Final answer:
Cytomegalovirus (CMV) is considered a successful pathogen due to its widespread infection capability, typically asymptomatic presence, and the ability to become serious in certain individuals leading to potentially severe outcomes.
Step-by-step explanation:
We can say that the cytomegalovirus (CMV), also known as human herpesvirus 5 (HHV-5), is a successful pathogen when it is able to effectively infect its host, typically causing no symptoms or mild ones such as fever and fatigue, which allows it to spread without being detected. However, CMV can become serious especially in individuals with weakened immune systems such as immunocompromised patients, transplant recipients, and in developing fetuses. The presence of the virus can be diagnosed through various methods including observing the cytopathic effect where infected cells exhibit a characteristic "owl's eye" appearance. In severe cases, treatments such as ganciclovir and valganciclovir are used.
CMV is considered a successful pathogen also because it has developed strategies to evade the immune system, remains latent within its host for long periods, and can reactivate under certain conditions. Infections are common in the population and can be transmitted through bodily fluids. For a virus that is often asymptomatic and widespread, effective transmission and the ability to avoid eradication by the host's immune response are key factors in its success as a pathogen.