DC Influenza Surveillance Data

• Influenza Surveillance Dashboard
• Archived District MMWR Reports (oldest season: 2011-2012)

Surveillance and Reporting

Reporting Guidelines

In the District, influenza is reportable for the following cases:

• Influenza associated pediatric deaths (<18 years old)
• Novel Influenza A infection
• Any influenza outbreak
• Reporting of influenza associated hospitalizations or non-pediatric deaths is strongly encouraged, but not required

No other individual cases of influenza are reportable to DC Health. Cases should be reported to DE-DSI online by submitting a Notifiable Disease and Condition Case Report Form using DC Reporting and Surveillance Center (DCRC). Please contact us at [email protected] with any questions about influenza reporting.

Influenza-Associated Pediatric Death Case Definition

An influenza associated pediatric death is defined as a death resulting from a clinically compatible illness that was confirmed to be influenza by an appropriate laboratory or rapid diagnostic test. There should be no period of complete recovery between the illness and death. Any such death in persons <18 years is required to be reported. Laboratory testing for influenza virus infection may be done on pre- or post-mortem clinical specimens.

A death should not be reported if:

• There is no laboratory confirmation of influenza virus infection.
• The influenza illness is followed by full recovery to baseline health status prior to death.
• After review and consultation there is an alternative agreed upon cause of death.

Novel Influenza A Infection Case Definition

Novel influenza A infection is defined as a human case of infection with an influenza A virus subtype that is different from currently circulating human influenza H1 and H3 viruses. Novel subtypes include, but are not limited to, H2, H5, H7 and H9 subtypes. Influenza H1 and H3 subtypes originating from a non-human species or from genetic reassortment between animal and human viruses are also novel subtypes.

Influenza Outbreak Definition

An outbreak is defined as an occurrence of disease greater than would otherwise be expected at a particular time and place. The definition of an influenza outbreak depends on the setting of the outbreak. Listed below are examples of when DC Health should be consulted:

• Outbreaks in institutions such as long-term facilities, prisons, sleepover camps etc. is defined as one laboratory-confirmed influenza positive case in the setting of a cluster (≥2 cases) of influenza-like illness(ILI)* within a 72-hour period.
• Outbreaks in schools should be considered if students or staff of the same classroom are experiencing influenza-like illness or other respiratory symptoms.

Defining an outbreak should be done in consultation with the epidemiologists at DC Health. Please contact the influenza team at [email protected] for further guidance about influenza outbreaks.