TDS Desk:

Scientists at icddr,b have recently identified five cases among patient samples collected in 2023, representing the first identification of a cluster of Zika-infected patients in Bangladesh.

The information was published on the icddr,b website on Monday.

Zika virus, classified as a significant emerging pathogen, was first detected in humans in Nigeria in 1954. It remained undetected in Asia and Africa for over fifty years.

In Bangladesh, a 2016 retrospective surveillance study by the Institute of Epidemiology, Disease Control & Research (IEDCR) confirmed the country’s first Zika-positive case. The sample, collected in 2014 from a patient with no history of international travel, indicated that the virus had been present in Bangladesh before the 2015 outbreak in Brazil.

In this study, the scientists screened samples from patients coming to the diagnostic facility of icddr,b at Mohakhali, Dhaka in 2023 and performed PCR-based testing for Zika virus in samples from 152 patients with fever and any one other symptom of Zika virus.

The presence of Zika virus infection in five of these samples suggests that a larger, nationwide screen is necessary to quantify the true burden of the disease in Bangladesh.

All five patients lived within a one-kilometer radius of each other, and had no travel history outside the country in the past two years.

The patients all got tested within about a month, suggesting they were part of the same chain of transmission. One of the five Zika virus cases was also infected with dengue virus — the first time this coinfection has been detected in Bangladesh.

Zika virus infection likely remains underdiagnosed and underreported for two reasons: many cases do not produce major symptoms, with only about 20% of infected individuals developing a noticeable febrile illness; and symptoms such as headache, fever, and muscle pain, when present, are similar to dengue and chikungunya.

However, Zika virus infection can also cause serious fetal complications when infecting pregnant women, such as microcephaly, leading to increased risk of death and intellectual disability in the infant.

Therefore, even though Zika virus infection is rarely fatal in healthy individuals, the risk of transmission to pregnant women makes surveillance and control of the virus a public health priority.

It can circulate not only through mosquitoes, but also via sexual intercourse, blood transfusion, mother-to-child perinatal transmission, or secondary non-sexual physical contact.

It is plausible that Bangladeshi immigrants working in different Zika-affected countries in Southeast Asia provide a route for the virus to circulate within and beyond their communities in Bangladesh. Routine Zika virus for travelers from Zika-affected countries, alongside more diagnostic capacity and systematic surveillance on a national level will be critical to stay ahead of major outbreaks in the future.