Zika virus is primarily transmitted via mosquito bite. However, it can also be transmitted by sexual contact and it can cross the placenta, allowing an infected mother to pass the virus to an unborn child. 

Koplik's spots are oral lesions seen early-on in infection with the measles virus. These spots are only present in a minority of cases, though. Other common symptoms of measles include high fever (often over 104 degrees fahrenheit), cough, runny nose, and a maculopapular rash which begins at the hair line and spreads down to the trunk and extremities. 

The most noticeable symptom in mumps infection is enlargement of the parotid glands, while Epstein Barr infection can result in fatigue, lymphadenopathy, and hepatosplenomegaly. Scarlet fever is not a viral infection, but rather is caused by the bacteria streptococcus pyogenes.

The measles virus is one of the most highly contagious of all childhood exanthems. It is spread primarily by respiratory droplets, or by touching a surface that has been in contact with an infected individual's saliva or mucus. It is not spread in feces, nor is it blood or vector borne. 

An infection of the finger, toe, or cuticle with the herpes simplex virus is known as a herpetic whitlow. This infection causes painful swelling and erythema at the site of contact and is often caused by the finger coming into contact with a cold sore (oral herpes simplex lesion). It is more common in individuals who are frequently in contact with oral mucosa, such as dentists and dental hygienist, nurses, and in individuals who bite their nails or suck their fingers or thumb.

The most common cause of infectious hearing loss in neonates is cytomegalovirus (CMV), also known as human herpes virus 5. While this disease rarely causes symptoms in adults, it can cause significant harm to a fetus. One of the primary fetal consequences of CMV infection in pregnancy is hearing loss. Other issues can include vision loss, developmental delays, and seizures. 

All of the other infections listed can have significant impacts on the health of a fetus or neonate, including pre-term birth, spontaneous abortion, and vision loss, though none are currently associated with risk of hearing loss.

The lesions described are most likely molluscum contagiosum, caused by the molluscum contagiosum virus. Molluscum contagiosum generally present as 1-5mm papules that are flesh-colored and dome shaped. The dimpled center may or may not be visible on papules, though this is considered pathognomonic for the virus. Common warts may present with a similar appearance, but will not generally present in such high numbers and don't have a dimpled appearance. Chicken pox lesions will generally be red and weeping or crusting, and herpes simplex lesions are not commonly seen outside of the oral mucosa, genital area, or fingers.

The majority of febrile seizures are caused by viral infections, with the most common virus involved being human herpes virus 6, or HHV-6. 

Infectious mononucleosis, a condition caused by Epstein Barr virus, has a very long incubation period: onset of the disease is typically 30-50 days after the time of initial infection.

Bell's palsy is associated with reactivation of herpes simplex 1, a human herpes virus that can exist in latent form in the dorsal root ganglia of nerves in the head and neck. Reactivation of the virus causes the temporary unilateral facial paralysis associated with Bell's palsy. 

Measles, while generally only a moderately severe disease, is fatal in one out of every 500 children who contract the virus.