The progress and challenge of Japanese encephalitis control and prevention in China / 中华预防医学杂志

Japanese encephalitis (JE) is the important viral encephalitis in China. In the 1940s, JE was confirmed to be epidemic in China. In 1971, the annual incidence rate was 20.92/100 000. Since 2008, JE vaccine was included in the national Expanded Program of Immunization (EPI). In 2013, the incidence of Japanese encephalitis decreased to 0.16/100 000. JE virus is divided into five genotypes, and genotype 1, 3 and 5 JE virus was isolated in China. Genotype 1 JE virus was the mainly genotype currently circulated in China. In recent years, the characteristics of the population of JE have been changed to adult, especially in the northern provinces of China. JE prevention and control faces new challenges.

The characteristics of cranial magnetic resonance imaging in adult Japanese encephalitis / 中华传染病杂志

Objective To analyze the magnetic resonance imaging (MRI) images of patients with adult Japanese encephalitis (JE),and to investigate the diagnostic value of MRI for the disease.Methods Thirty-two adult JE patients who underwent cranial MRI at General Hospital of Ningxia Medical University between August 2016 and September 2018 were enrolled.All patients had disease onset between August and September and they aged 17 to 83 years old.The clinical data,laboratory results,MRI signal characteristics of each scanning sequence and the distribution of the brain lesions were retrospectively analyzed.Results Of the 32 adult JE patients,29 (90.6％)cases had acute onset,28 (87.5％) cases had unconsciousness and cognitive impairment,26 (81.2％) cases had intracranial hypertension,3 (9.4％) cases had meningeal irritation,3 (9.4％) cases had Parkinson-like symptoms,10 (31.2％) cases had epilepsy,and 15 (46.9％) cases had decreased muscle strength.Twenty patients were positive for JE virus-specific IgM antibodies.Twenty-eight patients underwent cerebrospinal fluid examination,15 (53.6％) cases showed intracranial pressure ≥180 mmH2O (1 mmH2O =0.009 8 kPa),7 (25％) cases developed lymphocyte reaction,and 16 (57.1％) cases showed mixed cell reaction.Twenty-three cases (71.9％) showed lesions of brain on MRI,including thalamus (17 cases,73.9％),hippocampus (13 cases,56.5％),cerebral peduncle (6 cases,26.1％),cortical and subcortical (4 cases,17.4％),basal ganglia (2 cases,8.7％),brainstem (1 case,4.3％) and splenium of corpus callosum (1 case,4.3％).Positive T1 weight image (T1WI) and T2 weight image (T2WI) results were found in 21 patients,respectively,23 patients had positive T2-fluid attenuated inversion recovery (FLAIR) images,and 20 patients had positive diffusion weighted imaging (DWI) images.Among them,T2-FLAIR and DWI images showed more lesions,wider range of lesions and clearer boundary of cortical involvement range than T1WI and T2WI images.Conclusions Bilateral thalamus and hippocampus are often involved in adult JE.T2-FLAIR and DWI sequences are more sensitive to detect lesions.Combining MRI images with epidemiological characteristics,clinical manifestations,and laboratory tests is of great assistance for early diagnosis of JE.

Domestic and international trend of vector-borne disease

The incidence of vector-borne diseases has increased with climate change and developments of transportation. Malaria was eliminated in the early 1980s in Korea, but one domestic case was reported in 1993. The number of patients increased to 4,142 in 2002, and less than 700 cases of malaria are reported annually nowadays. Additionally, approximately 70 to 80 imported malaria cases were reported annually, and most of them are Plasmodium falciparum infections from Africa. Annually, 20 to 40 cases of Japanese encephalitis are reported, and the incidence is high in individuals between the ages of 40 and 59. Moreover, 313 cases of dengue fever were imported in 2016, and most of them were from Southeast Asia. In 2016, 11,000 cases of scrub typhus were reported, and most of the patients were older than 50. The number of reported cases of severe fever with thrombocytopenia syndrome has been increasing since 2013, mostly in patients older than 60. It is important to avoid vectors for the prevention, and for the doctors to diagnose the apatients as soon as possible.

Current status and outlook of mosquito-borne diseases in Korea

The recent epidemic of Zika virus in South America caused people around the world to exhibit an increased interest in the impact of arboviral illnesses. In Korea, malaria and Japanese encephalitis are the most important mosquito-borne diseases that occur indigenously. However, with the continuously increasing number of international travelers, the incidence of imported arboviral illnesses is also increasing. Currently, dengue fever is the most common mosquito-borne disease among Korean international travelers. The number of patients with Japanese encephalitis, chikungunya fever, and Zika virus infection is also on the rise. Many countries that have disease-transmitting mosquitoes have already experienced autochthonous arboviral infections due to the introduction of viruses by travelers. Moreover, with global warming and urbanization of the areas in which mosquito-borne diseases occur, the environment is becoming more favorable for mosquito-borne diseases. This concise review describes the current status and outlook of mosquito-borne diseases in Korea.

