Babesiosis Acquired through Blood Transfusion, California, USA

Babesiosis was reported in a California resident who received a transfusion of blood products collected in the disease-endemic northeastern region of the United States. Babesiosis should be considered year-round in the diagnosis of febrile and afebrile patients with abnormal blood cell counts who have received blood products from disease-endemic areas

COVID-19 vaccine hesitancy: misinformation and perceptions of vaccine safety

Despite COVID-19’s devastating toll, many Americans remain unwilling to receive the COVID-19 vaccine. The authors conducted a US national survey to understand the health literacy of adults regarding the vaccine, as well as their COVID-19 beliefs and experiences. People who believed the COVID-19 vaccine was unsafe were less willing to receive the vaccine, knew less about the virus and were more likely to believe COVID-19 vaccine myths. On average, they were less educated, lower income, and more rural than people who believed the vaccine is safe. The results highlight the importance of developing clear health communications accessible to individuals from varied socioeconomic and educational backgrounds

Comparison of Enzootic Risk Measures for Predicting West Nile Disease, Los Angeles, California, USA, 2004–2010

In Los Angeles, California, USA, 2 epidemics of West Nile virus (WNV) disease have occurred since WNV was recognized in 2003. To assess which measure of risk was most predictive of human cases, we compared 3 measures: the California Mosquito-Borne Virus Surveillance and Response Plan Assessment, the vector index, and the Dynamic Continuous-Area Space-Time system. A case–crossover study was performed by using symptom onset dates from 384 persons with WNV infection to determine their relative environmental exposure to high-risk conditions as measured by each method. Receiver-operating characteristic plots determined thresholds for each model, and the area under the curve was used to compare methods. We found that the best risk assessment model for human WNV cases included surveillance data from avian, mosquito, and climate sources

Varicella Vaccine Effectiveness in Preventing Community Transmission in the 2-Dose Era

OBJECTIVES: We examined overall and incremental effectiveness of 2-dose varicella abstract vaccination in preventing community transmission of varicella among children aged 4 to 18 years in 2 active surveillance sites. One-dose varicella vaccine effectiveness (VE) was examined in those aged 1 to 18 years. METHODS: From May 2009 through June 2011, varicella cases identified during active surveillance in Antelope Valley, CA and Philadelphia, PA were enrolled into a matched case–control study. Matched controls within 2 years of the patient’s age were selected from immunization registries. A standardized questionnaire was administered to participants’ parents, and varicella vaccination history was obtained from health care provider, immunization registry, or parent records. We used conditional logistic regression to estimate varicella VE against clinically diagnosed and laboratory-confirmed varicella. RESULTS: A total of 125 clinically diagnosed varicella cases and 408 matched controls were enrolled. Twenty-nine cases were laboratory confirmed. One-dose VE (1-dose versus unvaccinated) was 75.6% (95% confidence interval [CI], 38.7%–90.3%) in preventing any clinically diagnosed varicella and 78.1% (95% CI, 12.7%–94.5%) against moderate or severe, clinically diagnosed disease (≥50 lesions). Among subjects aged ≥4 years, 2-dose VE (2-dose versus unvaccinated) was 93.6% (95% CI, 75.6%–98.3%) against any varicella and 97.9% (95% CI, 83.0%–99.7%) against moderate or severe varicella. Incremental effectiveness (2-dose versus 1-dose) was 87.5% against clinically diagnosed varicella and 97.3% against laboratory-confirmed varicella. CONCLUSIONS: Two-dose varicella vaccination offered better protection against varicella from community transmission among school-aged children compared with 1-dose vaccination

Factors Influencing COVID-19 Vaccine Acceptance in the Workplace: Results From a Rapid Survey at 2 Corporations in Los Angeles County, California, 2021

ObjectivesAchieving widespread vaccine acceptance across various employment sectors is key to a successful public health response to COVID-19, but little is known about factors influencing vaccine acceptance among essential non-health care workers. We examined factors influencing vaccine acceptance among a sample of essential non-health care workers in California.MethodsWe conducted a survey in early spring 2021 at 2 corporations in Los Angeles County, California, to identify and describe factors influencing vaccine acceptance and the ability of incentives to increase this acceptance. We used modified Poisson regression analysis to estimate adjusted prevalence ratios and a best-subset selection algorithm to identify the strongest factors influencing vaccine acceptance.ResultsOf 678 workers who completed the survey, 450 were unvaccinated. Among unvaccinated participants, having trust in information about the vaccine from public health experts, having ≥1 chronic health condition related to COVID-19 severity, being Asian, and perceiving risk for COVID-19 were factors that most influenced vaccine acceptance. Most (271 of 296, 91.6%) participants who had trust in information from public health experts and 30.6% (30 of 98) of participants who did not have trust in information from public health experts said that they would accept the vaccine. Seventeen of 24 (70.8%) vaccine-hesitant workers who had trust in information from public health experts and 12 of 72 (16.7%) vaccine-hesitant workers who did not have trust in this information said that they would be more likely to accept the vaccine if an incentive were offered.ConclusionsEfforts to increase vaccine coverage at workplaces should focus on improving trust in the vaccine and increasing public awareness that the vaccine is free

A 2015 outbreak of flea-borne rickettsiosis in San Gabriel Valley, Los Angeles County, California.

Although flea-borne rickettsiosis is endemic in Los Angeles County, outbreaks are rare. In the spring of 2015 three human cases of flea-borne rickettsiosis among residents of a mobile home community (MHC) prompted an investigation. Fleas were ubiquitous in common areas due to presence of flea-infested opossums and overabundant outdoor cats and dogs. The MHC was summarily abated in June 2015, and within five months, flea control and removal of animals significantly reduced the flea population. Two additional epidemiologically-linked human cases of flea-borne rickettsiosis detected at the MHC were suspected to have occurred before control efforts began. Molecular testing of 106 individual and 85 pooled cat fleas, blood and ear tissue samples from three opossums and thirteen feral cats using PCR amplification and DNA sequencing detected rickettsial DNA in 18.8% of the fleas. Seventeen percent of these cat fleas tested positive for R. felis-specific DNA compared to under two (<2) percent for Candidatus R. senegalensis-specific DNA. In addition, serological testing of 13 cats using a group-specific IgG-ELISA detected antibodies against typhus group rickettsiae and spotted fever group rickettsiae in six (46.2%) and one (7.7%) cat, respectively. These results indicate that cats and their fleas may have played an active role in the epidemiology of the typhus group and/or spotted fever group rickettsial disease(s) in this outbreak