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Etiology and prognosis of acute viral encephalitis and meningitis in Chinese children: a multicentre prospective study

BMC Infectious DiseasesBMC series – open, inclusive and trusted201717:494

DOI: 10.1186/s12879-017-2572-9

Received: 12 July 2016

Accepted: 27 June 2017

Published: 14 July 2017

Abstract

Background

In China, there were few studies about the pathogens of acute viral encephalitis and meningitis in children in recent years. The aims of this study were to characterize the etiology and prognosis of acute viral encephalitis and meningitis in Chinese children.

Methods

This was a multicentre prospective study. Two hundred and sixty one viral encephalitis patients and 285 viral meningitis patients were enrolled. The mean age of viral encephalitis and meningitis were 5.88 ± 3.60 years and 6.39 ± 3.57 years, respectively. Real-time reverse transcription PCR and multiplex PCR were used to detect human enteroviruses and herpes viruses in cerebrospinal fluid (CSF) of patients with encephalitis or meningitis. The enzyme-linked immune absorbent assay (ELISA) was used for detecting IgM antibody against Japanese encephalitis virus (JEV) in CSF and against mumps virus, tick-borne encephalitis virus (TBEV), dengue virus and rubella virus in acute serum. The clinical and outcome data were collected during patients’ hospitalization.

Results

The etiology of viral encephalitis was confirmed in 52.5% patients. The primary pathogen was human enteroviruses (27.7%) in viral encephalitis. The incidence of sequelae and the fatality rate of viral encephalitis with confirmed etiology were 7.5% and 0.8%, respectively. The etiology of viral meningitis was identified in 42.8% cases. The leading pathogen was also human enteroviruses (37.7%) in viral meningitis. The prognosis of viral meningitis was favorable with only 0.7% patients had neurological sequelae.

Conclusions

Human enteroviruses were the leading cause both in acute viral encephalitis and viral meningitis in children. The incidence of sequelae and fatality rate of viral encephalitis with confirmed etiology were 7.5% and 0.8%, respectively. The prognosis of viral meningitis was favorable compared to viral encephalitis.

Keywords

Viral encephalitis Viral meningitis Etiology Prognosis Children

Background

Encephalitis is a serious form of neurologic disease with inflammation of the brain parenchyma. More than 100 infectious, post-infectious, and immune-mediated conditions can cause encephalitis [1]. Viral encephalitis is the most common among them [2]. The etiology of viral encephalitis varies according to the geographical region. In the United States, Italy and Australia, the most commonly identified pathogen was herpes simplex virus in children and adults [24]. In Southern Vietnam, Japanese encephalitis virus (JEV) was the leading cause of viral encephalitis in children [5]. In Uttar Pradesh, India, enterovirus was an important cause of encephalitis in children [6]. However, herpes simplex virus was the most commonly identified pathogen in eastern India (children and adults) [7].

Meningitis is a disease that involves the membranes surrounding the central nervous system (CNS) and is characterized by fever, headache, nausea, vomiting, meningeal irritation, and alterations in the cerebrospinal fluid (CSF). Bacterial conjugate vaccines have dramatically changed the epidemiology of childhood meningitis and viral causes are increasingly predominant [8].

In China, there were few studies about the pathogens of acute viral encephalitis and meningitis in children in recent years. Two decades ago, Xu et al. reported that the most frequently identified pathogens of acute encephalitis in children were enteroviruses, followed by mumps and rubella [9]. However, there were limitations in their study such as small sample size and limited to Beijing only. What’s more, the epidemiology of viral encephalitis and meningitis may have changed by the use of vaccines. Thus, the aims of this study were to characterize the etiology and prognosis of acute viral encephalitis and meningitis in Chinese children.

