Hinson VK, Tyor WR, 2001. Update on viral encephalitis. Curr Opin Neurol 14: 369–374.
Whitley RJ, Gnann JW, 2002. Viral encephalitis: familiar infections and emerging pathogens. Lancet 359: 507–513.
Le VT, Phan TQ, Do QH, Nguyen BH, Lam QB, Bach V, Truong H, Tran TH, Nguyen V, Tran T, Vo M, Tran VT, Schultsz C, Farrar J, van Doorn HR, de Jong MD, 2010. Viral etiology of encephalitis in children in southern Vietnam: results of a one-year prospective descriptive study. PLoS Negl Trop Dis 4: e854.
Granerod J, Crowcroft NS, 2007. The epidemiology of acute encephalitis. Neuropsychol Rehabil 17: 406–428.
Silva MTT, 2013. Viral encephalitis. Arq Neuropsiquiatr 71: 703–709.
Kennedy PGE, 2004. Viral encephalitis: causes, differential diagnosis, and management. J Neurol Neurosurg 75: i10–i15.
Johnston RT, 1998. Viral Infections of the Nervous System. Philadelphia, PA: Lippincott-Raven.
Glaser CA, Honarmand S, Anderson LJ, Schnurr DP, Forghani B, Cossen CK, Schuster FL, Christie LJ, Tureen JH, 2006. Beyond viruses: clinical profiles and etiologies associated with encephalitis. Clin Infect Dis 43: 1565–1577.
Davison KL, Crowcroft NS, Ramsay ME, Brown DW, Andrews NJ, 2003. Viral encephalitis in England, 1989–1998: what did we miss? Emerg Infect Dis 9: 234–240.
Trung NHD, Phuong TLT, Wolbers M, Van Minh HN, Thanh VN, Van MP, Thieu NTV, Van TL, Song DT, Thi PL, Phuong TNT, Van CB, Tang V, Anh THN, Nguyen D, Trung TP, Nam LNT, Kiem HT, Thanh TNT, Campbell J, Caws M, Day J, de Jong MD, Vinh CNV, Doorn HRV, Tinh HT, Farrar J, Schultsz C; the VIZION CNS Infection Network, 2012. Aetiologies of central nervous system infection in Viet Nam: a prospective provincial hospital-based descriptive surveillance study. PLoS One 7: e37825.
Yen NT, Duffy MR, Hong NM, Hien NT, Fischer M, Hills SL, 2010. Surveillance for Japanese encephalitis in Vietnam, 1998–2007. Am J Trop Med Hyg 83: 816–819.
Zheng Y, Li M, Wang H, Liang G, 2012. Japanese encephalitis and Japanese encephalitis virus in mainland China. Rev Med Virol 22: 301–322.
Solomon T, 2003. Recent advances in Japanese encephalitis. J Neurovirol 9: 274–283.
Solomon T, Dung NM, Kneen R, Thao LTT, Gainsborough M, Nisalak A, Day NP, Kirkham FJ, Vaughn DW, Smith S, White NJ, 2002. Seizures and raised intracranial pressure in Vietnamese patients with Japanese encephalitis. Brain 125: 1084–1093.
Tan LV, Thai LH, Phu NH, Nghia HDT, Van Chuong L, Sinh DX, Phong ND, Mai NTH, Man DNH, Hien VM, Vinh NT, Day J, Chau NVV, Hien TT, Farrar J, Jong MD, Thwaites G, Doorn HR, Chau TTH, 2014. Viral aetiology of central nervous system infections in adults admitted to a tertiary referral hospital in southern Vietnam over 12 years. PLoS Negl Trop Dis 8: e3127.
Halstead SB, Jacobson J, 2008. Japanese encephalitis vaccines. Plotkin SA, Orenstein WA, Offit PA, eds. Vaccines, 5th edition. Philadelphia, PA: Elsevier, 311–352.
Burke DS, Leake CJ, 1998. Japanese encephalitis. Monath TP, ed. The Arboviruses: Epidemiology and Ecology, Vol. 3. Boca Raton, FL: CRC Press, 63–92.
