• 1

    Pan American Health Organization, 1998. Status of Malaria Programs in the Americas: XLV Report. Available at http://165.158.1.110/english/hcp/hct-mala.htm.

  • 2

    Ministerio de Protección Social, 2003. Malaria: Estrategias para Afrontar una Prioridad en Salud Pública. Universidad del Valle, Cali: Ministerio de Protección Social, República de Colombia.

  • 3

    Kroeger A, Ordonez-Gonzalez J, Avina AI, 2002. Malaria control reinvented: health sector reform and strategy development in Colombia. Trop Med Int Health 7 :450–458.

    • Search Google Scholar
    • Export Citation
  • 4

    Alonso PL, Lindsay SW, Armstrong JR, Conteh M, Hill AG, David PH, Fegan G, de Francisco A, Hall AJ, Shenton FC, Cham K, Greenwood BM, 1991. The effect of insecticide-treated bed nets on mortality of Gambian children. Lancet 337 :1499–1502.

    • Search Google Scholar
    • Export Citation
  • 5

    Kamol-Ratanakul P, Prasittisuk C, 1992. The effectiveness of permethrin-impregnated bed nets against malaria for migrant workers in eastern Thailand. Am J Trop Med Hyg 47 :305–309.

    • Search Google Scholar
    • Export Citation
  • 6

    Choi HW, Breman JG, Teutsch SM, Liu S, Hightower AW, Sexton JD, 1995. The effectiveness of insecticide-impregnated bed nets in reducing cases of malaria infection: a meta-analysis of published results. Am J Trop Med Hyg 52 :377–382.

    • Search Google Scholar
    • Export Citation
  • 7

    Lengeler C, 2004. Insecticide-treated bednets and curtains for preventing malaria (Cochrane Review). The Cochrane Library, Issue 1. Chichester: John Wiley & Sons, Ltd.

  • 8

    Carnevale P, Bitsindou P, Diomande L, Robert V, 1992. Insecticide impregnation can restore the efficiency of torn bed nets and reduce man-vector contact in malaria endemic areas. Trans R Soc Trop Med Hyg 86 :362–364.

    • Search Google Scholar
    • Export Citation
  • 9

    Diallo DA, Cousens SN, Cuzin-Ouattara N, Nebie I, Ilboudo-Sanogo E, Esposito F, 2004. Child mortality in a West African population protected with insecticide-treated curtains for a period of up to 6 years. Bull WHO 82 :85–91.

    • Search Google Scholar
    • Export Citation
  • 10

    Zimmerman RH, Voorham J, 1997. Use of insecticide-impregnated mosquito nets and other impregnated materials for malaria control in the Americas. Pan American Journal of Public Health 2 :18–25.

    • Search Google Scholar
    • Export Citation
  • 11

    Kroeger A, Gonzalez M, Ordonez-Gonzalez J, 1999. Insecticide-treated materials for malaria control in Latin America: to use or not to use? Trans R Soc Trop Med Hyg 93 :565–570.

    • Search Google Scholar
    • Export Citation
  • 12

    Pérez L, Suárez M, Murcia L, de la Hoz F, Olano VA, Brochero H, Toro P, 1999. La malaria en el Amazonas: conocimientos, prácticas, prevalencia de parasitemia y evaluación entomológica en mayo de 1997. Biomédica 19 :93–102.

    • Search Google Scholar
    • Export Citation
  • 13

    Branquinho MS, Lagos CB, Rocha RM, Natal D, Barata JM, Cochrane AH, Nardin E, Nussenzweig RS, Kloetzel JK, 1993. Anophelines in the state of Acre, Brazil, infected with Plasmodium falciparum, P. vivax, the variant P. vivax VK247 and P. malariae.Trans R Soc Trop Med Hyg 87 :391–394.

    • Search Google Scholar
    • Export Citation
  • 14

    Rothman KJ, Greenland S, 1998. Modern Epidemiology. Philadelphia: Lippincott-Raven Publishers.

  • 15

    Hayes RJ, Marsh K, Snow RW, 1992. Case-control studies of severe malaria. J Trop Med Hyg 95 :157–166.

  • 16

    D’Alessandro U, Olaleye B, Langerock P, Bennett S, Cham K, Cham B, Greenwood BM, 1997. The Gambian National Impregnated Bed Net Programme: evaluation of effectiveness by means of case-control studies. Trans R Soc Trop Med Hyg 91 :638–642.

    • Search Google Scholar
    • Export Citation
  • 17

    Curtis CF, Maxwell CA, Finch RJ, Njunwa KJ, 1998. A comparison of use of a pyrethroid either for house spraying or for bednet treatment against malaria vectors. Trop Med Int Health 3 :619–631.

    • Search Google Scholar
    • Export Citation
  • 18

    Grandin BE, 1988. Wealth Ranking in Smallholder Communities: A Field Manual. Rugby: Intermediate Technology Development Group.

  • 19

    Rodrigues L, Kirkwood B, 1990. Case-control designs in the study of common diseases: updates on the demise of the rare disease assumption and the choice of sampling scheme for controls. Int J Epidemiol 19 :205–213.

    • Search Google Scholar
    • Export Citation
  • 20

    Last JM, 1995. Dictionary of Epidemiology. Oxford: Oxford University Press.

  • 21

    Alexander N, 2004. Triangle plots of three-level explanatory variables. Significance 1 :130–131.

