Dengue fever: My proposal for this year’s World Mosquito Day

In the next 100 days or so, the world will be talking about mosquitoes. That will be on World Mosquito Day which is observed on August 20 of each year to commemorate a British doctor, Sir Ronald Ross, who discovered in 1897 that it is the female anopheles mosquito – one of the most capable vectors of human disease – that transmits malaria among people.

Dr Ross’ discovery was a pivotal development in the fight against malaria today. However, the mosquito story has taken a different turn 110 years later.

Despite that malaria is still prevalent in 90 per cent of Tanzania with more deaths of infants and pregnant women being reported, people are currently afraid of a disease, whose burden remains unclear—dengue fever

If I were to suggest what should be at the centre of discussions on World Mosquito Day 2019, I wouldn’t hesitate to name Aedes aegypti mosquito, the female of which transmits not only dengue fever, but also Chikungunya, Zika, Mayaro and yellow fever viruses.

(Female) mosquitoes are indeed a menace, especially considering their ability to spread far and wide killer tropical diseases in humans. This arguably makes them the world’s deadliest creatures, judging by the havoc they wreak upon humanity.

The American billionaire philanthropist Bill Gates posited that “the mosquito is the most dangerous animal” on Planet Earth today.

He published the poser in his blog : “what would you say is the most dangerous animal on Earth: sharks? Snakes? Humans...?

In his view, these are not even close to being the most dangerous!

“I’ve had a thing about sharks since the first time I saw (the 1975 film) Jaws. But, if you’re judging by how many people are killed by an animal yearly, then the answer isn’t any of the above; it’s mosquitoes!

“When it comes to killing humans, no other animal comes even close,” Mr Gates pontificates – noting that “the viruses which cause Zika, dengue, chikungunya and yellow fever in humans are all transmitted by the Aedes aegypti mosquito.”

In 2015 alone, the mosquito-borne malaria killed 438,000 people worldwide, according to the World Health Organization.

No wonder mosquitoes are a major topic in Tanzania, where over 1,140 people have been diagnosed with dengue in Tanga, Singida and Dar es Salaam Regions from January to March, this year. Two people have died.

Countrywide data is still hard to collate.

Worldwide dengue incidence is reportedly increasing. WHO figures show a 30-fold rise in the last 30 years – with more and more countries reporting new dengue outbreaks.

According to research, surveillance mechanisms are not yet well-established to enable us collate sufficient data on the malady. Thus, we don’t know the strength of the enemy confronting us.

That’s even more reason to raise the Aedes aegypti issue on World Mosquito Day this August.

There have been suggestions by researchers that dengue should become part of regular disease surveillance in Tanzania. This is if control measures are to be sustainable – even as they must focus on building human resource capacity, as well as integrating control measures and interventions in ongoing health programmes.

Two years ago, researchers noted in a study published in the Tropical Medicine and International Health journal that Tanzania must strengthen its dengue surveillance mechanisms.

“This would help to treat cases of severe dengue and (avert) related mortality, as well as avoid cases of misdiagnosis,” says the study, titled Dengue Data and Surveillance in Tanzania: a Systematic Literature Review.