Containing a prowling killer

Before World Vision Malawi rolled out the mass indoor residual spraying (IRS) project in December 2019, Donnata Tobias was spending K5,000 every month to buy drugs to treat her three children who frequently got struck with bouts of malaria.

“Our nearest health facility is Nankhwali Health Centre, but it is overwhelmed during rainy seasons when cases of malaria triple in this area. Drugs don’t last at the facility during rainy seasons when malaria cases also go up,” recounts the 32-year-old mother from Group Village Head Kamphande, Senior Chief Nankumba in Mangochi.

Mangochi District Environmental Health Officer, Kondwani Mamba, says being a lakeshore district, always registers the highest cases of malaria, which is also a major contributor to child deaths in the district.

Mamba discloses that previously, the malaria attack rate was hovering around 40 to 50 percent of the patients assisted in the out-patient department.

“Malaria has been an endemic disease in Mangochi, contributing to loss of many lives annually. It is an endemic disease in the sense that we have high numbers of people who are suffering from the disease. It is a public health issue for this district,” he explains.

But this is no longer the case. Both Tobias and Mamba state that there has been a significant reduction in malaria prevalence rates following the rollout of the IRS project, which World Vision Malawi is implementing with a grant from Global Fund through the Ministry of Health.

As its name implies, IRS involves coating the walls and other surfaces of a house with a residual insecticide. For several months, the insecticide will kill mosquitoes and other insects that come in contact with these surfaces.

Of course, IRS does not directly prevent people from being bitten by mosquitoes.

Hence, World Vision Malawi has been using a combined insecticide‐treated nets (ITNs) and IRS approach to control malaria vectors in areas where it is implementing the project.

Both strategies use insecticides to kill mosquitoes that bite and rest indoors. For ITNs, the World Health Organisation (WHO) only recommended pyrethroids until 2018, but mosquito vectors are becoming resistant to this insecticide.

While for IRS, a range of insecticides are recommended. Adding IRS to ITNs may improve control, because two interventions may be better than one; it may improve malaria control where ITNs are failing due to pyrethroids resistance; and it may slow the emergence and spread of pyrethroid resistance.

Usually, the insecticide lasts for at least four months, killing mosquitoes that land on them.

WHO says implementing IRS in communities that are using ITNs is even better for malaria control than using ITNs alone.

“Furthermore, the combination of ITNs and IRS may also help to slow the emergence of pyrethroid resistance (where pyrethroids are no longer effective at killing mosquitoes,” WHO says.

Tobias confirms that since her house was sprayed in December 2019, her family has not suffered from mosquito bites and that they have not suffered from malaria attacks over the past five months.

“However, our appeal is that the spraying should be a continuous process because we cannot say malaria has been eradicated in this area. So, we are still at risk of suffering from the disease when its season comes,” she says.

World Vision Malawi Chief of Party, Alexander Chikonga, says the major objective of the project is to contribute to government’s goal of reducing the burden of malaria in at-risk population in Malawi, hence, the organisation conducted a number of activities to achieve its objectives, according to Chikonga.

“These activities included geographical mapping and registering of structures, capacity building trainings and orientations and environmental compliance related activities. At the end, the project sprayed 266,086 structures out of the 279,171 sprayable structures found in the district. This represented coverage of 95 percent,” he says.

He adds that the project protected 1,014, 763 residents, including 201,931 children under five years of age and 23,766 pregnant women.

It also trained 2,554 individuals to deliver IRS interventions in various capacities.

“We used multichannel communication approaches including publications, mass media and advocacy and community dialogue sessions to increase the community acceptance of the initiative. That’s why at the end of the day, the project exceeded its target of covering 90 percent of structures by achieving 95 percent coverage,” Chikonga explains.

Mangochi has an estimated total population of 1,304,130, with 234,743 being under-five children who are usually the worst hit by the disease.

This notwithstanding, the May 2020 Mangochi IRS Project Implementation Profile indicates that there has been a significant decline in malaria prevalence in the district since the programme rolled out.

The profile indicates that the combined use of IRS and ITNs has helped Mangochi to reduce malaria prevalence by 66 percent over the past five months.