Diphtheria

Reportable by Laboratories and Providers

About this Reportable Disease

Infectious agent: Corynebacterium diphtheriae

Description of illness: Diphtheria is a rare acute bacterial disease preventable through vaccination. Important sites of infection are the respiratory mucosa (respiratory diphtheria) and the skin (cutaneous diphtheria). Humans are the only known reservoir of the bacteria. The disease is transmitted from person to person by respiratory droplets or direct contact with respiratory secretions, discharges from skin lesions or, rarely, fomites. The onset of respiratory diphtheria is insidious and begins after an incubation period of 2-5 days (range 1-10 days). Initial symptoms of illness include sore throat, difficulty in swallowing, malaise, low grade fever and swollen glands in the neck. The hallmark of respiratory diphtheria is the presence of a tough, grayish-white pseudomembrane over the tonsils, the pharynx, or larynx.

Laboratory Reporting for this Disease

Corynebacterium diphtheriae

TEST NAME	Corynebacterium diphtheriae
DISEASE/DISORDER	Diphtheria
ALTERNATE NAME(S)	C.diphtheriae, diphtheria, pseudomembrane
METHODOLOGY	Culture
SPECIAL INSTRUCTIONS	CEDEP approval required prior to isolate submission.
ORDERING INFORMATION	Lab Web Portal

Specimen Requirements

Patient Preparation	None
Specimen Collection	Clinical Specimen: Throat, pharynx, or skin lesion: PAI/Loeffler's media or Culture transport swab (Dacron or rayon swab with with Stuart or Amies liquid medium). If no media is available, a swab may be placed in a sterile container. Isolate: PAI/Loeffler's media or Culture transport swab (Dacron or rayon swab with with Stuart or Amies liquid medium).
Specimen Labeling	Specimen should be labeled with at least two unique patient identifiers along with specimen source and match accompanying test order.
Specimen Processing	None
Specimen Storage and Preservation	Specimens and isolates should be stored in ambient conditions until shipment.
Specimen Transport	Ship overnight under ambient conditions within 24 hours. All infectious substance shipments must conform to U.S. Department of Transportation (DOT) Hazardous Materials Regulations (HMR 49 C.F.R. Parts 171-180).
Specimen Acceptability and Rejection	Specimens that do not adhere to all specimen requirements will be rejected.
Testing Location	Nashville

Laboratory Reporting

Reporting requirements apply to all laboratories located within Tennessee, as well as laboratories outside of Tennessee that test residents of Tennessee, including laboratories located within healthcare facilities. Healthcare providers and laboratories in the same healthcare facility both have a duty to report. The type of organisms and analytes laboratories must report to TDH for 2026 are indicated, and there are several ways laboratories can report results to TDH.

Manually report results to TDH by faxing or mailing a completed PH-1600 form to your local health department, or faxing to the state health office at (615) 741-3857
Automatically submit results to TDH via electronic laboratory reporting (ELR), which automates the process of sharing data with TDH using interoperability standards.
- See the ELR Onboarding Handbook for details on the onboarding process, checklist, frequently asked questions, business rules, message format, and vocabulary.
- To initiate the ELR onboarding process with TDH, register in the Trading Partner Registration (TPR) system TPR provides documentation for Promoting Interoperability (PI) attestation and milestone letters to document onboarding progress. Contact MU.Health@tn.gov for assistance.
Submit online via NBS. NBS is TDH's reportable disease system. To request an NBS account for reporting Complete this user survey to request an NBS account for reporting.
Blood lead levels can be sent via fax ( (615) 741-3857), entered online, or reported using the instructions at this link.

Information about this Reportable Disease for Healthcare Providers

Clinical Summary

Diphtheria is a toxin-mediated infection caused mainly by Corynebacterium diphtheriae. It affects the respiratory tract or skin. The toxin can lead to severe complications such as myocarditis and neuropathy. Transmitted via respiratory droplets or direct contact with lesions

Clinical Links & Info

Review the case definition | CDC

Diphtheria Case Report Form (2010) | TDH

Healthcare Provider Reporting

Healthcare reporting requirements apply to all providers located within Tennessee, as well as providers whose patients reside in Tennessee.

Providers must report cases of all diseases and conditions listed through one of these methods:

• Mail or fax a completed PH-1600 form to your local health department or fax to the state health office at (615) 741-3857

• Send automatically via electronic case reporting (eCR). See this TDH webpage for more information on eCR, register at the Trader Partner Registration website, or contact MU.Health@tn.gov for assistance.

• Submit online via NBS. NBS is TDH's reportable disease system. To request an NBS account for reporting Complete this user survey to request an NBS account for reporting.

• Blood lead levels can be sent via fax ( (615) 741-3857), entered online, or reported using the instructions at this link.

Information about this Reportable Disease for the Public

What it is

Diphtheria is a serious infection caused by the bacterium Corynebacterium diphtheriae. The main danger comes from the toxin produced by the bacteria, which can damage the throat, heart, and nerves.

Types of Diphtheria

Respiratory Diphtheria
- Affects the nose, throat, or voice box (larynx).
- Most dangerous type.
Cutaneous (Skin) Diphtheria
- Causes skin sores or ulcers.
- Less severe but still contagious.

Signs and Symptoms

Respiratory Diphtheria:

Sore throat and mild fever
Weakness and difficulty swallowing
Thick grayish membrane in the throat (pseudomembrane)
Swollen neck (“bull neck”)
In severe cases: breathing problems, heart or nerve complications

Cutaneous Diphtheria:

Skin sores or ulcers
May have a gray covering
Usually milder, but can spread infection

How It Spreads

Person-to-person through coughing or sneezing (respiratory droplets)
Direct contact with infected wounds or secretions
Rarely through contaminated objects (fomites)

Treatment

Antibiotics (Penicillin or Erythromycin) to kill bacteria
Diphtheria Antitoxin to neutralize the toxin (for respiratory cases)
Supportive care: Airway management, monitoring heart and nerves
Isolation until tests confirm the person is no longer contagious
Close contacts may need antibiotics and booster vaccination

Prevention

Vaccination (DTaP/Tdap) is the best protection.

This Page Last Updated: March 25, 2026 at 8:53 PM