World Health Organization (WHO), 2016. Japanese Encephalitis. Available at: http://www.who.int/ith/diseases/japanese_encephalitis/en/. Accessed July 26, 2016.
Erlanger TE, Weiss S, Keiser J, Utzinger J, Wiedenmayer K, 2009. Past, present, and future of Japanese encephalitis. Emerg Infect Dis 15: 1–7.
Hanna JN, Ritchie SA, Phillips DA, Lee JM, Hills SL, Van den Hurk AF, Pyke A, Johansen C, Mackenzie J, 1999. Japanese encephalitis in north Queensland, Australia, 1998. Med J Aust 170: 533–536.
Solomon T, Dung NM, Kneen R, Gainsborough M, Vaughn DW, Khanh VT, 2000. Japanese encephalitis. J Neurol Neurosurg 68: 405–415.
Kanojia P, Shetty P, Geevarghese G, 2003. A long-term study on vector abundance and seasonal prevalence in relation to the occurrence of Japanese encephalitis in Gorakhpur district, Uttar Pradesh. Indian J Med Sci 117: 104–110.
Buhl MR, Lindquist L, 2009. Japanese encephalitis in travelers: review of cases and seasonal risk. J Travel Med 16: 217–219.
Bi P, Zhang Y, Parton KA, 2007. Weather variables and Japanese encephalitis in the metropolitan area of Jinan city, China. J Infect 55: 551–556.
General Statistics Office, 2015. Available at: https://www.gso.gov.vn/Default_en.aspx?tabid=491/. Accessed November 1, 2015.
Cleveland RB, Cleveland WS, McRae JE, Terpenning I, 1990. STL: a seasonal-trend decomposition procedure based on loess. J Off Stat 6: 3–73.
Lee H, Levine M, Guptill-Yoran C, Johnson A, Kamecke P, Moore G, 2014. Regional and temporal variations of Leptospira seropositivity in dogs in the United States, 2000–2010. J Vet Intern Med 28: 779–788.
Gardner W, Mulvey EP, Shaw EC, 1995. Regression analyses of counts and rates: poisson, overdispersed poisson, and negative binomial models. Psychol Bull 118: 392–404.
Scott Long J, 1997. Regression Models for Categorical and Limited Dependent Variables. London, UK: SAGE Publications.
Solomon T, Ni H, Beasley DW, Ekkelenkamp M, Cardosa MJ, Barrett AD, 2003. Origin and evolution of Japanese encephalitis virus in southeast Asia. J Virol 77: 3091–3098.
Bi P, Tong S, Donald K, Parton KA, Ni J, 2003. Climate variability and transmission of Japanese encephalitis in eastern China. Vector Borne Zoonotic Dis 3: 111–115.
Zhou G, Minakawa N, Githeko AK, Yan G, 2004. Association between climate variability and malaria epidemics in the east African highlands. Proc Natl Acad Sci USA 101: 2375–2380.
Li CF, Lim TW, Han LL, Fang R, 1985. Rainfall, abundance of Aedes aegypti and dengue infection in Selangor, Malaysia. Southeast Asian J Trop Med Public Health 16: 560–568.
Thammapalo S, Chongsuwiwatwong V, McNeil D, Geater A, 2005. The climatic factors influencing the occurrence of dengue hemorrhagic fever in Thailand. Southeast Asian J Trop Med Public Health 36: 191–196.
Huo AM, Zhao DS, Fang LQ, Cao WC, 2011. Association between infectious diseases with natural foci and meteorological factors in North China. J Pathog Biol 1: 003.
OIE, 2013. Japanese Encephalitis. Available at: http://www.oie.int/fileadmin/Home/eng/Animal_Health_in_the_World/docs/pdf/Disease_cards/JAPANESE_ENCEPHALITIS.pdf/. Accessed December 2, 2015.
Ninh TU, 2000. Virological surveillance of dengue haemorrhagic fever in Viet Nam, 1987–1999. Dengue Bull 24: 18–23.
Do TT, Martens P, Luu NH, Wright P, Choisy M, 2014. Climatic-driven seasonality of emerging dengue fever in Hanoi, Vietnam. BMC Public Health 14: 1078.
Fisman D, 2012. Seasonality of viral infections: mechanisms and unknowns. Clin Microbiol Infect 18: 946–954.
