Understanding the exposure risk of aerosolized Coccidioides in a Valley fever endemic metropolis.

Coccidioides is the fungal causative agent of Valley fever, a primarily pulmonary disease caused by inhalation of fungal arthroconidia, or spores. Although Coccidioides has been an established pathogen for 120 years and is responsible for hundreds of thousands of infections per year, little is known about when and where infectious Coccidioides arthroconidia are present within the ambient air in endemic regions. Long-term air sampling programs provide a means to investigate these characteristics across space and time. Here we present data from > 18 months of collections from 11 air sampling sites across the Phoenix, Arizona, metropolitan area. Overall, prevalence was highly variable across space and time with no obvious spatial or temporal correlations. Several high prevalence periods were identified at select sites, with no obvious spatial or temporal associations. Comparing these data with weather and environmental factor data, wind gusts and temperature were positively associated with Coccidioides detection, while soil moisture was negatively associated with Coccidioides detection. These results provide critical insights into the frequency and distribution of airborne arthroconidia and the associated risk of inhalation and potential disease that is present across space and time in a highly endemic locale.

Burkholderia pseudomallei Laboratory Exposure, Arizona, USA.

We describe an incidental Burkholderia pseudomallei laboratory exposure in Arizona, USA. Because melioidosis cases are increasing in the United States and B. pseudomallei reservoirs have been discovered in the Gulf Coast Region, US laboratory staff could be at increased risk for B. pseudomallei exposure.

Investigation of a Severe Acute Respiratory Syndrome Coronavirus 2 Delta (B.1.617.2) Variant Outbreak Among Residents of a Skilled Nursing Facility and Vaccine Effectiveness Analysis: Maricopa County, Arizona, June-July 2021.

BACKGROUND: Short-term rehabilitation units present unique infection control challenges because of high turnover and medically complex residents. In June 2021, the Maricopa County Department of Public Health was notified of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta outbreak in a skilled nursing facility short-term rehabilitation unit. We describe the outbreak and assess vaccine effectiveness (VE). METHODS: Facility electronic medical records were reviewed for residents who spent > 1 night on the affected unit between June 10 and July 23, 2021, to collect demographics, SARS-CoV-2 test results, underlying medical conditions, vaccination status, and clinical outcomes. Coronavirus disease 2019 VE estimates using Cox proportional hazards models were calculated. RESULTS: Forty (37%) of 109 short-stay rehabilitation unit residents who met inclusion criteria tested positive for SARS-CoV-2. SARS-CoV-2-positive case-patients were mostly male (58%) and White (78%) with a median age of 65 (range, 27-92) years; 11 (27%) were immunocompromised. Of residents, 39% (10 cases, 32 noncases) received 2 doses and 9% (4 cases, 6 noncases) received 1 dose of messenger RNA (mRNA) vaccine. Among nonimmunocompromised residents, adjusted 2-dose primary-series mRNA VE against symptomatic infection was 80% (95% confidence interval, 15-95). More cases were hospitalized (33%) or died (38%) than noncases (10% hospitalized; 16% died). CONCLUSIONS: In this large SARS-CoV-2 Delta outbreak in a high-turnover short-term rehabilitation unit, a low vaccination rate and medically complex resident population were noted alongside severe outcomes. VE of 2-dose primary-series mRNA vaccine against symptomatic infection was the highest in nonimmunocompromised residents. Health departments can use vaccine coverage data to prioritize facilities for assistance in preventing outbreaks.

COVID-19 Outbreaks Associated With Youth Club Sports: Maricopa County, Arizona, September-November 2020.

The Maricopa County Department of Public Health in Arizona investigated three COVID-19 outbreaks associated with club sports, two in tournaments and one in a hockey league. During September through November 2020, 195 team-associated and 69 secondary household contact cases were identified among 2093 athletes, coaches, and staff members; the team attack rate ranged from 6% to 72%. Outbreaks occurred during high community transmission periods in Maricopa County. Identification of contacts and characterization of prevention strategies were challenging because of limited cooperation from athletes, families, and staff. (Am J Public Health. 2022;112(2):216-219. https://doi.org/10.2105/AJPH.2021.306579).

Accuracy of Case-Based Seroprevalence of SARS-CoV-2 Antibodies in Maricopa County, Arizona.

