Objectives: To study the major ecologic factors influencing the re-emergence of malaria in the areas along the Yellow River and Huai River by analyzing the relationship between the malaria incidence and the land use and cover change (LUCC).
Methods: The data of annual parasite incidence (API) and LUCC in the counties of Huaiyuan, Yongcheng and Tong ai in 1990-2006 were collected retrospectively. Considering the hysteresis effect of LUCC played on malaria transmission, analysis of LUCC in these counties were conducted based on the data of 1990-1995 and 1996-2000, while the API data in 1996-2000 and 2001-2005 were used to analyze the trends and changes of malaria incidence. The correlation and trend analyses were conducted between LUCC and malaria incidence change in the periods.
Results: The LUCC in 1990-1995 in Tongbai County was significant, being 3 265.79% in the farmland and -90.42% in paddy field. The increase of malaria incidence in Tongbai was also significant in 1996-2000, the change rate was 2 799.70%, showing a positive correlation. The LUCC of other 2 counties in 1990-1995 was -0.27% and -0.78%, respectively, while the rate of malaria incidence change in 1996-2000 was 206.25% and 0.00%. The LUCC of the 2 counties in 1996-2000 was -0.08% and -0.50%, while the rate of malaria incidence change in 2001-2005 was 153.22% and 2 500.00%, respectively. It indicated that there was no significant relationship between malaria re-emergence and LUCC in Huaiyuan and Yongcheng Counties.
Conclusion: It seems that the LUCC shows no significant impact on malaria re-emergence in areas along the Yellow River and Huai River since 2001, though there was a positive correlation between the two in Tonghai County in the late 1990s.