Trends in Burdens of Disease by Transmission Source (USA, 2005-2020) and Hazard Identification for Foods: Focus on Milkborne Disease

Abstract

Background: Robust solutions to global, national, and regional burdens of communicable and non-communicable diseases, particularly related to diet, demand interdisciplinary or transdisciplinary collaborations to effectively inform risk analysis and policy decisions.

Objective: U.S. outbreak data for 2005-2020 from all transmission sources were analyzed for trends in the burden of infectious disease and foodborne outbreaks.

Methods: Outbreak data from 58 Microsoft Access^® data tables were structured using systematic queries and pivot tables for analysis by transmission source, pathogen, and date. Trends were examined using graphical representations, smoothing splines, Spearman's rho rank correlations, and non-parametric testing for trend. Hazard Identification was conducted based on the number and severity of illnesses.

Results: The evidence does not support increasing trends in the burden of infectious foodborne disease, though strongly increasing trends were observed for other transmission sources. Morbidity and mortality were dominated by person-to-person transmission; foodborne and other transmission sources accounted for small portions of the disease burden. Foods representing the greatest hazards associated with the four major foodborne bacterial diseases were identified. Fatal foodborne disease was dominated by fruits, vegetables, peanut butter, and pasteurized dairy.

Conclusion: The available evidence conflicts with assumptions of zero risk for pasteurized milk and increasing trends in the burden of illness for raw milk. For future evidence-based risk management, transdisciplinary risk analysis methodologies are essential to balance both communicable and non-communicable diseases and both food safety and food security, considering scientific, sustainable, economic, cultural, social, and political factors to support health and wellness for humans and ecosystems.

Keywords: Etiology; Food safety; Food security; Interagency Food Safety Analytics Collaboration (IFSAC) food category; National Outbreak Reporting System (NORS).

Fig. 1

Process diagram for analysis of CDC NORS data by transmission source, food category, and etiology

Fig. 2

Numbers of U.S. outbreaks (A person-to-person 56%, foodborne 30%), illnesses (B person-to-person 68%, foodborne 21%), hospitalizations (C person-to-person 37%, foodborne 43%), and deaths (D person-to-person 60%, foodborne 19%) by modes of transmission (2005–2020) [27]

Fig. 3

Numbers of illnesses, hospitalizations, and deaths by transmission source reported in the U.S. (2005–2020) [27]

Fig. 4

Trends in numbers of illnesses per year for major transmission sources using smoothing splines (red lines) and bootstrapped 95% confidence intervals (blue lines) (2005–2020) [27]

Fig. 5

a Numbers of U.S. outbreaks and illnesses by pathogens or toxins across all transmission sources associated with less than 500 outbreaks (2005–2020) [27]. b Numbers of U.S. outbreaks and illnesses by pathogens or toxins across all transmission sources associated with more than 500 outbreaks (2005–2020) [27]

Fig. 6

Numbers of hospitalizations and deaths by transmission source (P to P = person-to-person) for the top six bacterial and parasitic pathogens reported in the U.S. (2005–2020) [27]

Fig. 7

a Cases of foodborne illness: campylobacteriosis (2005–2020) [27]. b Cases of foodborne illness: pathogenic E. coli (2005–2020) [27]. c Cases of foodborne illness: listeriosis 2005–2020) [27]. d Cases of foodborne illness: salmonellosis (2005–2020) [27]. Note that an additional 24 salmonellosis cases and 1 hospitalization were associated with pasteurized milk in this period for outbreaks that were not coded with IFSAC food groupings

Fig. 8

Foods associated with U.S. outbreaks reporting more than 2 deaths (2005–2020) [27]

Fig. 9

The total number of raw milk outbreaks by U.S. state reported from 2005 to 2020 [27]. Note that the map shows the results that expanded four multi-state outbreaks to their exposure states for a net increase of four outbreaks

Fig. 10

Numbers illnesses, outbreaks, hospitalizations, and deaths by year for unpasteurized (raw) and pasteurized milk (2005–2020) [27]

Fig. 11

Numbers illnesses by date of first illness for raw milk (2005–2020) [27] depicted using LOESS Smother (red lines) and 95% confidence intervals (red dashed lines)

Fig. 12

Numbers outbreaks by date of first illness for raw milk (2005–2020) [27] depicted using LOESS Smother (red lines) and 95% confidence intervals (red dashed lines)

Fig. 13

The numbers of raw milk illnesses (a) and outbreaks (b) by U.S. state reported from 2005 to 2020 [27]. No state demonstrated an increasing trend for this 16-year period

Fig. 14

a Numbers of annual licenses (2005–2022) approved by NY State for sale of raw milk versus outbreak rates per 1MM people [27, 55]. b Numbers of annual licenses (2005–2022) approved by NY State for sale of raw milk versus illnesses per outbreak [27, 55]

Fig. 15

a Annual retail production volumes in millions of gallons for one California dairy (personal communication) and outbreak rates per million across the state (not necessarily from this dairy) [27, 56]. b Annual retail production volumes in millions of gallons for one California dairy (personal communication) and illnesses per outbreak across the state (not necessarily from this dairy) [27, 56]