Relationship between Japanese encephalitis and S100B protein / 中华神经科杂志

Objective To investigate the role of S100B protein in the pathogenesis of patients with Japanese encephalitis (JE).Methods A total of 45 patients were enrolled in the Second Hospital of Hebei Medical University from August 2013 to October 2013,who were diagnosed as JE on the basis of clinical features and positive IgM antibodies against JE virus measured by enzyme-linked immunosorbent assay (ELISA) from the Center of Disease Control of Shijiazhuang.The JE patients were divided into initial phase group,acute phase group and convalescence group based on the course,mild JE group,moderate JE group and severe JE group based on the severity,MRI-no-lesion group and MRI lesions group based on the imaging findings of JE.Twelve cases with no evidence of infection in central nervous system in the meantime were chosen as control.The S100B protein was measured by ELISA.Results The content of S100B protein in cerebrospinal fluid was as follows:522.76 (393.35,620.37) pg/ml in mild JE group (acute phase group:609.77 (549.27,779.71) pg/ml,convalescence group:420.48 (344.36,453.19) pg/ml),792.09 (705.47,1 108.96) pg/ml in moderate JE group (acute phase group:770.19 (646.31,1 069.54) pg/ml,convalescence group:803.45 (602.90,1 396.84) pg/ml),and 1 021.94 (680.84,1 302.15) pg/ml in severe JE group (acute phase group:981.82 (680.84,1 826.28) pg/ml,convalescence group:989.00 (553.62,1 207.67) pg/ml).The S100B protein content was 561.52 (454.36,814.56) pg/ml,803.45 (602.90,1 104.01) pg/ml,762.22 (594.95,1 044.97) pg/ml,581.76 (442.51,1 069.10) pg/ml in MRI-no-lesion group,MRI lesions group,total acute phase group and total convalescence group,respectively.While in control group,the S100B protein content was 266.71 (205.72,390.05) pg/ml.The contents of S100B protein in moderate JE group,severe JE group,total acute phase group,total convalescence group,MRI-no-lesion group,MRI lesions group were higher than that in control group (H =4.864,5.497,5.075,3.918,2.971,4.981,P =0.000,0.000,0.000,0.000,0.009,0.000).The contents of S100B protein in mild JE group was lower than that in moderate JE group and severe JE group (H =-2.786,-3.514,P =0.032,0.003).Conclusions The level of S100B protein in cerebrospinal fluid is related with the severity,duration and imaging presentation of JE patients.The dynamic monitoring of S100B protein levels is of great significance for assessment of the patients' condition and curative effect.

Clinical characteristics of epidemic Japanese encephalitis in adults / 中华神经科杂志

Objective To study the clinical characteristics of epidemic Japanese encephalitis in 4 adult patients and to improve the level of diagnosis.Methods The clinical characteristics, laboratory results and MRI features of 4 adult patients with epidemic Japanese encephalitis hospitalized in our hospital between 2007 and 2008 was retrospectively reviewed and analyzed.Results All patients were sporadic.Two were female and others were male with the age from 34 to 68 years old and onset in summer and autumn.One patient had diarrhea at onset while others had fever and headache at onset.All patients had high fever and psychiatric symptoms.Two patients had respiratory failure.Obvious elevation of white cells in cerebrospinal fluid was seen in all patients and Japanese viral antibody of IgM was all positive whereas the image of MRI was abnormal only in one patient.Two patients had neurological sequelae.Conclusions The clinical manifestations of epidemic Japanese encephalitis in adults are severe and untypical and the respiratory failure is likely to occur.

Detection of cytokines in the serum and cerebrospinal fluid of the patients with epidemic encephalitis B and its clinical significance / 中华传染病杂志