Methods

Patients

This was a multicentre prospective study performed at five hospitals from June 2009 to October 2012 consecutively. The hospitals were Beijing Children’s Hospital, Capital Medical University, the Affiliated Hospital of Qingdao University, the First Hospital of Yulin, the First Hospital of Lanzhou University and Nanjing Children’s Hospital. These hospitals were located at Beijing, Shandong, Shanxi, Gansu and Jiangsu province, respectively. The patients come from the surrounding regions of each city. Thus, the study mainly represented the etiology of viral encephalitis and meningitis in northern China.

Inpatients suspected with viral encephalitis or meningitis were enrolled in the study on the first day of hospitalization.

The diagnostic criteria of acute viral encephalitis include: (1) acute onset; (2) altered mental status (defined as decreased or altered level of consciousness, lethargy or personality change) lasting ≥24 h with no alternative cause identified; (3) documented fever ≥38 °C (100.4 °F) within the 72 h before or after presentation; or generalized or partial seizures not fully attributable to a preexisting seizure disorder; (4) abnormality of brain parenchyma on neuroimaging suggestive of encephalitis; or abnormality on electroencephalography that is consistent with encephalitis; (5) no evidence of bacterial meningitis by microscopy and culture of CSF.

The diagnostic criteria of acute viral meningitis include: (1) acute onset of fever and symptoms such as headache, vomiting and/or nuchal rigidity; (2) absence of parenchymal involvement; (3) with no evidence of bacterial meningitis by microscopy and culture of CSF.

Patients with demyelinating, metabolic, toxic or neurological degenerative diseases and HIV infection were excluded.

Clinical data and specimen collection

A form was designed for collecting clinical information from the medical records during hospitalization. The information included general demographic characteristics, clinical symptoms and physical signs, laboratory findings, neuroimaging and electroencephalography results and outcome of the patients. Information collection was completed by physician.

Acute phase CSF samples (0.4–1.0 ml) and acute serum samples (1.0–1.5 ml) were collected within 3 days after admission. All specimens were transported to the laboratory and stored at −80 °C before detection.

Nucleic acid extraction from CSF

Viral nucleic acid was abstracted using the QIAamp MinElute Virus Spin Kit (QIAGEN, Germany, Cat. N. 57,704) from the CSF (0.2 ml), conducted by the manufacturer’s instruction. The elution volume was 50ul.

Real-time reverse transcription polymerase chain reaction (RT-PCR) amplification assay for human enteroviruses

Human enteroviruses were screened using a real-time RT-PCR by enteroviruses universal nucleic acid detection kit (PCR - fluorescent probe) (DA AN GENE, China, Cat. N. DA-BT 109). The serotypes of enterovirus were not identified here.

Multiplex PCR for herpes virus

For human enteroviruses negative samples, a multiplex PCR was tested for six herpes viruses which include herpes simplex virus 1 (HSV1), herpes simplex virus 2 (HSV2), varicella zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV) and human herpes virus 6 (HHV6) via the Seeplex® meningitis-V1 ACE Detection (V2.0) (Seegene, Korea, Cat. N. MG6611Y).

It has been reported that herpes virus DNA was detected in CSF of some patients with confirmed enterovirus meningitis [10]. However, the occurrence of coinfection of herpes viruses and enteroviruses in CNS seems to be a rather rare event in immunocompetent patients. What’s more, the reasons and clinical significance of coinfection of herpes viruses and enteroviruses are still unclear. In our pre-experiment, herpes virus DNA was not detected in CSF of patients with enterovirus encephalitis or meningitis. Therefore, we did not detect the herpes virus DNA in specimens with being positive of enterovirus.

Enzyme-linked immune absorbent assay (ELISA)

The IgM antibody against JEV in CSF was detected by antibody capture ELISA. The IgM antibodies of mumps virus, tick-borne encephalitis virus (TBEV), Dengue virus and rubella virus in acute serum samples were detected by ELISA according to the manufacturer’s instructions (Anti-Mumps viruses ELISA (IgM) (EUROIMMUN, Germany, Cat. N. EI2630–9601 M); Anti-TBE virus ELISA (IgM) (EUROIMMUN, Germany, Cat. N. EI 2661–9601 M); Anti-Dengue Virus ELISA (IgM) (EUROIMMUN, Germany, Cat. N. EI 266b-9601 M) and Anti-Rubella Virus ELISA (IgM) (EUROIMMUN, Germany, Cat. N. EI 2590–9601 M), respectively.

