Millions of teenagers in Africa may be unknowingly struggling with asthma because they haven’t received a diagnosis from a doctor and are therefore not receiving the necessary treatments, a new study has found.

Published last week in the journal Research The Lancetthe study’s findings are critical for a continent that has produced little data on the extent of asthma, despite the condition being one of the continent’s most common causes of chronic respiratory death.

Asthma, which affects the lungs and causes difficulty breathing, often begins in childhood or adolescence. It’s a condition that affects many teenagers worldwide, with an estimated 76 million young adults suffering from it in 2019, according to the National Library of Medicine, part of the United States government.

There is no absolute cure for childhood-onset asthma, but treatment can improve symptoms, which often continue into adulthood, according to scientists.

Here’s what we know about why a silent asthma epidemic could be harming children in some African countries:

What did the study find?

A team of researchers led by investigators from Queen Mary University of London (QMUL) found that 12% of teenagers in six African countries had severe asthma symptoms, but the vast majority – 80% – had not been diagnosed by an asthma expert. health.

The study, which was conducted between 2018 and 2021, focused on 20,000 children aged 12 to 14 from schools located in urban areas: Blantyre in Malawi, Durban in South Africa, Harare in Zimbabwe, Kampala in Uganda, Kumasi in Ghana and Lagos in Nigeria. . Durban had the highest number of students with asthma symptoms, while Blantyre had the lowest number.

The study also found that one-third of students who already had an asthma diagnosis and experienced severe symptoms were not using any medication to control the condition because they did not consider their condition to be serious and had poor knowledge of asthma therapies.

“Adolescence is a particularly interesting age to look at,” QMUL’s Gioia Mosler, who acted as the study’s research manager, told Al Jazeera. “It is the period of life with the highest prevalence of asthma. It’s also the time when we all form many of our perceptions about health and our bodies that we then carry into adulthood.”

It was not possible to generalize the results because of the different conditions in each African city, the researchers said. However, if their results are extrapolated, it could mean that about 15 million adolescents have undiagnosed asthma symptoms in sub-Saharan Africa, Mosler noted.

The researchers used questionnaires at baseline and later performed more rigorous lung function tests, typically used for the clinical diagnosis of asthma, to determine which children were likely to have the disease.

What is asthma and why is it affecting African cities?

Asthma is a chronic, often lifelong respiratory disease characterized by acute airway inflammation and airflow obstruction that affects 262 million people worldwide, according to the World Health Organization (WHO).

About half of those affected may be in Africa. The most recent estimate is from 2010, when 119 million were estimated to have asthma on the continent, according to a 2013 study in the archives of the US National Library of Medicine.

Asthma can be triggered by pollen, dust, or particles from burning waste or other materials. Symptoms often include shortness of breath, wheezing, chest tightness, and coughing.

Although rare, severe asthma can lead to death. About 455,000 people died from the condition in 2019, according to the WHO, mostly in low- and middle-income countries. Death rates in Africa are unclear, although country-level studies have been conducted. In Uganda, for example, deaths from asthma have been estimated at 19 deaths per 1,000 people per year. In contrast, Mexico has 10.41 deaths per 100,000 people, according to the study.

The exact causes of asthma are unknown, but asthma can be genetic. Environmental factors such as weather changes and air pollution are also common triggers linked to the development of asthma.

In African cities, the high number of asthma cases has been linked to the continent’s rapid urbanization and increased pollution.

At least two-thirds of the world’s population lives in cities. However, Africa has the fastest rate of urbanization in the world (3.5 percent growth per year compared to 1.8 percent on average), with large cities expanding and small towns growing.

While this offers economic opportunities, expanding urban centers also mean more polluted air from concentrated energy use, exhaust from cars, uncollected waste and a host of other factors that can trigger asthma.

A higher incidence of asthma in South Africa is likely linked to high cases of bronchitis, according to the Clean Air Fund. The country, which relies on polluting coal-fired power plants for electricity, has one of the worst levels of air pollution in Africa.

