What are the different types of dengue virus classified into?

Dengue Virus Overview

The dengue virus belongs to the Flaviviridae family and is a single-stranded, positive-sense RNA virus. Based on antigenic differences, it can be classified into four distinct serotypes: serotype 1, serotype 2, serotype 3, and serotype 4. Additionally, there exists an unclassified dengue hemorrhagic fever virus.

Serotype 1

Serotype 1 of the dengue hemorrhagic fever virus was first discovered in Thailand in 1952. It primarily causes mild dengue fever and occasionally progresses to severe dengue hemorrhagic fever.

Serotype 2

Serotype 2 of the dengue hemorrhagic fever virus was initially identified in Japan in 1960. It predominantly induces mild dengue fever but can also lead to severe dengue hemorrhagic fever in some cases.

Serotype 3

Serotype 3 of the dengue hemorrhagic fever virus was first detected in Taiwan Province, China, in 1978. This serotype is known to cause moderate dengue fever and, rarely, severe dengue hemorrhagic fever.

Serotype 4

Serotype 4 of the dengue hemorrhagic fever virus was initially discovered in Indonesia in 1981. It primarily causes severe dengue fever and, on occasion, progresses to severe dengue hemorrhagic fever.

All four serotypes mentioned above have the potential to cause severe dengue fever and possess a certain degree of pathogenicity. Furthermore, in Southeast Asia, there exists an unclassified dengue hemorrhagic fever virus, also referred to as non-classical dengue hemorrhagic fever virus. Compared to the first four serotypes, this virus differs in its genomic structure and envelope protein.

Apart from these, there is currently no evidence suggesting that other types of dengue hemorrhagic fever viruses are associated with human diseases.