Distribution and risk factors of hand, foot, and mouth disease in Changchun, northeastern China

Spatial heterogeneity of the association between temperature and hand, foot, and mouth disease risk in metropolitan and other areas

Interest in assessing the effects of temperature on hand, foot, and mouth disease (HFMD) has increased. However, little evidence is available on spatial heterogeneity in relationship to temperature and HFMD in metropolitan (capital city and municipal districts) and other areas where economic levels are significantly different. In this study, the Bayesian space-time hierarchy model was applied to identify the spatiotemporal heterogeneity of HFMD. GeoDetector was then used to quantify the determinant power of temperature to the disease in regions where the economic level has significant spatial heterogeneity. There was significant spatial heterogeneity in the influence of temperature on the incidence of HFMD in metropolitan and other areas. In metropolitan areas, where the disease risk is higher (hot spots), the HFMD incidence was higher alongside an increase in average temperature. However, in non-metropolitan areas, where the disease risk is lower (cold spots), there was an approximately S-shaped relationship between the temperature and the HFMD risk. More specifically, when the temperature was >25 °C, the HFMD incidence no longer increased monotonically with the increasing temperature. There was significant spatial heterogeneity in the effects of temperature on the HFMD incidence in metropolitan and non-metropolitan areas. This finding may serve as a suggestion and basis for the surveillance and control of this disease and it is conducive to the rational allocation of medical resources in different areas.

Space-time heterogeneity of hand, foot and mouth disease in children and its potential driving factors in Henan, China

BACKGROUND

Hand, foot and mouth disease (HFMD) has become a substantial threat recently. However few studies have quantified spatiotemporal heterogeneity of HFMD and detected spatiotemporal interactive effect of potential driving factors on this disease.

METHODS

Using GeoDetector and Bayesian space-time hierarchy model, we characterized the epidemiology of HFMD in Henan, one of the largest population provinces in China, from 2012 to 2013, and quantified the impacts of potential driving factors.

RESULTS

Notably, 21.43 and 24.60% counties were identified as hot and cold spots, respectively. Spatially, the hotspots were mainly clustered in regions where the economic level was high. Temporally, the highest incidence period of HFMD was discovered to be in late spring and early summer. The impact of meteorological and socio-economic factors on the disease are significant, and this study found that a 1 °C rise in temperature was related to an increase of 4.09% in the HFMD incidence, a 1% increment in relative humidity was associated with a 1.77% increase of the disease, and a 1% increment in ratio of urban to rural population was associated with a 0.16% increase of the disease.

CONCLUSION

Meteorological and socio-economic factors presented significantly association with HFMD incidence, high-risk mainly appeared in large cities and their adjacent regions in hot and humid season. These findings will be helpful for HFMD risk control and disease-prevention policies implementation.

Severity and burden of hand, foot and mouth disease in Asia: a modelling study

Background

Hand, foot and mouth disease (HFMD) affects millions of children across Asia annually, leading to an increase in implemented control policies such as surveillance, isolation and social distancing in affected jurisdictions. However, limited knowledge of disease burden and severity causes difficulty in policy optimisation as the associated economic cost cannot be easily estimated. We use a data synthesis approach to provide a comprehensive picture of HFMD disease burden, estimating infection risk, symptomatic rates, the risk of complications and death, and overall disability-adjusted life-year (DALY) losses, along with associated uncertainties.

Methods

Complementary data from a variety of sources were synthesised with mathematical models to obtain estimates of severity of HFMD. This includes serological and other data extracted through a systematic review of HFMD epidemiology previously published by the authors, and laboratory investigations and sentinel reports from Singapore's surveillance system.

Results

HFMD is estimated to cause 96 900 (95% CI 40 600 to 259 000) age-weighted DALYs per annum in eight high-burden countries in East and Southeast Asia, with the majority of DALYs attributed to years of life lost. The symptomatic case hospitalisation rate of HFMD is 6% (2.8%-14.9%), of which 18.7% (6.7%-31.5%) are expected to develop complications. 5% (2.9%-7.4%) of such cases are fatal, bringing the overall case fatality ratio to be 52.3 (24.4-92.7) per 100 000 symptomatic infections. In contrast, the EV-A71 case fatality ratio is estimated to be at least 229.7 (75.4-672.1) per 100 000 symptomatic cases. Asymptomatic rate for EV-A71 is 71.4% (68.3%-74.3%) for ages 1-4, the years of greatest incidence.