Chang HL, Chio CP, Su HJ, Liao CM, Lin CY, Shau WY, Chi YC, Cheng YT, Chou YL, Li CY, 2012. The association between enterovirus 71 infections and meteorological parameters in Taiwan. PLoS One 7: e46845.
Park SK, Park B, Ki M, Kim H, Lee K, Jung C, Sohn YM, Choi SM, Kim DK, Lee DS, 2010. Transmission of seasonal outbreak of childhood enteroviral aseptic meningitis and hand-foot-mouth disease. J Korean Med Sci 25: 677–683.
World Health Organization (WHO), 2015. Hand, Foot and Mouth Disease. Available at: http://www.wpro.who.int/vietnam/topics/hand_foot_mouth/factsheet/en/. Accessed December 4, 2015.
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In Vietnam, Japanese encephalitis virus accounts for 12–71% of viral encephalitis (VE) cases followed by enteroviruses and dengue virus among identified pathogens. This study is the first attempt to evaluate the seasonality of VE and associated environmental risk factors in two provinces from 2004 to 2013 using a seasonal trend-decomposition procedure based on loess regression and negative binomial regression models. We found seasonality with a peak of VE in August and June in Son La and Thai Binh, respectively. In Son La, the model showed that for every 1°C increase in average monthly temperature, there was a 4.0% increase in monthly VE incidence. There was a gradual decline in incidence rates as the relative humidity rose to its mean value (80%) and a dramatic rise in incidence rate as the relative humidity rose past 80%. Another model found that a 100 mm rise in precipitation in the preceding and same months corresponded to an increase in VE incidence of 23% and 21%, respectively. In Thai Binh, our model showed that a 1°C increase in temperature corresponded with a 9% increase in VE incidence. Another model found that VE incidence increased as monthly precipitation rose to its mean value of 130 mm but declined gradually as precipitation levels rose beyond that. The last model showed that a monthly increase in duration of sunshine of 1 hour corresponded to a 0.6% increase in VE incidence. The findings may assist clinicians by improving the evidence for diagnosis.
Financial support: This study was supported by a grant from the CGIAR Research Program on Climate Change, Agriculture and Food Security to the Pestforecast project, which was implemented by the ILRI Vietnam office. Financial support was also received from the CGIAR Research Program on Agriculture for Nutrition and Health, led by the International Food Policy Research Institute.
Authors' addresses: Hu Suk Lee and Hung Nguyen-Viet, International Livestock Research Institute, Hanoi, Vietnam, E-mails: h.s.lee@cgiar.org and h.nguyen@cgiar.org. Mihye Lee, Medical Microbiology Department, The Royal Bournemouth Hospital, Bournemouth, United Kingdom, E-mail: dr.mihaelee@googlemail.com. Phuc Pham Duc, Center for Public Health and Ecosystem Research, Hanoi School of Public Health, Hanoi, Vietnam, E-mail: Pdp@hsph.edu.vn. Delia Grace, International Livestock Research Institute, Nairobi, Kenya, E-mail: dd.grace@cgiar.org.
Hinson VK, Tyor WR, 2001. Update on viral encephalitis. Curr Opin Neurol 14: 369–374.
Whitley RJ, Gnann JW, 2002. Viral encephalitis: familiar infections and emerging pathogens. Lancet 359: 507–513.
Le VT, Phan TQ, Do QH, Nguyen BH, Lam QB, Bach V, Truong H, Tran TH, Nguyen V, Tran T, Vo M, Tran VT, Schultsz C, Farrar J, van Doorn HR, de Jong MD, 2010. Viral etiology of encephalitis in children in southern Vietnam: results of a one-year prospective descriptive study. PLoS Negl Trop Dis 4: e854.
Granerod J, Crowcroft NS, 2007. The epidemiology of acute encephalitis. Neuropsychol Rehabil 17: 406–428.
Silva MTT, 2013. Viral encephalitis. Arq Neuropsiquiatr 71: 703–709.
Kennedy PGE, 2004. Viral encephalitis: causes, differential diagnosis, and management. J Neurol Neurosurg 75: i10–i15.
