Yellow fever; why timely vaccination is important

Apart from that time when travellers are compelled to present certificates before going to certain countries, vaccination against yellow fever has for long received limited attention from the public. Even following fresh outbreaks in Angola and Uganda this year, regional governments only reinforced measures at main exit and entry points.

Sunday, April 17, 2016
A yellow fever patient receiving treatment. (Net photo)

Apart from that time when travellers are compelled to present certificates before going to certain countries, vaccination against yellow fever has for long received limited attention from the public. Even following fresh outbreaks in Angola and Uganda this year, regional governments only reinforced measures at main exit and entry points. 

According to the Ministry of Health, both citizens and non-citizens present certificates upon arrival or departure pay $40 or its equivalent in Rwandan francs for vaccination at Kanombe International Airport. Exceptions are only made for infants.

While there are vaccines to immunise people against several diseases, research continues to show that involuntary yellow fever testing and treatment is rare within African communities, which even makes the disease much harder to wipe out. But how is the disease spread?

Yellow fever is a serious, potentially deadly flu-like viral infection spread by a mosquito - Aedes Aegyptii. It is characterised by a high fever and jaundice. This jaundice or yellowing of the skin and eyes is the source for the name ‘yellow fever.’ While the disease is most prevalent in certain parts of Africa and South America, transmission from infected people is common around the world.

Dr Raymond Awazi, a pediatrician at a polyclinic at St Famillie in Kigali, explains that the symptoms of the disease are similar to those of a person infected with malaria.

"Most times people will have high fever, temperature, severe headache joint pains and vomiting,” he says.

Dr Awazi adds that without appropriate attention on contracting yellow fever, individuals risk damaging their internal organs.

"When one has yellow fever, organs such as the intestines, stomach, liver and kidneys may be damaged due to delayed treatment of the vector borne disease,” he adds.

Incubation

After three to five days of incubation within the body, mortality is expected to occur in 50 per cent of cases.

"Being haemorrhagic, death due to yellow fever often results from bleeding that occurs from the different sites in the body,” says Dr Rachna Pande, a specialist in internal health at Ruhengeri Hospital.

From between 84,000 and 170,000 annually, the World Health Organisation estimates that 60,000 die every year from yellow fever.

Within the three to six days of incubation, the infection occurs in one or two phases. The first - "acute” phase - regularly causes fever, muscle pain with prominent backache, headache, shivers, loss of appetite, and nausea or vomiting. Although most patients improve and their symptoms disappear after three to four days, 15 per cent of these enter a second, more toxic phase within 24 hours of the initial remission.

This is characterised by high fever, which affects several body systems. The patient rapidly develops jaundice with abdominal pain with vomiting. Bleeding can occur from the mouth, nose, eyes or stomach.

Once this happens, blood appears in the vomit and faeces. Kidney function deteriorates. And sadly, half of the patients who enter the toxic phase die within 10 to 14 days, the rest recover without significant organ damage.

Prevention of yellow fever

Like most viral infections, yellow fever has no cure, but treatment relies on vaccination approaches.

Dr Achille Manirakiza, a resident clinical oncologist at Mubimbili University in Tanzania, explains that the disease can be transmitted from an infected person to another.

"Yellow fever is as worrisome as Zika and Ebola. Through bites of infected mosquitoes, the disease can be spread from an infected person to another but we can prevent yellow fever the same way we can prevent diseases spread through mosquito bites,” says Dr Manirakiza.

Testing for yellow fever requires a blood sample. (Solomon Asaba)

He adds that vaccines against yellow fever are effective and individuals do not have to wait for emergency shots.

"Luckily enough, vaccination exists and does not need a travel emergency to work on it as if it is a formality. The vaccine is useful for at least 10 years,” he adds.

Dr Pande also points out that controlling the growth of mosquitoes can put the spread of yellow fever in check.

"Aedes mosquitoes also breed in closed water containers and stagnant cesspools. Individuals should ensure that no stagnant water remains in flower vases, coolers and jugs. Where possible, water containers such as tanks should be covered with larvicide. Bushes around the house should be kept trimmed,” adds Dr Pande.

On contracting the infection, Dr Awazi suggests that patients receive supportive care from their relatives.

"Much as there is no absolute cure, supportive care is needed to rehabilitate those affected,” he adds.