Etiology definition

The etiology of acute viral encephalitis and meningitis was defined if (1) the nucleic acid or specific IgM antibodies were positive in CSF; or (2) the specific IgM antibodies were positive in acute serum, and could not be explained with other diagnosis.

Results

Demographic characteristics of patients

Six hundred and forty two cases clinically diagnosed as viral encephalitis or viral meningitis were enrolled into this study from June 2009 to October 2012. Forty three patients were excluded according to the exclusion criteria and 53 cases were excluded for final diagnosis such as febrile convulsion, atypical purulent meningitis and so on.

A total of 546 patients including 261 viral encephalitis patients with a mean age of 5.88 ± 3.60 years (range 0.17–16.0 years) and 285 viral meningitis patients with a mean age of 6.39 ± 3.57 years (range 0.42–14.22 years) were enrolled. The male to female ratio of viral encephalitis and meningitis was 1.97 and 2.24, respectively (Table 1). Paired CSF and acute serum samples were collected from 312 cases (169 viral encephalitis and 143 viral meningitis). Single CSF samples were obtained from other 234 (92 viral encephalitis and 142 viral meningitis) patients. The seasonal distribution of viral encephalitis and meningitis is shown in Fig. 1.
Table 1

Demographic characteristics of patients

Disease

Sex

Age (year)

Male

Female

Sex ratio

Minimum

Maximum

Mean

Encephalitis (n = 261)

173

88

1.97

0.17

16.00

5.88 ± 3.60

Meningitis (n = 285)

197

88

2.24

0.42

14.22

6.39 ± 3.57

Fig. 1

Seasonal distribution of viral encephalitis and meningitis cases

Definitive etiology of viral encephalitis and meningitis

The etiology of acute viral encephalitis was confirmed in 52.5% (137/261) patients. The leading pathogen was human enteroviruses (27.7%, 38/137), followed by mumps virus (16.1%, 22/137) and HSV1 (13.9%, 19/137) (Fig. 2). JEV was rare in this study, detected only in 2 patients.
Fig. 2

Percentage of viral pathogens in viral encephalitis cases with confirmed etiology. HSV1: herpes simplex virus 1; HSV2: herpes simplex virus 2; VZV: varicella zoster virus; EBV: Epstein-Barr virus; CMV: cytomegalovirus; HHV6: human herpes virus 6; EVs: human enteroviruses; JEV: Japanese encephalitis virus; mumps: mumps virus; TBEV: tick-borne encephalitis virus; dengue: Dengue virus; rubella: rubella virus

The etiology of viral meningitis was identified in 42.8% (122/285) cases. The primary pathogen was also human enteroviruses (37.7%, 46/122), followed by HSV1 (13.9%, 17/122) and VZV (11.5%, 14/122) (Fig. 3). No JEV and CMV were detected.
Fig. 3

Percentage of viral pathogens in viral meningitis cases with confirmed etiology. HSV1: herpes simplex virus 1; HSV2: herpes simplex virus 2; VZV: varicella zoster virus; EBV: Epstein-Barr virus; CMV: cytomegalovirus; HHV6: human herpes virus 6; EVs: human enteroviruses; JEV: Japanese encephalitis virus; mumps: mumps virus; TBEV: tick-borne encephalitis virus; dengue: Dengue virus; rubella: rubella virus

Seasonal distribution of viral encephalitis and meningitis cases with confirmed etiology

It is known that human enteroviruses infection is prevalent in summer and autumn. The seasonal distribution of human enterovirus encephalitis and meningitis were from May to October in this study, in accordance with the prevalence of the virus (shown in Figs. 4 and 5). There was no obvious seasonal trend in other viral encephalitis and meningitis.
Fig. 4

