Knowledge and practices related to louse- and flea-borne diseases among staff providing services to people experiencing homelessness in the United States

BACKGROUND AND AIMS

Louse-borne Bartonella quintana infection and flea-borne murine typhus are two potentially serious vector-borne diseases that have led to periodic outbreaks among people experiencing homelessness in the United States. Little is known about louse- and flea-borne disease awareness and prevention among staff who provide services to the population. We surveyed staff in seven US states to identify gaps in knowledge and prevention practices for these diseases.

METHODS AND RESULTS

Surveys were administered to 333 staff at 89 homeless shelters and outreach teams in California, Colorado, Georgia, Maryland, Minnesota, New York and Washington from August 2022 to April 2023. Most participants (>68%) agreed that body lice and fleas are a problem for people experiencing homelessness. About half were aware that diseases could be transmitted by these vectors; however, most could not accurately identify which diseases. Less than a quarter of staff could describe an appropriate protocol for managing body lice or fleas. Misconceptions included that clients must isolate or be denied services until they are medically cleared.

CONCLUSIONS

Our findings reveal significant knowledge gaps among staff who provide services to people experiencing homelessness in the prevention and control of louse- and flea-borne diseases. This demonstrates an urgent need for staff training to both reduce disease and prevent unnecessary restrictions on services and housing.

Lyme disease vaccine attitudes and intentions among parents of children aged 5-18 years in the United States

BACKGROUND

Lyme disease (LD) is the most common vector-borne disease in the United States, with increasing incidence and geographic range. Case incidence peaks among school-aged children. New LD preventives are in clinical trials.

METHODS

We conducted an online survey of parents of children aged 5-18 years in states with high or emerging incidence of LD. Our primary outcome was willingness ("definitely" or "probably") for their child to receive an LD vaccine. Our secondary outcome was preference for annual monoclonal antibody injections compared to a 3-dose vaccine series with boosters. Analyses were weighted to reflect parent gender, parent race/ethnicity, and child age by state.

RESULTS

Among 1,351 parent respondents, most (68.0 %) would have their child vaccinated against LD, with significantly more being willing in high compared to emerging incidence states (70.4 % versus 63.6 %, p = 0.027). Of parents who were unsure or unwilling, 33.5 % and 16.5 %, respectively, would do so with a provider recommendation. Vaccine safety concerns were among the top reasons for LD vaccine hesitancy. More parents preferred a pre-formed antibody (42.3 %) compared to a 3-dose vaccine series (34.7 %). Significant predictors of willingness to have one's child vaccinated were higher parental education; higher perceived risk of child getting LD; child spending time outdoors daily or weekly; following a regular vaccine schedule; and positive attitude towards vaccines. Significant predictors of preference for monoclonal antibody over a 3-dose vaccine series included prior awareness of LD, living in a rural area, and less positive attitudes towards vaccines.

CONCLUSIONS

Two-thirds of parents in high and emerging incidence states would vaccinate their children against Lyme disease. Addressing safety concerns will be important, and a health care provider recommendation could also encourage those who are unsure or unwilling. Given the slight preference for monoclonal antibody over vaccine, particularly in rural areas, access to both may increase LD prevention.

Francisella tularensis Bone and Joint Infections: United States, 2004-2023

Tularemia is caused by the highly infectious bacterium Francisella tularensis, which is recognized as a Tier 1 bioterrorism agent. Tularemia has a range of recognized clinical manifestations, but fewer than 20 bone or joint infections from 6 countries have been reported in the literature to date. This series includes 13 cases of F. tularensis septic arthritis or osteomyelitis in the United States during 2004-2023 and describes exposures, clinical presentation, diagnosis, and outcomes for this rare but severe form of tularemia. Clinicians should consider F. tularensis in patients with compatible exposures or a history of joint replacement or immunosuppression.

