Epidemiology of fascioliasis in human endemic areas

2005 ◽  
Vol 79 (3) ◽  
pp. 207-216 ◽  
Author(s):  
S. Mas-Coma

AbstractConsidered a secondary zoonotic disease until the mid-1990s, human fascioliasis is at present emerging or re-emerging in many countries, including increases of prevalence and intensity and geographical expansion. Research in recent years has justified the inclusion of fascioliasis in the list of important human parasitic diseases. At present, fascioliasis is a vector-borne disease presenting the widest known latitudinal, longitudinal and altitudinal distribution.Fasciola hepaticahas succeeded in expanding from its European original geographical area to colonize five continents, despite theoretical restrictions related to its biology and in turn dependent upon environmental and human activities. Among the different epidemiological situations, human hypo- to hyperendemic areas, including epidemics, are noteworthy. A global analysis of the distribution of human cases shows that the expected correlation between animal and human fascioliasis only appears at a basic level. Areas presenting very high human prevalences and intensities, especially in children and females, have been recently described. In hypo- to hyperendemic areas of Central and South America, Europe, Africa and Asia, human fascioliasis presents a range of epidemiological characteristics related to a wide diversity of environments. Thus far well-known epidemiological patterns of fascioliasis may not always explain the transmission characteristics in any given area and control measures should consider the results of ecoepidemiological studies undertaken in the zones concerned.

2020 ◽  
Author(s):  
Xinyin Xu ◽  
Jing Zeng ◽  
Runyou Liu ◽  
Yang Liu ◽  
Xiaobo Zhou ◽  
...  

Abstract Background: The COVID-19 spread worldwide quickly. Exploring the epidemiological characteristics could provide a basis for responding to imported cases abroad and to formulate prevention and control strategies in areas where COVID-19 is still spreading rapidly. Methods: The number of confirmed cases, daily growth, incidence and length of time from the first reported case to the end of the local cases (i.e., non-overseas imported cases) were compared by spatial (geographical) and temporal classification and visualization of the development and changes of the epidemic situation by layers through maps. Results: In the first wave, a total of 539 cases were reported in Sichuan, with an incidence rate of 0.6462/100,000. The closer to Hubei the population centres were, the more pronounced the epidemic was. The peak in Sichuan Province occurred in the second week. Eight weeks after the Wuhan lockdown, the health crisis had eased. The longest epidemic length at the city level in China (except Wuhan, Taiwan, and Hong Kong) was 53 days, with a median of 23 days. Spatial autocorrelation analysis of China showed positive spatial correlation (Moran's Index >0, p<0.05). Most countries outside China began to experience a rapid rise in infection rates 4 weeks after their first case. Some European countries experienced that rise earlier than the USA. The pandemic in Germany, Spain, Italy, and China took 28, 29, 34, and 18 days, respectively, to reach the peak of daily infections, after their daily increase of up to 20 cases. During this time, countries in the African region and Southeast Asian region were at an early stage of infections, those in the Eastern Mediterranean region and region of the Americas were in a rapid growth phase. Conclusions: After the closure of the outbreak city, appropriate isolation and control measures in the next 8 weeks were key to control the outbreak, which reduced the peak value and length of the outbreak. Some countries with improved epidemic situations need to develop a continuous "local strategy at entry checkpoints" to respond to a possible second local epidemic.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Xinyin Xu ◽  
Jing Zeng ◽  
Runyou Liu ◽  
Yang Liu ◽  
Xiaobo Zhou ◽  
...  