Seasonal distribution of viral encephalitis cases with confirmed etiology. HSV1: herpes simplex virus 1; HSV2: herpes simplex virus 2; VZV: varicella zoster virus; EBV: Epstein-Barr virus; CMV: cytomegalovirus; HHV6: human herpes virus 6; EVs: human enteroviruses; JEV: Japanese encephalitis virus; mumps: mumps virus; TBEV: tick-borne encephalitis virus; dengue: Dengue virus; rubella: rubella virus

Fig. 5

Seasonal distribution of viral meningitis cases with confirmed etiology. HSV1: herpes simplex virus 1; HSV2: herpes simplex virus 2; VZV: varicella zoster virus; EBV: Epstein-Barr virus; CMV: cytomegalovirus; HHV6: human herpes virus 6; EVs: human enteroviruses; JEV: Japanese encephalitis virus; mumps: mumps virus; TBEV: tick-borne encephalitis virus; dengue: Dengue virus; rubella: rubella virus

Prognosis of the viral encephalitis and meningitis patients

The outcome data was available from patients except 6 children with viral encephalitis who transferred to another hospital. All outcome data was collected at discharge. Patients of viral encephalitis and viral meningitis with neurological sequelae or died were shown in Table 2.
Table 2

Patients with neurological sequelae or death

Number

Diseases

Age(years)

Pathogens

Prognosis

1

encephalitis

1.4

HSV1

coma

2

encephalitis

6.5

HSV1

aphasia

3

encephalitis

4.0

HSV1

aphasia

4

encephalitis

5.0

VZV

coma

5

encephalitis

9.0

VZV

secondary epilepsy

6

encephalitis

1.0

VZV

cognitive impairment

7

encephalitis

3.9

VZV

blind

8

encephalitis

7.0

EBV

ataxia

8

encephalitis

6.0

CMV

dysphasia

10

encephalitis

2.2

EVs

death

11

encephalitis

1.0

JEV

hearing impaired

12

encephalitis

0.6

TBEV

hemiplegia

13

encephalitis

5.0

unknown

coma

14

encephalitis

7.0

unknown

death

15

encephalitis

4.0

unknown

visual impaired

16

encephalitis

4.0

unknown

euphoria

17

encephalitis

1.7

unknown

aphasia

18

encephalitis

10.3

unknown

secondary epilepsy

19

encephalitis

11.4

unknown

convulsion

20

encephalitis

6.8

unknown

hearing impaired

21

encephalitis

3.9

unknown

hemiplegia

22

meningitis

11.8

HSV1

headache

23

meningitis

11.8

unknown

speech difficulties

HSV1 herpes simplex virus 1, VZV varicella zoster virus, EBV Epstein-Barr virus, CMV cytomegalovirus, EVs human enteroviruses, JEV Japanese encephalitis virus, TBEV tick-borne encephalitis virus

In viral encephalitis patients, 91.7% (234/255) got well, 7.5% (19/255) had neurological sequelae and 0.8% (2/255) died. The neurological sequelae included coma, aphasia, secondary epilepsy, cognitive impairment, blindness, ataxia, dysphasia, hearing impairment and hemiplegia. One patient died of unknown pathogen (Table 2). Another patient died of human enterovirus encephalitis. The fatality rate of human enterovirus encephalitis was 2.6% (1/38). No patients died of HSV1 and VZV encephalitis. In HSV1 and VZV encephalitis patients, 15.8% (3/19) and 40% (4/10) had neurological sequelae, respectively.

The prognosis of viral meningitis patients was favorable with 99.3% (283/285) recovery. There were only two (0.7%, 2/285) patients had neurological sequelae, one with unresolved headache (sporadically ongoing) and another with speech difficulties (Table 2).

Discussion

This is a multicentre prospective study about the etiology and prognosis of viral encephalitis and meningitis in Chinese children. The results showed that the leading pathogen of viral encephalitis and meningitis were human enterovirus in Chinese children.

