Herpes NAAT/PCR Test in Kathmandu — Lesion PCR for Fresh Sores The Most Reliable Acute Diagnostic — on the Right Specimen at the Right Time

What Herpes NAAT/PCR Is

Herpes NAAT — nucleic acid amplification, usually called PCR — detects viral DNA directly from a lesion swab. It is most reliable acute herpes diagnostic: more sensitive than older viral culture, and correct test for question "is this lesion herpes" when a fresh sore is present.

The specimen is whole thing: PCR is run on a swab from lesion itself — not on blood — because it detects virus at lesion. A blood test for herpes is serology (antibodies) — a different test answering a different question (status, not lesion diagnosis) — and two are sometimes confused.

The window is ~2–12 days of a fresh lesion: a fresh sore is rich in viral DNA; a healing lesion carries less virus and produces more false negatives. Attending while lesion is fresh is single most useful thing a suspected patient can do.

The Test — How It Works

The swab is taken across a fresh blister or ulcer — seconds, mildly uncomfortable at most — and laboratory amplifies any HSV DNA present. The typing distinguishes HSV-1 from HSV-2, which matters for prognosis (HSV-2 recurs more often) and for transmission counselling.

A positive is definitive for lesion — virus is there. A negative on a healing lesion may be a false negative — honestly stated rather than presented as a clean negative.

The ~2–12 Day Lesion Window

Viral DNA is abundant in a fresh lesion and declines as it heals — the PCR works best within ~2–12 days of lesion appearing, with early fresh lesions strongest sample. The window is reason for the "attend while fresh" advice that is core message of herpes testing.

The consequence: patients who wait for a convenient day often arrive after productive window — a false negative on a healing lesion where a definitive answer was available days earlier.

PCR vs Serology — Not Interchangeable

PCR and serology answer different questions: PCR answers "is this lesion herpes" (acute diagnosis); serology answers "have I been exposed to HSV-1 or HSV-2" (status). The commonest error is using serology to diagnose a lesion — a positive serology does not prove lesion is herpes because many people are seropositive.

The correct pairing: lesion present → PCR; no lesion but status wanted → serology (with the ~3–12 week antibody window); very recent exposure + no lesion → neither is useful yet.

The Result & What Follows

A positive PCR confirms herpes — with type (HSV-1 vs HSV-2) informing prognosis and counselling. A negative on a healing lesion is read honestly — possibly a false negative — with serology or repeat-on-next-fresh-lesion advised rather than a false all-clear.

Where positive, management follows at same service: episodic or suppressive antivirals, partner guidance (~50% transmission reduction with suppression, barrier-limit caveat), and honest counselling that puts a common diagnosis in proportion.

Herpes PCR & Costs

Transparent pricing; confirm when booking.

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