KUALA LUMPUR: Researchers have found that the dengue virus serotype 2 (DEN-2) poses the most risk to patients out of the four dengue strains.
Institute for Medical Research Malaysia’s (IMR) Infectious Diseases Research Centre (IDRC) had revealed that based on studies, DEN-2, which could cause dengue haemorrhagic fever, was associated with severe manifestations of the disease, which could be fatal if not detected at an early stage.
Its virology unit research officer, Dr Ravindran Thayan, said this could be because the virus was more efficient in multiplying itself in some individuals, resulting in higher viral load, or it had developed the ability to evade the immune system better than other dengue serotypes, causing it to stay longer in the body.
“It could be because the virus has better fitness compared with the other dengue serotypes. This leads to longer dengue epidemics,” he told the New Straits Times.
However, Dr Ravindran said the pathogenesis of dengue was not limited to viral factors as there were other factors that could cause severe clinical manifestations, such as secondary dengue infections and host factors, which included immune status, immune response and co-morbidities (simultaneous presence of two chronic diseases in a patient).
There are four serotypes (DEN-1 to DEN-4), and infection by one serotype does not provide long-term, cross-protective immunity against the other serotypes.
The Health Ministry said that DEN-1 and DEN-2 co-predominate the country since 2013.
DEN-1 currently is the predominant virus in Malaysia.
Dr Sylvia Daim, an expert on microbiology, infection and immunity from Universiti Malaysia Sabah, said Malaysia was highly endemic for all four dengue serotypes, which could pose equivalent risks.
However, she said DEN-1 and DEN-2 seemed to pose more risk to Malaysians, as these were the prevalent serotypes in circulation.
“With the dynamic evolution of dengue viruses and the right circumstances, DEN-3 and DEN-4 have the potential to overtake DEN-1 and DEN-2 and become the prevalent serotypes.”
Sylvia said collective immunity of the human population was the key in tackling dengue fever, because if more people were immune to dengue infection, the lesser the risks posed by the viruses.
“Vaccination is an important tool in the fight against any infectious diseases. In the case of dengue, effective vector control is crucial to combat the disease.”