Jigger infections tripled during school closures

In March 2020, a study investigating the burden of jiggers in schools was in its second month when President Uhuru Kenyatta abruptly closed all learning institutions to fight the spread of Covid-19.

The long closure lasted 10 months, until January 2021, when all schools reopened, and the study, led by the Kemri Wellcome Trust, resumed.

The researchers immediately noticed a clear change. The proportion of schoolchildren infested with jiggers had tripled.

This change, which was not envisioned in the original study plan, now sheds light on how jiggers devastated poor primary schoolchildren during the long closure.

“Inadvertently, this [break] enabled the study to identify what appears to be an unexpected indirect impact of Covid-19,” the researchers reported last week in the Infectious Diseases of Poverty journal.

The number of children with jiggers also lessened as school programmes rolled on in 2021.

“The proportion of the household population who were infected during surveys implemented when the schools had been closed, was triple that seen in surveys done prior to school closure and double in surveys done when schools reopened,” the researchers reported.

The study confirms a long-held assumption that schools protect children from many infections, including jiggers, also called tungiasis.

The researchers said the higher prevalence during school closure could have been caused by the different behaviours of children during that time.

“During school closures children were spending all day at home or at homes of friends and relatives, resulting in more exposure to transmission sites per unit of time compared to spending most of the day in school classrooms,” they suggested.

“This would corroborate our previous finding that children are at higher risk of infection at home than at school, where they spend most of the day on concrete classroom floors. When not attending school, children were also less likely to wear shoes.”

The infection intensity among infected children was also significantly higher during school closure.

“Since infection intensity was positively correlated with clinical scores and higher levels of pain and itching, this means that school closures due to Covid-19 resulted in more tungiasis-related suffering in children,” the researchers said.

Their study is titled: “Characterisation of tungiasis infection and morbidity using thermography in Kenya revealed higher disease burden during Covid-19 school closures."

The researchers are Kemri-Wellcome Trust’s Lynne Elson, and Abneel Matharu, Naomi Riithi, Paul Ouma and Ulrike Fillinger from the Kasarani-based International Centre of Insect Physiology and Ecology.

Others are Francis Mutebi from Makerere University, Hermann Feldmeier from Charité University Medicine (Germany) and Jürgen Krücken of Freie Universität Berlin.

When they set out in February 2020, the eight only aimed to characterise the tungiasis burden in Siaya and Kwale and to create a new two-level classification of disease severity to guide interventions.

They randomly selected 3,532 pupils aged 8-14 years in 35 public primary schools and examined them for jiggers and associated symptoms.

The overall prevalence of infection was 9.3 per cent, they reported.

The burden was three times higher in Kwale than in Siaya; three times higher in males than in females and three times lower among pupils sleeping in a house with a concrete floor.

“The survey spanned the Covid-19 school closures and demonstrated that when children spent an extended period out of school, the prevalence, intensity and morbidity of tungiasis increased significantly,” the survey reported.

"This indicated prevention measures and education should target household level infrastructure and behaviour."

According to the World Health Organisation, the poorest people carry the highest burden of jiggers.

WHO notes that jiggers thrive where living conditions are precarious, such as villages located on remote beaches, communities in the rural hinterland and shanty towns.

In resource-poor urban neighbourhoods and rural communities, the prevalence may be as high as 60 per cent in the general population and up to 80 per cent in children.

Elderly people and children aged five to 14 years, particularly boys, are at highest risk.

People with disabilities are also highly vulnerable to infection.