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Objective To analyze the seasonal characteristics of scarlet fever in Songjiang District from 2012 to 2021, and to provide references for the prevention and control of scarlet fevers. Methods The incidence data of scarlet fever in Songjiang District from 2012 to 2021 were collected through the China Disease Prevention and Control Information System. The seasonal characteristics and peak of scarlet fever incidence were analyzed using concentration and circular distribution methods. Results The average annual reported incidence rate of scarlet fever in Songjiang District from 2012 to 2021 was 20.15/100 000. The M value of the concentration analysis was 0.18. The results of the circular distribution method showed that the peak day of scarlet fever from March to August was May 12, and the epidemic peak period was from April 3 to June 20. From September to February of the next year, the peak day of scarlet fever was December 21, and the epidemic peak period was from December 2 to January 9 of the next year. The differences were all statistically significant (P values were all less than 0.05). Conclusion The peaks of scarlet fever in Songjiang District mainly occur in May and December. It is suggested that the monitoring methods and prevention strategies should be adjusted in time according to Seasonal characteristics of scarlet fever.
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Objective To understand the seasonal and etiological characteristics of the epidemic situation of cluster fever in Pudong New Area, Shanghai, and to provide a scientific basis for the formulation of prevention and control strategies. Methods The epidemic data of cluster fever in Pudong New Area of Shanghai from 2013 to 2021 were collected, and the data were analyzed by concentration degree and circular distribution methods. Results From 2013 to 2021, there were 109 cases of cluster fever reported in Pudong New Area, with primary schools reporting the most cases, 77 cases (70.64%). The M value was 0.59. Circular distribution results showed that angle dispersion index r value was 0.54, the average angle was 357.32°, and the average angle of Rayleigh’s test Z value was 32.07. The peak day was December 28, and the peak period was from October 25 to March 3 of the following year. The cluster of fever in Pudong New Area was mainly caused by influenza virus. Most cases were single pathogen infection, and some were double pathogen infection. Influenza A virus had the highest detection rate in both single pathogen infection and double pathogen infection. Conclusion Primary schools are the focus of prevention and control of the cluster of fever in Pudong New Area. The epidemic situation of cluster fever has a strong seasonal characteristic, and the peak of incidence is from late October to early March of the next year. Respiratory pathogens such as influenza virus are the main causes of the epidemic situation.
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Objective To analyze the epidemiological characteristics and seasonal distribution of hand, foot and mouth disease (HFMD) in a suburban town in Shanghai from 2012 to 2018, and to provide a scientific basis for formulating effective prevention and control strategies. Methods The incidence data of a suburban town in Shanghai from 2012 to 2018 was collected through the Chinese disease prevention and control information system and analyzed by descriptive epidemiological methods. Results From 2012 to 2018, a total of 538 cases of hand, foot and mouth disease were reported in the suburban town in Shanghai, with an average annual incidence of 186.27/100,000. The difference in incidence between each year was statistically significant (χ2=107.95, P<0.05). The age of onset was mainly children under 5 years old. Peak incidence was from May to September. The main occupation was scattered children. HFMD outbreaks mainly occurred in nurseries and schools, accounting for 60.53% of the total number of outbreaks. Conclusion From 2012 to 2018, the incidence of HFMD in a suburban town in Shanghai had a certain seasonality. It is recommended to implement preventive measures against HFMD for key populations and key places before the high incidence period to reduce the occurrence of severe cases and epidemic situations.
