A team of UKHSA staff, Zambia National Public Health Institute staff and Levy Mwanawasa Medical University (LMMU) visited Chongwe’s Chalimbana community on 28th February 2023. The visit aimed to explore the topic of potential toxic health effects of chemical use in mosquito control in Zambia, which had been highlighted as a priority for Zambia in previous discussions with stakeholders. UKHSA’s environmental epidemiology lead, Dr Leonardi, proposed that a team would visit Chongwe, a location in the vicinity of Lusaka, to interview health workers involved in Indoor Residual Spraying (IRS) and other activities as part of integrated mosquito management in that community.
Chalimbana community is located 7 kilometres south of Chongwe town. It is a mixed community of locals and students from different locations of Zambia. It has a population of about 5,000 people. It is one of the communities with high malaria cases in the town and IRS has been used as an intervention to reduce the incidence rate of malaria mainly towards or during the beginning of the rain season (October – January). The district IRS coordinator confirmed using Actellic 300 CS an organophosphate insecticide, Fludora Fusion containing neonicotinoid insecticide clothianidin and the pyrethroid insecticide deltamethrin and DichloroDiphenylTrichloroethane (DDT) an organochloride.
Figure 1. UKHSA team and colleagues from ZNPHI and LMMU in visit to mosquito-control community in Chongwe District, 27th February 2023. From left, Jones Chibuye, Audrey Mulungushi, Emmy Nkhama, Dabwitso Banda, Neelam Iqbal, Giovanni Leonardi.
The District IRS Coordinator’s office was thankful to government and partners for the intervention of IRS as it has drastically reduced the malaria cases in the district despite malaria still being the number one disease of concern in the area. The office called for more support in the malaria intervention of IRS and long-lasting Insecticide Treated mosquito Nets (ITNs).
However, there has been anecdotal reports of increased Asthma cases after the IRS exercise. The District Health Director’s office anecdotally confirmed this despite households with Asthma patients being left out from spraying.
Looking at the characteristics of the chemicals used in malaria control and their effects on human beings and the environment, there may be other possible effects and damages they may cause. Therefore UKHSA IHR Strengthening Project intends to support a case study that the Zambia FETP Program will undertake on this topic with the aim of advising how IRS can be done in a safer way not only in Chongwe but the whole country.