Climate crisis is causing even more cases of asthma, researchers say. According to experts, there could be increased exposure of vulnerable children to dust and fires that are intensifying globally due to global warming.

How common is asthma in Africa?

Total asthma cases on the continent rose from 94 million in 2000 to 119 million in 2010, according to the 2013 study.

Teenagers account for about 14 percent of asthma cases in Africa, although the numbers vary widely: in Nigeria, children account for about 13 percent of cases, while in South Africa, they account for about 20 percent.

Some studies have shown that there is a disproportionate number of premature deaths and severe cases of asthma in Africa and other low-income countries, largely due to inadequate healthcare systems, leading to underdiagnosis and undertreatment.

How is asthma treated?

Asthma is ideally managed by two approaches: short-acting inhalers or tablets that widen the airways and allow more air to enter the lungs during an attack. There are also longer-term therapies that can also come in the form of inhalers or preventive tablets that are used daily to prevent attacks from occurring.

However, in most African countries, asthma cases are treated on an attack-by-attack basis rather than being controlled long-term, the researchers said.

Treatment costs, even for short-term relief, are high. In Nigeria, which is in the grip of one of the worst economic crises in a generation, the cost of inhalers has nearly tripled in the past year alone from about 2,800 naira ($1.70) to 7,500 naira (4, 57 dollars). During the recession, pharmaceutical giant GlaxoSmithKline left the country, causing a shortage of its highly sought-after brand of inhalers.

Why do cases go undetected?

Many cases of asthma go undiagnosed because there is generally poor knowledge about the severity of the condition or how it can be effectively managed, the researchers said.

In the QMUL-led study, researchers found that among teenagers who had previously been diagnosed with asthma, only half knew that young people were dying from asthma in their country. More than half of them did not realize that using a spacer – a simple plastic breathing tube with a valve – attached to their inhalers would allow the drug to reach the lungs much more easily.

Furthermore, despite economic growth linked to rapid urbanization, poverty and economic inequality remain problems across Africa, meaning many lack access to healthcare.

About 60 percent of Africa’s urban dwellers live in slums, according to UNICEF. Many teens with these conditions don’t have access to regular health checkups or even emergency care, the researchers said.

Delayed diagnosis means children and young people are at risk of more severe lung complications from lack of care, Rebecca Nantanda, a senior researcher at Makerere University Lung Institute (MLI), who led the study in Uganda, told Al Jazeera.

A severe condition that can be triggered by untreated asthma is chronic obstructive pulmonary disease (COPD), which causes daily wheezing and a cough full of mucus. Untreated asthma can also cause more than just physical symptoms, Nantanda added, and can have a negative impact on how children connect with their peers, as they tend to miss school a lot.

“(Asthma) affects their education and other activities like sports and play. It also affects their mental and psychological well-being due to stigma, chronic illness, stress, worry and anxiety,” she said.

What is the solution?

In the long term, the WHO says that controlling air quality in cities is imperative to reduce the number of people with asthma.

Meanwhile, the researchers are calling on African governments to increase investment in asthma treatments: both long-term and short-term relief drugs, rather than pushing funds only into quick-fix drugs.

“Most hospitals could focus on treating asthma attacks and exacerbations, but these are more expensive for the patient and for health systems,” said MLI’s Nantanda. “Governments need to invest in appropriate long-term care for asthma patients because, in the long run, it is cheaper and therefore more affordable.”

Working with drugmakers and other key players to negotiate subsidies for asthma drugs and diagnostics is also crucial, she added.

One way to tackle under-detection in particular is to raise asthma awareness among pupils in schools, QMUL’s Mosler said.

“Mobile clinics that visit schools could be a very effective way of screening,” Mosler said, referring to a method he noted has been tested in low-health areas of the U.S. with some success.

“The mobile clinic could then provide diagnosis and treatment directly in schools to those with symptoms. Most African cities have good school attendance at the beginning of secondary schools. … (That) could provide a great way to address the problem,” she said.