Highlights:
- 420 cases detected nationwide since 2017
- Surveillance active at 103 sentinel sites
- Malaria tests returned negative in teacher’s case
- WHO says fatality can reach 30%
- Most infections reported in rural areas
- Children under 15 remain most vulnerable
The death of a Chattogram Veterinary and Animal Sciences University (CVASU) teacher whose symptoms led doctors to suspect Japanese encephalitis (JE) has renewed concern over the mosquito-borne virus in Chattogram.
Doctors say the disease, spread by Culex mosquitoes, can cause severe damage to the brain and nervous system. However, Reverse Transcription Polymerase Chain Reaction (RT-PCR) testing needed to help confirm infections is still unavailable in government and private laboratories in the port city.
The issue came back into focus after Zakia Sultana Juthi, 36, a teacher at the Department of Food Processing and Engineering under CVASU’s Faculty of Food Science and Technology, died on Thursday after developing fever, severe headache, vomiting and seizures. Doctors later confirmed, after her death, that she had contracted the Japanese encephalitis virus following specialised testing in Dhaka.
According to doctors, pigs and wild birds are the primary hosts of the virus. However, it does not spread from person to person.
No RT-PCR testing in Chattogram
Zakir Hossain, laboratory in-charge at the Bangladesh Institute of Tropical and Infectious Diseases (BITID) in Fouzdarhat, said the institute has PCR machines, but testing for the mosquito-borne disease is not conducted there.
Shubhashish Barua, laboratory in-charge at Chattogram Medical College Hospital (CMCH), also said the test is not available there.
Chattogram Civil Surgeon Dr Jahangir Alam told TBS that no major government or private diagnostic centre in the city currently conducts RT-PCR testing for the infection.
“Because patient numbers are low, the test is not conducted in government or private facilities in Chattogram,” he said.
However, doctors said RT-PCR testing for the disease is available at the Institute of Epidemiology, Disease Control and Research (IEDCR) in Dhaka. They added that some specialised private hospitals in the capital may also offer the test, although this could not be independently confirmed.
Doctors said patients with fever, headache or seizures are usually tested for dengue or malaria first, as the symptoms often overlap.
However, confirming the infection requires specialised laboratory testing, including RT-PCR, which is not commonly advised or available locally, they said. As a result, doctors fear some suspected infections may remain unconfirmed.
BITID Associate Professor Dr Mamunur Rashid said the mosquito-borne disease is already known in Bangladesh and greater importance should now be given to testing.
“Kits are needed for the RT-PCR test. The disease can severely damage the brain and may become fatal if treatment is delayed,” he said.
Teacher’s illness brought disease into focus
According to the case summary prepared while Dr Zakia was undergoing treatment at Chattogram Metropolitan Hospital, she had travelled to Bandarban around 15 days before falling ill.
She was admitted to the hospital around 1:30am on 5 May with fever, severe headache, repeated vomiting and breathing difficulties.
Doctors suspected Japanese encephalitis after she developed neurological symptoms, including seizures, according to physicians familiar with the case. They initially suspected meningoencephalitis as her condition worsened.
Several malaria tests later returned negative, while MRI scans showed signs of acute disseminated encephalomyelitis (ADEM), a serious inflammatory neurological condition.
Her specimens had earlier been sent to Dhaka for specialised testing, and doctors confirmed on Sunday, after her death, that she had contracted the Japanese encephalitis virus.
What is Japanese encephalitis?
Experts say Japanese encephalitis is a mosquito-borne viral brain infection caused by a flavivirus. The disease is more common in rural areas, particularly near paddy fields and pig farms.
Initial symptoms may include fever, headache and vomiting. In severe cases, patients may develop seizures, unconsciousness and paralysis.
There is no specific antiviral treatment for the disease. Patients are treated based on symptoms.
According to icddr,b and the World Health Organization (WHO), the disease can kill up to 30% of symptomatic patients.
Experts say many survivors develop long-term physical and neurological complications. These may include permanent intellectual, behavioural and neurological disorders, paralysis, repeated seizures and loss of speech.
Japanese encephalitis surveillance in Bangladesh
To understand the spread, risk factors and clinical characteristics of the disease, Bangladesh launched nationwide Japanese encephalitis surveillance in 2017.
The surveillance programme currently operates through 103 sentinel sites, including 82 government hospitals and specialised institutions and 21 private hospitals, according to Institute of Epidemiology, Disease Control and Research.
According to the latest surveillance data, 420 positive cases were detected in Bangladesh between 2017 and 2022.
Although vaccines against the disease are already used in several countries, Bangladesh has yet to introduce a vaccination strategy and plans to determine future policy based on surveillance findings.
Research by Dr Arifa Akram of the virology department at the National Institute of Laboratory Medicine and Referral Centre states that the first cases in Bangladesh were identified in Mymensingh in 1977, when 22 people were infected and seven died.
A separate study conducted by icddr,b and the US Centers for Disease Control and Prevention (CDC) between 2003 and 2005 found infections in around 6% of encephalitis patients.
Although infections were identified in Rajshahi, Khulna and Chattogram, the highest rate was recorded in Rajshahi. Most patients came from rural areas, while infections were more common between May and October.
Doctors say all age groups can be infected, although children aged 15 years or below remain the most vulnerable.
Doctors stress early diagnosis
Civil Surgeon Dr Jahangir Alam said the disease is a viral brain infection that may initially cause fever, headache and vomiting.
He added that there is no specific antiviral treatment for the disease and patients are treated according to symptoms.
“Mosquito control and preventive vaccination are important for reducing infections,” he said.
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