Introduction

Yellow fever is an acute infectious disease. Recognised in two different forms i.e. urban and jungle. Urban Yellow Fever occurs in cities and is spread from mosquito to human. In the jungle form, Yellow Fever is spread from mosquitoes to monkeys and also to humans (zoonosis). Although reported cases of human disease is the principal indicator of disease risk, they may be absent (because of a high level of immunity in population) or not detected as a result of poor surveillance.

Major public health threat in endemic countries.

Travellers to endemic areas of Africa, Central and South America are at risk. The presence of the suitable vector, Aedes mosquito in Asia may contribute to its potential occurrence. Malaysia is vulnerable and receptive to Yellow fever transmission.

Causative agent: Arbovirus of the Genus Flavivirus and family Flaviviridae.

Mode Of Transmission: through the bite of infective Aedes aegypti mosquitoes.

Incubation Period: 3 – 6 days (or longer) after the bite of an infected mosquito.

Yellow fever endemic countries

South & Central America

Africa

Note: The list of endemic countries will be updated by Ministry of Health Malaysia regularly based on WHO latest list

Sign & Symptoms

Some are asymptomatic but most lead to an acute illness characterized by two phases. Initially there is fever, muscular pain, headache, chills, anorexia, nausea and/or vomiting, often with bradycardia.

About 15% of patients progress to a second phase after a few days, with resurgence of fever, development of jaundice, abdominal pain, vomiting and haemorrhagic manifestations,

Death may occur 10 – 14 days after the onset of illness.

Complication

Haemorrhagic manifestation including epistaxis, gingival bleeding, hematemesis (coffee ground or black), melena, and liver and renal failure. 20 ? 50% are fatal.

Treatment

Symptomatic treatment. Advise rest, drink plenty of fluids and take regular painkillers (e.g. Paracetamol or Ibuprofen) to relieve symptoms of fever or aching

Specific treatment – None

Prevention & Precautions

Yellow fever vaccination requirement

• A Yellow fever vaccination certificate is required from all visitors or delegates (Malaysians and Foreigners) coming from or going to/through Yellow fever endemic countries (As stated in International Health Regulations 2005 and Prevention And Control Of Infectious Disease Act. 1988).
• Travellers or delegates without a valid Yellow fever vaccination certificate shall be quarantined upon arrival in Malaysia for a period not exceeding 6 days.
• The period of validity of an international certificate of vaccination against Yellow fever is 10 years, beginning 10 days after the date of vaccination.
• If a person is revaccinated before the end of this period, the validity is extended for a further 10 years from the date of vaccination.
• If the revaccination is recorded on a new certificate, travellers or delegates are advised to retain the old certificate for 10 days until the new certificate becomes valid.

Reminder to Malaysian who wants to go to the endemic countries

• Malaysians are advised to take the vaccination at least 10 days before the date of departure to endemic countries for protection against infection.
• To carry the international certificate of vaccination during travel for health check.
• To get the vaccination against Yellow fever disease at the Approved Yellow fever vaccinating Centres In Malaysia.
• To report to Entry Point Health Office on arrival in Malaysia for health check.

Yellow fever vaccine

Type of vaccine: Live attenuated vaccine

Number of doses: one priming dose of o.5ml

Booster: 10 – yearly

Contraindications:

Egg allergy, immunodeficiency from medication, disease or symptomatic HIV infection, hypersensitivity to a previous dose and pregnancy.

Adverse reactions: Rarely encephalitis or hepatic failure

Before departure: International certificate of vaccination becomes valid 10days after the date of vaccination.

Recommended for: All travelers to endemic zones and wherever mandatory

Special precautions: Not for infants under 12months of age.

APPROVED YELLOW FEVER VACCINATING CENTRES IN MALAYSIA (Based on Ministry of Health List August 2014)