Limits...
The epidemiology of Plasmodium vivax and Plasmodium falciparum malaria in China, 2004-2012: from intensified control to elimination.

Zhang Q, Lai S, Zheng C, Zhang H, Zhou S, Hu W, Clements AC, Zhou XN, Yang W, Hay SI, Yu H, Li Z - Malar. J. (2014)

Bottom Line: The secular trend, gender and age features, seasonality, and spatial distribution by Plasmodium species were analysed.Males and young age groups became the predominantly affected population.The areas affected by Plasmodium vivax malaria shrunk, while areas affected by P. falciparum malaria expanded from 294 counties in 2004 to 600 counties in 2012.

View Article: PubMed Central - PubMed

Affiliation: Division of Infectious Diseases, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China. yuhj@chinacdc.cn.

ABSTRACT

Background: In China, the national malaria elimination programme has been operating since 2010. This study aimed to explore the epidemiological changes in patterns of malaria in China from intensified control to elimination stages.

Methods: Data on nationwide malaria cases from 2004 to 2012 were extracted from the Chinese national malaria surveillance system. The secular trend, gender and age features, seasonality, and spatial distribution by Plasmodium species were analysed.

Results: In total, 238,443 malaria cases were reported, and the proportion of Plasmodium falciparum increased drastically from <10% before 2010 to 55.2% in 2012. From 2004 to 2006, malaria showed a significantly increasing trend and with the highest incidence peak in 2006 (4.6/100,000), while from 2007 onwards, malaria decreased sharply to only 0.18/100,000 in 2012. Males and young age groups became the predominantly affected population. The areas affected by Plasmodium vivax malaria shrunk, while areas affected by P. falciparum malaria expanded from 294 counties in 2004 to 600 counties in 2012.

Conclusions: This study demonstrated that malaria has decreased dramatically in the last five years, especially since the Chinese government launched a malaria elimination programme in 2010, and areas with reported falciparum malaria cases have expanded over recent years. These findings suggest that elimination efforts should be improved to meet these changes, so as to achieve the nationwide malaria elimination goal in China in 2020.

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The seasonal distribution of malaria cases by month in China, 2004–2012. (A) The epidemic curve of cases by plasmodium species. Others contained Plasmodium ovale, Plasmodium malariae, mixed infection cases and untyped cases. (B) The seasonal index of P. vivax and P. falciparum malaria. The index was calculated by month, and it was the average case number for a given month (i.e. May) divided by the mean of case number in that corresponding month (i.e. May) during the whole nine years of 2004-2012. No obvious seasonal fluctuation was expected if the seasonal index of each month was close to 1.0.
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Fig1: The seasonal distribution of malaria cases by month in China, 2004–2012. (A) The epidemic curve of cases by plasmodium species. Others contained Plasmodium ovale, Plasmodium malariae, mixed infection cases and untyped cases. (B) The seasonal index of P. vivax and P. falciparum malaria. The index was calculated by month, and it was the average case number for a given month (i.e. May) divided by the mean of case number in that corresponding month (i.e. May) during the whole nine years of 2004-2012. No obvious seasonal fluctuation was expected if the seasonal index of each month was close to 1.0.

Mentions: The average annual incidence rate was 2.0 cases/100,000 during the whole nine years. Annual incidence rate presented striking variation by year, with the highest recorded in 2006 (4.6/100,000) and the lowest level in 2012 (0.18/100,000). Table 1 and Figure 1A showed that P. vivax malaria increased continuously from 2004 to 2006, with annual incidence rate of 2.11-3.65 cases/100,000, peaking in 2006, and then decreasing sharply from 2007 to 2012, with an annual incidence rate of 0.08-2.92 cases/100,000. P. falciparum malaria was relatively stable from 2004 to 2006, with an annual incidence rate of 0.21-0.29 cases/100,000, then decreasing in 2007 to a rate that has since remained stable at 0.08-0.13 cases/100,000.Figure 1


The epidemiology of Plasmodium vivax and Plasmodium falciparum malaria in China, 2004-2012: from intensified control to elimination.

