By Nelson Mandela Ogema
Zanzibar, a semi-autonomous region of Tanzania with a population of about 1.4 million, is a high-transmission area for malaria. This makes it a “unique case study” to test prospects for elimination in other parts of Sub-Saharan Africa where malaria is widespread, according to a study published in BMC Medicine (22 January).
The island aims to eliminate malaria by 2023, according to the Zanzibar Malaria Elimination Programme.
“This study shows greater impact which in turn is thanks to better implementation with higher coverage.”
Anders Bjorkman, Karolinska Institutet
Anders Bjorkman, the lead author of the study, says making available tools accessible to all was a key to success. “This study shows greater impact … thanks to better implementation with higher coverage and the fact that all tools for prevention, diagnosis and treatment were free of charge and thus fully accessible,” he explains.
The researchers accessed data from nine cross-sectional household surveys conducted from May to June each year between 2003 and 2015, in two rural districts. They also used vital monthly data from 26 health facilities for the period between 1999 and 2015.
“Human biting rates [by mosquitoes] decreased by 98 per cent,” according to the findings reported in the journal. “The total [malaria] parasite load decreased over 1000-fold (99.9 per cent) between 2003 and 2015.”
Björkman, a senior professor at the Karolinska Institutet, Sweden, tells SciDev.Net that what made the difference in Zanzibar was higher coverage of community-based interventions such as insecticide-treated bed nets and indoor residual spray.
He attributes the recent success to the commitment of Zanzibar government, the National Malaria Elimination Programme and participation by community residents.
But Björkman cautions that mosquitoes have resisted control measures in previous years, so new strategies need to be developed in order to win the fight against malaria and see its complete eradication in Zanzibar.
Eliningaya Kweka, a vector biologist and associate research professor at the Catholic University of Health and Allied Sciences in Tanzania, says the study has demonstrated that community acceptability of strategies can play a major role in the malaria eradication in islands of Africa, and touts Zanzibar’s success as a model for the continent.
But Andrew Githeko, chief research officer at Kenya Medical Research Institute, says that eradicating malaria in Sub-Saharan Africa remains a challenge.
“It is well known that malaria eradication or elimination is feasible in islands,” he says. “This is not the case for continental Africa.”
Kweka calls on African government to increase funding to boost surveillance, prevention and treatment of malaria.
This piece was produced by SciDev.Net’s Sub-Saharan Africa English desk.
Anders Bjorkman and others From high to low malaria transmission in Zanzibar—challenges and opportunities to achieve elimination (BMC Medicine, 22 January 2019).