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Objective To understand the epidemic characteristics of different virus types of hand, foot and mouth disease (HFMD) in Zhaotong City, and provide guidance and recommendations for the prevention and control of HFMD, and to analyze seasonal characteristics of different virus types of HFMD in Zhaotong City. Methods The epidemiological characteristics of different virus types of HFMD in Zhaotong City from 2014 to 2017 were analyzed using the concentration and circular distribution methods. Results The main pathogens detected were EV71, Cox A16 and other enteroviruses, which were 216, 182, and 294, respectively, accounting for 57.45%, 73.44%, and 67.11%. M was 0.86, indicating that EV71 had strong seasonality. The Rayleigh test showed statistically significant differences (Z = 99.53, P <0.001). ā = 157 °, the peak day of onset was May 10, similar to untyped (May 16), the peak period was April 21-June 1, and the epidemic period was April 1-June 21. Conclusion According to the incubation period of hand-foot-mouth disease and the period of time during which the vaccine develops protective effects, vaccination of hand-foot-mouth disease vaccine at the peak period has a good guiding significance for the timeliness and pertinence of vaccination.
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Objective@#To understand the seasonality and etiological characteristics of infectious diarrhea in adults from Shanghai.@*Methods@#Adult patients with diarrhea who had visited the enteric disease clinics in 22 hospitals that carrying on the Diarrhea Comprehensive Surveillance sentinel programs in Shanghai during 2014-2017, were surveyed. Stool specimens were collected according to the different intervals of sampling and detected for 12 bacteria and 5 viruses. Concentration ratio and circular distribution method were used for data analysis.@*Results@#From 2014 to 2017, a total of 9 573 stool specimens were collected from the targeted diarrhea patients ≥18 years old (n=96 067), through the Shanghai Diarrhea Comprehensive Surveillance program. The positive rate of detection was 46.44%. Seasonal peaks of infectious diarrhea were both seen in summer (bacteria peak, diarrheagenic Escherichia coli and Vibrio parahaemolyticus, etc.) and in winter (virus peak, Norovirus, etc.). Both bacterial and viral infections presented seasonal concentration (Raleigh’s test P<0.001) but more obvious with bacterial infection. Viral infection accounted for 60.19% of the cause of infectious diarrhea. The top five predominant pathogens appeared as Norovirus, Rotavirus, diarrheagenic Escherichia coli, Vibrio parahaemolyticus, and Salmonella spp..@*Conclusions@#Among the adult outpatients with infectious diarrhea in Shanghai, obvious seasonality was seen, with peaks in both summer and winter. Viral infection with Norovirus in particular, appeared as the predominant source of infection. Active, continuous and comprehensive diarrhea-related surveillance programs would be able to monitor the changing dynamic of pathogen spectrum, and lead to the adoption of targeted preventive measures.
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Objective@#To understand the dynamics and epidemiological characteristics of hand, foot and mouth disease (HFMD) in Shaanxi province during 2009-2018 and provide evidence for prevention and control of HFMD.@*Methods@#Information on HFMD was collected from the Chinese Disease Prevention and Control Information System in Shaanxi Province during 2009-2018 and was analyzed by descriptive, dynamic geometric series averaging and circular distribution methods.@*Results@#The annual average incidence rate of HFMD was 140.04/100 000 in Shaanxi province during 2009-2018. The highest incidence rates were seen in age groups as 1-year olds (3 494.24/100 000), 2-year olds (2 734.79/100 000) and 3-year olds (2 608.58/100 000). The highest reported mortality rates appeared in: 1-year olds as 1.42/100 000, 2-year olds as 0.77/100 000) and 0-year olds (0.53/100 000). The incidence rate increased most rapidly in the 1-year olds and the 0-year olds groups. The top three incidence rates were reported in Xi’an (251.34/100 000), Weinan (161.21/100 000) and Xianyang (123.73/100 000) cities in Guanzhong area of Shaanxi province. In the whole province, incidence rate was on the rise, and the average increases of incidence rates were all greater than zero in these cities. The proportion of severe cases in most cities somehow declined. Results from the circular distribution method estimated that the peak incidence would appear in April 10-11 each year, and the high incidence season was from April to July. In 2018, the composition of enterviruses (EV) 71 was 26.47% (1 303/4 922). In 2014 to 2018, the proportion of Coxsackie virus A16 (Cox A16) was between 20.06%(753/3 753) and 23.08% (855/3 705). The proportions of other EVs increased from 6.09% (14/230) to 51.91% (2 555/4 922) during 2009-2018.@*Conclusions@#The overall incidence rate of HFMD was increasing, with high risk population appeared in children under 3 year olds, in Shaanxi province during 2009-2018. However, both mortality and fatality rates were declining, with severe cases also showing a downward trend in most of the areas. Composition of pathogens was changing over time.
