Home▸STI Diagnosis & Treatment▸Chlamydia/Gonorrhea NAAT Testing Simulator

🦠 Chlamydia/Gonorrhea NAAT Testing Simulator

This simulation illustrates the use of nucleic acid amplification tests (NAAT) for detecting Chlamydia trachomatis and Neisseria gonorrhoeae. It covers sensitivity and specificity based on sample location and the window period after exposure.

STI Diagnosis & Treatment2DModerate60 FPS

Choosing the Collection Site for NAAT Sampling

Placeholder: locus choice shapes sensitivity and specificity outcomes.

87%: Urine sensitivity (Placeholder reference value)
94%: Vaginal sensitivity (Placeholder reference value)
85%: Rectal sensitivity (Placeholder reference value)
80%: Pharyngeal sensitivity (Placeholder reference value)

Locus-dependent yield

Placeholder: each anatomical site yields different bacterial load.

Nucleic Acid Extraction from Swab Material

Placeholder: lysis and purification isolate target DNA/RNA.

Chemical: Lysis method (Placeholder short note)
Bead-based: Purification (Placeholder short note)
~20 min: Yield time (Placeholder short note)
Wash steps: Inhibitor removal (Placeholder short note)

Extraction fidelity

Placeholder: clean extraction lowers inhibition and false negatives.

PCR-like Exponential Amplification of Target Sequence

Placeholder: repeated cycles double the target copy count.

~35: Cycle count (Placeholder short note)
2x: Doubling per cycle (Placeholder short note)
~90 min: Assay time (Placeholder short note)
CT/NG specific: Target genes (Placeholder short note)

Exponential kinetics

Placeholder: low starting copies still amplify to detectable levels.

Detection Threshold and Positive Call Logic

Placeholder: signal crossing threshold cycle confirms detection.

Ct value: Threshold cycle (Placeholder short note)
95-99%: Specificity (Placeholder short note)
Low: Cross-reactivity (Placeholder short note)
Fluorescent probe: Signal type (Placeholder short note)

Threshold calling

Placeholder: earlier threshold crossing means higher starting load.

Interpreting the Post-Exposure False-Negative Window

Placeholder: testing too early after exposure risks missed detection.

~14 days: Window period (Placeholder short note)
High: Early-test risk (Placeholder short note)
Day 14+: Retest advice (Placeholder short note)
Pharyngeal lowest: Locus effect (Placeholder short note)

Retest guidance

Placeholder: repeat testing after the window reduces missed cases.

Placeholder: retest after day 14 if initial test was early.

⚙ Under the hood

CanvasBiomedicine

2D · HTML5 Canvas 2D · 60 FPS target · runs fully client-side, no install