5 - The epidemiology of infected food and the limits of sanitary jurisdiction

Summary

TYPHOID FEVER AND OYSTERS

By the middle nineties Brighton had done everything that had been thought necessary to conquer typhoid fever. It had built main intercepting sewers to divert sewage from the sea front. It had required owners to connect their houses to this system and to fill in their cesspools. Its Sanitary Department mounted an energetic inspection program to see that household drainage was properly installed and maintained. The town also provided pure water as a municipal service. Furthermore, it acted to prevent direct interpersonal transmission by requiring and closely supervising notification, isolation, and disinfection. Why then had the decline in the incidence and mortality from typhoid leveled off, leaving the town with a substantial endemic typhoid problem? Newsholme began to suspect that while the town had solved most of its old sanitary problems, some previously unappreciated factor continued to spread the contagion. Careful inquiry following notification indicated that after one excluded cases that had been acquired outside Brighton and cases for which there was a known source of infection, between 30 and 40 percent of notified cases were unaccounted for during these years.

In March 1894 Newsholme announced to the Sanitary Committee that he had found the cause of such unexplained cases. His postnotification investigation in an outbreak of eleven cases led him to conclude that the only likely cause of at least five, and perhaps as many as eight, of these cases was the consumption of sewage-contaminated oysters.