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Objective To investigate the time distribution of pre-hospital emergency stroke patients,so as to provide recommendations for stroke prevention and control.Methods The information of 2844 stroke patients from 2013 to 2016 was collected from emergency medical center of Wenzhou,and circular distribution method was used to analyze the seasonal stroke incidence.Results Both seasonal and daily occurrence of cerebralvascular accidents showed weak(all r<0.3) trends of centralization(all P<0.05).The average angle for each year was not equal,and the average angle of 2014 was significantly different from the other years(P<0.05). The peak time point of every year(except 2014)was on the 4th of January and the peak time period was from the 2nd of September to the 9th of May of next year. The average angle for every day was(230.965±108.999)°(P<0.05),which suggested that the peak time point was 14:35,and the peak time period was from 7:19 to 21:51.Conclusion Stroke morbidity has obvious seasonality in Wenzhou,and the peak time was in winter and spring. Besides,the cerebralvascular accidents occures more often in the day time.The time distribution characteristics of stroke patients should be considered when studying the causes of stroke.
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Objective To investigate the features of time distribution in the onset of aortic dissection (AD).Methods The retrospective cross-sectional study was conducted.The clinical data of 476 AD patients who were admitted to the First Affiliated Hospital of Anhui Medical University from January 2009 to June 2017 were collected.The patients were divided by the following criteria:gender,age [youth(＜45 years),middle-age (45-59 years) and elderly (≥ 60 years)],Stanford types (type A and type B),with or without hypertension.All variables were analyzed by circular distribution statistics to illuminate the features of time distribution in the onset of AD (monthly rhythm and circadian rhythm).Observation indicators:(1) overall time distribution of AD;(2) time distribution of subgroups with different genders;(3) time distribution of subgroups with different age;(4) time distribution of subgroups with different Stanford types;(5) time distribution of subgroups with or without hypertension.Measurement data with normal distribution were represented as (x)±s and count data were described as constituent ratio.The circular distrbution statistics were used to calculate time data of onset after trigonometric function transformation.The monthly rhythm and circadian rhythm were done using the Rayleigh test (Z value).Results (1) Overall time distribution of AD:the AD patients had the monthly rhythm and circadian rhythm (Z=14.79,31.60,P＜0.05).The months with the maximum and minimum cases were November (59 cases) and August (24 cases) respectively,the peak day was on January 12.AD often occurred from 16:00 to 17:00 (37 cases) but barely occurred from 3:00 to 4:00 (8 cases),with a peak of 14:55.(2) Time distribution of subgroups with different gender:male subgroup had the monthly rhythm and circadian rhythm (Z =11.28,27.81,P＜0.05);female subgroup had the monthly rhythm and circadian rhythm (Z=3.48,4.37,P＜0.05).(3) Time distribution of subgroups with different age:patients in the youth subgroup had no monthly rhythm (Z=1.33,P＞0.05),and there was the circadian rhythm (Z=4.29,P＜0.05);patients in the middle-age subgroup had the monthly rhythm and circadian rhythm (Z =7.48,17.41,P＜0.05);patients in the old-age subgroup had the monthly rhythm and circadian rhythm (Z =6.62,11.04,P ＜ 0.05).(4) Time distribution of subgroups with different Stanford type:patients inthe type A subgroup had no monthly rhythm (Z=1.60,P＞0.05),and there was the circadian rhythm (Z=10.51,P＜0.05);patients in the type B subgroup had the monthly rhythm and circadian rhythm (Z=13.94,21.70,P＜0.05).(5) Time distribution of subgroups with or without hypertension:subgroups with hypertension had the monthly rhythm and circadian rhythm (Z =12.08,29.81,P＜ 0.05).Subgroups without hypertension had no monthly rhythm (Z=3.84,P＞0.05),showing a statistically significant difference in the circadian rhythm (Z=4.78,P＜0.05).Conclusion AD often occurs in cold months and afternoon.
