Infectious Disease Testing

This hub is for people with new symptomsknown exposuresroutine screening needs (e.g., HIV/STIs, TB, hepatitis), pre-procedure/employment checks, or post-treatment follow-up. Core test types include NAAT/PCRantigencultureantibody (IgM/IgG)neutralization, and IGRA for TB. Results inform screening cadenceneed for confirmationreturn-to-work/travel documentation, and medical follow-up.


What It Tests

“Infectious disease testing” spans screeningdiagnosismonitoring, and post-exposure evaluation:

  • STIs & Viral Hepatitis: HIV, syphilis, chlamydia, gonorrhea, trichomonas, HSV; hepatitis B & C with reflex confirmation.

  • Respiratory infections: COVID-19, influenza A/B, RSV; multiplex respiratory PCR in select cases.

  • Tuberculosis: IGRA for latent TB infection (LTBI) screening; evaluation for active TB needs clinical assessment, imaging, and sometimes sputum testing.

  • Gastrointestinal pathogens: stool PCR panels, C. difficile, ova & parasite where indicated.

  • Vector-borne & others: Lyme and other tick-borne illnesses; EBV/CMV; MRSA screening; rabies neutralizing antibodies for programmatic use.


Key Tests

Test Also Called (Synonyms) What It Detects Typical Prep Specimen Turnaround Related Panels Use Type (Screen / Dx / Mon / Post-Exp) Window/Timing & Confirmation
HIV-1/2 Ag/Ab (4th-gen) Combo Ag/Ab Early HIV screening (p24 Ag Ab) None Blood ~1–3 d Comprehensive STI Screen / Dx Use supplemental Ab differentiation ± HIV RNA NATif reactive or early exposure
HIV RNA (NAT) Qual/Quant RNA Very early HIV infection None Blood ~1–3 d Early Exposure Dx / Post-Exp Use for suspected acuteinfection or high-risk recent exposure
Syphilis RPR/VDRL treponemal confirm Reverse or traditional algorithm Active infection (non-treponemal) & specific confirm None Blood ~1–3 d Comprehensive STI Screen / Dx / Mon Pair RPR/VDRLwith TP-PA/EIA; titers for monitoring
Chlamydia NAAT CT NAAT Chlamydia trachomatis DNA/RNA First-catch urine or swab per site Urine/Swab ~1–3 d STI NAAT Screen / Dx Consider extragenitalsites per exposure
Gonorrhea NAAT NG NAAT Neisseria gonorrhoeae DNA/RNA As above Urine/Swab ~1–3 d STI NAAT Screen / Dx Extragenital site testing may be needed
Trichomonas NAAT TV NAAT Trichomonas vaginalis None Urine/Swab ~1–3 d STI NAAT Screen / Dx Sensitive vs wet mount
HSV testing Lesion PCR; HSV-1/2 IgG HSV DNA from lesion; IgG = past exposure None Swab/Blood ~1–3 d STI Panel Dx / Clinical Prefer lesion PCR for symptoms; avoid IgM
HBV Panel HBsAg, anti-HBc (total/IgM), anti-HBs HBV status (infected, immune, susceptible) None Blood ~1–3 d Viral Hepatitis Screen / Dx / Mon Interpret markers together; post-exposure needs urgent care
HCV Ab with reflex RNA Anti-HCV RNA Exposure/active infection None Blood ~1–3 d Viral Hepatitis Screen / Dx / Mon RNA confirms active infection when Ab positive
SARS-CoV-2 NAAT/Ag COVID-19 PCR/antigen Acute infection None Swab Same–1 d Respiratory Dx / Return-to-work Antibody not for protection status
Influenza A/B NAAT/Ag; RSV NAAT Flu/RSV PCR/antigen Acute respiratory infections None Swab Same–1 d Respiratory Dx Consider during respiratory season
Respiratory Multiplex PCR Panel PCR Multiple respiratory pathogens None Swab ~1–2 d Respiratory Dx Use when results may change management
IGRA for TB QuantiFERON-TB / T-SPOT.TB Latent TB infection None Blood ~1–3 d TB Screening Screen Not a rule-out for active TB
GI Pathogen Stool PCR Panel Multiplex stool PCR Bacterial/viral/parasitic pathogens None Stool ~1–3 d GI Infection Dx Collect before antibiotics if possible
Clostridioides difficile tests Toxin EIA ± NAAT C. diff toxin/organism None Stool ~1–3 d GI Infection Dx / Mon Interpret with symptoms; colonization exists
Ova & Parasite exam O&P Microscopy for parasites None Stool ~1–3 d Travel GI Dx Travel/parasite risk settings
Lyme two-tier testing EIA/ELISA ± immunoblot/2-EIA Borrelia exposure None Blood ~1–7 d Tick-borne Dx Timing & stage matter; early false-negatives possible
Anaplasma/Ehrlichia/Babesia PCR ± serology Tick-borne infections None Blood ~1–3 d Tick-borne Dx Choose PCR vs serology by illness phase
EBV panel VCA IgM/IgG, EBNA ± heterophile Mono workup None Blood ~1–3 d General ID Dx Pattern across antibodies informs staging
CMV testing CMV IgM/IgG ± PCR Exposure/active CMV None Blood ~1–3 d Pregnancy/Immunocomp Dx / Mon Confirm positives; special contexts apply
MRSA screening PCR/culture Colonization None Swab ~1–2 d Employment/Pre-op Screen Use per policy
Rabies neutralizing Ab RFFIT Programmatic immunity check None Blood ~7–14 d Special-risk Post-Exp / Program Public-health schedules apply

