‘Highly infectious’ wild poliovirus case detected in Mozambique, says WHO

Mozambique health authorities confirmed that a child from the north-eastern Tete province contracted the highly infectious wild poliovirus type 1 disease on Wednesday, according to the World Health Organization (WHO).

In a statement on Wednesday, the WHO said this marks the second imported case of wild poliovirus in southern Africa this year, following an outbreak in Malawi in mid-February.

WHO said this is Mozambique’s first case detected since 1992.

It said globally, wild poliovirus is endemic (occurring at the level of a region or community) only in Afghanistan and Pakistan.

“Polio is highly infectious and largely affects children younger than 5 years. There is no cure for polio, and it can only be prevented by immunisation. Children across the world remain at risk of wild polio type 1 as long as the virus is not eradicated in the last remaining areas in which it is still circulating,’ said WHO.

The UN health organisation said the virus was found in a child in Mozambique who began experiencing onset of paralysis in late March.

“Genomic sequencing analysis indicates that the newly confirmed case is linked to a strain that had been circulating in Pakistan in 2019, similar to the case reported in Malawi earlier this year,” it said.

The organisation said the case in Mozambique and the earlier one in Malawi do not affect Africa’s wild poliovirus-free certification because the virus strain is not indigenous.

“Africa was declared free of indigenous wild polio in August 2020 after eliminating all forms of wild polio from the region,” said WHO.

However, Dr Matshidiso Moeti, WHO Regional Director for Africa, said the detection of another case of wild polio virus in Africa is greatly concerning, even if it’s unsurprising given the recent outbreak in Malawi

“It shows how dangerous this virus is and how quickly it can spread,” she said.

Moeti said the WHO is supporting southern African governments to step up the polio fight.

She said this includes carrying out large-scale, effective vaccination campaigns to halt the virus and protect children from its damaging impact.

“Further investigations are under way in Mozambique to determine the extent of the risk posed by the new wild poliovirus case and the targeted responses needed. Preliminary analysis of samples collected from three contacts of the newly-detected case were all negative for wild poliovirus type 1,” said the organisation.

Mozambique recently carried out two mass vaccination campaigns in response to the Malawi outbreak, in which 4.2 million children were vaccinated against the disease, said WHO.

It said efforts are currently under way to help strengthen disease surveillance in Malawi, Mozambique, Tanzania, Zambia and Zimbabwe.

“The five countries will continue with mass vaccinations, with plans to reach 23 million children aged 5 years and below with the polio vaccine in the coming weeks,” it said.

Meanwhile, last week IOL reported that the National Institute of Communicable Diseases (NICD) had identified a single case of Lassa fever in KwaZulu-Natal.

Lassa fever is a viral infection endemic to the West African countries and mostly reported in Sierra Leone, Liberia, Guinea, and Nigeria. Lassa fever is less frequently reported from Mali, Burkina Faso, Ghana, Togo, Benin and Ivory Coast.

The institute explained that the natural host of this virus is a rodent species called the multimammate rat, which is common in homes and other areas where a food source can be found.

"The rats are persistently infected and shed the virus in their urine and faeces. Humans can come into contact with the virus through direct contact or inhalation of the virus in areas infested with the infected rats. For example, contact with contaminated materials, ingestion of contaminated food or inhalation of air that has been contaminated with urine droplets. Person-to-person transmission of the virus does not occur readily and the virus is not spread through casual contact," the NICD said.

According to IOL, the NICD reported that the male patient had an extensive travel history in Nigeria before returning to South Africa.

"He fell ill after entering South Africa and was hospitalised in a Pietermaritzburg. The diagnosis of Lassa fever was confirmed through laboratory testing conducted at the NICD. Sadly, the man succumbed to the infection.

“Efforts are under way to trace and monitor all possible contacts. No secondary cases of Lassa fever have been confirmed at this stage,” the NICD said.