High-resolution serotyping reveals Salmonella surveillance challenges in the turkey industry.

Despite extensive Salmonella controls used at processing, 5.5% of salmonellosis cases are linked to turkey. This study had two objectives: i) to summarize USDA-FSIS turkey Salmonella verification program data and ii) to evaluate Salmonella through turkey production and processing of 22 flocks. In objective 1, USDA-FSIS data shows the average Salmonella prevalence in ground turkey from 2016-2022 was 15.9%, and that the leading serovar changes frequently. For objective 2, bootsocks (n=22) were collected on-farm right after load-out. At processing, pre-scald wingtips (n=6 composites of 10/flock), pre-chill wingtips (n=6 composites of 10/flock), mechanically separated turkey (MST; n=6 bins/flock) and ground turkey (n=6 bins/flock) were collected. Salmonella prevalence was determined by a commercial qPCR and culture confirmed. In 33.2% of PCR-positive samples, Salmonella was not confirmed by culture, highlighting a discrepancy between molecular and culture detection. On-farm, 8/22 flocks were Salmonella positive, compared to 21 flocks that were positive at one or more processing locations, including 18 flocks that were positive in at least one final product sample. A logistic regression showed higher Salmonella prevalence in pre-scald (53.8%) than in pre-chill (18.2%), MST (27.3%) or ground turkey (26.5%). CRISPR-SeroSeq analysis of 148 culture positive samples detected 18 Salmonella serovars and showed 35.1% of samples contained multiple serovars. In 16 flocks, one or more serovars detected in final products were absent from any upstream samples. Two thirds of final product samples containing serovar Typhimurium typed as a live-attenuated Typhimurium vaccine strain. Salmonella on-farm and at pre-scald did not reflect Salmonella observed in final product. This data underscores the complexity of serovar tracking in turkey production and highlights challenges to identify surveillance samples that accurately represent Salmonella in turkey products.

Genotyping and Subtyping Cryptosporidium To Identify Risk Factors and Transmission Patterns - Nebraska, 2015-2017.

Cryptosporidium is an enteric pathogen that is transmitted through animal-to-person or person-to-person contact or through ingestion of contaminated water or food. In the United States, Cryptosporidium affects an estimated 750,000 persons each year; however, only approximately 11,000 cases are reported nationally (1,2). Persons infected with Cryptosporidium typically develop symptoms within 2 to 10 days after exposure. Common symptoms include watery diarrhea, abdominal cramps, nausea, vomiting, or fever, which can last 1 to 2 weeks. Cryptosporidiosis is a nationally notifiable disease in the United States. Nebraska presents a unique setting for the evaluation of this pathogen because, compared with other states, Nebraska has a greater reliance on agriculture and a higher proportion of the population residing and working in rural communities. Cryptosporidium species and subtypes are generally indistinguishable using conventional diagnostic methods. Using molecular characterization, Nebraska evaluated the genetic diversity of Cryptosporidium and found a dichotomy in the distribution of cases of cryptosporidiosis caused by Cryptosporidium parvum and Cryptosporidium hominis among rural and urban settings. Characterizing clusters of C. hominis cases revealed that several child care facilities were affected by the same subtype, suggesting community-wide transmission and indicating a need for effective exclusion policies. Several cases of cryptosporidiosis caused by non-C. parvum or non-C. hominis species and genotypes indicated unique animal exposures that were previously unidentified. This study enhanced epidemiologic data by validating known Cryptosporidium sources, confirming outbreaks, and, through repeat interviews, providing additional information to inform cryptosporidiosis prevention and control efforts.

Salmonella enterica Serotype Panama: An exceptionally virulent cause of illness in children?

Salmonella enterica serotype Panama accounts for <1% of all reported cases of Salmonellosis. Previous reports suggest that it may be unusually virulent in children. We report the case of a family, five of six of whom developed a diarrheal illness due to this organism following exposure during a trip to Costa Rica. Included among these patients were three children, all of whom developed clinical shock requiring aggressive fluid resuscitation, and all of whom ultimately recovered. DNA fingerprinting, using pulsed-field gel electrophoresis, demonstrated that all three children were infected with an identical strain of Salmonella. Moreover, this strain was unique among strains recovered in Nebraska. Clinicians should be aware of the propensity of Salmonella enterica serotype Panama to cause especially severe disease in children; laboratory personnel should be aware of the unique need for thiourea buffering when attempting to perform pulsed-field gel electrophoresis analysis on such strains.

Campylobacteriosis Outbreak Associated with Contaminated Municipal Water Supply - Nebraska, 2017.

In March 2017, the Nebraska Department of Health and Human Services (NDHHS) and the Southwest Nebraska Public Health Department were notified of an apparent cluster of Campylobacter jejuni infections in city A and initiated an investigation. Overall, 39 cases were investigated, including six confirmed and 33 probable. Untreated, unboiled city A tap water (i.e., well water) was the only exposure significantly associated with illness (odds ratio [OR] = 7.84; 95% confidence interval [CI] = 1.69-36.36). City A is served by four untreated wells and an interconnected distribution system. Onsite investigations identified that a center pivot irrigation system intended to pump livestock wastewater from a nearby concentrated animal feeding operation onto adjacent farmland had malfunctioned, allowing excessive runoff to collect in a road ditch near two wells that supplied water to the city. These wells were promptly removed from service, after which no subsequent cases occurred. This coordinated response rapidly identified an important risk to city A's municipal water supply and provided the evidence needed to decommission the affected wells, with plans to build a new well to safely serve this community.

Occupational Animal Exposure Among Persons with Campylobacteriosis and Cryptosporidiosis - Nebraska, 2005-2015.

Campylobacter and Cryptosporidium are two common causes of gastroenteritis in the United States. National incidence rates measured for these pathogens in 2015 were 17.7 and 3.0 per 100,000 population, respectively; Nebraska was among the states with the highest incidence for both campylobacteriosis (26.6) and cryptosporidiosis (≥6.01) (1). Although campylobacteriosis and cryptosporidiosis are primarily transmitted via consumption of contaminated food or water, they can also be acquired through contact with live animals or animal products, including through occupational exposure (2). This exposure route is of particular interest in Nebraska, where animal agriculture and associated industries are an important part of the state's economy. To estimate the percentage of disease that might be related to occupational animal exposure in Nebraska, the Nebraska Department of Health and Human Services (NDHHS) and CDC reviewed deidentified investigation reports from 2005 to 2015 of cases of campylobacteriosis and cryptosporidiosis among Nebraska residents aged ≥14 years. Case investigation notes were searched for evidence of occupational animal exposures, which were classified into discrete categories based on industry, animal/meat, and specific work activity/exposure. Occupational animal exposure was identified in 16.6% of 3,352 campylobacteriosis and 8.7% of 1,070 cryptosporidiosis cases, among which animal production (e.g., farming or ranching) was the most commonly mentioned industry type (68.2% and 78.5%, respectively), followed by employment in animal slaughter and processing facilities (16.3% and 5.4%, respectively). Among animal/meat occupational exposures, cattle/beef was most commonly mentioned, with exposure to feedlots (concentrated animal feeding operations in which animals are fed on stored feeds) reported in 29.9% of campylobacteriosis and 7.9% of cryptosporidiosis cases. Close contact with animals and manure in feedlots and other farm settings might place workers in these areas at increased risk for infection. It is important to educate workers with occupational animal exposure about the symptoms of enteric diseases and prevention measures. Targeting prevention strategies to high-risk workplaces and activities could help reduce disease.