When to Test

  • Routine screening: HIV, HCV, and STI panels per age and risk; employment/student onboarding (e.g., TB, MRSA).

  • New symptoms: fever, sore throat, cough, shortness of breath, loss of taste/smell, GI upset, painful urination/discharge, genital ulcers or rash—order tests aligned to symptoms.

  • Known exposure: sexual contact with a diagnosed partner, needle-stickhousehold or respiratory exposure, traveltick bite—respect window periods and seek post-exposure care when indicated.

  • Pre-procedure / return-to-work policies (respiratory/TB screens).

  • Post-treatment monitoring: confirm cure or check for reinfection where recommended (e.g., certain STIs, HCV RNA after therapy).

  • Pregnancy care: screening for HIV, syphilis, HBV, HCV, CT/NG per guidelines.


How to Prepare

  • General: Most serology and NAATs require no fasting. Bring exposure dates, symptoms, current medications(recent antibiotics/antivirals can affect some tests).

  • Urine NAAT (CT/NG/Trich): Provide first-catch urine; commonly avoid urinating ≥1 hour before collection; follow kit instructions.

  • Swabs: Use the correct site (throat, vaginal/cervical, rectal, urethral, nasopharyngeal) and follow handling directions.

  • Stool tests: Collect before starting antibiotics when possible; avoid toilet-water contamination; follow transport instructions.

  • TB IGRA: No special prep; verify timing if you recently received live vaccines.

  • Timing matters: Test within the appropriate window period or plan retesting to avoid false reassurance.


Interpreting Results

  • Positive NAAT/PCR generally indicates current infection; some assays detect colonization (e.g., C. difficile)—interpret with symptoms.

  • Antibody tests: IgM suggests recent/acute infection; IgG shows past exposure or vaccine response (not always protective).

  • Confirmatory algorithms:

    • HIV: 4th-gen screen → supplemental differentiation ± RNA NAT.

    • Syphilis: RPR/VDRL ↔ TP-PA/EIA per algorithm; titers track response.

    • HCV: Ab screen requires RNA to confirm active infection.

  • Window periods: A negative result soon after exposure may be too early—plan repeat testing per pathogen.

  • Test-of-cure vs reinfection checks: Only some infections need test-of-cure; many recommend re-screening later to catch reinfection.

  • Not medical advice: Pair results with clinical evaluation; urgent symptoms or exposures require in-person care.


Related Conditions

  • STI/STD Screening & Sexual Health

  • Hepatitis (A/B/C) Testing

  • Respiratory Infections (COVID-19/Flu/RSV)

  • Tuberculosis (TB) Screening

  • Gastrointestinal Infections

  • Tick-borne Diseases

  • Immunity & Titer Tests (proof of immunity lives there)

  • Employment & Travel Testing


Bundles & Panels

  • Tetanus Titer Test – Measures IgG antibodies to tetanus toxin to assess immunity status after vaccination or exposure. 

  • MMR Titer Test – Quantifies IgG antibodies against measles, mumps, and rubella to confirm prior immunity. 

  • Student Health Immunity Titers – A four-test bundle covering 10 IgG titers (e.g. measles, mumps, rubella, varicella) ideal for school or work immunity verification. 

  • Child Caregiver Infectious Disease Profile – Covers key infectious diseases relevant to caregivers, including chlamydia, gonorrhea, hepatitis panel, herpes simplex 1 & 2, and syphilis.

  • Viruses Diagnostic Assay Panel – Offers comprehensive viral antibody testing to detect and quantify immune response to various viral infections.


FAQs

PCR/NAAT vs antigen vs antibody—what’s the difference?
NAAT/PCR detects genetic material (very sensitive); antigen detects proteins (faster, a bit less sensitive); antibodyshows your immune response (past or recent exposure).

How soon after exposure should I test for HIV/STIs?
It depends on the window period. Early negatives may need retesting. Ask your clinician for timing by pathogen.