Tularemia From Veterinary Occupational Exposure

Tularemia is a disease caused by Francisella tularensis, a highly infectious bacteria that can be transmitted to humans by direct contact with infected animals. Because of the potential for zoonotic transmission of F. tularensis, veterinary occupational risk is a concern. Here, we report on a human case of tularemia in a veterinarian after an accidental needlestick injury during abscess drainage in a sick dog. The veterinarian developed ulceroglandular tularemia requiring hospitalization but fully recovered after abscess drainage and a course of effective antibiotics. To systematically assess veterinary occupational transmission risk of F. tularensis, we conducted a survey of veterinary clinical staff after occupational exposure to animals with confirmed tularemia. We defined a high-risk exposure as direct contact to the infected animal's body fluids or potential aerosol inhalation without use of standard personal protective equipment (PPE). Survey data included information on 20 veterinary occupational exposures to animals with F. tularensis in 4 states. Veterinarians were the clinical staff most often exposed (40%), followed by veterinarian technicians and assistants (30% and 20%, respectively). Exposures to infected cats were most common (80%). Standard PPE was not used during 80% of exposures; a total of 7 exposures were categorized as high risk. Transmission of F. tularensis in the veterinary clinical setting is possible but overall risk is likely low. Veterinary clinical staff should use standard PPE and employ environmental precautions when handling sick animals to minimize risk of tularemia and other zoonotic infections; postexposure prophylaxis should be considered after high-risk exposures to animals with suspected or confirmed F. tularensis infection to prevent tularemia.

Lyme Disease Knowledge, Practices, and Vaccine Acceptability Among Nurse Practitioners in Pediatric Practice

INTRODUCTION

Lyme disease (LD) is a major public health problem in the United States. Given its incidence and geographic expansion, nurse practitioners (NPs) will likely encounter patients with this condition.

METHOD

NPs were invited to participate in an electronic survey via email, newsletter, and social media posts. The 31-question survey collected information on provider characteristics, clinical scenario decisions, resources used, and vaccine sentiment for LD.

RESULTS

Survey participants (n = 606) were primarily cisgender female (75%) and aged 30-49 years (62%). Responding to six hypothetical clinical scenarios, only 31% of participants answered most questions correctly. If an LD vaccine becomes available, 39% said they would incorporate it into practice; 48% would seek further information before deciding.

DISCUSSION

Additional education on LD prevention, diagnosis, and treatment is needed for NPs. Increasing provider awareness of current guidelines and developing tailored resources for NPs may improve patient care.

Mpox vaccine acceptability among people experiencing homelessness in San Francisco - October-November 2022

Mpox has affected many communities in the United States (U.S.), including people experiencing homelessness (PEH). Mpox vaccination has been an important tool to disrupt transmission and protect communities at risk of infection. To better understand mpox vaccine knowledge and attitudes, we surveyed 273 PEH and people accessing homeless service sites in San Francisco. Among 64 participants previously offered mpox vaccination, 38 (59 %) had received the vaccine. Among 209 participants not previously offered mpox vaccination, 108 (52 %) reported they would receive the vaccine. Vaccine acceptance was higher among transgender female participants and among male participants who reported male sex partner preference (MSM). Half of participants who declined vaccination identified that perception of personal risk and vaccine education may increase their likelihood of receiving an mpox vaccine. Leveraging trusted information sources to provide risk communication and vaccine education may increase vaccine uptake among PEH.

Soft Tick Relapsing Fever - United States, 2012-2021

Soft tick relapsing fever (STRF) (also known as tickborne relapsing fever) is a rare infection caused by certain Borrelia spirochetes and transmitted to humans by soft-bodied Ornithodoros ticks. In the United States, acquisition of STRF is commonly associated with exposure to rustic cabins, camping, and caves. Antibiotic treatment is highly effective for STRF, but without timely treatment, STRF can result in severe complications, including death. No nationally standardized case definition for STRF exists; however, the disease is reportable in 12 states. This report summarizes demographic and clinical information for STRF cases reported during 2012-2021 from states where STRF is reportable. During this period, 251 cases were identified in 11 states. The median annual case count was 24. Most patients with STRF (55%) were hospitalized; no fatalities were reported. The geographic distribution and seasonal pattern of STRF have remained relatively constant since the 1990s. Persons should avoid rodent-infested structures and rodent habitats, such as caves, in areas where STRF is endemic. STRF surveillance, prevention, and control efforts would benefit from a standardized case definition and increased awareness of the disease among the public and clinicians.

