Many studies have showed that rapid point-of-care (POC) c-reactive protein (CRP) test can reduce inappropriate use of antibiotic at primary health care level. In Vietnam, prevalence of antibiotic abuse for community acute respiratory infection has been reported. This study will test the hypothesis that CRP POC testing for patients with non-severe acute respiratory illness at primary healthcare stations reduces inappropriate antibiotic use safely.

The study will be conducted at ten district health care facilities in Hanoi, Viet Nam. Investigators intend to enroll 2,000 participants aged 6-65 years with non-severe acute respiratory infection. Patients will be randomly allocated to the control or the intervention arm. Participants in the control group will be treated according to routine care. Participants in the intervention arm will have a CRP test, the results of which will be available to the health care practitioner to contribute to their diagnosis and treatment decisions.

All patients will be followed-up via telephone call after 14 days. The study will compare the proportion of patients in each arm receiving any antibiotics within 2 weeks of study enrollment.

Inclusion Criteria:

• Patients, aged 6 to 65 years, that visit one of the 10 selected primary healthcare centers
• Suspected to have acute respiratory tract infection (ARI) by treating physician
• Informed consent

Exclusion Criteria:

• Severe respiratory disease as determined by treating doctor
• Any disease or symptom requiring hospital referral as determined by treating doctor
• Immunosuppressed patients (e.g. HIV, long term steroid use)
• Suspicion of tuberculosis
• Evidence of acute or chronic liver disease (e.g. hepatitis or cirrhosis due to any cause)
• Past medical history of: neoplastic disease, congestive cardiac failure, chronic obstructive pulmonary disease, insulin-dependent diabetes or renal disease
• Pregnancy
• No access to telephone
• Not able to come for follow up visit on day 3 or 4.
• Already taking antibiotics at the time of presentation
• Symptoms present for more than 2 weeks
• Presence of any sign of severe diseases as defined by the British Thoracic Society modified CRP-65 system for severity scoring of pneumonia in primary care.

For children (Age ≥ 6 years and < 16 years) additional exclusion criteria include: Tachypnea, signs of chest wall in drawing, reduced consciousness, confusion, dehydration, hypothermia, severe malnutrition, unable to feed or drink, vomiting, and convulsions.