Changing Patterns of Malaria Epidemiology between 2002 and 2010 in Western Kenya: The Fall and Rise of Malaria
2011

Changing Patterns of Malaria Epidemiology in Western Kenya (2002-2010)

Sample size: 33640 publication 10 minutes Evidence: moderate

Author Information

Author(s): Zhou Guofa, Afrane Yaw A., Vardo-Zalik Anne M., Atieli Harrysone, Zhong Daibin, Wamae Peter, Himeidan Yousif E., Minakawa Noboru, Githeko Andrew K., Yan Guiyun

Primary Institution: University of California Irvine

Hypothesis

What are the impacts of insecticide treated nets (ITNs) on malaria transmission in Western Kenya?

Conclusion

Despite high ownership of ITNs, malaria parasite prevalence and vector populations have resurged in two out of three sentinel sites in Western Kenya.

Supporting Evidence

  • Malaria parasite prevalence rates were 47.1%, 28.4%, and 6.2% in Kombewa, Iguhu, and Marani, respectively.
  • ITN ownership was at 50-70% in 2009, but effective coverage was much lower.
  • Vector populations increased significantly after 2007 despite high ITN ownership.

Takeaway

The study shows that even though many people have bed nets to protect against malaria, the number of malaria cases is going back up because the nets might not be working as well anymore.

Methodology

Monthly surveys were conducted in three sentinel sites to assess malaria parasite prevalence and vector abundance from 2002 to 2010.

Potential Biases

Potential biases in self-reported ITN usage and the reliance on health facility data for malaria incidence.

Limitations

The study may not account for all factors affecting malaria transmission, such as climate variations and human behavior.

Participant Demographics

Asymptomatic school children aged 6-13 years were primarily surveyed.

Statistical Information

P-Value

p<0.0001

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1371/journal.pone.0020318

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