Borrelia miyamotoi Infection in Immunocompromised Man, California, USA, 2021

Infection with Borrelia miyamotoi in California, USA, has been suggested by serologic studies. We diagnosed B. miyamotoi infection in an immunocompromised man in California. Diagnosis was aided by plasma microbial cell-free DNA sequencing. We conclude that the infection was acquired in California.

Possible Undetected Mpox Infection Among Persons Accessing Homeless Services and Staying in Encampments - San Francisco, California, October-November 2022

Monkeypox (mpox) is a disease caused by an Orthopoxvirus. The 2022 multinational outbreak, which began in May 2022, has spread primarily by close skin-to-skin contact, including through sexual contact. Persons experiencing homelessness have been disproportionately affected by severe mpox (1). However, mpox prevalence and transmission pathways among persons experiencing homelessness are not known, and persons experiencing homelessness have not been specifically recommended to receive mpox vaccine during the 2022 outbreak (2,3). During October 25-November 3, 2022, a CDC field team conducted an orthopoxvirus seroprevalence survey among persons accessing homeless services or staying in encampments, shelters, or permanent supportive housing in San Francisco, California that had noted at least one case of mpox or served populations at risk. During field team visits to 16 unique sites, 209 participants completed a 15-minute survey and provided a blood specimen. Among 80 participants aged <50 years who did not report smallpox or mpox vaccination or previous mpox infection, two (2.5%) had detectable antiorthopoxvirus immunoglobulin (Ig) G antibody. Among 73 participants who did not report mpox vaccination or previous mpox infection and who were tested for IgM, one (1.4%) had detectable antiorthopoxvirus IgM. Together, these results suggest that three possible undetected mpox infections occurred among a sample of persons experiencing homelessness, highlighting the need to ensure that community outreach and prevention interventions, such as vaccination, are accessible to this population.

Bartonella spp. Infections Identified by Molecular Methods, United States

Molecular methods can enable rapid identification of Bartonella spp. infections, which are difficult to diagnose by using culture or serology. We analyzed clinical test results of PCR that targeted bacterial 16S rRNA hypervariable V1-V2 regions only or in parallel with PCR of Bartonella-specific ribC gene. We identified 430 clinical specimens infected with Bartonella spp. from 420 patients in the United States. Median patient age was 37 (range 1-79) years; 62% were male. We identified B. henselae in 77%, B. quintana in 13%, B. clarridgeiae in 1%, B. vinsonii in 1%, and B. washoensis in 1% of specimens. B. quintana was detected in 83% of cardiac specimens; B. henselae was detected in 34% of lymph node specimens. We detected novel or uncommon Bartonella spp. in 9 patients. Molecular diagnostic testing can identify Bartonella spp. infections, including uncommon and undescribed species, and might be particularly useful for patients who have culture-negative endocarditis or lymphadenitis.

Relapsing Fever Caused by Borrelia lonestari after Tick Bite in Alabama, USA

We report an immunocompromised patient in Alabama, USA, 75 years of age, with relapsing fevers and pancytopenia who had spirochetemia after a tick bite. We identified Borrelia lonestari by using PCR, sequencing, and phylogenetic analysis. Increasing clinical availability of molecular diagnostics might identify B. lonestari as an emerging tickborne pathogen.

1375. Validation of a Syndromic Surveillance Query for Lyme Carditis – New York, 2017-2021

Background

Lyme carditis is a rare and potentially fatal manifestation of Lyme disease. Although Lyme disease is nationally notifiable, data on specific clinical manifestations are not collected systematically. We sought to use a novel syndromic surveillance query to identify patients with Lyme carditis in New York State (excluding New York City) during 2017-2021.

Methods

Using the National Syndromic Surveillance Program’s BioSense Platform, we developed a query using a combination of diagnosis codes and chief complaint terms to identify emergency department visits related to Lyme carditis. We systematically reviewed and abstracted key information in each identified individual medical record through New York’s regional health information exchange system, requesting supplemental records when needed. Two physicians independently assigned a clinical case status (confirmed; probable; not a case) to each abstracted record; when adjudications differed, an infectious disease physician provided a final adjudication. Positive predictive value for the query was calculated and characteristics of cases and non-cases were described.

