Mobile population dynamics and malaria vulnerability:a modelling study in the China-Myanmar border region of Yunnan Province,China

Background:The China-Myanmar border region presents a great challenge in malaria elimination in China,and it is essential to understand the relationship between malaria vulnerability and population mobility in this region.Methods:A community-based,cross-sectional survey was performed in five villages of Yingjiang county during September 2016.Finger-prick blood samples were obtained to identify asymptomatic infections,and imported cases were identified in each village(between January 2013 and September 2016).A stochastic simulation model(SSM)was used to test the relationship between population mobility and malaria vulnerability,according to the mechanisms of malaria importation.Results:Thirty-two imported cases were identified in the five villages,with a 4-year average of 1 case/year(range:0-5 cases/year).No parasites were detected in the 353 blood samples from 2016.The median density of malaria vulnerability was 0.012(range:0.000-0.033).The average proportion of mobile members of the study population was 32.56%(range:28.38-71.95%).Most mobile individuals lived indoors at night with mosquito protection.The SSM model fit the investigated data(χ2=0.487,P=0.485).The average probability of infection in the members of the population that moved to Myanmar was 0.011(range:0.0048-0.1585).The values for simulated vulnerability increased with greater population mobility in each village.Conclusions:A high proportion of population mobility was associated with greater malaria vulnerability in the China-Myanmar border region.Mobile population-specific measures should be used to decrease the risk of malaria re-establishment in China.

Malaria:elimination tale from Yunnan Province of China and new challenges for reintroduction

Background::Eradication of infectious disease is the sanctified public health and sustainable development goal around the world.Main body::Three antimalarial barriers were developed to control imported malarial cases,and an effective surveillance strategy known as the"1-3-7 approach"was developed to eliminate malaria from the Chinese population.From 2011 to 2019,5254 confirmed malaria cases were reported and treated in Yunnan Province,China.Among them,4566 cases were imported from other countries,and 688 cases were indigenous from 2011 to 2016.Since 2017,no new local malarial case has been reported in China.Thus,malaria has been completely eliminated in Yunnan Province.However,malaria is detected in overseas travellers on a regular basis,such as visitors from neighbouring Myanmar.Conclusion::Hence,the strategies should be further strengthened to maintain a robust public health infrastructure for disease surveillance and vector control programs in border areas.Such programs should be supported technically and financially by the government to avert the possibility of a malarial resurgence in Yunnan Province.

Assessment of malaria control consultation and service posts in Yunnan, P. R. China

Background:This paper seeks to assess the function of malaria control consultation and service posts(MCCSPs)that are located on the border areas of Yunnan province,P.R.China,as a strategy for eliminating malaria among the mobile and migrant population in these areas.Methods:A retrospective descriptive analytical study was conducted.Blood smear examinations conducted at all MCCSPs in Yunnan from 2008 to 2014 were analysed.A cross-sectional survey was conducted in 2014 to understand how the MCCSPs function and to elucidate the quality of the blood smear examinations that they conduct.Results:Out of the surveyed MCCSPs,66%(39/59),22%(13/59),and 12%(7/59)were attached to local township hospitals,village health clinics,and the county centre for disease control and prevention or private clinics,respectively.More than 64%(38/59)of the posts’staff were part-time workers from township hospitals and village health facilities.Less than 31%(18/59)of the posts’staff were full-time workers.A total of 35 positive malaria cases were reported from seven MCCSPs in 2014.Four MCCSPs were unable to perform their functions due to under staffing in 2014.There was a small fluctuation in blood smear examinations from January 2008 to June 2009,with two peaks during the period from July 2009 to October 2010.The number of blood smear examinations has been increasing since 2011.The yearly mean number of blood smear examinations in each post increased from 44 per month in 2011 to 109 per month in 2014,and the number of positive malaria cases detected by blood smear examinations has declined(χ^(2)=90.67,P=0.000).The percentage of people from Yingjiang county getting blood smear examinations increased between 2008 and 2014,while percentages of the mobile population including Myanmar people,people from other provinces,and people from other Yunnan counties getting blood smear examinations decreased.Conclusion:MCCSPs face challenges in the phase of malaria elimination in Yunnan,China.New case detection strategies should be designed for MCCSPs taking into account the current trends of migration.