Zhang Q, Lai S, Zheng C, Zhang H, Zhou S, Hu W, Clements AC, Zhou XN, Yang W, Hay SI, Yu H, Li Z - Malar. J. (2014)

The seasonal distribution of malaria cases by month in China, 2004–2012. (A) The epidemic curve of cases by plasmodium species. Others contained Plasmodium ovale, Plasmodium malariae, mixed infection cases and untyped cases. (B) The seasonal index of P. vivax and P. falciparum malaria. The index was calculated by month, and it was the average case number for a given month (i.e. May) divided by the mean of case number in that corresponding month (i.e. May) during the whole nine years of 2004-2012. No obvious seasonal fluctuation was expected if the seasonal index of each month was close to 1.0.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4232696&req=5

Fig1: The seasonal distribution of malaria cases by month in China, 2004–2012. (A) The epidemic curve of cases by plasmodium species. Others contained Plasmodium ovale, Plasmodium malariae, mixed infection cases and untyped cases. (B) The seasonal index of P. vivax and P. falciparum malaria. The index was calculated by month, and it was the average case number for a given month (i.e. May) divided by the mean of case number in that corresponding month (i.e. May) during the whole nine years of 2004-2012. No obvious seasonal fluctuation was expected if the seasonal index of each month was close to 1.0.
Mentions: The average annual incidence rate was 2.0 cases/100,000 during the whole nine years. Annual incidence rate presented striking variation by year, with the highest recorded in 2006 (4.6/100,000) and the lowest level in 2012 (0.18/100,000). Table 1 and Figure 1A showed that P. vivax malaria increased continuously from 2004 to 2006, with annual incidence rate of 2.11-3.65 cases/100,000, peaking in 2006, and then decreasing sharply from 2007 to 2012, with an annual incidence rate of 0.08-2.92 cases/100,000. P. falciparum malaria was relatively stable from 2004 to 2006, with an annual incidence rate of 0.21-0.29 cases/100,000, then decreasing in 2007 to a rate that has since remained stable at 0.08-0.13 cases/100,000.Figure 1

Bottom Line: The secular trend, gender and age features, seasonality, and spatial distribution by Plasmodium species were analysed.Males and young age groups became the predominantly affected population.The areas affected by Plasmodium vivax malaria shrunk, while areas affected by P. falciparum malaria expanded from 294 counties in 2004 to 600 counties in 2012.

View Article: PubMed Central - PubMed

Affiliation: Division of Infectious Diseases, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China. yuhj@chinacdc.cn.

ABSTRACT

Background: In China, the national malaria elimination programme has been operating since 2010. This study aimed to explore the epidemiological changes in patterns of malaria in China from intensified control to elimination stages.

Methods: Data on nationwide malaria cases from 2004 to 2012 were extracted from the Chinese national malaria surveillance system. The secular trend, gender and age features, seasonality, and spatial distribution by Plasmodium species were analysed.

Results: In total, 238,443 malaria cases were reported, and the proportion of Plasmodium falciparum increased drastically from <10% before 2010 to 55.2% in 2012. From 2004 to 2006, malaria showed a significantly increasing trend and with the highest incidence peak in 2006 (4.6/100,000), while from 2007 onwards, malaria decreased sharply to only 0.18/100,000 in 2012. Males and young age groups became the predominantly affected population. The areas affected by Plasmodium vivax malaria shrunk, while areas affected by P. falciparum malaria expanded from 294 counties in 2004 to 600 counties in 2012.

Conclusions: This study demonstrated that malaria has decreased dramatically in the last five years, especially since the Chinese government launched a malaria elimination programme in 2010, and areas with reported falciparum malaria cases have expanded over recent years. These findings suggest that elimination efforts should be improved to meet these changes, so as to achieve the nationwide malaria elimination goal in China in 2020.

Show MeSH
Related in: MedlinePlus