Results

The query identified 175 individuals. Records were available for review for 139 individuals. Among these, 37% (n = 52) were classified as confirmed, 17% (n = 24) as probable, and 45% (n = 63) as not a case. In total, we identified 76 cases of confirmed or probable Lyme carditis for which records were available; the positive predictive value of the query was 45%. Cases occurred in 28 of New York’s 57 counties (excluding New York City); most (64%) occurred during May–September. Median age was 60 years for cases (IQR 33 – 73) and 67 years for non-cases (IQR 42 – 78) (p = 0.13); 29% of cases and 38% of non-cases were female (p = 0.23). Among cases, 76% had positive IgG or IgM immunoblots and 37% had second- or third-degree atrioventricular block.

Conclusion

Using a syndromic surveillance query, we detected 76 cases of Lyme carditis, a rare disease of public health importance. Syndromic surveillance using this query may provide a useful marker for Lyme-endemic states to use to detect changing disease patterns, including temporal or spatial clusters of severe Lyme disease manifestations.

Disclosures

All Authors: No reported disclosures.

Severe Monkeypox in Hospitalized Patients - United States, August 10-October 10, 2022

As of October 21, 2022, a total of 27,884 monkeypox cases (confirmed and probable) have been reported in the United States.§ Gay, bisexual, and other men who have sex with men have constituted a majority of cases, and persons with HIV infection and those from racial and ethnic minority groups have been disproportionately affected (1,2). During previous monkeypox outbreaks, severe manifestations of disease and poor outcomes have been reported among persons with HIV infection, particularly those with AIDS (3-5). This report summarizes findings from CDC clinical consultations provided for 57 patients aged ≥18 years who were hospitalized with severe manifestations of monkeypox¶ during August 10-October 10, 2022, and highlights three clinically representative cases. Overall, 47 (82%) patients had HIV infection, four (9%) of whom were receiving antiretroviral therapy (ART) before monkeypox diagnosis. Most patients were male (95%) and 68% were non-Hispanic Black (Black). Overall, 17 (30%) patients received intensive care unit (ICU)-level care, and 12 (21%) have died. As of this report, monkeypox was a cause of death or contributing factor in five of these deaths; six deaths remain under investigation to determine whether monkeypox was a causal or contributing factor; and in one death, monkeypox was not a cause or contributing factor.** Health care providers and public health professionals should be aware that severe morbidity and mortality associated with monkeypox have been observed during the current outbreak in the United States (6,7), particularly among highly immunocompromised persons. Providers should test all sexually active patients with suspected monkeypox for HIV at the time of monkeypox testing unless a patient is already known to have HIV infection. Providers should consider early commencement and extended duration of monkeypox-directed therapy†† in highly immunocompromised patients with suspected or laboratory-diagnosed monkeypox.§§ Engaging all persons with HIV in sustained care remains a critical public health priority.

Lessons Learned through Implementing SARS-CoV-2 Testing and Isolation for People Experiencing Homelessness in Congregate Shelters

BACKGROUND

The Denver COVID-19 Joint Task Force is a multisector community partnership which formed to coordinate Denver's pandemic response in people experiencing homelessness (PEH).

OBJECTIVES

Describe how interdisciplinary community partners collaborated to develop, implement, and pilot severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing and isolation protocols in congregate shelters, and discuss lessons learned and subsequently applied.

METHODS

In March through May 2020, community partners collaborated to design, implement and conduct pilot testing paired with isolation in a subset of PEH at a congregate shelter to assess feasibility and inform protocol development.Results and Lessons Learned: We performed SARS-CoV-2 testing in 52 PEH with 14 (27%) testing positive or inconclusive. Thirteen (93%) positive or inconclusive participants were transferred to isolation hotels with 9 of 13 (69%) transferred within 72 hours of testing.

CONCLUSIONS

Our findings informed development of coronavirus disease 2019 surveillance testing and isolation protocols for PEH and highlight the value of community partnerships in nimbly responding to the pandemic.

