“I have been a sewerage operator for more than 20 years now,” says Fundi Mzee, smiling as he leaves his office at the Dar es Salaam Water and Sewerage Authority premises for his weekly hunting expedition for polio.
“I never thought such a harmful virus could be hiding in the waste waters that I deal with every day,” he explains. “Such work requires a good understanding of wastewater networks and mechanics. A typical day for me involves routine maintenance and cleaning of public sewers, plus dealing with any blockages.”
For his hunt, Mzee is loaded down with a protective gown, apron, gloves, boots, face mask, sample containers, a bucket with a rope and a cool box.
He is one of 12 sample collectors recently trained by the World Health Organization (WHO) to conduct polio environmental surveillance in four sites in Dar es Salaam, the largest city, industrial centre and commercial port on the United Republic of Tanzania’s Indian Ocean coast.
As the Africa region begins the last step towards being declared free of wild polio, the surveillance of such unusual polio hunters as Mzee and his colleagues are exceptionally critical. It has been three years since the last case was detected in Nigeria, and if no evidence of polio is found in the coming months, the 47 countries of the WHO Africa region will be certified wild polio-free.
Making sure that the wild and other strains of the virus are not lurking is part of the massively concerted lengths that governments and WHO are going to finally eradicate the disease. Finding poliovirus in sewage indicates the virus is circulating among the local population even though no actual cases have yet been reported. It is a proactive means to indicate where immunity might be weak and where immunization activities should be strengthened.
Immunizing every child is the most effective way to guard against a polio outbreak. Due to its sustained high coverage of oral polio vaccines, Tanzania has not detected a polio case since 1996.
But the country is not taking any chances.