Ampath Laboratories DxINSIGHTS - Issue 11 - May 2025

Introduction

THE LABORATORY DIAGNOSIS OF ASTHMA

Asthma is a serious global health problem that affects all age groups. Asthma is one of the most common chronic non-communicable diseases that affects over 260 million people and is responsible for over 450 000 deaths annually worldwide, most of which are preventable.1 It is also the most common chronic disease of childhood. Asthma is defined by chronic inflammation of the airways, airway hyperresponsiveness and variable airflow limitation, which can be triggered by viruses, allergens, irritants and exercise. This leads to recurrent episodes of wheezing, breathlessness, chest tightness and/or coughing that can vary over time and in intensity. Symptom episodes are associated with widespread, but variable, airflow obstruction within the lungs that is usually reversible, either spontaneously, or with appropriate asthma treatment such as a fast-acting bronchodilator.

A PARADIGM SHIFT IN THE DETECTION OF PNEUMONIA PATHOGENS – THE ROLE OF MULTIPLEX MOLECULAR PANELS

Severe community-acquired pneumonia (CAP), non-ventilator hospital acquired pneumonia (NV-HAP) and ventilator acquired pneumonia (VAP) continue to result in high morbidity and mortality. The timeous identification of the causative pathogen/pathogens may aid in antimicrobial stewardship and infection control efforts as well as improving patient outcomes by directing antibiotic therapy.2 Culture based identification of respiratory tract pathogens still remains the reference test to identify the causative agents of pneumonia, however compared to molecular methods it lacks sensitivity, cannot detect viral or atypical bacterial pathogens and has a prolonged turn-around time. Molecular testing has emerged as an useful adjunct to culture for the rapid, sensitive detection of causative pathogens.

PULMONARY DISEASE DUE TO NONTUBERCULOUS MYCOBACTERIA

Strict pathogens, potential or opportunistic pathogens, and non-pathogenic, saprophytic species make up the genus Mycobacterium. The immunologic status of the patient and the site (sterile versus non-sterile) from which the culture is taken influences the pathogenic significance of mycobacterial species. Nontuberculous mycobacteria (NTM) comprise more than 190 species, separate from Mycobacterium tuberculosis complex and Mycobacterium leprae complex.