Photo Credit: Dr Microbe
The following is a summary of “Assessing the Impact of the 2020 Council of State and Territorial Epidemiologists Case Definition for Pertussis on Reported Pertussis Cases,” published in the April 2024 issue of Infectious Diseases by Rubis et al.
The Council of State and Territorial Epidemiologists (CSTE) updated the definition of pertussis, now considering PCR tests positive for the bacteria as confirmed cases even without a cough.
Researchers conducted a retrospective study understanding the effect of this change through Enhanced Pertussis Surveillance (EPS) and the National Notifiable Diseases Surveillance System (NNDSS).
They checked EPS cases in 2020 that started with cough compared to the previous 2014 CSTE definition. Then, the change was used to estimate how many extra cases were captured nationally in the 2020 NNDSS data. The data on 2020 EPS cases with cough onset was compared to the previous numbers based on the 2014 CSTE case definition. The proportion of EPS cases newly reportable under the 2020 CSTE case definition was applied to 2020 NNDSS data to estimate the extra cases.
The result showed 442 cases reported to EPS states in 2020, 42 of which (9.5%) were newly reportable under the 2020 case definition. When this proportion was applied to the 6,124 confirmed and probable cases reported in 2020, 582 new cases were added because of a change in the case definition. Without the change, 2020 cases would have decreased by 70% compared to 2019; the actual decrease was 6.7%.
Investigators concluded that, even though fewer pertussis cases were reported during COVID-19, findings revealed that the 2020 case definition change led to more cases being reported, eventually helping in public health actions such as treating close contacts.
Source: academic.oup.com/cid/advance-article/doi/10.1093/cid/ciae207/7644889