  • 22

    Bruzzi P, Green SB, Byar DP, Brinton LA, Schairer C, 1985. Estimating the population attributable risk for multiple risk factors using case-control data. Am J Epidemiol 122 :904–914.

    • Search Google Scholar
    • Export Citation
  • 23

    Armitage P, Berry G, Matthews JNS, 2001. Statistical Methods in Medical Research. Oxford: Blackwell Scientific Publications.

  • 24

    Kroeger A, Mancheno M, Alarcon J, Pesse K, 1995. Insecticide-impregnated bed nets for malaria control: varying experiences from Ecuador, Colombia, and Peru concerning acceptability and effectiveness. Am J Trop Med Hyg 53 :313–323.

    • Search Google Scholar
    • Export Citation
  • 25

    Secretaría de Salud del Amazonas, 1999. Reunión Tripartita Brasil, Colombia, Perú. Leticia: Secretaría de Salud del Amazonas.

  • 26

    Magris Crestini M, 2004. Malaria Control Trial Using Lambda-cyhalothrin Treated Nets in Yanomami Communities in Amazonas State, Venezuela. Department of Infectious and Tropical Diseases: London School of Hygiene and Tropical Medicine (University of London).

  • 27

    Tadei WP, Dutary Thatcher B, 2000. Malaria vectors in the Brazilian Amazon: Anopheles of the subgenus Nyssorhynchus.Revista do Instituto de Medicina Tropical de Sao Paulo 42 :87–94.

    • Search Google Scholar
    • Export Citation
  • 28

    Osorio L, Todd J, Bradley DJ, 2004. Travel histories as risk factors in the analysis of urban malaria in Colombia. Am J Trop Med Hyg 71 :380–386.

    • Search Google Scholar
    • Export Citation
  • 29

    van der Hoek W, Konradsen F, Dijkstra DS, Amerasinghe PH, Amerasinghe FP, 1998. Risk factors for malaria: a microepidemiological study in a village in Sri Lanka. Trans R Soc Trop Med Hyg 92 :265–269.

    • Search Google Scholar
    • Export Citation
  • 30

    Castilla RE, Sawyer DO, 1993. Malaria rates and fate: a socioeconomic study of malaria in Brazil. Social Sci and Med 37 :1137–1145.

  • 31

    Guthmann JP, Hall AJ, Jaffar S, Palacios A, Lines J, Llanos-Cuentas A, 2001. Environmental risk factors for clinical malaria: a case-control study in the Grau region of Peru. Trans R Soc Trop Med Hyg 95 :577–583.

    • Search Google Scholar
    • Export Citation
  • 32

    Thompson R, Begtrup K, Cuamba N, Dgedge M, Mendis C, Gamage-Mendis A, Enosse SM, Barreto J, Sinden RE, Hogh B, 1997. The Matola malaria project: a temporal and spatial study of malaria transmission and disease in a suburban area of Maputo, Mozambique. Am J Trop Med Hyg 57 :550–559.

    • Search Google Scholar
    • Export Citation
  • 33

    Gómez A, Sotomayor H, Lesmes A, 2000. Amazonía Colombiana: Enfermedades y Epidemias. Un Estudio de Bioantropologia Histórica. Bogotá: Panamericana Formas e Impresos S.A.

  • 34

    Alves FP, Durlacher RR, Menezes MJ, Krieger H, Silva LH, Camargo EP, 2002. High prevalence of asymptomatic Plasmodium vivax and Plasmodium falciparum infections in native Amazonian populations. Am J Trop Med Hyg 66 :641–648.

    • Search Google Scholar
    • Export Citation
  • 35

    Salzano FM, Callegari-Jacques SM, 1988. South American Indians: A Case Study in Evolution. Oxford: Clarendon Press.

 
 
 

 

 
 
 

 

 

 

 

 

 

CASE-CONTROL STUDY OF MOSQUITO NETS AGAINST MALARIA IN THE AMAZON REGION OF COLOMBIA

View More View Less
  • 1 London School of Hygiene and Tropical Medicine, London, UK; Secretaría de Salud del Amazonas, Leticia, Amazonas, Colombia; Universidad Nacional de Colombia, Leticia and Bogotá, Colombia

The degree of effectiveness of mosquito nets against malaria in the Americas has remained uncertain. We carried out a case-control study of net use and mild malaria in the Amazonas state of Colombia. Two hundred ninety cases were enrolled via the Health Department services, and 977 community-based controls matched for age, sex, and place of residence. We found that a large proportion of the population (96% of controls) slept under nets. Nevertheless, we found a benefit of impregnated nets compared with no net use: adjusted odds ratio (OR) for mild malaria 0.44, 95% confidence interval (CI) 0.20–0.98. Nonimpregnated nets had a benefit that was only slightly smaller but not statistically significant (OR for mild malaria 0.54, 95% CI 0.25–1.18). Travel in the previous month had an odds ratio of 6.2 (95% CI 3.1–8.8) and a population attributable fraction of 13% compared with 11% for failure to use an impregnated net. We conclude that, in the Amazon region, promotion of mosquito net use and impregnation is justified, and that there is a need for measures to protect travelers from malaria.

Author Notes

Reprint requests: Neal Alexander, Infectious Disease Epidemiology Unit, Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK. Telephone: (+44) 20 7927 2483, Fax: (+44) 20 7636 8739, E-mail: neal.alexander@lshtm.ac.uk.
Save