Human enteroviruses are the most common pathogen of viral meningitis in children worldwide [11]. Our results are consistent with data from other countries. But the most common pathogen of viral encephalitis varies in different countries and areas. HSV was the most common pathogen of viral encephalitis in France, England, the United States and eastern India [3, 7, 1214]. However, in Southern Vietnam, the primary pathogen of viral encephalitis in children was JEV (26%) [5]. The most common pathogen of viral encephalitis in Chinese children was human enteroviruses in this study. This result is consistent with previous studies from China and Greece [15].

Japanese encephalitis (JE) is one of the most important viral encephalitis in the world. China was one of the most prevalent countries for JE in 1950s–1960s [16, 17]. Since JE vaccine became available in the late 1970s, the incidence of JE has declined significantly [18]. In 1980, China participated in the Expanded Program on Immunization (EPI) of WHO. In 2008, the JE vaccine was included in the national planned immunization. After that the number of JE cases in China has been decreased dramatically [19]. In this study, among 261 viral encephalitis patients, only 2 were JE patients. It is reported that JE is more prevalent in south China and the morbidity rates of JE in south and north China differed by 20-fold [20]. As for this multicentre study, the most cases came from northern China. Thus, the lower morbidity rate of JE in this study was consistent with other findings [20].

The fatality rate was 0.8% in this study, which is lower than a study conducted in southwest China where 2.5% patients died before being discharged from the hospital [21]. The different fatality rates may be contributed to the age difference of patients between the two studies. The mean age was 38.7 years (9–96) in the study of southwest China, while there were only children in our study.

The morbidity and mortality of viral encephalitis vary among different pathogens. Herpes simplex encephalitis (HSE) is the most common cause of sporadic viral encephalitis in Western countries. If untreated, the mortality rate associated with HSE is approximately 70% [22]. Despite antiviral therapy, the mortality is still higher than 30%, and almost 60% of surviving individuals develop neurological sequelae [22]. A recent international study suggested that rapid diagnosis and early administration of antiviral therapy at the onset of HSE are keys to a favorable outcome [23]. In this study, 15.8% (3/19) of HSV1 encephalitis patients had neurological sequelae and no patients died. This result is different from the data of Western countries. The rapid diagnosis, early supported and antiviral therapy may be the reason of favorable prognosis in this study.

This study has some limitations. First, there are more than 100 serotypes of human enteroviruses and the virulence varies in different serotypes [24]. The serotypes of human enteroviruses were not identified in this study. Second, it was not a long term follow-up study. The clinical data was collected during hospitalization.

Conclusions

In conclusion, human enteroviruses were the most common etiology identified both in acute viral encephalitis and viral meningitis in children. The incidence of sequelae and fatality rate of viral encephalitis with confirmed etiology were 7.5% and 0.8%, respectively. The prognosis of viral meningitis was favorable compared to viral encephalitis.

Abbreviations

CMV: 

Cytomegalovirus

CNS: 

Central nervous system

CSF: 

Cerebrospinal fluid

EBV: 

Epstein-Barr virus

ELISA: 

Enzyme-linked immune absorbent assay

HHV6: 

Human herpes virus 6

HSE: 

Herpes simplex encephalitis

HSV1: 

Herpes simplex virus 1

HSV2: 

Herpes simplex virus 2

JE: 

Japanese encephalitis

JEV: 

Japanese encephalitis virus

RT-PCR: 

Reverse transcription polymerase chain reaction

TBEV: 

Tick-borne encephalitis virus

VZV: 

Varicella zoster virus

Declarations

Acknowledgements

This study was supported by Beijing Children’s Hospital, Capital Medical University, the Affiliated Hospital of Qingdao University, the First Hospital of Yulin, the First Hospital of Lanzhou University and Nanjing Children’s Hospital. We would like to extend our sincere gratitude to all the physicians and participants.

