Trend of the incidence of EV71 cases between 2016 and 2021 shown by joinpoint regression.

The red squares denote the observed values of the incidence, and the blue line is the slope of the APC. The APC was the annual percent change.</p

Seasonal distribution trends of EV71, Cox A16 and other enterovirus cases.

Seasonal distribution trends of EV71, Cox A16 and other enterovirus cases.</p

Spatial characteristics and the epidemiology of human infections with avian influenza A(H7N9) virus in five waves from 2013 to 2017 in Zhejiang Province, China

<div><p>Background</p><p>The five-wave epidemic of H7N9 in China emerged in the second half of 2016. This study aimed to compare the epidemiological characteristics among the five waves, estimating the possible infected cases and inferring the extent of the possible epidemic in the areas that have not reported cases before.</p><p>Methods</p><p>The data for the H7N9 cases from Zhejiang Province between 2013 and 2017 was obtained from the China Information Network System of Disease Prevention and Control. The start date of each wave was 16 March 2013, 1 July 2013, 1 July 2014, 1 July 2015 and 1 July 2016. The <i>F</i> test or Pearson’s chi-square test were used to compare the characteristics of the five waves. Global and local autocorrelation analysis was carried out to identify spatial autocorrelations. Ordinary kriging interpolation was analyzed to estimate the number of human infections with H7N9 virus and to infer the extent of infections in the areas with no cases reported before.</p><p>Result</p><p>There were 45, 94, 45, 34 and 80 cases identified from the first wave to the fifth, respectively. The death rate was significantly different among the five waves of epidemics (<i>χ</i>² = 10.784, <i>P</i> = 0.029). The age distribution (<i>F</i> = 0.903, <i>P</i> = 0.462), gender (<i>χ</i>² = 2.674, <i>P</i> = 0.614) and occupation(<i>χ</i>² = 19.764, <i>P</i> = 0.407) were similar in each period. Most of the cases were males and farmers. A significant trend (<i>χ</i>² = 70.328, <i>P</i><0.001) was identified that showed a growing proportion of rural cases. There were 31 high-high clusters and 3 high-low clusters at the county level among the five waves and 12, 8, 2, 9 and 3 clusters in each wave, respectively. The total cases infected with the H7N9 virus were far more than those that have been reported now, and the affected areas continue to expand. The epidemic in the north of Zhejiang Province persisted in all five waves. Since the second wave, the virus spread to the south areas and central areas. There was an obvious decline in the infected cases in the urban areas, and the epidemics mostly occurred in the rural areas after the fourth wave. The epidemic was relatively dispersed since the third wave had fewer than two cases in most of the areas and showed a reinforcing trend again in the fifth wave.</p><p>Conclusions</p><p>The study revealed that there were few differences in the epidemiologic characteristics among the five waves of the epidemic. However, the areas where the possible epidemic circulated was larger than reported. The epidemic cross-regional expansion continued and mostly occurred in rural areas. Continuous closure of the live poultry market (LPM) is strongly recommended in both rural and urban areas. Illegal and scattered live poultry trading, especially in rural areas, must be forbidden. It is suggested too that a more rigorous management be performed on live poultry trade and wholesale across the area. Health education, surveillance of cases and pathogenicity should also be strengthened.</p></div

Wavelet spectrum of HFMD for total cases, EV71 cases, Cox A16 cases and other enterovirus cases.

(A) Wavelet spectrum of the total case. (B) Wavelet spectrum of the EV71 case. (C) Wavelet spectrum of Cox the A16 case. (D) Wavelet spectrum of other enteroviruses.</p

The monthly counts of HFMD during 2010–2021 and the comparison with expected infection among 2017–2021 in Zhejiang Province, China.

The first panel shows the data and a counterfactual prediction for the posttreatment period. The second panel shows the difference between observed data and counterfactual predictions. The third panel sums the pointwise contributions from the second panel, resulting in a plot of the cumulative effect of the intervention.</p

Database of the monthly distribution of HFMD cases in Zhejiang Province.

(XLSX)</p

Virological surveillance of HFMD from 2010 to 2021.

Virological surveillance of HFMD from 2010 to 2021.</p

The average power of HFMD for the total case, EV71 case, Cox A16 case and Other enteroviruses cases.

(A) Wavelet spectrum of the total case. (B) Wavelet spectrum of the EV71 case. (C) Wavelet spectrum of Cox A16 case. (D) Wavelet spectrum of other enteroviruses.</p

The figure of semivariogram of H7N9 human infections in Zhejiang Province among five waves.

<p>The figure of semivariogram of H7N9 human infections in Zhejiang Province among five waves.</p

Maps of the local autocorrelation analysis of H7N9 human infections in Zhejiang Province among five waves by Local Moran’I.

<p>Maps of the local autocorrelation analysis of H7N9 human infections in Zhejiang Province among five waves by Local Moran’I.</p