Situation on regional incidences

At least 151 suspected cases were reported from the Democratic Republic of Congo and two cases in Kenya.

Some cases have also been confirmed in Uganda. Luckily no incidences have been detected in Rwanda.

Despite cases of yellow fever in the neighbouring countries, Nathan Mugume, the head of communications at Rwanda Biomedical Centre, maintains that such cases were imported from other countries outside East Africa.

"You realise most people who had the disease travelled from other countries, but the cases appeared after reaching their destination,” says Mugume.

Yellow fever may have no cure but the biggest challenge is that several communities have overlooked it. A study published by the University of California in the journal PLOS Neglected Tropical Diseases concluded that yellow fever is just another neglected tropical disease for which at least 900 million are at risk.

editorial@newtimes.co.rw

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Vaccination

A safe and highly effective vaccine prevents yellow fever. Yellow fever is known to be present in sub-Saharan Africa and parts of South America. If you live in one of these areas, talk to your doctor about whether you need the yellow fever vaccine. If you plan to travel in these areas, talk with your doctor at least 10 days, but preferably three to four weeks, before your trip begins. Some countries require travelers to present a valid certificate of immunisation upon entry.

A single dose of the yellow fever vaccine provides protection for at least 10 years. Side effects are usually mild, lasting five to 10 days, and may include headaches, low-grade fevers, muscle pain, fatigue and soreness at the site of injection. More-significant reactions — such as developing a syndrome similar to actual yellow fever, inflammation of the brain (encephalitis) or death - can occur, most often in infants and older adults. The vaccine is considered safest for those between the ages of 9 months and 60 years.

Talk to your doctor about whether the yellow fever vaccine is appropriate if your child is younger than 9 months, if you have a weakened immune system (immunocompromised), or if you’re older than 60 years.

Mosquito protection

In addition to getting the vaccine, you can help protect yourself against yellow fever by protecting yourself against mosquitoes.

To reduce your exposure to mosquitoes:

Avoid unnecessary outdoor activity when mosquitoes are most active.

Wear long-sleeved shirts and long pants when you go into mosquito-infested areas.

Stay in air-conditioned or well-screened housing.

If your accommodations don’t have good window screens or air-conditioning, use bed nets. Nets that have been pre-treated with insecticide offer additional protection.

To ward off mosquitoes with repellent, use both of the following:

- Non-skin repellent. Apply permethrin-containing mosquito repellent to your clothing, shoes, camping gear and bed netting. You can buy some articles of clothing and gear pre-treated with permethrin. Permethrin is not intended for use on your skin.

- Skin repellent. Products with the active ingredients DEET, IR3535 or picaridin provide long-lasting skin protection. Choose the concentration based on the hours of protection you need. In general, higher concentrations last longer.

Keep in mind that chemical repellents can be toxic, and use only the amount needed for the time you’ll be outdoors. Don’t use DEET on the hands of young children or on infants under 2 months of age. Instead, cover your infant’s stroller or playpen with mosquito netting when outside.

According to the Centers for Disease Control and Prevention, oil of lemon eucalyptus, a more natural product, offers the same protection as DEET when used in similar concentrations. But these products should not be used on children younger than age 3.

Agencies

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What do you know about yellow fever?

Sylvester Kalisa

Sylvester Kalisa

I recently heard there was an outbreak in Angola, but I haven’t been vaccinated against it. I would like to know the procedure of getting vaccinated. People should be sensitised about the disease and how to prevent it.

Danny Nkurunziza, a Kicukiro resident

Danny Nkurunziza

I was once vaccinated against yellow fever when I was travelling to China for my education. Since then I haven’t bothered to go for the vaccine again. I think the vaccination is very vital since one can’t travel to some countries without proof that you have been vaccinated against the disease.

Fabric Nyirumuringa, a student

Fabric Nyirumuringa

I think most people are not aware of it; they only hear about it attacking people in other countries. It would be better if they are sensitized about it so that they take the right steps in fighting against it. Also, the government should take the right measures to ensure that it doesn’t come to our country.

Isaac Masabo, a Kigali bus driver

Isaac Masabo

I haven’t been vaccinated against yellow fever. I think it’s because it’s not a common disease in our country. Besides, however much I would love to be vaccinated, the cost is also too high and it makes people like us ignore it.

Compiled by Lydia Atieno