Funding

This work was funded by National Major Science and Technology Research Projects for the Control and Prevention of Major Infectious Diseases in China. (2013ZX10004–202), Capital Clinical Feature Project of Beijing Technology Program (Z151100004015046).

Availability of data and materials

The datasets generated and/or analyzed during the current study are not publicly available due to the respect and protection of privacy of the patients, but are available from the corresponding author on reasonable request.

Authors’ contributions

ZDX and KLS designed the study. GL, ZBC, YY, YNL, JC and GZ collected specimens and clinical information, and analyzed clinical data. JHA performed the experiment, analyzed laboratory data and wrote the manuscript. ZDX revised it critically for important intellectual content. All authors read and approved the final manuscript.

Ethics approval and consent to participate

This study was approved by Medical Ethics Committee of Beijing Children’s Hospital, Capital Medical University. Written informed consent was obtained from the patients’ parents.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

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Authors’ Affiliations

(1)
Key Laboratory of Major Diseases in Children, Ministry of Education, Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Virology Laboratory, Beijing Pediatric Research Institute, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health
(2)
The Affiliated Hospital of Qingdao University
(3)
The First Hospital of Yulin
(4)
The First Hospital of Lanzhou University
(5)
Nanjing Children’s Hospital
(6)
National Clinical Research Center for Respiratory Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, Respiratory Department, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health

