Using an autologistic regression model to identify spatial risk factors and spatial risk patterns of hand, foot and mouth disease (HFMD) in Mainland China

Abstract

BackgroundThere have been large-scale outbreaks of hand, foot and mouth disease (HFMD) in Mainland China over the last decade. These events varied greatly across the country. It is necessary to identify the spatial risk factors and spatial distribution patterns of HFMD for public health control and prevention. Climate risk factors associated with HFMD occurrence have been recognized. However, few studies discussed the socio-economic determinants of HFMD risk at a space scale.MethodsHFMD records in Mainland China in May 2008 were collected. Both climate and socio-economic factors were selected as potential risk exposures of HFMD. Odds ratio (OR) was used to identify the spatial risk factors. A spatial autologistic regression model was employed to get OR values of each exposures and model the spatial distribution patterns of HFMD risk.ResultsResults showed that both climate and socio-economic variables were spatial risk factors for HFMD transmission in Mainland China. The statistically significant risk factors are monthly average precipitation (OR = 1.4354), monthly average temperature (OR = 1.379), monthly average wind speed (OR = 1.186), the number of industrial enterprises above designated size (OR = 17.699), the population density (OR = 1.953), and the proportion of student population (OR = 1.286). The spatial autologistic regression model has a good goodness of fit (ROC = 0.817) and prediction accuracy (Correct ratio = 78.45%) of HFMD occurrence. The autologistic regression model also reduces the contribution of the residual term in the ordinary logistic regression model significantly, from 17.25 to 1.25 for the odds ratio. Based on the prediction results of the spatial model, we obtained a map of the probability of HFMD occurrence that shows the spatial distribution pattern and local epidemic risk over Mainland China.ConclusionsThe autologistic regression model was used to identify spatial risk factors and model spatial risk patterns of HFMD. HFMD occurrences were found to be spatially heterogeneous over the Mainland China, which is related to both the climate and socio-economic variables. The combination of socio-economic and climate exposures can explain the HFMD occurrences more comprehensively and objectively than those with only climate exposures. The modeled probability of HFMD occurrence at the county level reveals not only the spatial trends, but also the local details of epidemic risk, even in the regions where there were no HFMD case records.

Age patterns and transmission characteristics of hand, foot and mouth disease in China

“…In Tibet, the 10–14 year age group has the highest force of infection hence the highest risk. Many factors, such as population density, economic development or social behavior had been shown to be associated with nationwide variation in HFMD occurrence [11, 23, 25]. These factors may cause the significant difference in the distribution of the force of infection in Tibet, which should be deeply investigated.…”

“…Causing millions of illness and hundreds of deaths every year [7] and without efficacious vaccines [8], HFMD has been a growing public health problem in China. Most research effort about HFMD has focused on effects of meteorological factors on the incidence seasonality [1, 9, 10], determinants of nationwide variation of report cases [1, 11], the spatio-temporal clustering in a locale [12], the development and efficacy of vaccines [13, 14], clinical features and diagnosis [15], and analyses of virology and pathogenesis [16]. In order to plan control measures to ease or even to eliminate HFMD, we need to understand factors that determine the incidence, the transfer and the persistence of the disease.…”

“…Magnitudes of seasonality of HFMD varied greatly from south to north and from east to west in China showing spatial patterns [11, 22]. The spatial variation in HFMD occurrence has been associated with meteorological factors [1, 22–24], or social factors [11, 25].…”

“…The spatial variation in HFMD occurrence has been associated with meteorological factors [1, 22–24], or social factors [11, 25]. Disagreements exist about the type of factors that is more responsible for HFMD occurrence in China.…”

Joint diagnosis of pediatric and dermatology clinics: Prospective observation of thirtynine patients with hand, foot and mouth disease

“…Lezyonlar hastaların %94,9'unda ellerde, %87,2'sinde ayaklarda ve %61,5'inde kol, bacak ve/veya gluteal bölgelerde gözlendi. Bu sonuçlar, yurtdışından ve ülkemizden yapılan çalışmalar ile uyumlu idi 4,[6][7][8][9][14][15][16][17][18] . EAAH tanısı için genellikle klinik bulgular yeterlidir, kuşkulu durumlarda virüsün saptanmasıyla tanı kesinleştirilebilir 4 .…”