor residual spraying and the promotion of insect repellent use in the early evening as additional vector interventions. Conducting joint malaria surveys by staff of two countries proved to be effective in stimulating better collaboration and improve cross-border malaria control.
authors.affiliation: Department of Parasitology and International Health, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
authors.forename: Tiengkham
authors.initials: T
authors.lastname: Pongvongsa
authors.forename: Hoang
authors.initials: H
authors.lastname: Ha
authors.forename: Le
authors.initials: L
authors.lastname: Thanh
authors.forename: Ron P
authors.initials: RP
authors.lastname: Marchand
authors.forename: Daisuke
authors.initials: D
authors.lastname: Nonaka
authors.forename: Bumpei
authors.initials: B
authors.lastname: Tojo
authors.forename: Panom
authors.initials: P
authors.lastname: Phongmany
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Moji
authors.forename: Jun
authors.initials: J
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D000852:Anopheles / Q000254:growth & development; D017753:Ecosystem; D062665:Epidemiological Monitoring; D006801:Humans; D007306:Insecticides / Q000008:administration & dosage; D007391:International Cooperation; D007812:Laos / Q000453:epidemiology; D008288:Malaria / Q000453:epidemiology* / Q000517:prevention & control*; D009032:Mosquito Control / Q000379:methods; D057147:Mosquito Nets / Q000706:statistics & numerical data; D015995:Prevalence; D014744:Vietnam / Q000453:epidemiology
chemical_list: D007306:Insecticides