We conducted a community seroprevalence survey in Arizona, from September 12 to October 1, 2020, to determine the presence of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We used the seroprevalence estimate to predict SARS-CoV-2 infections in the jurisdiction by applying the adjusted seroprevalence to the county's population. The estimated community seroprevalence of SARS-CoV-2 infections was 4.3 times greater (95% confidence interval = 2.2, 7.5) than the number of reported cases. Field surveys with representative sampling provide data that may help fill in gaps in traditional public health reporting. (Am J Public Health. 2022;112(1):38-42. https://doi.org/10.2105/AJPH.2021.306568).

Clinical, diagnostic, and epidemiological features of a community-wide outbreak of canine leptospirosis in a low-prevalence region (Maricopa County, Arizona).

OBJECTIVE: To describe clinical, diagnostic, and epidemiological features of an outbreak of leptospirosis in dogs in Maricopa County, Ariz, from January 2016 through June 2017. ANIMALS: 71 case and 281 control dogs. PROCEDURES: Cases were classified as confirmed, probable, suspect, or not a case on the basis of medical record data that fulfilled clinical, diagnostic, and epidemiological criteria. Potential exposures were assessed by owner survey. For the case-control investigation, control dogs were recruited through owner completion of a July 2017 survey. Summary statistics and ORs for case dog lifestyle factors were reported. RESULTS: 54 dogs were classified as confirmed and 17 as probable cases. For 4 dogs of a household cluster (5 confirmed and 3 probable), the highest microscopic agglutination titer was for serovar Djasiman (Leptospira kirschneri detected by PCR assay), and for 13 dogs of a community outbreak (49 confirmed and 14 probable cases), the highest titer was for serovar Canicola (Leptospira interrogans detected by PCR assay). The 44 case dogs included in the case-control investigation were 7.7 (95% CI, 3.5 to 16.7) and 2.9 times (95% CI, 1.3 to 6.6) as likely as control dogs to have visited dog daycare or to have been kenneled overnight at a boarding facility, respectively, 30 days prior to the onset of clinical signs or diagnosis. CONCLUSIONS AND CLINICAL RELEVANCE: Diagnostic and epidemiological findings indicated 2 outbreaks. Transmission where dogs congregated likely propagated the community outbreak. Outbreaks of leptospiral infections can occur in regions of low prevalence, and a dog's exposure to areas where dogs congregate should be considered when making Leptospira vaccination recommendations.

Heat-Associated Mortality in a Hot Climate : Maricopa County, Arizona, 2006-2016.

OBJECTIVES: Maricopa County, Arizona (2017 population about 4.3 million), is located in the Sonoran Desert. In 2005, the Maricopa County Department of Public Health (MCDPH) established a heat-associated mortality surveillance system that captures data on circumstances of death for Maricopa County residents and visitors. We analyzed 2006-2016 surveillance system data to understand the characteristics and circumstances of heat-associated deaths. METHODS: We classified heat-associated deaths based on International Classification of Diseases, Tenth Revision codes (X30, T67.X, and P81.0) and phrases (heat exposure, environ, exhaustion, sun, heat stress, heat stroke, or hyperthermia) in part I or part II of the death certificate. We summarized data on decedents' demographic characteristics, years lived in Arizona, location of death (indoors vs outdoors), presence and functionality of air conditioning, and whether the decedent had been homeless. We examined significant associations between variables by using the Pearson χ2 tests and logistic regression. RESULTS: During 2006-2016, MCDPH recorded data on 920 heat-associated deaths, 912 of which included location of injury. Of 565 (62%) heat-associated deaths that occurred outdoors, 458 (81%) were among male decedents and 243 (43%) were among decedents aged 20-49. Of 347 (38%) heat-associated deaths that occurred indoors, 201 (58%) were among decedents aged ≥65. Non-Arizona residents were 5 times as likely as Arizona residents to have a heat-associated death outdoors (P < .001). Of 727 decedents with data on duration of Arizona residency, 438 (60%) had resided in Arizona ≥20 years. CONCLUSIONS: Ongoing evaluation of interventions that target populations at risk for both outdoor and indoor heat-associated deaths can further inform refinement of the surveillance system and identify best practices to prevent heat-associated deaths.

Assessment of Immunoglobulin M Enzyme-Linked Immunosorbent Assay Ratios to Identify West Nile Virus and St. Louis Encephalitis Virus Infections During Concurrent Outbreaks of West Nile Virus and St. Louis Encephalitis Virus Diseases, Arizona 2015.