Conclusion

Despite the high incidence rate of HFMD, total DALY due to HFMD is limited in comparison to other endemic diseases in the region, such as dengue and upper respiratory tract infection. With the majority of DALY caused by years of life lost, it is possible to mitigate most with increased EV-A71 vaccine coverage.

The Epidemiology of Hand, Foot and Mouth Disease in Asia: A Systematic Review and Analysis

CONTEXT

Hand, foot and mouth disease (HFMD) is a widespread pediatric disease caused primarily by human enterovirus 71 (EV-A71) and Coxsackievirus A16 (CV-A16).

OBJECTIVE

This study reports a systematic review of the epidemiology of HFMD in Asia.

DATA SOURCES

PubMed, Web of Science and Google Scholar were searched up to December 2014.

STUDY SELECTION

Two reviewers independently assessed studies for epidemiologic and serologic information about prevalence and incidence of HFMD against predetermined inclusion/exclusion criteria.

DATA EXTRACTION

Two reviewers extracted answers for 8 specific research questions on HFMD epidemiology. The results are checked by 3 others.

RESULTS

HFMD is found to be seasonal in temperate Asia with a summer peak and in subtropical Asia with spring and fall peaks, but not in tropical Asia; evidence of a climatic role was identified for temperate Japan. Risk factors for HFMD include hygiene, age, gender and social contacts, but most studies were underpowered to adjust rigorously for confounding variables. Both community-level and school-level transmission have been implicated, but their relative importance for HFMD is inconclusive. Epidemiologic indices are poorly understood: No supporting quantitative evidence was found for the incubation period of EV-A71; the symptomatic rate of EV-A71/Coxsackievirus A16 infection was from 10% to 71% in 4 studies; while the basic reproduction number was between 1.1 and 5.5 in 3 studies. The uncertainty in these estimates inhibits their use for further analysis.

LIMITATIONS

Diversity of study designs complicates attempts to identify features of HFMD epidemiology.

CONCLUSIONS

Knowledge on HFMD remains insufficient to guide interventions such as the incorporation of an EV-A71 vaccine in pediatric vaccination schedules. Research is urgently needed to fill these gaps.

Spatial-temporal mapping of hand foot and mouth disease and the long-term effects associated with climate and socio-economic variables in Sichuan Province, China from 2009 to 2013

BACKGROUND

Hand, foot and mouth disease (HFMD) is a common infectious disease caused by enteroviruses. The annual HFMD incidence increased from 37.6/100,000 in 2008 to 139.6/100,000 in 2014 in mainland China. In this study, we try to model spatial-temporal association between HFMD incidence and climate and socio-economic variables.

METHODS

The annual numbers of reported cases of HFMD and populations from 2009 to 2013 were obtained from the Chinese infectious disease surveillance system. The climate data were obtained from a data sharing website hosted by the China Meteorological Administration. The socio-economic data were obtained from the statistic Yearbook of Sichuan province. Moran's I statistics were used to detect the counties' global spatial clusters. The hierarchical Bayesian spatial temporal interactive models were used to analyze the association between the annual HFMD incidence rate and climate variables.

RESULTS

An increasing trend in the annual HFMD incidence was detected in south-western counties. Spatial temporal clusters existed in Sichuan Province. A highly county level spatial structured RR (relative risk, RR) of HFMD incidence was detected in the northern and central of Sichuan Province. Annual HFMD incidence of counties were positively associated with the average annual temperature (RR:1.171, 95%CI:1.0435-1.3134), the second quartile of the per capital of GDP (reference: the first quartile of GDP, RR: 1.258, 95%CI: 1.0418-1.5200), the third quartile of per capital of GDP (RR:1.7726, 95%CI:1.3709-2.2907) and the fourth quartile of the per capital GDP (RR:1.9026, 95%CI1.3318-2.7086).

CONCLUSION

The HFMD incidence exhibited a heterogeneous spatial-temporal distribution in Sichuan Province. In the counties with greater wealth, the temperature was the primary risk factor, whereas in the counties with less wealth, GDP was the primary risk factor attributed to the spatial structured of HFMD incidence. Different preventive measures should be implemented in counties with different economic conditions.