Understanding consumer and clinician perceptions of a potential Lyme disease vaccine

Each year, over 450 000 Lyme disease diagnoses are estimated to occur in the United States, and current preventive measures have been insufficient to stem the rising incidence. An effective human Lyme disease vaccine could be a powerful intervention for population-level impact. In advance of new Lyme disease vaccines coming to market, this study explored barriers to acceptability and motivations for the uptake of a new Lyme disease vaccine. Researchers conducted 9 online focus groups among consumers who may potentially benefit from the vaccine and 30 in-depth interviews among clinician groups who may provide the vaccine. All participants were recruited from three US regions of high Lyme disease incidence. Researchers found that participants shared common motivators to either recommend (clinicians) or accept (consumers) a Lyme disease vaccine, largely driven by perceived benefits of the vaccine, the lack of current effective preventive measures and a greater peace of mind. The concern about the challenges associated with diagnosing and treating Lyme disease is a primary motivator for clinicians to recommend the vaccine, while the concern about getting Lyme disease is a primary motivator for consumers to desire the vaccine.

Lower Prevalence of SARS-CoV-2 Infection Among People Experiencing Homelessness Tested in Outdoor Encampments Compared with Overnight Shelters - Denver, Colorado, June - July 2020

BACKGROUND

A better understanding of the risk for COVID-19 that people experiencing homelessness (PEH) face in congregate shelters versus unsheltered encampments is critical for an effective pandemic response.

METHODS

We analyzed factors associated with current and past SARS-CoV-2 infection among PEH in day and overnight shelters and encampments in Denver, Colorado, during June 2-July 28, 2020, and constructed multivariable logistic regression models to examine risk factors for SARS-CoV-2 RNA and seropositivity with age, race/ethnicity, testing location, testing month, and symptom status as predictor variables.

RESULTS

A total of 823 participants were tested for SARS-CoV-2 RNA, and 276 individuals were tested for SARS-CoV-2 antibodies. A greater percentage of PEH at overnight shelters tested positive for SARS-CoV-2 RNA (8.6% vs 2.5%, p<0.01) and antibodies (21.5% vs 8.7%, p=0.03) compared to encampments. In regression models, testing at an overnight shelter compared to testing at encampments (OR=3.03, 95% CI 1.16-9.02) had increased odds of a positive SARS-CoV-2 RNA result. Age >60 years compared to age <40 years (OR=5.92, 95% CI 1.83-20.3), Hispanic ethnicity (OR=3.43, 95% CI 1.36-8.95) and non-Hispanic Black race compared to non-Hispanic White race (OR=3.07, 95% CI 1.16-8.26), and testing at an overnight shelter compared to testing at encampments (OR=2.45, 95% CI 1.04-6.17) had increased odds of a positive antibody result.

CONCLUSIONS

Our findings support the need for continuing assessment of mitigation strategies in shelters, increasing access to individual rooms and linkage to housing options for PEH, and supporting people to remain in encampments when these options are not available.

153. Utilization of Post-Exposure Prophylaxis to Prevent Lyme Disease in a Large US Healthcare Database

Background

In the United States, at least 50,000 emergency department visits for tick bite and an estimated 476,000 Lyme disease diagnoses occur annually, with incidence of both high among children. The majority of these healthcare visits occur in the northeastern and midwestern states having high Lyme disease incidence and during the summer and fall months, corresponding to peak opportunities for exposure to blacklegged ticks. Post-exposure prophylaxis (PEP) with a single dose of doxycycline can effectively prevent Lyme disease after a tick bite that is high risk for transmission of Lyme disease. We describe characteristics of patients with dispensings of single-dose doxycycline in a large US-based system that includes patients enrolled in private and public health insurance plans.

Methods

Single-dose doxycycline (≤200 mg) dispensings during January 2009 – February 2020 were identified for patients enrolled in seven Data Partners that contributed electronic healthcare data to the Food and Drug Administration Sentinel Distributed Database, including large national insurers, an integrated delivery care network, a state Medicaid, and the 100% Medicare fee-for-service plan. We examined patient and PEP dispensing characteristics by patient age, state of residence, and month of dispensing.

