PATHOGENCondition Library
Diagnostic protocols, visible before you refer.
The first two rows of every table are open. We show our methodology before asking for anything in return.
HIV & AIDS
| Category | Diagnostic Approach | Typical Timeline | Specialist Role | What to Bring |
|---|---|---|---|---|
| Initial Workup | HIV-1/2 Ag/Ab 4th gen; CD4 count; viral load; resistance genotype | 24–48 hrs for serology; 7–10 days for genotype | ID physician reviews full resistance panel before ART selection | All prior HIV labs, current medications, vaccination records |
| Opportunistic Infections | CMV, MAC, PCP, toxoplasma, cryptococcal antigen based on CD4 threshold | 48–72 hrs baseline; cultures 5–14 days | Subspecialty coordination for CNS, pulmonary, GI involvement | Recent CD4/VL, imaging reports, any prior OI treatment |
ART Optimization Resistance testing, drug-drug interaction review, renal/hepatic panels 7–14 days for full resistance interpretation Pharmacist-ID collaboration for complex regimens Current ART regimen, adherence history, comorbidity list Long-term Monitoring Quarterly viral load, annual metabolic/cardiovascular risk assessment Ongoing — structured 3-month intervals Coordinated care with PCP, cardiology, nephrology as indicated Complete medication list, insurance/pharmacy details | ||||
HIV management requires understanding resistance patterns accumulated over years of treatment. We review the full arc of a patient's viral history before recommending regimen changes.
Transparent Process
The diagnostic journey, made visible.
We demystify every step so referring physicians and patients understand not just what we're doing, but why — and why it takes the time it takes.
How a referral moves through intake
When a physician submits a referral — by fax, portal, or phone — our intake coordinator reviews the reason for consult and assigns an urgency tier within four business hours. Urgent cases (fever in immunocompromised, suspected endocarditis, CNS infection) receive same-day specialist contact. Routine referrals are scheduled within 48–72 hours. Patients receive a preparation packet before their first visit listing exactly which labs, imaging, and records to bring — because the first appointment should begin with context, not collection.
What happens during antimicrobial stewardship review
Every patient arriving on antibiotics — whether empiric or targeted — receives a stewardship review at the first visit. We audit the spectrum, duration, and indication of current therapy against culture data and clinical trajectory. Broad-spectrum agents are narrowed when sensitivities allow; duration is recalculated from the documented source-control date, not the admission date. This review prevents the two most common errors in outpatient ID: under-treatment of resistant organisms and over-treatment of colonizers that don't require therapy at all.
Why sensitivity testing takes the days it takes
Organisms don't grow on demand. A blood culture flagged positive initiates a cascade: Gram stain in hours, preliminary identification in 12–24 hours, full speciation in 24–48 hours, and phenotypic susceptibility testing in 48–72 hours beyond that. Molecular methods (PCR, MALDI-TOF) compress some steps — but phenotypic MIC testing, the gold standard for directing therapy, requires the organism to grow in the presence of each antibiotic concentration. Calling a result "pending" isn't a delay in care — it's the interval during which the organism is teaching us what will kill it.
Our Specialists
The clinicians who name what others couldn't.
Every specialist at Pathogen is fellowship-trained in infectious disease with sub-specialty depth.
Dr. Margaret Osei-Bonsu
Medical Director, ID
Focus: HIV, Opportunistic Infections, Antimicrobial Stewardship
18 years at academic medical centers. Former infectious disease fellowship director. Peer-reviewed publications in HIV resistance and ART optimization.
Dr. Arjun Krishnamurthy
Senior ID Physician
Focus: Tropical Medicine, Travel Infections, Parasitology
Diploma in Tropical Medicine & Hygiene, London School. Extensive fieldwork in sub-Saharan Africa and South Asia. Specialist in imported parasitic and vector-borne disease.
Dr. Claudine Beaumont
ID Physician
Focus: Tuberculosis, Mycobacterial Disease, Drug-Resistant TB
PhD in mycobacterial pathogenesis. WHO consultant on MDR-TB management protocols. Certified directly-observed therapy supervisor.
Dr. James Whitfield
ID Physician
Focus: Post-Surgical Infections, Prosthetic Joint Infections, Endocarditis
Dual-trained in internal medicine and infectious disease. Surgical site infection specialist with 200+ prosthetic joint infection cases managed in collaboration with orthopedics.
94%
Cases resolved without re-referral
< 48h
Urgent consult response time
2,400+
Complex cases managed annually
40+
Conditions in active protocol
Resources
The referral guide that earns the click.
Two rows of every table are already open. The full guide — tailored to your role — is one form away.
Download Our Referral Guide
Select your role for a version tailored to how you interact with our clinic.
Condition Library
Ungated educational pages on specific infections. No form required — the information is public because patients and physicians deserve it.
Urgent Consult
Suspected endocarditis, CNS infection, or fever in immunocompromised?
Same-day specialist contact for urgent referrals. Call our intake line directly.
1-800-555-0199