Question

Epidemiologists have noted that cases of salmonellosis are much higher during the summer than during the rest of the year. Cases of typhoid fever, however, are constant throughout the year. How can you explain these observations?

Answer 1

Salmonella illness or salmonellosis is an infection caused by Salmonella bacteria. It is higher during summer than during the rest of the year. The main reason behind this is warmer weather gives the bacteria more opportunitiy to contaminate food. Salmonella responds well to heat and becomes more prevalent during summer and hot climates. The risk of salmonella infection increases proportionately with the increase in the number of extreme precipitation or temperature events. This is because the bacteria grows vigorously in hot climates.

In contrast, typhoid fever occurs due to the toxin released from the bacteria Salmonella typhi. Humans are the only hosts being affected by this toxin. In addition, they keep spreading the disease irrespective of the climate. Bacterial infections can be treated by antibiotics, but toxins cannot be treated. Therefore, the toxin from the infected persons spreads to new persons if proper hygenic conditions are not maintained.

Thus, Salmonellosis being caused by bacterial organism, it is more common in summers, and typhoid fever being caused by the baterial toxin is common all through the year.