West Nile virus (WNV) and St. Louis encephalitis virus (SLEV) are closely related mosquito-borne flaviviruses that cause clinical disease ranging from febrile illness to encephalitis. The standard for serological diagnosis is immunoglobulin M (IgM) testing followed by confirmatory plaque reduction neutralization test (PRNT) to differentiate the infecting virus. However, the PRNT is time-consuming and requires manipulation of live virus. During concurrent WNV and SLEV outbreaks in Arizona in 2015, we assessed use of a diagnostic algorithm to simplify testing. It incorporated WNV and SLEV ratios based on positive-to-negative (P/N) values derived from the IgM antibody-capture enzyme-linked immunosorbent assay. We compared each sample's ratio-based result with the confirmed WNV or SLEV sample result indicated by PRNT or PCR testing. We analyzed data from 70 patients with 77 serum and cerebrospinal fluid samples, including 53 patients with confirmed WNV infection and 17 patients with confirmed SLEV infection. Both WNV and SLEV ratios had specificity ≥95%, indicating a high likelihood that each ratio was correctly identifying the infecting virus. The SLEV ratio sensitivity of 30% was much lower than the WNV ratio sensitivity of 91%, likely because of higher cross-reactivity of SLEV antibodies and generation of lower P/N values. The standard for serological diagnosis of WNV and SLEV infections remains IgM testing followed by PRNT. However, these results suggest the ratios could potentially be used as part of a diagnostic algorithm in outbreaks to substantially reduce the need for PRNTs.

First Mildly Ill, Nonhospitalized Case of Coronavirus Disease 2019 (COVID-19) Without Viral Transmission in the United States-Maricopa County, Arizona, 2020.

BACKGROUND: Coronavirus disease 2019 (COVID-19) causes a range of illness severity. Mild illness has been reported, but whether illness severity correlates with infectivity is unknown. We describe the public health investigation of a mildly ill, nonhospitalized COVID-19 case who traveled to China. METHODS: The case was a Maricopa County resident with multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive specimens collected on 22 January 2020. Contacts were persons exposed to the case on or after the day before case diagnostic specimen collection. Contacts were monitored for 14 days after last known exposure. High-risk contacts had close, prolonged case contact (≥ 10 minutes within 2 m). Medium-risk contacts wore all US Centers for Disease Control and Prevention-recommended personal protective equipment during interactions. Nasopharyngeal and oropharyngeal (NP/OP) specimens were collected from the case and high-risk contacts and tested for SARS-CoV-2. RESULTS: Paired case NP/OP specimens were collected for SARS-CoV-2 testing at 11 time points. In 8 pairs (73%), ≥ 1 specimen tested positive or indeterminate, and in 3 pairs (27%) both tested negative. Specimens collected 18 days after diagnosis tested positive. Sixteen contacts were identified; 11 (69%) had high-risk exposure, including 1 intimate contact, and 5 (31%) had medium-risk exposure. In total, 35 high-risk contact NP/OP specimens were collected for SARS-CoV-2 testing; all 35 pairs (100%) tested negative. CONCLUSIONS: This report demonstrates that SARS-CoV-2 infection can cause mild illness and result in positive tests for up to 18 days after diagnosis, without evidence of transmission to close contacts. These data might inform public health strategies to manage individuals with asymptomatic infection or mild illness.

Comparison of Characteristics of Patients with West Nile Virus or St. Louis Encephalitis Virus Neuroinvasive Disease During Concurrent Outbreaks, Maricopa County, Arizona, 2015.

West Nile virus (WNV) and St. Louis encephalitis virus (SLEV) are closely related mosquito-borne flaviviruses that can cause neuroinvasive disease. No concurrent WNV and SLEV disease outbreaks have previously been identified. When concurrent outbreaks occurred in 2015 in Maricopa County, Arizona, we collected data to describe the epidemiology, and to compare features of patients with WNV and SLEV neuroinvasive disease. We performed enhanced case finding, and gathered information from medical records and patient interviews. A case was defined as a clinically compatible illness and laboratory evidence of WNV, SLEV, or unspecified flavivirus infection in a person residing in Maricopa County in 2015. We compared demographic and clinical features of WNV and SLEV neuroinvasive cases; for this analysis, a case was defined as physician-documented encephalitis or meningitis and a white blood cell count >5 cells/mm3 in cerebrospinal fluid. In total, we identified 82 cases, including 39 WNV, 21 SLEV, and 22 unspecified flavivirus cases. The comparative analysis included 21 WNV and 14 SLEV neuroinvasive cases. Among neuroinvasive cases, the median age of patients with SLEV (63 years) was higher than WNV (52 years). Patients had similar symptoms; rash was identified more frequently in WNV (33%) neuroinvasive cases than in SLEV (7%) cases, but this difference was not statistically significant (p = 0.11). In summary, during the first known concurrent WNV and SLEV disease outbreaks, no specific clinical features were identified that could differentiate between WNV and SLEV neuroinvasive cases. Health care providers should consider both infections in patients with aseptic meningitis or encephalitis.