References

  1. Parpia AS, Li Y, Chen C, Dhar B, Crowcroft NS. Encephalitis, Ontario, Canada, 2002–2013. Emerg Infect Dis. 2016;22(3):426–32.View ArticlePubMedPubMed CentralGoogle Scholar
  2. Barbadoro P, Marigliano A, Ricciardi A, D'Errico MM, Prospero E. Trend of hospital utilization for encephalitis. Epidemiol Infect. 2012;140(4):753–64.View ArticlePubMedGoogle Scholar
  3. Vora NM, Holman RC, Mehal JM, Steiner CA, Blanton J, Sejvar J. Burden of encephalitis-associated hospitalizations in the United States, 1998–2010. Neurology. 2014;82(5):443–51.View ArticlePubMedGoogle Scholar
  4. Huppatz C, Durrheim DN, Levi C, Dalton C, Williams D, Clements MS, Kelly PM. Etiology of encephalitis in Australia, 1990–2007. Emerg Infect Dis. 2009;15(9):1359–65.View ArticlePubMedPubMed CentralGoogle Scholar
  5. Le VT, Phan TQ, Do QH, Nguyen BH, Lam QB, Bach V, et al. Viral etiology of encephalitis in children in southern Vietnam: results of a one-year prospective descriptive study. PLoS Negl Trop Dis. 2010;4(10):e854.View ArticlePubMedGoogle Scholar
  6. Kumar A, Shukla D, Kumar R, Idris MZ, Misra UK, Dhole TN. Molecular epidemiological study of enteroviruses associated with encephalitis in children from India. J Clin Microbiol. 2012;50(11):3509–12.View ArticlePubMedPubMed CentralGoogle Scholar
  7. Rathore SK, Dwibedi B, Kar SK, Dixit S, Sabat J, Panda M. Viral aetiology and clinico-epidemiological features of acute encephalitis syndrome in eastern India. Epidemiol Infect. 2014;142(12):2514–21.View ArticlePubMedGoogle Scholar
  8. Sadarangani M, Willis L, Kadambari S, Gormley S, Young Z, Beckley R, et al. Childhood meningitis in the conjugate vaccine era: a prospective cohort study. Arch Dis Child. 2015;100(3):292–4.View ArticlePubMedGoogle Scholar
  9. Xu Y, Zhaori G, Vene S, Shen K, Zhou Y, Magnius LO, Wahren B, Linde A. Viral etiology of acute childhood encephalitis in Beijing diagnosed by analysis of single samples. Pediatr Infect Dis J. 1996;15(11):1018–24.View ArticlePubMedGoogle Scholar
  10. Labska K, Roubalova K, Picha D, Maresova V. Presence of herpesvirus DNA in cerebrospinal fluid of patients with tick-borne encephalitis and enteroviral meningoencephalitis. J Med Virol. 2015;87(7):1235–40.View ArticlePubMedGoogle Scholar
  11. Han SH, Choi HY, Kim JM, Park KR, Youn YC, Shin HW. Etiology of aseptic meningitis and clinical characteristics in immune-competent adults. J Med Virol. 2016;88(1):175–9.View ArticlePubMedGoogle Scholar
  12. Mailles A, Stahl JP. Infectious encephalitis in france in 2007: a national prospective study. Clin Infect Dis. 2009;49(12):1838–47.View ArticlePubMedGoogle Scholar
  13. Granerod J, Ambrose HE, Davies NW, Clewley JP, Walsh AL, Morgan D, et al. Causes of encephalitis and differences in their clinical presentations in England: a multicentre, population-based prospective study. Lancet Infect Dis. 2010;10(12):835–44.View ArticlePubMedGoogle Scholar
  14. Singh TD, Fugate JE, Rabinstein AA. The spectrum of acute encephalitis: causes, management, and predictors of outcome. Neurology. 2015;84(4):359–66.View ArticlePubMedGoogle Scholar
  15. Galanakis E, Tzoufi M, Katragkou A, Nakou I, Roilides E. A prospective multicenter study of childhood encephalitis in Greece. Pediatr Infect Dis J. 2009;28(8):740–2.View ArticlePubMedGoogle Scholar
  16. Gao X, Nasci R, Liang G. The neglected arboviral infections in mainland China. PLoS Negl Trop Dis. 2010;4(4):e624.View ArticlePubMedPubMed CentralGoogle Scholar
  17. Wang H, Li Y, Liang X, Liang G. Japanese encephalitis in mainland china. Jpn J Infect Dis. 2009;62(5):331–6.PubMedGoogle Scholar
  18. Yang Y, Liang N, Tan Y, Xie Z. Epidemiological trends and characteristics of Japanese encephalitis changed based on the vaccination program between 1960 and 2013 in Guangxi Zhuang Autonomous Region, southern China. Int J Infect Dis. 2016;45:135–8.View ArticlePubMedGoogle Scholar
  19. Zheng Y, Li M, Wang H, Liang G. Japanese encephalitis and Japanese encephalitis virus in mainland China. Rev Med Virol. 2012;22(5):301–22.View ArticlePubMedGoogle Scholar
  20. Yin Z, Wang H, Yang J, Luo H, Li Y, Hadler SC, et al. Japanese encephalitis disease burden and clinical features of Japanese encephalitis in four cities in the People's Republic of China. Am J Trop Med Hyg. 2010;83(4):766–73.View ArticlePubMedPubMed CentralGoogle Scholar
  21. Zhao L, Zhou M, Wang B, Guo J, Chen N, He L. Clinical characteristics and outcome of clinically diagnosed viral encephalitis in southwest China. Neurol Sci. 2015;36(12):2191–7.View ArticlePubMedGoogle Scholar
  22. Piret J, Boivin G. Innate immune response during herpes simplex virus encephalitis and development of immunomodulatory strategies. Rev Med Virol. 2015;25(5):300–19.View ArticlePubMedGoogle Scholar
  23. Erdem H, Cag Y, Ozturk-Engin D, Defres S, Kaya S, Larsen L, et al. Results of a multinational study suggest the need for rapid diagnosis and early antiviral treatment at the onset of herpetic meningoencephalitis. Antimicrob Agents Chemother. 2015;59(6):3084–9.View ArticlePubMedPubMed CentralGoogle Scholar
  24. Khetsuriani N, Lamonte A, Oberste MS, Pallansch M. Neonatal enterovirus infections reported to the national enterovirus surveillance system in the United States, 1983–2003. Pediatr Infect Dis J. 2006;25(10):889–93.View ArticlePubMedGoogle Scholar

Copyright

© The Author(s). 2017

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