Transiting passengers must also show certificate

South Africa will apply the regulations to all passengers – even those who make airport transfers and do not actually enter the country.

“We understand the new requirement will apply regardless of how little time passengers spend in transit – even those who are simply changing for connecting flights, which is common with Australians visiting Victoria Falls,” Ms Buzzolini said.

Travel agents should advise their clients that they will be required to show an official International Certificate of Vaccination against Yellow Fever dated at least 10 days prior to arrival in South Africa after visited Zambia or Tanzania, or any of the other yellow fever-endemic countries.

Consequences as yet unknown

“As yet, we don’t know what will happen if passengers cannot show proof of vaccination,” Ms Buzzolini said.

“They may be required to get vaccinated or they could be refused entry – we’ve seen both scenarios in Africa. Obviously, neither option is desirable so we are monitoring this situation.”

Travellers arriving back to Australia without a valid certificate are questioned by immigration officials about their itinerary. They are given a Fact Sheet on possible symptoms of yellow fever and must report to local health authorities within 6 days of their return.

Travellers with a specific medical contraindication to the yellow fever vaccine can request a waiver from a doctor licensed to provide yellow fever vaccine. 

The WHO amends criteria for yellow fever

In consultation with experts, WHO has revised the risk of yellow fever transmission for 7 African countries, and 10 in Latin America, including the Caribbean.

These include: LATIN AMERICA - Argentina, Bolivarian Republic of Venezuela, Brazil, Colombia, Ecuador, Panama, Paraguay, Peru, Sao Tome and Principe, and Trinidad and Tobago; AFRICA – The Democratic Republic of the Congo, Eritrea, Ethiopia, Kenya, Somalia, United Republic of Tanzania, and Zambia. Read more.

The list of countries with a risk of yellow fever transmission and those requiring proof of yellow fever vaccination can be viewed. 

Yellow fever: Rare, but lethal

Yellow fever virus (YFV) is transmitted by infected mosquitoes, primarily the Aedes or Haemagogus types.

For western travellers, the risk of yellow fever is very low: estimated at 10 in 100,000 in Africa; 1 in 100,000 in South America.

Australia has recorded a single case in the last decade, while on average there is a case every 3.5 years among the tens of thousands of North American and Western European travellers who visit Africa or South America each year.

That said, yellow fever has a high mortality rate. Of the 9 cases of yellow fever reported among unvaccinated travellers from the USA and Europe who travelled to West Africa (5 cases) or South America (4 cases) from 1970 to 2002, 8 died.

When Yellow fever is a risk

In Africa, YFV transmission is seasonal and occurs mainly in rural West Africa. There is a higher risk at the end of the rainy season and the beginning of the dry season (usually July–October). However, Aedes egypti mosquitoes can pass on the disease during the dry season in both rural and densely settled urban areas.

In South America, the risk for infection is highest during the rainy season (January–May), peaking in February and March. Given high carriage rates in local populations living in endemic areas and the widespread distribution of Aedes mosquitoes in many towns and cities, there is a risk of large-scale urban epidemics.

The CDC has a comprehensive Fact Sheet on yellow fever.

Why vaccination is mandatory

There are 2 reasons why travellers are required to be vaccinated when travelling to endemic areas:

- To protect them against the disease

- To reduce the chance of them returning to infect mosquito populations in their own country.

If an infected traveller was to ‘import’ yellow fever into a country where it does not currently exist – including Australia – there is the potential for it to become established among local Aedes egypti mosquitoes.

A.egypti, which also transmits dengue fever, is widespread in Australia’s tropical north.