To improve the sensitivity of polio detection and response, the Ministry of Health with technical support from the World Health Organisation(WHO), recently established established Environmental Surveillance(ES) for the country.

Environmental Surveillance is the regular collection of sewage or wastewater that is contaminated with human faecal matter and testing the samples for the presence or absence of poliovirus. Environmental Surveillance can detect poliovirus transmission even in the absence of polio cases among humans and can provide additional justification for the elimination and certification of poliovirus transmission.

“Going by the recent upsurge in the outbreak of circulating vaccine-derived poliovirus in the region, the WHO is determined to improve polio surveillance for early detection and response. Lesotho has become the 44th country in the region to initiate Environmental Surveillance”, says Dr. Hamisu Walla, Environmental Surveillance (ES) Consultant and ES focal point at WHO AFRO.

Malekhetho Motenalapi, National Surveillance Officer at the Ministry of Health said this new system will complement the existing Acute flaccid paralysis (AFP) surveillance.

“The Ministry of Health is excited that ES has finally been established in Lesotho. Given that many tourists are visiting Lesotho from Polio endemic countries, the ES will complement (AFP) surveillance by increasing the sensitivity of poliovirus detection. The system can be upgraded later to detect other pathogens of importance”, says Motenalapi.

The African region started implementing ES in Nigeria in 2011 and with gradual expansion, the number of countries implementing ES by the end of 2023 was 42 out of the 47 countries in the region. In April 2024, ES was established in Lesotho with two functional sample collection sites.

The World Health Organization (WHO) aims to improve polio surveillance for early detection and response. Lesotho has become the 44th country in the region to initiate Environmental Surveillance.