Yellow Fever on the Rise in Southern Africa

According to Angolan Health Minister, Luis Sambo, the disease has now spread to 16 of the country's 18 provinces, despite a preventative vaccination campaign launched in February which reached 6 million of the capital's 7.4 million inhabitants.

"We need to increase the response capacity ... in both technological resources (such) as medicines and vaccines, as well as in personnel," said Sambo.

There is no cure for yellow fever, but there is a vaccine which protects people from contracting the disease.

However supplies of the vaccine are low, according to the WHO (which sent 6 million doses of the vaccine to Angola) the global emergency stockpile of vaccines is already empty.

• Yellow fever is an acute viral haemorrhagic disease transmitted by infected mosquitoes. The "yellow" in the name refers to the jaundice that affects some patients.
  
• Up to 50% of severely affected persons without treatment will die from yellow fever.
  
• According to the recent analysis, there are an estimated 84 000–170 000 cases and up to 60 000 deaths due to yellow fever per year.
  
• The virus is endemic in tropical areas of Africa and Latin America, with a combined population of over 900 million people.
  
• The number of yellow fever cases has been decreasing over the past 10 years since the launch of Yellow Fever Initiative in 2006.
  
• There is no specific treatment for yellow fever. Treatment is symptomatic, aimed at reducing the symptoms for the comfort of the patient.
  
• Vaccination is the most important preventive measure against yellow fever. The vaccine is safe, affordable, and highly effective. A single dose of yellow fever vaccine is sufficient to confer sustained immunity and life-long protection against yellow fever disease and a booster dose of yellow fever vaccine is not needed. The vaccine provides effective immunity within 30 days for 99% of persons vaccinated.

Once contracted, the yellow fever virus incubates in the body for 3 to 6 days, followed by infection that can occur in one or two phases. The first, "acute", phase usually causes fever, muscle pain with prominent backache, headache, shivers, loss of appetite, and nausea or vomiting. Most patients improve and their symptoms disappear after 3 to 4 days.

However, 15% of patients enter a second, more toxic phase within 24 hours of the initial remission. High fever returns and several body systems are affected. The patient rapidly develops jaundice and complains of abdominal pain with vomiting. Half of the patients who enter the toxic phase die within 10 to 14 days, the rest recover without significant organ damage.

At risk are 44 endemic countries in Africa and Latin America, with a combined population of over 900 million. In Africa, an estimated 508 million people live in 31 countries at risk. The remaining population at risk are in 13 countries in Latin America, with Bolivia, Brazil, Colombia, Ecuador and Peru at greatest risk.

Small numbers of imported cases occur in countries free of yellow fever. 

Several different species of the Aedes and Haemogogus mosquitoes transmit the virus, which is an arbovirus of the flavivirus genus, and the mosquito is the primary vector. It carries the virus from one host to another, primarily between monkeys, from monkeys to humans, and from humans to humans.

There is no specific treatment for yellow fever, only supportive care to treat dehydration, respiratory failure, and fever. Associated bacterial infections can be treated with antibiotics. Supportive care may improve outcomes for seriously ill patients, but it is rarely available in poorer areas.

Vaccination is the single most important measure for preventing yellow fever. In high-risk areas where vaccination coverage is low, prompt recognition and control of outbreaks through immunisation is critical to prevent epidemics. To prevent outbreaks throughout affected regions, vaccination coverage must reach at least 60% to 80% of a population at risk.

A single dose of yellow fever vaccine is sufficient to confer sustained immunity and life-long protection against yellow fever disease and a booster dose of yellow fever vaccine is not needed. 

• Infants aged less than 9 months (with the exception that infants aged 6-9 months should be vaccinated during an epidemic where the risk of disease is higher than the risk of an adverse effect of the vaccine);
• Pregnant women – except during a yellow fever outbreak when the risk of infection is high;
• People with severe allergies to egg protein
• People with severe immunodeficiency due to symptomatic HIV/AIDS or other causes, or in the presence of a thymus disorder.

• If you are planning to travel to an area where you may be at risk of yellow fever, make sure you are vaccinated before making your trip.
  
  Under regulations set out by the WHO, anyone travelling to a country or area where there is a risk of picking up or spreading the virus that causes yellow fever must have an International Certificate of Vaccination or Prophylaxis (ICVP)
  
  For a list of all countries which require an ICVP, click here.

• "All Allianz Worldwide Care insured members residing in an endemic yellow fever country are fully covered for the vaccination and/or treatment after infection." Dr. Ulrike Sucher, Medical Director at Allianz Worldwide Care.

If you are an employer and would like more information on international health insurance plans for employees, please visit:
→ Corporate Group Scheme International Health Insurance

For an individual international health insurance quote, please visit:
→ International health insurance