Table 1. Case definitions used in the investigation of concurrent outbreaks of hepatitis A, invasive meningococcal disease, and mpox, Florida, USA, 2021–2022*.

Disease	Definition
Hepatitis A
Inclusion criteria	Florida residents meeting the surveillance case definition for hepatitis A† with symptom onset during November 1, 2021–November 30, 2022
Confirmed case	A hepatitis A case with laboratory evidence of infection with HAV genotype IA, A17 cluster 21, or epidemiologically linked to a case with HAV A17 cluster 21 infection
Probable case	A hepatitis A case who identified as transgender or MSM or had sexual contact with MSM, irrespective of other risk factors for hepatitis A
Suspected case	A male hepatitis A case with unknown sexual history, and absence of other risk factors for hepatitis A (e.g., foreign travel, drug use, homelessness, incarceration)
Epidemiologically linked	Household or sexual contact during the 15–50 d before symptom onset
Exclusions	Cases with sequencing results indicating infection with HAV other than genotype IA, A17 cluster 21
Invasive meningococcal disease
Inclusion criteria	Florida residents meeting the surveillance case definition for invasive meningococcal disease† with symptom onset during November 1, 2021–November 30, 2022
Confirmed case	An invasive meningococcal disease case who identifies as MSM or had sexual contact with MSM and evidence of serogroup C infection; or laboratory evidence of infection with ST11 CC11 serogroup C, with <100 SNPs difference to the outbreak strain, irrespective of sexual history
Probable case	An invasive meningococcal disease case who identifies as MSM or had sexual contact with MSM and for whom no additional serogroup, ST, or CC typing is available; or who had evidence of serogroup C infection regardless of sexual history
Exclusions	Cases with sequencing results indicating infection with Neisseria meningitides other than ST11 CC11 serogroup C or with >100 SNP differences to the outbreak strain
Mpox
Inclusion criteria	Florida residents meeting the surveillance case definition for confirmed or probable mpox‡ with symptom onset during May 1­–November 30, 2022

*CC, clonal complex; HAV, hepatitis A virus; MSM, men who have sex with men; SNP, single-nucleotide polymorphism; ST, sequence type; STI, sexually transmitted infection. †Per Florida Department of Health definition (15). ‡Per Centers for Disease Control and Prevention definition (16).