Abstract Background The COVID-19 spread worldwide quickly. Exploring the epidemiological characteristics could provide a basis for responding to imported cases abroad and to formulate prevention and control strategies in areas where COVID-19 is still spreading rapidly. Methods The number of confirmed cases, daily growth, incidence and length of time from the first reported case to the end of the local cases (i.e., non-overseas imported cases) were compared by spatial (geographical) and temporal classification and visualization of the development and changes of the epidemic situation by layers through maps. Results In the first wave, a total of 539 cases were reported in Sichuan, with an incidence rate of 0.6462/100,000. The closer to Hubei the population centres were, the more pronounced the epidemic was. The peak in Sichuan Province occurred in the second week. Eight weeks after the Wuhan lockdown, the health crisis had eased. The longest epidemic length at the city level in China (except Wuhan, Taiwan, and Hong Kong) was 53 days, with a median of 23 days. Spatial autocorrelation analysis of China showed positive spatial correlation (Moran’s Index > 0, p < 0.05). Most countries outside China began to experience a rapid rise in infection rates 4 weeks after their first case. Some European countries experienced that rise earlier than the USA. The pandemic in Germany, Spain, Italy, and China took 28, 29, 34, and 18 days, respectively, to reach the peak of daily infections, after their daily increase of up to 20 cases. During this time, countries in the African region and Southeast Asian region were at an early stage of infections, those in the Eastern Mediterranean region and region of the Americas were in a rapid growth phase. Conclusions After the closure of the outbreak city, appropriate isolation and control measures in the next 8 weeks were key to control the outbreak, which reduced the peak value and length of the outbreak. Some countries with improved epidemic situations need to develop a continuous “local strategy at entry checkpoints” to to fend off imported COVID-19.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Huijie Chen ◽  
Ye Chen ◽  
Baijun Sun ◽  
Lihai Wen ◽  
Xiangdong An

Abstract Background Since 2011, there has been an increase in the incidence of scarlet fever across China. The main objective of this study was to depict the spatiotemporal epidemiological characteristics of the incidence of scarlet fever in Shenyang, China, in 2018 so as to provide the scientific basis for effective strategies of scarlet control and prevention. Methods Excel 2010 was used to demonstrate the temporal distribution at the month level and ArcGIS10.3 was used to demonstrate the spatial distribution at the district/county level. Moran’s autocorrelation coefficient was used to examine the spatial autocorrelation and the Getis-Ord statistic was used to determine the hot-spot areas of scarlet fever. Results A total of 2314 scarlet fever cases were reported in Shenyang in 2018 with an annual incidence of 31.24 per 100,000. The incidence among males was higher than that among females(p<0.001). A vast majority of the cases (96.89%) were among children aged 3 to 11 years. The highest incidence was 625.34/100,000 in children aged 5–9 years. In 2018 there were two seasonal peaks of scarlet fever in June (summer-peak) and December (winter-peak). The incidence of scarlet fever in urban areas was significantly higher than that in rural areas(p<0.001). The incidence of scarlet fever was randomly distributed in Shenyang. There are hotspot areas located in seven districts. Conclusions Urban areas are the hot spots of scarlet fever and joint prevention and control measures between districts should be applied. Children aged 3–11 are the main source of scarlet fever and therefore the introduction of prevention and control into kindergarten and primary schools may be key to the control of scarlet fever epidemics.


2019 ◽  
Author(s):  
Huijie Chen ◽  
Ye Chen ◽  
Baijun Sun ◽  
Lihai Wen ◽  
Xiangdong An

Abstract Background : Since 2011, the rising incidence of scarlet fever has exerted a marked influence on people. The main objective of this study was to depict the Spatiotemporal epidemiological characteristics of the incidence of scarlet fever in Shenyang, China, in 2018 so as to provide the scientific basis for effective strategies of scarlet control and prevention. Methods: Excel 2010 was used to demonstrate the temporal distribution at the month level and ArcGIS10.3 was used to demonstrate the spatial distribution at the district/county level. Moran’s autocorrelation coefficient was used to examine the spatial autocorrelation and the Getis-Ord statistic was used to determine the hot-spot areas of scarlet fever. Results: A total of 2,314 scarlet fever cases were reported in Shenyang in 2018 with an annual incidence of 31.24 per 100,000. The incidence among males was higher than that among females( p <0.001). A vast majority of the cases (96.89%) were among children aged 3 to 11 years. The highest incidence was 625.34/100,000 in children aged 5-9 years. There are two seasonal peaks occurred in June (Summer-peak) and in December (Winter-peak) in 2018. The incidence of scarlet fever in urban areas was significantly higher than that in rural areas( p <0.001).The incidence of scarlet fever was randomly distributed in Shenyang. There are hotspot areas located in seven districts. Conclusions: Urban areas are the hot spots of scarlet fever and joint prevention and control measures between districts should be applied. Children in the kindergartens and the primary schools are the main population of scarlet fever and measures for prevention and control in kindergartens and primary schools may be the key to control the epidemic of scarlet fever.