Johnston RT, 1998. Viral Infections of the Nervous System. Philadelphia, PA: Lippincott-Raven.
Glaser CA, Honarmand S, Anderson LJ, Schnurr DP, Forghani B, Cossen CK, Schuster FL, Christie LJ, Tureen JH, 2006. Beyond viruses: clinical profiles and etiologies associated with encephalitis. Clin Infect Dis 43: 1565–1577.
Davison KL, Crowcroft NS, Ramsay ME, Brown DW, Andrews NJ, 2003. Viral encephalitis in England, 1989–1998: what did we miss? Emerg Infect Dis 9: 234–240.
Trung NHD, Phuong TLT, Wolbers M, Van Minh HN, Thanh VN, Van MP, Thieu NTV, Van TL, Song DT, Thi PL, Phuong TNT, Van CB, Tang V, Anh THN, Nguyen D, Trung TP, Nam LNT, Kiem HT, Thanh TNT, Campbell J, Caws M, Day J, de Jong MD, Vinh CNV, Doorn HRV, Tinh HT, Farrar J, Schultsz C; the VIZION CNS Infection Network, 2012. Aetiologies of central nervous system infection in Viet Nam: a prospective provincial hospital-based descriptive surveillance study. PLoS One 7: e37825.
Yen NT, Duffy MR, Hong NM, Hien NT, Fischer M, Hills SL, 2010. Surveillance for Japanese encephalitis in Vietnam, 1998–2007. Am J Trop Med Hyg 83: 816–819.
Zheng Y, Li M, Wang H, Liang G, 2012. Japanese encephalitis and Japanese encephalitis virus in mainland China. Rev Med Virol 22: 301–322.
Solomon T, 2003. Recent advances in Japanese encephalitis. J Neurovirol 9: 274–283.
Solomon T, Dung NM, Kneen R, Thao LTT, Gainsborough M, Nisalak A, Day NP, Kirkham FJ, Vaughn DW, Smith S, White NJ, 2002. Seizures and raised intracranial pressure in Vietnamese patients with Japanese encephalitis. Brain 125: 1084–1093.
Tan LV, Thai LH, Phu NH, Nghia HDT, Van Chuong L, Sinh DX, Phong ND, Mai NTH, Man DNH, Hien VM, Vinh NT, Day J, Chau NVV, Hien TT, Farrar J, Jong MD, Thwaites G, Doorn HR, Chau TTH, 2014. Viral aetiology of central nervous system infections in adults admitted to a tertiary referral hospital in southern Vietnam over 12 years. PLoS Negl Trop Dis 8: e3127.
Halstead SB, Jacobson J, 2008. Japanese encephalitis vaccines. Plotkin SA, Orenstein WA, Offit PA, eds. Vaccines, 5th edition. Philadelphia, PA: Elsevier, 311–352.
Burke DS, Leake CJ, 1998. Japanese encephalitis. Monath TP, ed. The Arboviruses: Epidemiology and Ecology, Vol. 3. Boca Raton, FL: CRC Press, 63–92.
World Health Organization (WHO), 2016. Japanese Encephalitis. Available at: http://www.who.int/ith/diseases/japanese_encephalitis/en/. Accessed July 26, 2016.
Erlanger TE, Weiss S, Keiser J, Utzinger J, Wiedenmayer K, 2009. Past, present, and future of Japanese encephalitis. Emerg Infect Dis 15: 1–7.
Hanna JN, Ritchie SA, Phillips DA, Lee JM, Hills SL, Van den Hurk AF, Pyke A, Johansen C, Mackenzie J, 1999. Japanese encephalitis in north Queensland, Australia, 1998. Med J Aust 170: 533–536.
Solomon T, Dung NM, Kneen R, Gainsborough M, Vaughn DW, Khanh VT, 2000. Japanese encephalitis. J Neurol Neurosurg 68: 405–415.
Kanojia P, Shetty P, Geevarghese G, 2003. A long-term study on vector abundance and seasonal prevalence in relation to the occurrence of Japanese encephalitis in Gorakhpur district, Uttar Pradesh. Indian J Med Sci 117: 104–110.
