FOUR IN EVERY Five People
In Africa Are Carrying Undetected Tuberculosis (TB), Facilitating Its Spread
And Presenting Significant Challenges For Tuberculosis Control Efforts,
Scientists Have Said.
Researchers Said It Was
Concerning That More Than 80 Percent Of Patients With TB, Considered The
World’s Deadliest Infections, Are Not Exhibiting A Persistent Cough — Which Is
Traditionally Considered To Be The Most Common Symptom Of The Infectious
Disease.
“This Raises The
Possibility That Those Who Have Tested Negative May Be Unknowingly Transmitting
The Infection.”
TB Is Predominantly
Transmitted By Coughing, But Probably Also Through Simply Breathing.
“Cough Has For Long Been
Perceived As The Primary Mechanism By Which Tuberculosis Is Transmitted,
Although Recent Bioaerosol Studies Suggest That Cough Is Not Needed For
Expelling Bacilli,” Say The Scientists.
In The Results Published March
12, In The Lancet Infectious Diseases, Researchers, Led By Amsterdam
UMC And The Amsterdam Institute For Global Health And Development, Data On More
Than 600,000 Individuals In Africa And Asia Showed That 82.8 Percent Of Those
With Tuberculosis Had No Persistent Cough And 62.5 Percent Had No Cough At All.
Further, The Study
Carried Out Between 2007 And 2020 Showed That A Quarter Of Those Without Cough
Had High Loads Of Bacteria In Their Sputum And Were Probably Highly Infectious.
Yet In Many TB Control Programmes, Persistent Cough Is The Primary Symptom That
Sets Off The Diagnostic Process For HIV-Negative Patients Presenting At Health
Facilities.
High-Incidence Settings
The Team Found 21 Percent
Of Detected TB Patients Without Persistent Cough And 18 Percent Of Patients
Without Any Cough Had A Positive Sputum Smear. Smear-Positive TB Is 4–5 Times
More Contagious Than Smear-Negative TB.
The Results Give A
Probable Explanation As To Why Despite Huge Efforts To Diagnose And Treat The
Disease, The TB Burden In Africa And Asia Is Not Declining.
“We Already Knew There
Was A Giant Gap Between The 10.6 Million Who Get Ill With TB And The 7.5
Million Cases That Were Registered By Health Authorities In 2022,” Says Frank
Cobelens, Professor Of Global Health At Amsterdam UMC And Senior Fellow At The AIGHD.
“A Persistent Cough Is
Often The Entry Point For A Diagnosis, But If 80 Percent Of Those With TB Don’t
Have One, It Means That A Diagnosis Will Happen Later, Possibly After The
Infection Has Already Been Transmitted To Many Others,” He Added.
In High-Incidence
Settings, This Could Contribute Considerably To Disease Transmission And To The
TB Burden.
The Study Analysed The
Results Of National Monitoring Schemes In 12 Countries, And Found That,
Alongside The Lack Of A Cough, More Than A Quarter Of Those With TB Had No
Symptoms At All. With Both Of These Traits Being More Common In Women Than In
Men.
“When We Take All Of
These Factors Into Account, It Becomes Clear That We Need To Really Rethink
Large Aspects Of How We Identify People With TB. It’s Clear That Current Practice,
Especially In The Most Resource-Poor Settings Will Miss Large Numbers Of
Patients With TB. We Should Instead Focus On X-Ray Screening And The
Development Of New Inexpensive And Easy-To-Use Tests,” Says Cobelens.
Over The Past Few
Decades, Significant Strides Have Been Made In The Diagnosis And Treatment Of TB.
However, Out Of An Estimated 10.6 Million People Worldwide Who Fell Ill With TB
In 2022, Only 7.5 Million Cases Were Notified With The 3·1 Million Difference
Largely Reflecting Patients Who Were Not Diagnosed.
Part Of This Diagnostic
Gap Might Be Missed Diagnoses In People With TB Pathology Who Do Not Report
Tuberculosis-Suggestive Symptoms.
Consequently, This Could Serve As A Significant Factor Leading To Delayed Or
Overlooked Diagnoses, Thus Contributing To The Lower-Than-Expected Impact Of Tuberculosis
Control Initiatives On The Global TB Incidence In Recent Decades.
In Africa, TB Is The
Second Leading Cause Of Death From A Single Infectious Agent, Surpassing The
Toll Of HIV And Aids. In 2022, Some 2.5 Million Individuals On The Continent
Contracted The Disease, Equating To One Person Every 13 Seconds, And
Representing A Quarter Of All New TB Cases Globally.
Africa Accounts For Over
33 Percent Of All TB-Related Deaths In 2022, With An Estimated 424,000 Deaths
Of The 1.267 Million Total Global Deaths.