Institution: PROBASHI KALLYAN BANK Exam: অফিসার (জেনারেল) (05-05-2023) || 2023
Topic: International General Knowledge, Subject: General knowledge(সাধারণ জ্ঞান)

Best Answer Explained in Below-:

Den-3 refers to the Den-3 serotype of the Dengue virus, which is a member of the Flavivirus family. Dengue fever is caused by four different serotypes of the virus, namely Den-1, Den-2, Den-3, and Den-4. Each serotype can cause similar clinical presentations but can also vary in terms of severity. The Den-3 variant is particularly noted for its association with more severe forms of dengue, such as dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS).

This distinction is crucial because the immune response to one serotype does not provide complete protection against the others. Consequently, a person infected with Den-3 after having had a prior infection with another serotype may experience a heightened risk of severe disease due to antibody-dependent enhancement (ADE). This phenomenon occurs when antibodies from a previous infection facilitate the entry of the virus into host cells, exacerbating the infection.

In contrast, the other options—COVID-19, Malaria, and Chikungunya—are associated with different pathogens (SARS-CoV-2, Plasmodium species, and Chikungunya virus, respectively) and do not include the Den-3 variant. Therefore, option B, Dengue, is the correct answer.