Why could a silent asthma epidemic take hold in Africa? | Health news

A new study has found that millions of teenagers across Africa may be unknowingly struggling with asthma because they have not received a diagnosis from a doctor and are therefore not receiving necessary treatment.

Published last week in a scientific journal LancetThe study’s findings are crucial for a continent where little data has been collected on the severity of asthma, even though the disease is one of the most common causes of chronic respiratory disease death on the continent.

Asthma, which attacks the lungs and causes difficulty breathing, often begins in childhood or adolescence. According to the National Library of Medicine, part of the United States government, it is a condition that affects many teenagers around the world. In 2019, an estimated 76 million young adults suffered from it.

According to scientists, there is no complete cure for asthma that develops in childhood, but treatment can improve the symptoms, which often persist into adulthood.

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

What did the study show?

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

The study, which was conducted between 2018 and 2021, included 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, Nigeria. Durban had the highest number of students with asthma symptoms and Blantyre had the lowest number.

The study also found that one-third of students who had already been diagnosed with asthma and had severe symptoms were not taking any medications to control the disease because they did not perceive their disease as serious and had poor knowledge of asthma treatment.

“Adolescence is a particularly interesting age,” Gioia Mosler of QMUL, who served as principal investigator on the study, told Al Jazeera. “This is the period of life when the incidence of asthma is highest. It is also a time when we all develop many perceptions of health and bodies that we then carry into adulthood.”

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

In the initial phase, researchers used questionnaires and then conducted more rigorous lung function tests typically used in the clinical diagnosis of asthma to determine which children were likely to have the disease.

What is asthma and why does it affect African cities?

According to the World Health Organization (WHO), asthma is a chronic, often lifelong respiratory disease characterized by acute inflammation of the airways and airway obstruction, affecting 262 million people worldwide.

About half of those affected may be in Africa. The latest estimates come from 2010, when a 2013 study in the archives of the United States National Library of Medicine estimated that 119 million people on the continent would suffer from asthma.

Asthma can be caused by pollen, dust or particles from burning waste or other materials. Symptoms often include difficulty breathing, wheezing, chest tightness and coughing.

Although rare, severe asthma can lead to death. According to the WHO, approximately 455,000 people died from the disease in 2019, mostly in low- and middle-income countries. Mortality rates in Africa are not clear, although studies have been conducted at the national level. In Uganda, for example, asthma deaths are estimated at 19 deaths per 1,000 people per year. In turn, according to research, Mexico has 10.41 deaths per 100,000 inhabitants.

The exact causes of asthma are not known, but asthma may have a genetic component. Environmental factors such as weather changes and air pollution are also common triggers for the development of asthma.

In African cities, high rates of asthma have been linked to the continent’s rapid urbanization and rising pollution.

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

While this provides economic opportunities, growing urban centers also mean more polluted air due to concentrated energy use, car exhaust fumes, uncollected waste and many other factors that can trigger asthma.

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

Scientists say the climate crisis is also causing more cases of asthma. Experts say there may be an increased exposure of vulnerable children to dust and fires, which are increasing around the world as a result of global warming.

How common is asthma in Africa?

According to a 2013 study, the total number of asthma cases on the continent increased from 94 million in 2000 to 119 million in 2010.

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

Some studies have found a disproportionately higher number of premature deaths and severe cases of asthma in Africa and other low-income countries, largely due to inadequate health systems, resulting in underdiagnosis and undertreatment.

How is asthma treated?

Asthma is best treated in two ways: with short-acting inhalers or tablets, which widen the airways and let more air into the lungs during an attack. There are also long-term treatments, which may also come in the form of preventive inhalers or tablets, and which are used daily to prevent attacks from occurring.

But scientists say that in most African countries, asthma cases are treated on a crisis-by-crisis basis rather than controlled over the long term.

The costs of treatment, even short-term treatment, are high. In Nigeria, which is mired in one of its worst economic crises in a generation, the cost of inhalers has almost tripled over the past year, from about 2,800 naira ($1.70) to 7,500 naira ($4.57). During the recession, pharmaceutical giant GlaxoSmithKline left the country, causing a shortage of a highly sought-after brand of inhalers.

Why do cases go undetected?

Scientists say many cases of asthma go undiagnosed due to generally poor knowledge of the severity of the disease and how to effectively treat it.

In a study led by QMUL, researchers found that among teenagers previously 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 regular plastic breathing tube with a valve – attached to the inhaler would allow the medicine to get into the lungs much more easily.

Moreover, despite economic growth linked to rapid urbanization, poverty and economic inequality remain problems across Africa, leaving many people without access to health care.

According to UNICEF, about 60 percent of urban residents in Africa live in slums. Researchers say many teenagers in such facilities do not have access to regular check-ups or even emergency care.

The delay in diagnosis means children and young people are at risk of more serious lung complications as a result of lack of care, Rebecca Natanda, a senior research fellow at Makerere University Lung Institute (MLI) who led the Uganda study, told Al Jazeera.

One serious disease that untreated asthma can cause is chronic obstructive pulmonary disease (COPD), which causes daily wheezing and a cough filled with mucus. Natanda added that untreated asthma can cause more than just physical symptoms and can negatively impact the way children connect with peers because they often miss school.

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

What is the solution?

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

Meanwhile, researchers are calling on African governments to increase investment in asthma treatments: both acute, long-term and short-term medications, rather than allocating funds solely to acute medications.

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

She added that working with drugmakers and other key players to negotiate subsidies for asthma drugs and diagnostics is also key.

QMUL’s Mosler said one way to combat under-detection of the disease is to increase students’ awareness of asthma in schools.

“Mobile clinics visiting schools can be a very effective screening method,” Mosler said, referring to a method she noted has been tested with some success in underserved areas in the US.

“The mobile clinic could then provide diagnosis and treatment to people who have symptoms directly in schools. Most African cities have good enrollment in secondary school. … (It) could be a great way to solve the problem,” she said.