The historical association between measles and pertussis: A case of immune suppression?

OBJECTIVES: According to historical medical reports, many children with measles subsequently contracted pertussis, often with fatal results. The likelihood of a child contracting pertussis after a measles infection is increased by its immune-suppressing effects. This research aims to verify the historical reports. METHODS: The analysis examines statistically the historical relationship between average measles and pertussis incidence rates in the United States from 1938 to 1954 at the state level and in average weekly rates. Analysis of incidence rates is cross-sectional at the state level using public health data. RESULTS: The results show that, on average and over time, states with higher measles rates have higher pertussis rates, and the peaks and nadirs of average weekly incidence rates of pertussis lag measles by a delay of about 3–4 weeks, well within the duration of immune suppression. Measles and pertussis have similar geographical distributions. CONCLUSION: The research tentatively supports the hypothesis that because of its immune-suppressing effects, measles causes an increase in pertussis, but other factors may be involved. Epidemic models should give more attention to the possibility of immune suppression for diseases such as measles where that might be a risk factor. The findings reemphasize the importance of measles vaccination for the prevention of other diseases.