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Objective To investigate pulmonary embolism (PE) clinical characteristics, the first clinical symptoms, and risk factors.Methods Incidence trends, clinical manifestations, etiology and inducing factors of 459 PE cases were analyzed retrospectively.Results For women the two peak period of PE incidence are 20-25 years of age and 60-70 years of age, for men are 20-30 years and 60-70 years;For both men and women PE incidence is peaked at 40-65 years of age.Circular distribution statistics showed the peak incidence of PE falls from November 30 through April 4, roughly in seasons of winter and spring.Dyspnea, chest distress, were among the most common symptoms (64.04％).Pulmonary infarction trilogy accounted for only 8.50％.Surgery, trauma, fracture were the primary causes for PE (44.88％), with tumor accounting for 13.0％.The veins affected by DVT are plexus venosus leg muscle, femora popliteal vein, iliac veins, tibial and peroneal veins.Conclusions The incidence of PE has obvious central tendency of age, season.Clinical symptoms are varied and non-specific.Surgery, trauma and fractures are the primary cause of PE, tumor is an independent risk factor for PE.
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Objective To investigate the regularity of variation in number of emergency patients visiting doctors within each 24 h during holidays and festival days,so as to provide a scientific basis for hospital administration and the rational allocation of human resources.Methods Based on the hospital's statistical data of emergency patients visiting doctors during winters from December 2010 to February 2014,a retrospective analysis was carried out for the number and the visiting time of emergency patients on holidays (weekends,the minor long holiday of 3 days for New Year and the major long holiday of 7 days for spring festival) and on general working days (Monday to Friday),respectively.The variation in number of patients and peak time of visiting doctors were analyzed by using circular distribution method,and compared the differences in the number of emergency patients visiting doctors and peak time period between holidays and working days.Results Most of emergency patient visitors were 50-79 years old males; the number of emergency patients on holidays was significantly higher than that on general working days,especially during the seven-day spring festival (P ＜ 0.01),while the number on New Year' s day was similar to that on weekends; peak time for emergency patients' visiting doctors was from 13:05 to 0:28 during general working days.On the contrary,the peak time occurred earlier at 10:05 until 21:05 during the holidays if the hospital offers half-day outpatient service,and in the absence of outpatient service,the peak time emerged further earlier at 9:16 until 21:26 during holidays.Conclusions The ages,number and the peak time of emergency patients visiting doctors on holidays are different from those on the general working days,so medical staff on duty should be arranged reasonably to follow this regularity.
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ABSTRACT:The seasonal characteristics of Japanese encephalitis (JE) in Gansu Province in 1962-2010 were analyzed in order to provide reference for making strategies of disease control and prevention .The JE data is the Epidemic Data between 1962 and 2003 from Gansu CDC ,and National Notifiable Diseases Registry System (NNDRS ,2004-2010) .Concentration ra‐tio and circular distribution method were used in this study .Results showed that the M‐value of the seasonal distribution of JE in 1962-2010 was 0 .825 9 .The corresponding peak date of JE was the 30th August (95% CI:22 July to 7 October) .The Z value of Rayleigh test was 3 506 .092 5 (P<0 .01) .In conclusion ,the concentration and circular distribution method helps us to grasp the JE epidemic peak season more accurately .There were significant seasona1 characteristics for JE in Gansu Province and the epidemic peak was from late July to early October .
