Contact with backyard poultry in most cases of salmonellosis in the United States

Investigations of cases Salmonella infections began in January of this year and have so far revealed 11 different serotypes – Agona, Alachua, Anatum, Braenderup, Enteritidis, Infantis, Manhattan, Montevideo, Muenchen, Newport and Oranienburg – with contact of poultry from backyard as a unit factor.

Up to now, 768 people have been infected in 48 states. 489 have taken place since the last update on June 13, 2019, with no sign of a decline.

With cases ranging from very young (less than one year old) to very old (ninety-nine years old), it is not only the frail people who contract the disease, the calculated median age being 30 years old. Of the total number of cases, 122 people (29%) were hospitalized and two deaths were reported: one in Ohio and one in Texas.

A list of states and the number of cases in each can be found here.

Farmyard poultry contact

Surveys conducted by the CDC and public health officials in several states have found that contact with backyard poultry from several hatcheries was a common factor that was likely the cause. Interviews with 315 infected persons revealed that 75% of them reported having been in contact with chicks or ducklings the week before their illness. in various sources, including agriculture stores, websites and hatcheries.

Genetic fingerprints to identify and track

Public health investigators use a system called PulseNet to identify diseases that may be part of these outbreaks. PulseNet is the national network of subtyped public health laboratories coordinated by the CDC.

Genetic fingerprints are performed on Salmonella bacteria isolated from sick people using techniques such as pulsed field gel electrophoresis (PFGE) and whole genome sequencing (WGS). CDC PulseNet maintains a national database of these DNA fingerprints to identify potential outbreaks. WGS gives a more detailed DNA fingerprint than PFGE and when the technique was performed on the Salmonella bacteria from infected individuals, it has been shown that they are closely related genetically. This indicates that sick people are more likely to share a common source of infection.

Five of the strains of the outbreak were identified in samples taken from backyard poultry environments in four states. The sampling was conducted in backyard poultry environments located at the home of infected people in California and Ohio and in poultry environments of retailers in Michigan and Oregon. Additional tests are underway in several states.

The CDC emphasized that all poultry can carry Salmonella germs no matter where they are purchased. They advise the owners of backyard poultry to always follow these steps in order to stay healthy around their animals.

This survey is ongoing and the CDC will provide updates as more information becomes available.