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Certain laboratorians and health care personnel can be exposed to orthopoxviruses through occupational activities. Because orthopoxvirus infections resulting from occupational exposures can be serious, the Advisory Committee on Immunization Practices (ACIP) has continued to recommend preexposure vaccination for these persons since 1980 (1), when smallpox was eradicated (2). In 2015, ACIP made recommendations for the use of ACAM2000, the only orthopoxvirus vaccine available in the United States at that time (3). During 2020-2021, ACIP considered evidence for use of JYNNEOS, a replication-deficient Vaccinia virus vaccine, as an alternative to ACAM2000. In November 2021, ACIP unanimously voted in favor of JYNNEOS as an alternative to ACAM2000 for primary vaccination and booster doses. With these recommendations for use of JYNNEOS, two vaccines (ACAM2000 and JYNNEOS) are now available and recommended for preexposure prophylaxis against orthopoxvirus infection among persons at risk for such exposures.

PURPOSE. Neisseria gonorrhoeae is a sexually transmitted bacterial pathogen that continues to evolve to become resistant to known antibiotics. In preparing for potential emergence, the Centers for Disease Control and Prevention recommends that clinical laboratories maintain or develop protocols to assess antibiotic susceptibly for this organism. This study examines the intra-laboratory variability of using the Etest method to provide consistent MIC values for N. gonorrhoeae and also compared the results of the Etest to known agar dilution MIC values. METHODOLOGY. Clinical N. gonorrhoeae isolates, 100 paired duplicates, were tested by eight laboratories for antibiotic susceptibility to ceftriaxone, cefixime and azithromycin using Etest strips. RESULTS/KEY FINDINGS. Overall, >80 % of the paired Etest MIC values were within one log(2) dilution of the replicate. When compared to the agar dilution reference method, the cefixime Etest MIC values were consistently underreported by one dilution (seven laboratories) or two dilutions (one laboratory). The azithromycin Etest MIC values agreed 90.7 % with the agar dilution MIC values while the agreement with ceftriaxone was 90.9 %. CONCLUSION. Overall, the Etest method yielded reproducible MIC values within each laboratory with the azithromycin and ceftriaxone MIC results consistent to the reference agar dilution method while the cefixime result tended to provide a lower MIC value.

The use of culture-independent diagnostic tests (CIDTs), such as stool antigen tests, as standalone tests for the detection of Campylobacter in stool is increasing. We conducted a prospective, multicenter study to evaluate the performance of stool antigen CIDTs compared to culture and PCR for Campylobacter detection. Between July and October 2010, we tested 2,767 stool specimens from patients with gastrointestinal illness with the following methods: four types of Campylobacter selective media, four commercial stool antigen assays, and a commercial PCR assay. Illnesses from which specimens were positive by one or more culture media or at least one CIDT and PCR were designated “cases.” A total of 95 specimens (3.4%) met the case definition. The stool antigen CIDTs ranged from 79.6% to 87.6% in sensitivity, 95.9 to 99.5% in specificity, and 41.3 to 84.3% in positive predictive value. Culture alone detected 80/89 (89.9% sensitivity) Campylobacter jejuni/Campylobacter coli -positive cases. Of the 209 noncases that were positive by at least one CIDT, only one (0.48%) was positive by all four stool antigen tests, and 73% were positive by just one stool antigen test. The questionable relevance of unconfirmed positive stool antigen CIDT results was supported by the finding that noncases were less likely than cases to have gastrointestinal symptoms. Thus, while the tests were convenient to use, the sensitivity, specificity, and positive predictive value of Campylobacter stool antigen tests were highly variable. Given the relatively low incidence of Campylobacter disease and the generally poor diagnostic test characteristics, this study calls into question the use of commercially available stool antigen CIDTs as standalone tests for direct detection of Campylobacter in stool.