2020 ◽  
Vol 148 ◽  
Author(s):  
Wen-ting Zha ◽  
Feng-rui Pang ◽  
Nan Zhou ◽  
Bin Wu ◽  
Ying Liu ◽  
...  

Abstract Varicella is an acute respiratory infectious diseases, with high transmissibility and quick dissemination. In this study, an SEIR (susceptible-exposed-infected-recovered) dynamic model was established to explore the optimal prevention and control measures according to the epidemiological characteristics about varicella outbreak in a school in a central city of China. Berkeley Madonna 8.3.18 and Microsoft Office Excel 2010 software were employed for the model simulation and data management, respectively. The result showed that the simulated result of SEIR model agreed well with the reported data when β (infected rate) equal to 0.067. Models showed that the cumulative number of cases was only 13 when isolation adopted when the infected individuals were identified (assuming isolation rate was up to 100%); the cumulative number of cases was only two and the TAR (total attack rate) was 0.56% when the vaccination coefficient reached 50%. The cumulative number of cases did not change significantly with the change of efficiency of ventilation and disinfection, but the peak time was delayed; when δ (vaccination coefficient) = 0.1, m (ventilation efficiency) = 0.7 or δ = 0.2, m = 0.5 or δ = 0.3, m = 0.1 or δ = 0.4 and above, the cumulative number of cases would reduce to one case and TAR would reduce to 0.28% with combined interventions. Varicella outbreak in school could be controlled through strict isolation or vaccination singly; combined interventions have been adopted when the vaccination coefficient was low.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Reza Shafiei ◽  
Bahador Sarkari ◽  
Seyed Mahmuod Sadjjadi ◽  
Gholam Reza Mowlavi ◽  
Abdolali Moshfe

The current study aimed to find out the morphometric and genotypic divergences of the flukes isolated from different hosts in a newly emerging focus of human fascioliasis in Iran. AdultFasciolaspp. were collected from 34 cattle, 13 sheep, and 11 goats from Kohgiluyeh and Boyer-Ahmad province, southwest of Iran. Genomic DNA was extracted from the flukes and PCR-RFLP was used to characterize the isolates. The ITS1, ITS2, and mitochondrial genes (mtDNA) of NDI and COI from individual liver flukes were amplified and the amplicons were sequenced. Genetic variation within and between the species was evaluated by comparing the sequences. Moreover, morphometric characteristics of flukes were measured through a computer image analysis system. Based on RFLP profile, from the total of 58 isolates, 41 isolates (from cattle, sheep, and goat) were identified asFasciola hepatica, while 17 isolates from cattle were identified asFasciola gigantica. Comparison of the ITS1 and ITS2 sequences showed six and seven single-base substitutions, resulting in segregation of the specimens into two different genotypes. The sequences of COI markers showed seven DNA polymorphic sites forF. hepaticaand 35 DNA polymorphic sites forF. gigantica. Morphological diversity of the two species was observed in linear, ratios, and areas measurements. The findings have implications for studying the population genetics, epidemiology, and control of the disease.


2019 ◽  
Author(s):  
Huijie Chen ◽  
Ye Chen ◽  
Baijun Sun ◽  
Lihai Wen ◽  
Xiangdong An

Abstract Background: Since 2011, there has been an increase in the incidence of scarlet fever across China. The main objective of this study was to depict the spatiotemporal epidemiological characteristics of the incidence of scarlet fever in Shenyang, China, in 2018 so as to provide the scientific basis for effective strategies of scarlet control and prevention. Methods: Excel 2010 was used to demonstrate the temporal distribution at the month level and ArcGIS10.3 was used to demonstrate the spatial distribution at the district/county level. Moran’s autocorrelation coefficient was used to examine the spatial autocorrelation and the Getis-Ord statistic was used to determine the hot-spot areas of scarlet fever. Results: A total of 2,314 scarlet fever cases were reported in Shenyang in 2018 with an annual incidence of 31.24 per 100,000. The incidence among males was higher than that among females(p<0.001). A vast majority of the cases (96.89%) were among children aged 3 to 11 years. The highest incidence was 625.34/100,000 in children aged 5-9 years. In 2018 there were two seasonal peaks of scarlet fever in June (summer-peak) and December (winter-peak).The incidence of scarlet fever in urban areas was significantly higher than that in rural areas(p<0.001).The incidence of scarlet fever was randomly distributed in Shenyang. There are hotspot areas located in seven districts. Conclusions: Urban areas are the hot spots of scarlet fever and joint prevention and control measures between districts should be applied. Children aged 3-11 are the main source of scarlet fever and therefore the introduction of prevention and control into kindergarten and primary schools may be key to the control of scarlet fever epidemics.