The detection of Coccidioides from ambient air in Phoenix, Arizona: Evidence of uneven distribution and seasonality.

Coccidioidomycosis is a debilitating fungal disease caused by inhalation of arthroconidia. We developed a novel approach for detection of airborne Coccidioides and used it to investigate the distribution of arthroconidia across the Phoenix, Arizona, metropolitan area. Air filters were collected daily from 21 stationary air-sampling units across the area: the first set collected before, during and after a large dust storm on August 25, 2015, and the second over the 45-day period September 25-November 8, 2016. Analysis of DNA extracted from the filters demonstrated that the day of the dust storm was not associated with increase of Coccidioides in air samples, although evidence of the low-level polymerase chain reaction (PCR) inhibition was observed in DNA extracted from samples collected on the day of the dust storm. Testing over 45 days identified uneven geographic distribution suggesting Coccidioides hot spots. In 2016, highest daily concentration of arthroconidia was observed between September 25-October 20, and only sporadic low levels were detected after that. These results provide evidence of seasonality and uneven spatial distribution of Coccidioides in the air. Our results demonstrate that routine air monitoring for arthroconidia is possible and provides an important tool for Coccidioides surveillance, which can address important questions about environmental exposure and human infection.

Association of Presence of a School Nurse With Increased Sixth-Grade Immunization Rates in Low-Income Arizona Schools in 2014-2015.

School nurses often play large roles in implementation of school vaccination requirements aimed at controlling the spread of communicable disease. We analyzed the association between the presence of a school nurse and school-level vaccination rates in Arizona. Using school-level data from Arizona sixth-grade schools (n = 749), we regressed average sixth-grade school-level immunization rates on presence of a school nurse (registered nurse [RN] or licensed practical nurse [LPN]) and school-level socioeconomic status (SES), controlling for other school- and district-level characteristics. Schools with a nurse had higher overall vaccination rates than those without a nurse (96.1% vs. 95.0%, p < .01). For schools in the lowest SES quartile, the presence of a school nurse was associated with approximately 2 percentage point higher immunization rates. These findings add to the growing literature that defines the impact of school nurses on student health status and outcomes, emphasizing the value of school nurses, especially in lower SES schools.

Update on the Epidemiology of coccidioidomycosis in the United States.

The incidence of reported coccidioidomycosis in the past two decades has increased greatly; monitoring its changing epidemiology is essential for understanding its burden on patients and the healthcare system and for identifying opportunities for prevention and education. We provide an update on recent coccidioidomycosis trends and public health efforts nationally and in Arizona, California, and Washington State. In Arizona, enhanced surveillance shows that coccidioidomycosis continues to be associated with substantial morbidity. California reported its highest yearly number of cases ever in 2016 and has implemented interventions to reduce coccidioidomycosis in the prison population by excluding certain inmates from residing in prisons in high-risk areas. Coccidioidomycosis is emerging in Washington State, where phylogenetic analyses confirm the existence of a unique Coccidioides clade. Additional studies of the molecular epidemiology of Coccidioides will improve understanding its expanding endemic range. Ongoing public health collaborations and future research priorities are focused on characterizing geographic risk, particularly in the context of environmental change; identifying further risk reduction strategies for high-risk groups; and improving reporting of cases to public health agencies.

Despite high-risk exposures, no evidence of zoonotic transmission during a canine outbreak of leptospirosis.