Salmonella outbreaks associated with the consumption of raw tomatoes have been prevalent in recent years. However, sources of Salmonella contamination of tomatoes remain poorly understood. The objectives of this study were to identify ecological reservoirs of Salmonella on tomato farms, and to test antimicrobial susceptibilities of recovered Salmonella isolates. Fourteen Mid-Atlantic tomato farms in the U.S. were sampled in 2009 and 2010. Groundwater, irrigation pond water, pond sediment, irrigation ditch water, rhizosphere and irrigation ditch soil, leaves, tomatoes, and swabs of harvest bins and worker sanitary facilities were analyzed for Salmonella using standard culture methods and/or a flow-through immunocapture method. All presumptive Salmonella isolates (n=63) were confirmed using PCR and the Vitek(®) 2 Compact System, and serotyped using the Premi(®)Test Salmonella and a conventional serotyping method. Antimicrobial susceptibility testing was carried out using the Sensititre™ microbroth dilution system. Four of the 14 farms (29%) and 12 out of 1,091 samples (1.1%) were found to harbor Salmonella enterica subsp. enterica. Salmonella was isolated by the immunocapture method from soil, while the culture method recovered isolates from irrigation pond water and sediment, and irrigation ditch water. No Salmonella was detected on leaves or tomatoes. Multiple serotypes were identified from soil and water, four of which-S. Braenderup, S. Javiana, S. Newport and S. Typhimurium-have been previously implicated in Salmonella outbreaks associated with tomato consumption. Resistance to sulfisoxazole was prevalent and some resistance to ampicillin, cefoxitin, amoxicillin/clavulanic acid, and tetracycline was also observed. This study implicates irrigation water and soil as possible reservoirs of Salmonella on tomato farms and irrigation ditches as ephemeral habitats for Salmonella. The findings point to the potential for pre-harvest contamination of tomatoes from contaminated irrigation water or from soil or water splash from irrigation ditches onto low-lying portions of tomato plants.

Summary Extensively drug-resistant (XDR) tuberculosis is becoming increasingly prevalent worldwide, but little is known about XDR tuberculosis in young children. In this Grand Round we describe a 2-year-old child from the USA who developed pneumonia after a 3 month visit to India. Symptoms resolved with empirical first-line tuberculosis treatment; however, a XDR strain of Mycobacterium tuberculosis grew in culture. In the absence of clinical or microbiological markers, low-radiation exposure pulmonary CT imaging was used to monitor treatment response, and guide an individualised drug regimen. Management was complicated by delays in diagnosis, uncertainties about drug selection, and a scarcity of child-friendly formulations. Treatment has been successful so far, and the child is in remission. This report of XDR tuberculosis in a young child in the USA highlights the risks of acquiring drug-resistant tuberculosis overseas, and the unique challenges in management of tuberculosis in this susceptible population.

By using standard restriction fragment length polymorphism, 6 zero-copy IS6110 Mycobacterium tuberculosis isolates were identified from 1180 Maryland isolates as part of the National Tuberculosis Genotyping and Surveillance Network Project. By using various genotyping methods, we demonstrated that this zero band cluster can be differentiated into six genotypes.

Restriction fragment length polymorphism (RFLP) analysis of IS 6110 is commonly used to DNA fingerprint Mycobacterium tuberculosis . However, low-copy (≤5) IS 6110 M. tuberculosis strains are poorly differentiated, requiring secondary typing. When spoligotyping was used as the secondary method, only 13% of Maryland culture-positive tuberculosis (TB) patients with low-copy IS 6110 -spoligotyped clustered strains had epidemiologic linkages to another patient, compared to 48% of those with high-copy strains clustered by IS 6110 alone ( P < 0.01). Spoligotyping did not improve a population-based molecular epidemiologic study of recent TB transmission.

We report the first human case of Salmonella enterica Serotype Landwasser infection. The identification of this extremely unusual serotype was established at the Enterics Section of the Public Health Diagnostic Microbiology Laboratory of the State of Maryland Department of Health in Baltimore. A 47