Do I need to fast?
Usually no. Follow any kit-specific instructions.

Can antibiotics make my test negative?
They can affect some tests (e.g., culture). Tell your clinician about recent antibiotics/antivirals.

Why do some tests need confirmation?
To avoid false results and to stage infection (e.g., HIV 4th-gen → supplemental test; HCV Ab → RNA).

What’s the difference between test-of-cure and retesting for reinfection?
Test-of-cure checks if the infection cleared; retesting looks for new infection after treatment.

Does a positive IgG mean I’m immune?
Not always. It often means prior exposure/vaccination, but protection varies by disease.

Is an IGRA a test for active TB?
No—IGRA screens for latent TB infection. Active TB needs clinical evaluation and additional testing.

My test was negative right after exposure—am I clear?
Maybe too early. Plan repeat testing per pathogen’s window period.

Who sets return-to-work rules?
Your employer or public-health authority


References

  • CDC — Testing guidance for HIV/STIs, hepatitis, respiratory infections, GI pathogens, vector-borne diseases, and TB.

  • IDSA — Diagnostic guidelines (e.g., C. difficile, Lyme, respiratory testing).

  • USPSTF — Screening recommendations (HIV, HCV, STIs, TB).

  • WHO — Global testing strategies and TB guidance.

  • AASLD — Hepatitis B/C testing and confirmation guidance.

  • Local public health — Rabies programs and travel recommendations.

Last reviewed: September 2025 by Ulta Lab Tests Medical Review Team

Click on the links below to find lab tests for a variety of infectious disorders that may be affected by changes in your health.

To find out more about infections and Infectious disease lab tests, click the link below.

Read about infectious disease testing, the benefits, and the types of lab tests used to screen, diagnose and monitor them. Learn about risk factors, causes, and more.    

Browse Infectious Disease Testing Subcategories

Did you know that in 2018 there were 3.4 million emergency room visits due to infectious diseases? In addition, every year in the US, thousands of cases of infectious diseases such as tuberculosis and Lyme disease are diagnosed.

For this reason, infectious disease testing is crucial for the proper management of the diagnosis and treatment of contagious diseases. It is essential to know who to turn to for advice about infectious disease testing and the best place to get it.

Want to learn more about infectious diseases and infectious disease testing? Then keep reading this guide to learn everything you need to know.

What Are Infectious Diseases?

Infectious diseases are diseases caused by different pathogens like viruses, bacteria, fungi, and parasites. Many organisms live in our bodies yet are harmless and don't cause disease.

We have organisms that help break down the food we eat, and the microbes in our digestive system play a huge role in our immune system function. Common infectious diseases include:

  • Influenza
  • Common cold
  • Tuberculosis
  • Hepatitis
  • Malaria
  • Whooping cough
  • Rubella
  • Sexually transmitted infections

How Are Infectious Diseases Spread?

You're most likely to get an infectious disease if you come in contact with an infected person or animal. Person-to-person contact can spread infectious diseases by kissing, touching, or sneezing. You can also spread infectious diseases by the exchange of body fluids from sexual contact with another person.

Another way infectious diseases are transmitted from an animal to a person. If an infected animal bites you, it's possible you can become sick. You can also get a toxoplasmosis infection by cleaning a litter box and coming into contact with the infected feces from a cat. 

If you're pregnant, it's possible to pass along germs that cause infectious diseases to your unborn baby. Sometimes, germs can pass to the baby from the placenta, the vagina during birth, or breast milk.

You can also get infectious diseases from indirect contact. Often germs and viruses can linger on objects like tables, doorknobs, or faucets. You can touch a doorknob that was touched by someone who was sick with the flu, then touch your mouth or nose and get infected.

You can also catch infectious diseases from contamination through food and water. Bacteria like Escherichia coli (E. coli) can live in foods like undercooked red meat, contaminated water, or other drinks that aren't pasteurized.

Some germs and viruses depend on mosquitoes, fleas, and ticks to move from person to person. Mosquitoes carry malaria or West Nile Virus, and ticks often carry the bacteria that cause Lyme disease.

Risk Factors for Infectious Diseases

Anyone is at risk for catching an infectious disease. If you are in the wrong place at the wrong time, you have the potential to catch bacteria or a virus. But certain risk factors make you more likely to get sick, such as:

  • Illnesses like HIV or AIDS
  • Cancer or any disease that affects your immune system function
  • Taking medications or steroids that suppress your immune system function
  • Old age

Other risk factors, like having an implanted medical device or suffering from malnutrition, can impact your body's ability to fight off infections as it usually would.

Causes of Infectious Diseases

Infectious diseases are usually caused by organisms you come into contact with from the environment or another person.