Leptospirosis is a bacterial zoonosis that affects many mammals, including humans and dogs; dogs can transmit the bacteria to humans, but the frequency of transmission and highest risk exposures are poorly understood. During 2016-2017, the Maricopa County Department of Public Health, Arizona Department of Health Services and Centers for Disease Control and Prevention investigated the zoonotic potential of a canine leptospirosis outbreak in the Phoenix metro area. We identified symptomatic persons exposed to canine leptospirosis cases by conducting active and passive surveillance. We tested dog owners (n = 9) and animal care providers (n = 109) for serological evidence of Leptospira spp. infection (via the microscopic agglutination test [MAT]) and interviewed these persons about their specific exposures to canine cases and general exposures to canine blood and urine. Through surveillance, seven symptomatic persons were identified; six were tested and all were negative by MAT, and of these six, four persons were negative by PCR (two did not have PCR testing). All serosurvey participants (n = 118) were also seronegative. Among animal care providers, bare skin contact with urine/blood from a canine case was reported by 23.2%; two persons reported dog urine splashing in their face. Veterinary technicians were more likely to have bare skin contact with blood from a canine case compared to veterinarians and boarding facility staff (p < 0.001). Infection control practices were inconsistent; when working with specimens from a canine leptospirosis case, 44.6% of participants reported always wearing gloves when working with urine (i.e., collecting specimens), and 54.5% always wore gloves when working with blood. Veterinary technicians were also most likely to engage in all activities involving potential urine/blood contact, such as conducting laboratory tests (p < 0.01). We therefore recommend that veterinary technicians specifically receive targeted education about infection control practices. Our results suggest that dog-to-human transmission of leptospirosis is uncommon.

Interlaboratory agreement of coccidioidomycosis enzyme immunoassay from two different manufacturers.

Coccidioidomycosis, a fungal infection endemic to the Southwestern United States, is challenging to diagnose. The coccidioidomycosis enzyme immunoassay (EIA) test is the least expensive and simplest to perform to detect coccidioidomycosis antibodies in the serum. Concerns regarding falsely positive immunoglobulin (Ig) M EIA test results have led to questions about the agreement of commercially available EIA test kits among laboratories. We sought to evaluate the laboratory agreement of the EIA test at three laboratories using both IMMY and Meridian EIA test kits. Sensitivity and specificity of EIA IgM and IgG were calculated as secondary outcomes. The percent agreement of the EIA IgM and IgG test results among all three laboratories was 90% and 89% for IMMY test kits, respectively, and 67% and 80.5% for Meridian test kits, respectively. Agreement between IgM and IgG combined test results was 85.5% and 70.5%, for IMMY and Meridian, respectively. Combined IgM and IgG assays demonstrated a sensitivity of 68% (62.7%-76%) and a specificity of 99.3% (98%-100%) [IMMY] and a sensitivity of 72.4% (57.3%-87.3%) and a specificity of 91.3% (74%-100%) [Meridian]. In summary, results from the IMMY EIA test kit agreed more often across laboratories than Meridian EIA results, especially for the IgM assay. Isolated positive IgM EIA results using the Meridian test kit should be interpreted with caution and consideration of clinical information and test methodology. Further study of the sensitivity and specificity of coccidioidomycosis EIA test kits is warranted.

Human Rabies Postexposure Prophylaxis Knowledge and Retention Among Health Professionals by Using an Online Continuing Education Module: Arizona, 2012 to 2015.

Rabies postexposure prophylaxis (PEP) is administered for rabies prevention after a human exposure to a potentially rabid animal, such as a bite. Previous studies have reported that rabies PEP is often inappropriately administered. Health professional education was proposed as one potential solution to address inappropriate PEP use. We assessed baseline knowledge, knowledge gain, and knowledge retention among health professionals in Arizona of rabies epidemiology and appropriate PEP administration. Maricopa County Department of Public Health created an online rabies PEP continuing education module and measured knowledge before and after module completion using a 10-question test. The same test was administered three times (pretest, posttest, and retention test at ≥3 months). To assess knowledge gain and retention, we compared median scores using nonparametric methods. A total of 302 respondents completed the pretest (median score, 60%) and posttest (median score, 90%; p < .001); 98 respondents completed all three tests with median scores 60% (pretest), 90% (posttest, p < .01), and 80% (retention test and compared with pretest, p < .01). Sixty-nine (70%) respondents improved their pretest to retention test score by a mean of 2.4 points out of a total 10 points (median: 2 points; range: -5 to 7 points). Only 48% of pretest respondents correctly answered that PEP should not be administered immediately to anyone bitten by a healthy dog. However, 81% and 70% answered correctly on the posttest (p < .0001) and retention test (p = .002), respectively. Respondents demonstrated rabies epidemiology and PEP knowledge gain and ≥3-month knowledge retention after completing the online continuing education module.