Related Experiment Video
Updated: Jun 17, 2025

The MODS method for diagnosis of tuberculosis and multidrug resistant tuberculosis
Published on: August 11, 2008
Barriers and facilitators to tuberculosis diagnosis in Lima, Peru: a mixed methods study
Carolina Geadas1,2, Ana Karina Millones3, Diana Acosta3
1Brigham and Women's Hospital, Division of Infectious Diseases, Boston, MA, USA. cgeadas@bwh.harvard.edu.
Background:
Tuberculosis (TB) infectiousness decreases significantly with only a few days of treatment, but delayed diagnosis often leads to late treatment initiation. We conducted a sequential explanatory mixed methods study to understand the barriers and facilitators to prompt diagnosis among people with TB.
Methods:
We enrolled 100 adults who started TB treatment in the Carabayllo district of Lima, Peru, between November 2020 and February 2022 and administered a survey about their symptoms and healthcare encounters. We calculated total diagnostic delay as time from symptom onset to diagnosis. We conducted semi-structured interviews of 26 participants who had a range of delays investigating their experience navigating the health system. Interview transcripts were inductively coded for concepts related to diagnostic barriers and facilitators.
Results:
Overall, 38% of participants sought care first from public facilities and 42% from the private sector. Only 14% reported being diagnosed with TB on their first visit, and participants visited a median of 3 (interquartile range [IQR] health facilities before diagnosis. The median total diagnostic delay was 9 weeks (interquartile range [IQR] 4-22), with a median of 4 weeks (IQR 0-9) before contact with the health system and of 3 weeks (IQR 0-9) after. Barriers to prompt diagnosis included participants attributing their symptoms to an alternative cause or having misconceptions about TB, and leading them to postpone seeking care. Once connected to care, variations in clinical management, health facility resource limitations, and lack of formal referral processes contributed to the need for multiple healthcare visits before obtaining a diagnosis. Facilitators to prompt diagnosis included knowing someone with TB, supportive friends and family, referral documents, and seeing a pulmonologist.
Conclusions:
Misinformation about TB among people with TB and providers, poor accessibility of health services, and the need for multiple encounters to obtain diagnostic tests were major factors leading to delays. Extending the hours of operation of public health facilities, improving community awareness and provider training, and creating a formal referral process between the public and private sectors should be priorities in the efforts to combat TB.
Related Concept Videos
Pulmonary Tuberculosis IV
Several diagnostic approaches are used to detect TB. The conventional method is the Tuberculin Skin Test (TST), also known as the Mantoux test. However, this method has...
Pulmonary Tuberculosis V
Latent tuberculosis infection occurs when TB bacteria are present in a person's body, but are not causing illness or symptoms. It is not contagious, and preventive treatment is crucial to avoid the...
Pulmonary Tuberculosis I
Causative Organism
The primary infectious agent causing tuberculosis is Mycobacterium tuberculosis, a slow-growing, acid-fast, aerobic rod that exhibits sensitivity to heat and ultraviolet light. Instances of Mycobacterium bovis and Mycobacterium avium contributing to the development of TB infection are rare.
Mode of...
Pulmonary Tuberculosis III
The first classification is based on the development of the disease, and it includes the following categories:
Pulmonary Tuberculosis II
Here is a detailed explanation of its pathophysiology:
Transmission: The process begins when a person inhales droplet nuclei containing M. tuberculosis. These are typically released into the air when an individual with pulmonary or...

