ABSTRACT
After achieving malaria elimination, preventing re-establishment from imported malaria and consolidating malaria elimination achievements are top priorities of the national malaria control program in China. Due to the long-term existence of overseas imported malaria cases and incomplete eradication of local epidemic conditions, there are multiple challenges for prevention of re-establishment from imported malaria in China. Hereby, we propose that regular assessment is an effective approach to maintaining the capability of prevention of re-establishment from imported malaria, and describe the purpose, significance, management and implementation of the capability assessment for prevention of re-establishment from imported malaria, so as to provide insights into the formulation and adjustment of malaria control strategies during the post-elimination phase.
ABSTRACT
Objective To create a risk assessment indicator system for re-establishment of imported malaria. Methods The risk assessment indicator system for re-establishment of imported malaria was preliminarily constructed through literature review and thematic discussions. A total of 26 malaria control experts were selected to carry out a two-round Delphi consultation of the indicator system. The active coefficient, authority coefficient and coordination coefficient of the experts and the coefficient of variation on each indicator were calculated for indicator screening and the weight of each indicator was calculated. The reliability of the indicator system was evaluated using Cronbach’s coefficient α, and the content validity of the indicator system was evaluated using the authority coefficient of the expert, while the structural validity of the indicator system was evaluated using Kaiser-Meyer-Olkin (KMO) test and factor analysis. Results Two rounds of Delphi expert consultations were completed by 23 malaria control experts, and a risk assessment indicator system for re-establishment of imported malaria was constructed, including 3 primary indicators, 7 secondary indicators, and 21 tertiary indicators. The active coefficient (100.00% vs. 88.46%; P < 0.01) and coordination coefficient of the expert (0.372 vs. 0.286; P < 0.01) were significantly greater in the second round of the Delphi expert consultation than in the first round. After the second round of the Delphi expert consultation, the authority coefficient of the experts ranged from 0.757 to 0.930 on each indicator, and the coefficients of variation were 0.098 to 0.136, 0.112 to 0.276 and 0.139 to 0.335 for the primary, secondary and tertiary indicators, respectively. The overall Cronbach’s coefficient α of the indicator system was 0.941, and there were significant differences in the KMO values for primary (KMO value = 0.523; χ2 = 18.192, P < 0.05), secondary (KMO value = 0.694, χ2 = 51.499, P < 0.01) and tertiary indicators (KMO value = 0.519; χ2 = 477.638, P < 0.01), while the cumulative contribution rate of six principal components in the tertiary indicators was 84.23%. The normalized weights of three primary indicators of the source of infection, transmission condition and control capability were 0.337, 0.333 and 0.329, and the three secondary indicators with the greatest normalized weights included the number of imported cases and malaria parasite species (0.160), introduction of imported cases in China and medical care seeking (0.152), vector species and density (0.152), while the five tertiary indicators with the greatest normalized weights included the malaria parasite species of imported cases (0.065), vector populations (0.064), and the time interval from onset to medical care seeking (0.059), number of imported cases (0.056), and the time interval from medical care seeking to definitive diagnosis (0.055). Conclusions A risk assessment indicator system for re-establishment of imported malaria is successfully created, which provides insights into the assessment of the risk of re-establishment of imported malaria and management of key high-risk factors in malaria-eliminated areas.
ABSTRACT
Malaria was one for the most serious communicable diseases in China. Following the concerted efforts for decades, remarkable achievements have been gained for malaria control in China. Since the national malaria elimination programme was initiated in China in 2010, local malaria transmission was rapidly interrupted, with zero indigenous malaria case reported for the first time in the country in 2017, and the country will undergo the certification of malaria elimination by WHO. Currently, however, malaria remains hyper-endemic across the world. In China, there are more than 2 000 overseas imported malaria cases each year, and prevention of re-establishment of imported malaria will become the major task in future malaria control activities. Here by, we analyze the main challenges in the prevention of re-establishment of imported malaria in China, and propose the corresponding countermeasures, so as to provide insights into the consolidation of malaria elimination achievements.