This study is a prospective observational multicentre cohort study of asthma patients in Eastern Africa whose objectives will be; The primary objective of this project is to identify and characterize severe asthma in Eastern Africa in order to understand its demographic, clinical, physiologic, pathologic, genomic and immunologic determinants.

Secondary objective(s) are; Compare the annual healthcare utilisation (HCU) (emergency room visits, hospitalization including admission to critical care units and unscheduled outpatient clinic or office visits), exacerbation, quality of life and mortality rates of severe and not- severe asthma patients Determine the factors associated with the asthma HCU events, quality of life, exacerbations and mortality The study will enroll 1676 patients aged between 12 and 70 years and follow up each patient for up to one year.

This study is a prospective observational multicentre cohort study of asthma patients in Eastern Africa. whose objectives will be; The primary objective of this project is to identify and characterize severe asthma in Eastern Africa in order to understand its demographic, clinical, physiologic, pathologic, genomic and immunologic determinants.

Secondary objective(s) are; Compare the annual healthcare utilisation (HCU) (emergency room visits, hospitalization including admission to critical care units and unscheduled outpatient clinic or office visits), exacerbation, quality of life and mortality rates of severe and not- severe asthma patients Determine the factors associated with the asthma HCU events, quality of life, exacerbations and mortality.

The study will enroll 1676 patients aged between 12 and 70 years and follow up each patient for up to one year.

Measurements; The following will be done

• Asthma Diagnosis. This will be done and will be an entry point to the study. It will be done to ensure patients enrolled onto the study fulfill a clinical diagnosis of Asthma.
• Cohort Characterisation. Through use of a predeveloped clinical review form, data on demographics, symptoms, exposures to pollutants, known asthma triggers, tobacco smoking, psychosocial issues, comorbidities, asthma control, adherence to medication and inhaler technique will be collected. Asthma quality of life will also be ascertained through use of a questionnaire.

Further measurements to characterise asthma will be performed and include;

• Spirometry
• Bronchial hyperresponsiveness testing using methacholine challenge tests
• Skin prick test (SPT), total IgE assays and complete blood count (for eosinophils)
• FeNO for airway inflammation according to published guidelines.
• Stool microscopy for helminths infestation
• Replicative single nucleotide polymorphisms (SNP) genotying
• HIV testing Each patient will be followed up at intervals (initially monthly for 6 months and then at month 9 and 12). At each clinic visit, treatment will be optimised.

Inclusion Criteria:

• All Asthma Patients presenting at study clinics who are between 12 and 70 years and older resident within 30km of the enrolling sites.

Exclusion Criteria:

• Asthma patients with contra-indications to any of the study procedures and tests.

In addition the following patients will be excluded:

• Patients with a primary diagnosis of an alternative lung disease (e.g.: COPD, or bronchiectasis, pulmonary fibrosis.),
• Patients with another significant disease likely to confound assessment of asthma (e.g: active tuberculosis),
• Patients unable to perform study tests and procedures,
• Patients over 70 years of age, patients who have been exposed to experimental treatments within the past three months
• Pregnant women.

All Asthma Patients presenting at study clinics during the study period. These will have to be 12 years and older resident within 30km radius 'of the enrolling sites.

Asthma will be defined as either doctor diagnosed, clinical/treated asthma and wheezing/whistling breath in the last 12 months as used in the World Health Survey and other surveys.