Abstract
Introduction: Japanese encephalitis (JE) is a mosquito-borne disease caused by a flavivirus, namely Japanese encephalitis virus (JEV) whereby it was transmitted by mosquito vector Culex tritaeniorhynchus . This study aims to study the distribution of JE by geography and timeline from 2012 to 2021 as well as reviewing the clinical profile of all JE cases captured.
Methods: JE is a notifiable infectious disease in Malaysia whereby notification within 24 hours of the result release is compulsory. Secondary data on JE were analysed from the Vekpro Online database used to capture all of the confirmed JE cases. Case definition is laboratory confirmation via a positive JE IgM serology or JE virus PCR from blood sera or cerebrospinal fluid (CSF). There were 35 JE cases in Kedah state from 2012 to 2021 (10 years). SPSS were used to analyse the demographic characteristics and its clinical profile while geographical mapping was done using Google Earth.
Results: There were 35 JE cases identified from 2012 till 2021, with average of 1 to 2 cases per annum from 2012 to 2017. However, the cases increased exponentially to 12 cases in 2021. The median age was 11 years old, with the majority were 20 years-old and less (24/35, 68.5%). Demographically, there was male preponderance (23/35, 65.7%) and majorly were of Malay ethnicity (33/35, 94.3%). The commonest symptoms were fever (35/35, 100%) followed by headache (24/35, 68.6%), lethargy (13/35, 37.1%), altered behaviours (8/35, 22.9%) and symptoms of meningism (4/35, 11.4%). Of these 35 cases, there were 5 mortality (15.1%), 8 survived with post infection neurological deficiency (22.6%) and the remaining 22 had full recovery with no sequelae (62.9%). However, 2 patients had missing data on the disease outcome. By geographical distribution, JE was mostly reported in the district of Kota Setar (9/35, 25.7%) and Kuala Muda (9/35, 25.7%) while the rest of districts reported 3 cases or less. By annual timeline, 7 cases were reported in July and November respectively, followed by 4 cases in June and August while the rest of the months reported 3 cases and less.
Discussions : WHO data showed 75.0% of JE cases are children who are 0 to 14 years-old which is comparable to our finding. In addition, male preponderance was also reported from WHO data (1.53: 1) as compared to our study (1.92: 1). By clinical presentations, our findings were mainly conforming with the classical manifestation of JE cases reported. As for the disease outcome, case fatality rate could be as high as 30.0% in some Asia countries while our case fatality rate over 10-year duration was 15.1%. In conclusion, the demographic and clinical profiles of JE cases in Kedah state are conforming to the global findings while the JE cases were more frequently reported in the highly populous district of the state. This study provides an important insight of JE cases in Kedah state, Malaysia.
Links
- https://apcph.cphm.my/wp-content/uploads/2022/07/APCPH2022-O-33.pdf
- https://apcph.cphm.my/events/oral-session-9-ballroom-C/
BibTeX (Download)
@proceedings{APCPH2022-O-33,
title = {Japanese Encephalitis: Distribution and Clinical Profile in Kedah State, Malaysia},
author = {Joash LT and LL Low and A Shauqi and WL Tan},
url = {https://apcph.cphm.my/wp-content/uploads/2022/07/APCPH2022-O-33.pdf
https://apcph.cphm.my/events/oral-session-9-ballroom-C/},
year = {2022},
date = {2022-08-01},
urldate = {2022-08-02},
issue = {7},
abstract = {Introduction: Japanese encephalitis (JE) is a mosquito-borne disease caused by a flavivirus, namely Japanese encephalitis virus (JEV) whereby it was transmitted by mosquito vector Culex tritaeniorhynchus . This study aims to study the distribution of JE by geography and timeline from 2012 to 2021 as well as reviewing the clinical profile of all JE cases captured.
Methods: JE is a notifiable infectious disease in Malaysia whereby notification within 24 hours of the result release is compulsory. Secondary data on JE were analysed from the Vekpro Online database used to capture all of the confirmed JE cases. Case definition is laboratory confirmation via a positive JE IgM serology or JE virus PCR from blood sera or cerebrospinal fluid (CSF). There were 35 JE cases in Kedah state from 2012 to 2021 (10 years). SPSS were used to analyse the demographic characteristics and its clinical profile while geographical mapping was done using Google Earth.
Results: There were 35 JE cases identified from 2012 till 2021, with average of 1 to 2 cases per annum from 2012 to 2017. However, the cases increased exponentially to 12 cases in 2021. The median age was 11 years old, with the majority were 20 years-old and less (24/35, 68.5%). Demographically, there was male preponderance (23/35, 65.7%) and majorly were of Malay ethnicity (33/35, 94.3%). The commonest symptoms were fever (35/35, 100%) followed by headache (24/35, 68.6%), lethargy (13/35, 37.1%), altered behaviours (8/35, 22.9%) and symptoms of meningism (4/35, 11.4%). Of these 35 cases, there were 5 mortality (15.1%), 8 survived with post infection neurological deficiency (22.6%) and the remaining 22 had full recovery with no sequelae (62.9%). However, 2 patients had missing data on the disease outcome. By geographical distribution, JE was mostly reported in the district of Kota Setar (9/35, 25.7%) and Kuala Muda (9/35, 25.7%) while the rest of districts reported 3 cases or less. By annual timeline, 7 cases were reported in July and November respectively, followed by 4 cases in June and August while the rest of the months reported 3 cases and less.
Discussions : WHO data showed 75.0% of JE cases are children who are 0 to 14 years-old which is comparable to our finding. In addition, male preponderance was also reported from WHO data (1.53: 1) as compared to our study (1.92: 1). By clinical presentations, our findings were mainly conforming with the classical manifestation of JE cases reported. As for the disease outcome, case fatality rate could be as high as 30.0% in some Asia countries while our case fatality rate over 10-year duration was 15.1%. In conclusion, the demographic and clinical profiles of JE cases in Kedah state are conforming to the global findings while the JE cases were more frequently reported in the highly populous district of the state. This study provides an important insight of JE cases in Kedah state, Malaysia.},
howpublished = {published online at https://apcph.cphm.my},
note = {Type: ORAL PRESENTATION; Organisation: Sultanah Bahiyah Hospital, Kedah State Health Department},
keywords = {Japanese Encephalitis},
pubstate = {published},
tppubtype = {proceedings}
}