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Objective To analyze the prevalent feature and variant tendency of Scrub Typhus in Guangdong Province from 2006 to 2012, and provide a basis of strategy and measure on prevention and protection of Scrub Typhus. Methods Clinical information of all individual cases was gained from China Information System for Disease Control and Prevention. Cochran-Armitage trend χ2 test was used to describe the variance of Scrub Typhus incidence and the clinical cases of 2013 were predicted by autoregressive integrated moving average (ARIMA) model, while descriptive epidemiological analysis was adopted to describe the endemic distribution, seasonal characteristics and population distribution of Scrub Typhus. Results A total of 8 163 Scrub typhus cases were reported in Guangdong Province from 2006 to 2012. Annual mean incidence of the disease was 1.15/100 000 with the incidence showing an upward tendency (χ2 = 3 191.976, P < 0.01). There were 14 dead clinical cases reported with a fatality rate to be 1.72‰(14/8 163). Totally 3 166 people were predicted to infect Scrub Typhus in 2013 by ARIMA model. The disease was prevalent from the end of May to early October and the peak time was in late August (Z = 2 303.71, P < 0.01). The top five cities developed Scrub Typhus were Zhaoqing, Guangzhou, Yunfu, Shaoguan and Qingyuan. Male-female ratio was 1.00 ∶ 1.08 in all reported cases in which 52.78%(4 309/8 163) of them aged from 40 to 65 years old and 59.30%(4 841/8 163) of them were farmers. Conclusions The incidence of Scrub Typhus is rising in Guangdong Province, with the prevalent peak in summer and autumn, and rural populations are at high risk. The most effective preventions are strengthening health education , enhancing individual protection and protecting key populations in special districts.
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Objective To investigate the seasonal variability of the onset of acute deep vein thrombosis(DVT).Methods The clinical manifestations in 774 DVT patients during January 2008 to December 2012 were collected and circular distribution statistics was used to identify seasonal variability.Results The total sample had the significant seasonal variability (P ＜ 0.01):DVT was most frequent in winter while less frequent in summer and the peak day was January 1.Female subgroup has significant seasonal variability (P ＜0.01):on peak in winter and at trough in summer while male subgroup has no significant seasonal variability (P ＜ 0.01).Different age subgroups (＜ 40 years,40-69 years,＜70 years)have significant seasonal variability(P ＜ 0.05,P ＜ 0.01,P ＜ 0.01).DVT was most common in December and less frequent in August.Left lower limb subgroup and both lower limb subgroup has significant seasonal variability (P ＜ 0.01,P ＜ 0.01),on peak in December-January.Immobilization subgroup also has significant seasonal variability (P ＜ 0.001):frequent in winter,January 1 is on the peak.Conclusions DVT has significant seasonal variability in onset:it is most frequently seen in winter while less frequent in summer.Some subgroups (female,＜70 years and immobilization) have the most significant seasonal variability in onset.
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Objective To analyze the prevalence season and trend of meningococcal disease in China by epidemic years from 2004 to 2008 in order to provide scientific basis for making strategies of meningococcal disease prevention and control.Methods The incidence numbers of meningococcal disease were calculated by weeks,epidemic years and areas.The seasonality and prevalence trends of meningococcal disease were analyzed by circular distribution.Results The incidence trend of meningococcal disease had obvious seasonality in China (P
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Objective To study the relationship between cerebral vascular disease (CVD) and meteorological factors. Methods From 1998 to 2002, 6186 patients with CVD in Qingdao urban were studied. There were 1179 cases of intracerebral hemorrhage (CH), 4821cases of cerebral infarction (CI) and 186 cases of subarachnoid hemorrage (SAH). The relationship between the onset of CVD and meteorological factors including temperature, air pressure, relative humidity, wind velocity was analyzed by circular distribution analysis, Pearson correlation and multiple stepwise regression. Results High incidence of CH was found in winter and the mean angle was in January ((P