2021 ◽  
Vol 1 (1) ◽  
pp. 3-8
Author(s):  
Zhenwei Pan ◽  
Yong Zhang ◽  
Tengfei Pan ◽  
Haihai Liang ◽  
Baofeng Yang

Abstract Hypertension is the most common cardiovascular condition in clinical practice and a major risk factor for stroke and cardiovascular events. There are more than 270 million hypertension patients in China, and the prevalence of hypertension in the high-latitude cold areas is significantly higher than in the low-latitude warm areas. The unique epidemiological characteristics and risk factors of hypertension in the cold regions of China urge for establishment of the prevention and control system for targeted and more effective management of the condition.


2019 ◽  
Author(s):  
Huijie Chen ◽  
Ye Chen ◽  
Baijun Sun ◽  
Lihai Wen ◽  
Xiangdong An

Abstract Objectives: To depict the Spatiotemporal epidemiological characteristics of the incidence of scarlet fever in Shenyang, China, in 2018 so as to provide the scientific basis for effective strategies of scarlet control and prevention. Methods: Excel 2010 was used to demonstrate the temporal distribution at the month level and ArcGIS10.3 was used to demonstrate the spatial distribution at the district/county level. Moran’s autocorrelation coefficient was used to examine the spatial autocorrelation and the Getis-Ord statistic was used to determine the hot-spot areas of scarlet fever. Results: A total of 2,314 scarlet fever cases were reported in Shenyang in 2018 with an annual incidence of 31.24 per 100,000. The incidence among males was higher than that among females(X2=95.013, P≤0.001). A vast majority of the cases (96.89%) were among children aged 3 to 11 years. The highest incidence was 625.34/100,000 in children aged 5-9 years. There are two seasonal peaks occurred in June (Summer-peak) and in December (Winter-peak) in 2018. The incidence of scarlet fever in urban areas was significantly higher than that in rural areas(X2=514.115, P≤0.001).The incidence of scarlet fever was randomly distributed in Shenyang. There are hot-spots areas located in seven districts. Conclusions: Urban areas are the hot spots of scarlet fever and joint prevention and control measures between districts should be applied. Children in the kindergartens and the primary school students are the main population of scarlet fever and the time distribution of scarlet fever is highly consistent with their school and vacation time. It is suggested that measure for prevention and control of scarlet fever in kindergartens and primary schools is the key to control the epidemic of scarlet fever.


2021 ◽  
Vol 8 ◽  
Author(s):  
Ying Peng ◽  
Tianlong Yang ◽  
Yuanzhao Zhu ◽  
Qingqing Hu ◽  
Yao Wang ◽  
...  

Despite the adoption of a national immunization program in China, the incidence of mumps remains high. This study aimed to describe the epidemiological characteristics, including the time, region, occupation, and age, of mumps in Wuhan from 2005 to 2018 and to evaluate its transmissibility. In this study, the susceptible–exposed–infectious–asymptomatic–recovered (SEIAR) model fitted the actual incidence data of mumps. The effective reproduction number (Rt) was used to evaluate and compare the transmission capacity in different areas. From 2005 to 2018, there were 36,415 cases. The incidence of mumps was highest among people aged 5–10 years (460.02 per 100,000). The SEIAR model fitted the reported mumps data well (P &lt; 0.01). The median transmissibility (Rt) was 1.04 (range = 0–2.50). There were two peak spreads every year (from March to May and from October to December). The Rt peak always appeared in the first 2 months of the peak incidence rate. The peak time of the epidemic spread of mumps was 1–2 months earlier than the peak incidence rate. The prevention and control measures of vaccination for children aged 5–10 years should be taken before the peak transmission capacity each year, 2 months before the peak of the outbreak, to reduce the spread of mumps.


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