Bacteria are tiny one-celled organisms responsible for illnesses like tuberculosis, strep throat, or urinary tract infections. Viruses are even smaller and are responsible for various diseases like the common cold, influenza, and COVID-19.

Often you'll see skin diseases like ringworm that are caused by fungi. Fungi can also infect your brain, nervous system, or lungs. And finally, parasites can cause diseases like malaria or toxoplasmosis.

Signs and Symptoms of Infectious Diseases

Signs and symptoms you notice depend entirely on the type of infectious disease you have. But there are general signs and symptoms to watch out for, like the following:

  • Fever
  • Muscle aches
  • Coughing
  • Vomiting and diarrhea
  • Bloody diarrhea
  • Chills
  • Headache
  • Dehydration

Infectious diseases can often cause complications like fatigue, skin rashes, breathing difficulty, and congestion. Some infectious diseases like hepatitis B and C can lead to liver cancer, and the human papillomavirus (HPV) can lead to cervical cancer.

How Infectious Diseases Are Diagnosed

If you have signs and symptoms of infectious disease, it's important to see your doctor. The doctor will start by asking you about your medical history and current symptoms and do a complete physical exam.

Many infectious diseases have similar signs and symptoms, so your doctor will order laboratory tests to help determine what is causing your illness. Blood tests, urine tests, and throat swabs are fantastic tools to detect what disease is causing your symptoms.

Stool samples are often ordered to check for parasites or other organisms, and a spinal tap can measure your cerebrospinal fluid for signs of infection.

Your doctor may also order imaging scans like x-rays or CT scans and take biopsy samples. Often, a lung biopsy is taken to check for the types of fungi that cause infectious respiratory diseases.

Lab Tests for Infectious Diseases

If you're wondering how to do infectious disease testing, then it's time to turn to Ulta Lab Tests for infectious disease testing services. Common tests start with an Epstein-Barr (EBV) comprehensive panel, which tests for the Epstein-Barr virus. The EBV virus commonly causes mononucleosis, often referred to as the kissing disease.

Next is the Lyme Disease test, which measures for Borrelia burgdorferi antibodies, which are the antibodies your body produces after coming into contact with Lyme Disease. The West Nile virus is an infectious disease spread by mosquitoes that can cause mild to severe symptoms, and the West Nile virus antibody test checks for West Nile virus antibodies in your body.

The Influenza (Flu) test can detect if you're infected with influenza A or B. Adults are still susceptible to infectious childhood diseases, so your doctor may also order a measles, mumps, and rubella immunity test to check your antibody levels.

Toxoplasma Antibodies testing measures your antibody levels to detect a toxoplasmosis infection, and a tuberculosis blood test is an excellent diagnostic tool to measure both active and dormant infections.

Sexually transmitted diseases are another cause of infectious disease symptoms, so it's a good idea to order an STD basic panel to check for sexually transmitted diseases like herpes or chlamydia. 

There are also respiratory infectious diseases, so if you have lung symptoms, your doctor might order a mycoplasma pneumonia test to check for mycoplasma, which is a cause of pneumonia. 

FAQs About Infectious Diseases

Should I get vaccinated against influenza? The CDC recommends that all people ages 6 months or older be vaccinated to prevent the transmission of influenza viruses. Each year, flu vaccines are updated to reflect the strains that are most likely circulating that year.

You can decrease the risk to yourself and others by getting vaccinated. It is important to talk to your doctor to make sure the vaccine is safe for you.

Tuberculosis (TB) is caused by mycobacterium tuberculosis and usually affects your lungs, but it can also affect other parts of your body like the brain, kidneys, bones, and joints. 

How easily is tuberculosis spread? The bacteria that causes tuberculosis is easily spread through the air. If a person with TB coughs, sneezes, or speaks, the bacteria circulate into the air. This bacteria can stay in the air for hours, depending on if it's an enclosed environment. 

How is a person diagnosed with tuberculosis? There are two kinds of tests used to diagnose TB. A TB skin test will show a raised bump that indicates a positive reaction. A TB blood test can indicate if you've been infected at some point, But a chest x-ray or CT scan and a sample of your sputum are all needed if a person tests positive for TB via a blood test.

Infectious Disease Testing at Ulta Lab Tests

Ulta Lab Tests offers highly accurate tests, allowing you to make informed decisions about your health. Here are a few things to love about Ulta Lab Tests:

  • You'll always get secure and confidential results
  • You don't need to worry about health insurance
  • No need for a physician's referral
  • Always affordable pricing
  • A 100% satisfaction guarantee

Order your infectious disease lab tests today, and you'll get secure results online in 24 to 48 hours in most cases.

If you're searching Google for infectious disease testing near me, then look no further than Ulta Lab Tests. Take charge of your health and shop with Ulta Lab Tests today!