Poor drainage in towns creating 'urban malaria'

More than 13 million deaths around the world are due to avoidable environmental causes, with the climate crisis as the single biggest health threat facing humanity, according to the World Health Organization (WHO).

During this year’s World Health Day under the theme, ‘Our Planet, our Health,’ experts noted the need to bridge the gap between evidence and policy regarding climate change and the environment.

Dr Bernard Onyango, a Senior Research Analyst at African Institute for Development Policy (Afidep), said there are direct and indirect linkages between climate change, environmental pollution and health.

Dr Onyango said to achieve the WHO goal of a healthy planet with clean air, water and food means modifying areas where vectors thrive to suit changes that prevent vector-borne diseases.

Though extreme weather episodes lead to flooding creating a conducive environment for breeding of mosquitoes, Dr Onyango said changes in urban areas have led to the outbreak of urban malaria. It was not there before since there was no poor drainage that creates breeding areas.

Flooding brings other heath related issues such as an outbreak of infectious diseases like cholera, poisoning and disruption to health services. Changing weather patterns result in prolonged drought and flooding leads to poor harvest.

But Kenya still bears the burden of malaria morbidity and mortality despite improvements in the diagnosis of the pathogens and large-scale deployment of vector control measures.

According to Lutta Alphayo, a Research and Policy Associate at Afidep, about 30 per cent of Kenya’s total population live in urban areas.

The distribution of vector population and malaria transmission patterns in urban areas, he explains, is aggravated by rapid and unplanned urbanisation characterised by houses in lowland areas without proper drainage systems.

There is also stagnant water caused by the bad state of roads and poor housing.

“You can tell that cases of urban malaria are bound to increase because malaria-causing vectors have found favourable breeding grounds,” says the expert.

Alphayo adds that many urban areas report increased peripheral urban agriculture, creating favourable breeding habitats for mosquitoes.

Rapid unplanned urbanisation also promotes malaria and transmissions of other diseases in areas with “poor quality housing, unpaved roads, and reduced access to healthcare which provides little protection against malaria.

The worst hit are slums-like areas with poor housing, high population and inadequate management of waste.

This is not the case with areas with a high socioeconomic level and good infrastructure.

 On average though, Alphayo says the risk of malaria transmission remains low in urban compared to rural areas but urban malaria is likely to increase as unplanned urbanization continues.

“Unplanned urbanisation leads to a proliferation of suitable breeding habitats for malaria vectors and thus increases the risk of exposure to mosquito bites and malaria transmission,” he says, adding that this could be due to the low use of insecticide-treated nets.

Some preventive measures by the Ministry of Health include proper use of insecticide-treated nets and mosquito repellent spray.  Other proposed actions are the effective control of vector-borne diseases in urban areas besides monitoring and targeting. Urban malaria is highly reported in areas of low socioeconomic status, said Alphayo, adding that close attention ought to be given to urban agricultural fields and environmentally susceptible sites such as coastal lagoons, rivers, and floodplains where human activity can lead to the formation of breeding sites.