Strain of Multidrug-Resistant Salmonella Newport Remains Linked to Travel to Mexico and U.S. Beef Products - United States, 2021-2022.

In 2016, CDC identified a multidrug-resistant (MDR) strain of Salmonella enterica serotype Newport that is now monitored as a persisting strain (REPJJP01). Isolates have been obtained from U.S.

Shigellosis outbreak among persons experiencing homelessness-San Diego County, California, October-December 2021.

During October 2021, the County of San Diego Health and Human Services Agency identified five cases of shigellosis among persons experiencing homelessness (PEH). We conducted an outbreak investigation and developed interventions to respond to shigellosis outbreaks among PEH. Confirmed cases occurred among PEH with stool-cultured ; probable cases were among PEH with -positive culture-independent diagnostic testing.

Possible Exposures Among Mpox Patients Without Reported Male-to-Male Sexual Contact - Six U.S. Jurisdictions, November 1-December 14, 2022.

The extent to which the 2022 mpox outbreak has affected persons without a recent history of male-to-male sexual contact (MMSC) is not well understood. During November 1-December 14, 2022, CDC partnered with six jurisdictional health departments to characterize possible exposures among mpox patients aged ≥18 years who did not report MMSC during the 3 weeks preceding symptom onset. Among 52 patients included in the analysis, 14 (27%) had a known exposure to a person with mpox, including sexual activity and other close intimate contact (eight) and household contact (six).

Two Listeria monocytogenes Pseudo-outbreaks Caused by Contaminated Laboratory Culture Media.

Listeriosis is a serious foodborne infection that disproportionately affects elderly adults, pregnant women, newborns, and immunocompromised individuals. Diagnosis is made by culturing Listeria monocytogenes from sterile body fluids or from products of conception. This report describes the investigations of two listeriosis pseudo-outbreaks caused by contaminated laboratory media made from sheep blood.

The first cases of 2009 pandemic influenza A (H1N1) virus infection in the United States: a serologic investigation demonstrating early transmission.

Background: The first two laboratory-confirmed cases of 2009 pandemic influenza A (H1N1) virus (H1N1pdm09) infection were detected in San Diego (SD) and Imperial County (IC) in southern California, April 2009.

Objectives: To describe H1N1pdm09 infections and transmission early in the 2009 H1N1 pandemic.

Patients/methods: We identified index case-patients from SD and IC with polymerase chain reaction (PCR)-confirmed H1N1pdm09 infections and investigated close contacts for a subset of case-patients from April 17-May 6, 2009.

Surveillance for repeat gonorrhea infection, San Diego, California, 1995-2001: establishing definitions and methods.

Background: Persons with repeat gonorrhea (GC) infection often participate in sexual networks that maintain and spread GC throughout the community. However, there are no established methods for collecting repeat GC surveillance data that are needed to monitor trends and risk factors for repeat infection.

Goal: The goal of this study was to evaluate definitions and methods for establishing surveillance for repeat gonorrhea infection.