Infectious Disease & Sepsis Labs
Every infectious disease & sepsis labs calculator on CalcEngines — unit converters, derived indices and interpretive tools, each with its formula, a worked example and the reference intervals it is judged against.
30 calculators in this section
- Anti-HBs Titre InterpreterRead a quantitative anti-HBs result after hepatitis B vaccination: the 10 mIU/mL threshold, what a waned titre in a documented responder means, and what to do at each level.
- APACHE II Score CalculatorScore all twelve APACHE II physiological variables plus age and chronic health, with the oxygenation branch and the acute-renal-failure doubling handled for you.
- BK Virus DNA Unit ConverterBK virus guideline thresholds are written in copies/mL, every current assay reports IU/mL, and the WHO standard meant to bridge them carries deletions that make some assays over-report between five- and tenfold.
- CMV DNA IU/mL to Copies/mL ConverterThe WHO cytomegalovirus standard assigns a potency in international units and no copy number at all. Convert with the factor published for your assay, and see how far apart three platforms put the same specimen.
- CURB-65 Score CalculatorScore community-acquired pneumonia severity from five bedside criteria, and see what the score deliberately leaves out.
- EBV DNA IU/mL to Copies/mL ConverterOne laboratory's own cross-over study found 1 IU/mL of EBV DNA equal to 0.12 copies/mL on the assay it replaced — a more than eightfold gap. That is the only published factor, and this page explains why there are no others.
- HBV DNA IU/mL to Copies/mL ConverterConvert HBV DNA between IU/mL and copies/mL using an assay-specific factor, and see the log value guidelines are written against.
- HCV RNA IU to Copies ConverterConvert HCV RNA from IU/mL to copies/mL using the factor published for the assay that produced it — and see why there is no universal one.
- Hepatitis B Serology InterpreterTurn HBsAg, anti-HBs and anti-HBc results into a plain-English pattern — one of the most confusing readings in laboratory medicine.
- HIV Test Window Period InterpreterWork out what a negative HIV test does and does not exclude, from the days since exposure, the assay generation, and whether PEP or PrEP was taken.
- HIV-1 RNA Copies/mL to IU/mL ConverterHIV-1 RNA is reported in copies/mL and the international standard is in IU/mL. Convert between them with the factor published for the assay that produced the result, and see why the two numbers differ by about 0.23 log.
- Interleukin-6 (IL-6) Unit Converterpg/mL and ng/L are the same number for IL-6, and ng/mL is a thousandth of either. The harder fact is that IL-6 has no established decision threshold — the same serum reads fiftyfold apart on different assays.
- Lipopolysaccharide Binding Protein Unit ConverterConvert LBP between µg/mL, mg/L and ng/mL — the first two are the same number. The honest framing belongs in the first paragraph rather than the last: LBP has been proposed as a sepsis marker for twenty-five years, and in a head-to-head emergency department study it performed like CRP and worse than procalcitonin.
- Malaria Parasitaemia CalculatorCalculate percentage parasitaemia from a thin film count, and see why every level — not just a high one — is abnormal.
- NEWS2 Score CalculatorAggregate seven routine observations into the standard ward early-warning score, and the single-parameter rule that overrides the total.
- Pentraxin-3 (PTX3) Unit Converterng/mL and µg/L are the same number for PTX3, and healthy values are low enough that pg/mL is common. No molar conversion is offered: the sources disagree on how many subunits PTX3 even has.
- Pneumonia Severity Index (PSI/PORT) CalculatorScore all twenty PSI variables, including the step-1 rule that decides risk class I, and see the 30-day mortality Fine et al published for the class.
- Presepsin Unit Converterpg/mL and ng/L are the same number for presepsin. The molar conversion is not offered, because the 13 kDa its manufacturer quotes is a gel mobility and a 64-residue peptide weighs about half that.
- Procalcitonin InterpreterRead a procalcitonin result against the bacterial-infection thresholds used in antibiotic stewardship, and see where it misleads.
- Procalcitonin Unit Converterng/mL and µg/L are the same number for procalcitonin, and every published threshold is written in them. The molar figure is arithmetically exact at 78.17 pmol/L per ng/mL and used by nobody.
- qSOFA Score CalculatorFlag suspected infection at higher risk of death or prolonged critical care using three bedside observations and no laboratory tests.
- Sepsis-3 Criteria InterpreterRead the 2016 Sepsis-3 definitions: infection plus a SOFA rise of 2 or more is sepsis, and what has to be added to that before it is septic shock.
- Shock Index CalculatorDivide heart rate by systolic blood pressure to catch compensated shock earlier than either number does alone.
- SIRS Criteria CalculatorScreen for the systemic inflammatory response — four bedside-and-lab criteria that once defined sepsis and are now a screening prompt, not a diagnosis.
- SOFA Score CalculatorScore organ dysfunction across six systems — the score whose 2-point rise, with suspected infection, is the Sepsis-3 definition of sepsis.
- suPAR Unit Converterng/mL and µg/L are the same number for suPAR. There is no molar conversion, because the assay counts full-length suPAR and two cleaved fragments together and reports one figure.
- Syphilis Serology InterpreterRead a treponemal and a non-treponemal result together — including the prozone trap, the discordant reverse-sequence result and the fourfold titre change.
- Tuberculin Skin Test (Mantoux) InterpreterApply the correct induration threshold for the patient's risk group, from 5 mm in the highest-risk groups to 15 mm with no risk factors.
- Viral Load Log Change CalculatorTurn two viral load results into a log₁₀ change, and see how much of that change is real rather than assay noise.
- Viral Load Log ConverterConvert an absolute viral load in copies/mL or IU/mL to its base-10 logarithm, and see what a log change actually means for treatment response.