Table: Infectious illnesses

Illness Early signs Time from first contact to first sign of illness Infectious to others What to do
Immunisation prevents these illnesses. 
Hepatitis B

Vomiting, tiredness, jaundice

6 weeks to 6 months


A few are infectious for years

See your doctor for testing.


Running nose and eyes


7–18 days

From 5 days before rash appears to 5 days after rash appears Other children who have not had measles and are not fully immunised should be kept home for 2 weeks.
Blotchy red rash About 10 days


Pain in jaw then swelling in front of ear

About 16–18 days 

For 1 week before signs to 9 days after first signs Other children can go to school.
Fever About 18 days

Pertussis (whooping cough)

Cold in nose, persistent cough

About 7 days

For 3 weeks from first signs if not treated with antibiotics. If the child has antibiotics, until 5 days of the treatment completed

If other children in the house are not fully immunised, keep at home for 2 weeks. Keep babies and toddlers right away from patient.

(OR keep home until 5 days of course of antibiotics completed) 

Later ‘whoop’ following coughing bouts, and vomiting About 10 days


Diarrhoea (runny, watery poo, tūtae)


Abdominal (tummy) pain

24–72 hours From first day of illness until about 8 days later Make sure your child has plenty to drink. Wash and dry your hands well after changing nappies and going to the toilet, and before touching food. Keep child away from others – they shouldn’t go to childcare while they are infected.


A spotty pink rash and swollen neck glands


About 16–18 days From 7 days before rash until 7 days after rash started Pregnant women should avoid contact with rubella, but if contact occurs, see your doctor.

Some babies with chronic health conditions may be offered free influenza vaccine.

If you wish to immunise your healthy child against influenza or chickenpox, talk to your doctor. There is a charge for immunising healthy children against these diseases. 


High fever, muscle aches, cough, runny nose

1–3 days Up to 7 days Give fluids, cool child down, see your doctor if concerned.

Chicken pox

Fever and spots

About 14 days

From up to 5 days before first lot of blisters until blisters have crusted (usually about 5 days after last blisters appear) Other children can go to school

A blister later develops on top of each spot

About 15 days