Dengue and Zika case studies

Extrinsic Incubation period

Time from when the host is exposed to the disease (Receives virus via mosquito bite) until The host shows symptoms

Intrinsic Incubation period

Time from when the vector acquires the virus (by Biting an infected host) Until the vector is infective (Capable of infecting, a new susceptible host)

• ex: How long until Virus sufficiently replicates inside the vector so there is enough virus to infect someone new. We’re not there yet we’ll get there.

Zika & dengue s/s - these two diseases have a lot in common

• High fever

• Joint pain

• Rash

• Bloodshot eyes

• Eye pain

• Headache

Dengue fever is also referred to as

Breakbone fever because people who’ve had it Say that it feels like their bones are breaking from the inside

Both dengue And Zika are ___ illnesses

Viral

Dengue fever host populations

You can have

• asymptomatic infection

• mild infection

• Serious infection

• Hemorrhagic infection (dengue Hemorrhagic fever)

Who is at most risk for developing dengue hemorrhagic fever

Those who have been exposed more than once

Population most at risk for Zika

fetuses developing in utero (vertical transmission)

• At high risk for microcephaly =Underdevelopment of the brain

  Zika for an average adult Will be self limiting = The person will recover

Primary vector for dengue and Zika Illnesses

Aedes aegypti

Aedes aegypti (Breeding grounds)

Standing water

• They can breed in very, very small quantities of water (even cap full)

• Girls takes 7 to 10ish days

Aedes aegypti (day or night, biting mosquitoes)

DAY BITING

• Rarely active at night

• Active during sunrise and sunset

Where does the Aedes aegypti Like to be

• Indoors and in cool Shaded places

• They also like to stay close to home (<1mile From breeding sites)

Who transmits the dengue or Zika virus

Female Aedes aegypti

• Because females bite (blood is needed for reproduction) not males

Vertical transmission and mosquitoes

A small proportion of her offspring eggs will carry that virus

• But main issue is horizontal transmission