OI
Abbreviation with 3 meanings
| Stands for | Opportunistic infection |
|---|---|
| Meanings | 3 |
| Categories | Medical, Business & Finance |
OI has three meanings. The most common are Opportunistic infection (infectious disease) and Osteogenesis imperfecta (musculoskeletal & rheumatology); it can also stand for Open interest.
Meanings of OI at a glance
| # | OI stands for | Context |
|---|---|---|
| 1 | Opportunistic infection | Medical › Infectious Disease |
| 2 | Osteogenesis imperfecta | Medical › Musculoskeletal & Rheumatology |
| 3 | Open interest | Business & Finance › Stock Market & Investing |
1. Opportunistic infection
Medical · Infectious Disease Abbreviations
Infection caused by organisms that rarely make healthy people seriously ill but exploit a weakened immune system, as in advanced HIV, transplant recipients and chemotherapy patients. Examples include Pneumocystis pneumonia, cryptococcal meningitis, toxoplasmosis, CMV retinitis and MAC.
Example: CD4 under 50: screen for cryptococcal antigen and review OI prophylaxis.
US guidelines on preventing and treating OIs in adults and adolescents with HIV are maintained by the NIH, CDC and IDSA. Starting ART promptly is the most effective way to prevent OIs, though it can unmask hidden infections through immune reconstitution inflammatory syndrome (IRIS). In orthopedics and genetics OI means osteogenesis imperfecta.
2. Osteogenesis imperfecta
Medical · Musculoskeletal & Rheumatology Abbreviations
Inherited connective tissue disorder, usually caused by mutations in the type I collagen genes COL1A1 or COL1A2, that makes bones fragile and prone to fracture with little trauma. Other features include blue-gray sclerae, hearing loss, short stature and dental problems.
Example: Type III OI, 14th fracture this year; continue IV pamidronate cycles every 3 months.
Commonly called brittle bone disease. The Sillence classification (1979) described types I to IV, and more types have since been added as new genes were found. Bisphosphonates reduce fracture rates in children. Unexplained fractures in infants require careful evaluation to distinguish OI from abuse. In HIV care OI means opportunistic infection.
3. Open interest
Business & Finance · Stock Market & Investing Abbreviations
Total number of outstanding options or futures contracts that have not been closed, exercised or delivered. Rising open interest alongside rising prices is often read as new money entering a trend.
Example: OI in the $200 calls jumped to 85,000 contracts, signaling heavy bets on a rally.
Open interest differs from volume, which counts contracts traded during a day; OI changes only when positions are opened or closed. Exchanges report it daily after the close. Large OI at particular strikes can create "pin risk" around expiration.
Related abbreviations
More infectious disease abbreviations
- N95 – N95 filtering facepiece respirator
- NHSN – National Healthcare Safety Network
- NSTI – Necrotizing soft tissue infection
- NTM – Nontuberculous mycobacteria
- OPAT – Outpatient parenteral antimicrobial therapy
- PAPR – Powered air-purifying respirator
- PCP – Pneumocystis pneumonia
- PEP – Post-exposure prophylaxis
See all 92 infectious disease abbreviations →
More musculoskeletal & rheumatology abbreviations
- MUA – Manipulation under anesthesia
- NOF – Neck of femur (fracture)
- OA – Osteoarthritis
- OCD – Osteochondritis dissecans
- ORIF – Open reduction and internal fixation
- PFPS – Patellofemoral pain syndrome
- PJI – Periprosthetic joint infection
- PM – Polymyositis
See all 71 musculoskeletal & rheumatology abbreviations →
This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.