Objective To detect the levels of tumor necrosis factor (TNF)-a,interleukin (IL)-1β,IL-2,1L-6,IL-8,1L-10,IL-12 and interferon (IFN)-α in the serum and cerebrospinal fluid of the patients with epidemic encephalitis B,and to investigate the roles in pathogenesis of epidemic encephalitis B.Methods Approximately of 2 mL serum and 2 mL cerebrospinal fluid from 24 patients with epidemic encephalitis B during acute phase were collected,and 2 mL serum from 20 healthy controls were collected.The levels of eytokines in serum and cerebrospinal fluid were detected by enzyme linked immunosorbent assay (ELISA).Means of multi-sample were compared by analysis of variance and means of two-sample were compared by t test.Results The levels of TNF-α,IL-1β,IL-6,IL-8,IL-10 and IFN-α in eerebrospinal fluid were (24.5±6.6),(7.8±2.4),(16.0±5.7),(17.6±4.8),(130.2±33.6) and (45.2±10.8) ng/L,respectively,and in serum were (25.3±11.2),(7.1±3.2),(14.5±6.2),(16.0±6.5),(82.0±27.8) and (42.5±16.2) ng/L,respectively.The levels of TNF-α,IL-1β,IL-6,IL-8,IL-10 and IFN-α in serum and cerebrospinal fluid from patients with epidemic encephalitis B were all higher than those in serum of healthy controls [(12.7±7.9),(2.6±1.0),(6.2±2.2),(9.6±3.3),(71.4±12.8) and (30.0±14.0) ng/L;F value was 14.10,29.46,23.38,14.78,32.59,7.52;all P＜0.01];while the levels of IL-2 and IL-12 were not increased significantly.The levels of IL-1β,IL-6,IL-8,IL-10,IL-12 and IFN-α in cerebrospinal fluid were higher than those in serum,while the levels of TNF-± and IL-2 in cerebrospinal fluid were lower than those in serum.The levels of IL-6 and IL-8 in cerebrospinal fluid from patients with severe type of epidemic encephalitis B were (18.8±5.4) ng/L and (20.7±2.7) ng/L,and were higher than those with common type [(12.1±3.0) and (13.3±3.3) ng/L;t=3.50,t=5.96;P＜0.05],while the levels of IL-2 in serum and in cerebrospinal fluid from patients with severe type were lower than those with common type. Conclusions Oversecretions of TNF-α,IL-1β,IL-6,IL-8,IL-10 and IFN-a are involved in the inflammatory damage of epidemic encephalitis B,while under-secretions of IL 2 and ILl2 may be involved in cellular immune responses.

Epidemiology and clinical characteristics of epidemic encephalitis B in Yuncheng area of Shanxi Province / 中华传染病杂志

Objective To analyze the epidemiology and clinical characteristics of epidemic encephalitis B in Yuneheng area of Shanxi Province in 2006.Methods Seventy-nine cases diagnosed with epidemic encephalitis B were enrolled in this study and correlated data,epidemic and clinical characteristics,laboratory examinations and treatment outcome were analyzed.Results Sixty-two of 79 patients(78.5%)were middle-aged or old people,all cases(100%)occurred in July,August and September,69 cases(87.3%)were peasants.All patients(100%)had fever,73(92.4%)had conscious disturbance,27(34.2%)had respiratory failure.Encephalitis B specific IgM antibody was examined and 40 cases(85.1%)were positive.Twenty cases(25.3%)had complications.When they were discharged,37 cases(46.8%)recovered completely,14 cases(17.7%)died,12 were improved and 16 were voluntarily discharged,7 cases(8.9%)left more or less neurological deficits. Conclusion The epidemiology and clinical characteristics are important basis to diagnose epidemic encephalitis B.

Japanese encephalitis in children:conventional MR imaging and diffusion weighted imaging features / 中华放射学杂志

Objective To study the conventional MRI and dittusion weighted imaging(DWI) features of Japanese encephalitis(JE)in children.Methods Sixteen patients with JE were included. Conventional MRI and DWI sequences were performed in all patients.Seven patients received MRI within 10 days of onset and 9 after 10 days.The appearances on DWI and T_2 WI were recorded.The ADC values of lesions were calculated,and then were correlated with the corresponding time interval between onset of neurological symptoms and MRI scanning.Results The lesions of JE mainly showed long T_1 and long T_2 signal intensity on MRI.The thalami were the most frequently involved areas,and 15 out of 16 showed thalamic involvement and 6 patients only showed thalamic abnormalities without other lesions.Seven patients within 10 days of onset showed lesions with high signal intensity on both DWI and T_2WI,but whole or partial lesions showed clearer on DWI than on T_2WI,and 2 patients showed extra lesions that were invisible on T_2WI.As for the other 9 patients after 10 days of onset,the lesions showed clearer on T_2WI than on DWI. There was a direct correlations between thalamic ADC values and the disease duration (r=0.84,P

Some epidemiological aspects of the outbreak of Japanese Encephalitis in Anuradhapura district, Sri Lanka 1985-86

Epidemiological findings of the first major outbreak of Japanese encephalitis which occurred between November, 1985, and February, 1986, in Anuradhapura and the surrounding districts, Sri lanka are herewith presented. Out of the 326 cases admitted during the period of 20th November, 1985 to 20th February, 1986 120 cases were serologically confirmed. there were 65 deaths. The case fatality rate was 19.9. the Anuradhapura District had 288 cases, and out of that, 105 were serologically confirmed. the incidence rate was 45.6 per 100,000 population and the mortality rate was 7.9 per 100.000 population. The highest age specific incidence rate (71.9 per 100.000 population) and the highest age specific mortality rate (57.5 per 100,000 population) were seen in the age group of 65-69. the case fatality rate was high (100) in the 55-59 and 60-64 age groups. the above-15 years age group incidence was higher than the below-15 years age group. The difference was statistically significant (p\<.05). the sex specific incidence rate was higher (54.2 per 100,000 population) in males. the difference was statistically significant (p\<.01). the inter-relationship between the patients and their occupations, period of stay in the district and animal rearing habits too, have been discussed. Compairing the epidemiological findings of the countries in the South-East Asian region, the probable factors which led to the occurrence of the outbreak, are enumerated.