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Photos: Olaba TV, Canva
Text: Murchana Roychoudhury / Caroline Kiuru
A photo story by the Unitaid-funded BOHEMIA project, being implemented in Mopeia (Mozambique) by the Barcelona Institute for Global Health (ISGlobal) and the Manhiça Health Research Centre (CISM).
A breeding ground for mosquitoes
In northern Mozambique, next to the magnificent Zambezi river, is Mopeia district, a conglomeration of hundreds of hamlets (bairros in Portuguese) dotted across the landscape. The nearest town is Quelimane, where Portuguese explorer Vasco da Gama first landed in 1498.
Two annual seasons of extreme rain and its location in the floodplains of the river make this region a perfect breeding ground for mosquitoes, including the potentially deadly Anopheles mosquitoes, known for carrying malaria parasites.
The shadow of malaria in Mozambique
Mozambique has long battled malaria and the disease continues to shadow the lives of every person in the country. It is one of the four African countries accounting for over half of all malaria deaths worldwide.
In 2020 alone, more than 10 million malaria cases and over 23,500 deaths due to malaria were estimated in the country. And the brunt of this is borne by children under five years of age. Though much progress has been made in the fight against malaria, progress has plateaued in recent years.
An addition to the malaria vector control toolbox
Vector control, one of the most effective malaria strategies, now stands to be threatened by widespread insecticide resistance and residual transmission. It was in this context of slowed progress and the emergence of new threats that the BOHEMIA project was born.
“What if people and livestock could kill Anopheles mosquitoes with their own blood?” This was the question that led to the formation of the Unitaid-funded BOHEMIA consortium, aimed at reducing malaria transmission by administering ivermectin, a well-tolerated anti-parasitic drug, to humans and livestock.
Arrival of the entomologists
“I loved collecting insects as a child and always had a deep desire to witness a caterpillar turn into a butterfly or know how the fireflies produce light.” — Caroline Kiuru
The world of insects always fascinated Caroline Kiuru, who is leading BOHEMIA's entomology activities in Mopeia.
“On my first day in Mopeia, while driving past the rice fields in the Zambezian landscape, I vividly remembered the one time I caught malaria in Kenya. I was only 10 years old and was visiting a region characterized by its irrigated rice fields.”
Though Kiuru has been lucky in Mopeia and has not suffered from malaria yet, she has seen members of her team of 30, catch the disease every other week.
During the rainy season
"I find it startling that we can collect more than 1000 malaria vectors a night, inside households in Mopeia during the rainy season."
Collecting mosquitoes from dusk to dawn
The goal of the BOHEMIA project’s entomology activities is to conduct an analysis of the dominant malaria vector species in Mopeia and observe their behavior following the mass administration of ivermectin to the local human and livestock populations.
Most mosquitoes feed between dusk and dawn. Thus, Kiuru and her team are often found collecting mosquitoes when most of Mopeia is sleeping. At night, they are usually trying to trap host-seeking mosquitos that are attempting to feed. While in the morning, they collect resting mosquitoes that have already fed.
For host-seeking mosquitoes, the team sets up CDC light traps inside people's homes at dusk. They are placed next to occupied sleeping spaces that are protected by bed nets. The sleeping person attracts mosquitoes to the trap but is protected by the bed net. "At dawn, we remove the traps with the collected mosquitoes and transfer them to the insectary for identification and further analysis," explains Kiuru.
Human-baited Double Net (HDN) traps are also used to collect mosquitoes. For this, a person sits inside the trap throughout the night and collects and separates mosquitoes every hour. "This helps us study the biting time of the mosquitoes as different species have different bitting times. Additionally, as we place the traps both inside and outside the homes, we can also study the biting locations of the mosquitoes," says Kiuru.
During the day, the team can be found collecting aquatic mosquito larval stages in swamps, ponds, and the paddy fields in the region. The mosquitoes are then transferred to the insectary in cool boxes that maintain cold and humid temperatures for the mosquitoes.
Enthusiasm and DIY ideas
When speaking about the insectary, Kiuru admits, "We did not have much to begin with. The insectary was set up with the bare minimum resources, a lot of DIY ideas, and a team of enthusiastic entomologists and fieldworkers."
Inside the insectary
The insectary has two rearing rooms, one for the larvae and the other for the adult mosquitoes. The larvae room is maintained at 30°C and the adult room at 28°C with 60-80% humidity.
The unicorn-themed paper cups in the above photo, contain adult mosquitoes that are provided with 10% sugar, waiting to be used for tests.
Some of the tests involve transferring adult mosquitoes to insecticide resistance monitoring tubes, to expose them to insecticides.
The benefits of having an insectary in Mopeia are far-reaching
It has enabled us to generate insecticide resistance profile data for malaria vectors in the district. This data will be very useful for the malaria control program while deciding on the type of vector control tools to be used," shares Kiuru.
Traps to tests
A glance of the range of activities being carried out by the entomology team.
"I am grateful to work alongside a dynamic team, that is able to improvise, adjust and adapt to new challenges on a daily basis," expresses Kiuru.
Meanwhile, the presence of the entomology team has planted little seeds in the minds of the children of the hamlet. They too want to wear a lab coat and play their part in the fight against malaria.
Credits:
Olaba TV & Canva