Smallpox

Reportable by Laboratories and Providers

About this Reportable Disease

This is an immediately reportable condition. Please contact the Tennessee Department of Health at 615-741-7247 and ask to speak to the epidemiologist on call. 

Infectious agent:  Variola  virus

Description of illness: An infectious disease that spreads from direct and prolonged face-to-face contact and is spread by humans only.  Symptoms vary based on stage of the disease progression and can include high fever, head and body aches, rash/sores on the tongue and mouth. Due to the success of vaccination efforts, smallpox was eradicated in 1980, with no known case of naturally occurring outbreaks since 1977. Since eradication, the vaccine is no longer required but the virus that causes smallpox can be used in biological attacks.

Laboratory Reporting for this Disease

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.

Information about this Reportable Disease for Healthcare Providers

Clinical Summary

  • Smallpox is a highly contagious and potentially fatal illness caused by the variola virus. Naturally occurring smallpox has been eradicated; any suspected case should be treated as a public health emergency and coordinated immediately with public health authorities.
  • Clinical course typically begins with a febrile prodrome followed by a characteristic rash that progresses from macules → papules → vesicles → pustules → scabs, with lesions that are often deep-seated and in the same stage of development on a given body area. Incubation is typically 7–19 days.
  • Diagnosis/testing should be public-health directed: for patients at high risk, the state health department coordinates with CDC for laboratory testing; indiscriminate testing is discouraged because predictive value is low when disease is absent.
  • Management is supportive plus use of medical countermeasures is as directed during an emergency response. CDC lists tecovirimat and brincidofovir as FDA-approved for smallpox treatment, with additional response guidance tied to declared emergencies and SNS availability.
  • Prevention includes smallpox vaccination (vaccinia-based vaccines); CDC notes there are two licensed smallpox vaccines in the U.S.

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 Is It

Smallpox is a serious contagious disease caused by the variola virus. It was eradicated worldwide; there have been no naturally occurring cases since 1977, and eradication was declared in 1980.

Signs and Symptoms

Smallpox illness occurs in stages and includes fever and a distinctive rash that progresses to pustules and then scabs. It can take 7 to 19 days after infection for symptoms to appear.

How It Spreads

Historically, smallpox spread from person to person through close contact and respiratory droplets. Because smallpox no longer occurs naturally, preparedness efforts focus on rapid recognition and response if a case were ever suspected.

Prevention

Smallpox can be prevented by smallpox vaccines (vaccinia-based). In the U.S., these vaccines are used for preparedness and specific occupational/public health indications rather than routine public vaccination.

Tennessee Information

TDH’s Vaccine-Preventable Diseases and Immunization Program (VPDIP) maintains a Smallpox information section in the Diseases & Vaccines area, with vaccine and preparedness resources.

This Page Last Updated: March 25, 2026 at 10:02 PM