Buhl MR, Lindquist L, 2009. Japanese encephalitis in travelers: review of cases and seasonal risk. J Travel Med 16: 217–219.
Bi P, Zhang Y, Parton KA, 2007. Weather variables and Japanese encephalitis in the metropolitan area of Jinan city, China. J Infect 55: 551–556.
General Statistics Office, 2015. Available at: https://www.gso.gov.vn/Default_en.aspx?tabid=491/. Accessed November 1, 2015.
Cleveland RB, Cleveland WS, McRae JE, Terpenning I, 1990. STL: a seasonal-trend decomposition procedure based on loess. J Off Stat 6: 3–73.
Lee H, Levine M, Guptill-Yoran C, Johnson A, Kamecke P, Moore G, 2014. Regional and temporal variations of Leptospira seropositivity in dogs in the United States, 2000–2010. J Vet Intern Med 28: 779–788.
Gardner W, Mulvey EP, Shaw EC, 1995. Regression analyses of counts and rates: poisson, overdispersed poisson, and negative binomial models. Psychol Bull 118: 392–404.
Scott Long J, 1997. Regression Models for Categorical and Limited Dependent Variables. London, UK: SAGE Publications.
Solomon T, Ni H, Beasley DW, Ekkelenkamp M, Cardosa MJ, Barrett AD, 2003. Origin and evolution of Japanese encephalitis virus in southeast Asia. J Virol 77: 3091–3098.
Bi P, Tong S, Donald K, Parton KA, Ni J, 2003. Climate variability and transmission of Japanese encephalitis in eastern China. Vector Borne Zoonotic Dis 3: 111–115.
Zhou G, Minakawa N, Githeko AK, Yan G, 2004. Association between climate variability and malaria epidemics in the east African highlands. Proc Natl Acad Sci USA 101: 2375–2380.
Li CF, Lim TW, Han LL, Fang R, 1985. Rainfall, abundance of Aedes aegypti and dengue infection in Selangor, Malaysia. Southeast Asian J Trop Med Public Health 16: 560–568.
Thammapalo S, Chongsuwiwatwong V, McNeil D, Geater A, 2005. The climatic factors influencing the occurrence of dengue hemorrhagic fever in Thailand. Southeast Asian J Trop Med Public Health 36: 191–196.
Huo AM, Zhao DS, Fang LQ, Cao WC, 2011. Association between infectious diseases with natural foci and meteorological factors in North China. J Pathog Biol 1: 003.
OIE, 2013. Japanese Encephalitis. Available at: http://www.oie.int/fileadmin/Home/eng/Animal_Health_in_the_World/docs/pdf/Disease_cards/JAPANESE_ENCEPHALITIS.pdf/. Accessed December 2, 2015.
Ninh TU, 2000. Virological surveillance of dengue haemorrhagic fever in Viet Nam, 1987–1999. Dengue Bull 24: 18–23.
Do TT, Martens P, Luu NH, Wright P, Choisy M, 2014. Climatic-driven seasonality of emerging dengue fever in Hanoi, Vietnam. BMC Public Health 14: 1078.
Fisman D, 2012. Seasonality of viral infections: mechanisms and unknowns. Clin Microbiol Infect 18: 946–954.
Chang HL, Chio CP, Su HJ, Liao CM, Lin CY, Shau WY, Chi YC, Cheng YT, Chou YL, Li CY, 2012. The association between enterovirus 71 infections and meteorological parameters in Taiwan. PLoS One 7: e46845.
Park SK, Park B, Ki M, Kim H, Lee K, Jung C, Sohn YM, Choi SM, Kim DK, Lee DS, 2010. Transmission of seasonal outbreak of childhood enteroviral aseptic meningitis and hand-foot-mouth disease. J Korean Med Sci 25: 677–683.
World Health Organization (WHO), 2015. Hand, Foot and Mouth Disease. Available at: http://www.wpro.who.int/vietnam/topics/hand_foot_mouth/factsheet/en/. Accessed December 4, 2015.
Past two years | Past Year | Past 30 Days | |
---|---|---|---|
Abstract Views | 24 | 24 | 4 |
Full Text Views | 347 | 112 | 1 |
PDF Downloads | 149 | 34 | 0 |