Results

We identified 408,897 patients with PEP (n=474,414 total dispensings) with a mean age of 60 years at first dispensing. Overall, there were 21 patients per 10,000 eligible members with PEP dispensings. Dispensings were less common in children (< 1 and 4 patients per 10,000 eligible members aged < 8 and 8-18 years, respectively). Most dispensings (72%) occurred in states with high incidence of Lyme disease. Seasonality of dispensings was bimodal, with most occurring during April – July and October – November (71 – 83%, by year).

Conclusion

Lyme disease PEP was relatively common and mirrored geographic and seasonal trends observed for ED visits for tick bites and Lyme disease diagnoses. However, we observed more PEP among older adults, and few dispensings among children. Despite healthcare visits for tick bites and Lyme disease occurring disproportionately among pediatric age groups, PEP appears to be underutilized in children.

Disclosures

All Authors: No reported disclosures

1198. Lyme Disease Post-Exposure Prophylaxis by Single-Dose Doxycycline in Three Healthcare Systems

Background

Lyme disease, the most common tickborne disease in the United States, may be prevented by taking a single 200-mg dose of oral doxycycline after a high-risk bite from a blacklegged tick. Currently, it is not known how Lyme disease post-exposure prophylaxis (PEP) might vary by region and healthcare system. We identified single-dose doxycycline medication orders in three healthcare systems in states with high incidence of Lyme disease and compared associated patient and provider characteristics.

Methods

Electronic health record data during 2012 – 2016 were obtained from three healthcare systems: Geisinger (Pennsylvania), Marshfield Clinic (Wisconsin), and Mayo Clinic (Minnesota/Wisconsin). Creation of analytic variables and analysis were harmonized across the three sites. Medication orders for single-dose doxycycline ≤200 mg that were accompanied by specific key words or diagnostic codes (e.g., tick bite; Lyme disease prevention) were considered evidence of PEP. Manual chart review was performed from a random subset to evaluate the algorithms used to identify PEP.

Results

Among 2,937,585 patients with at least one medication order or clinical encounter during the study period, 14,102 single-dose doxycycline orders for Lyme disease PEP for 13,172 unique patients were identified. The typical patient receiving PEP was older (mean age 51 – 58 years), male (56 – 59%), and non-Hispanic White (81 – 98%). The annual seasonality of medication orders was bimodal, with peaks occurring during April – July and October – November. The most common encounter setting was an outpatient clinic or urgent care center (80 – 91%); medication orders after patient phone calls in the absence of an in-person visit occurred frequently (14 – 19%) in two health systems. Chart abstractions (n=600) revealed instances of PEP prescribed inappropriately (e.g., bite from a non-blacklegged tick; patient with symptoms of acute Lyme disease).

Conclusion

Lyme disease PEP with a single dose of doxycycline was frequently prescribed in healthcare systems where there is a high incidence of Lyme disease. PEP was most commonly prescribed to non-Hispanic Whites over the age of 50 years. Public health initiatives for tickborne disease prevention should include clinician education on the appropriate use of Lyme disease PEP.

Disclosures

Anna M. Schotthoefer, PhD, HelixBind (Other Financial or Material Support, salary support) John Zeuli, PharmD, INSMED (Other Financial or Material Support, honoraria for educational speaking)

Effects of COVID-19 Pandemic on Reported Lyme Disease, United States, 2020

Surveys indicate US residents spent more time outdoors in 2020 than in 2019, but fewer tick bite–related emergency department visits and Lyme disease laboratory tests were reported. Despite ongoing exposure, Lyme disease case reporting for 2020 might be artificially reduced due to coronavirus disease–associated changes in healthcare-seeking behavior.

Detection of Severe Acute Respiratory Syndrome Coronavirus 2 on Self-Collected Saliva or Anterior Nasal Specimens Compared With Healthcare Personnel-Collected Nasopharyngeal Specimens

BACKGROUND

Nasopharyngeal specimens (NPS) are commonly used for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing but can be uncomfortable for patients. Self-collected saliva specimens (SS) or anterior nasal specimens (ANS) for SARS-CoV-2 detection are less invasive, but the sensitivity of these specimen types has not been thoroughly evaluated.

METHODS

During September-November 2020, 730 adults undergoing SARS-CoV-2 testing at community testing events and homeless shelters in Denver provided self-collected SS and ANS before NPS collection and answered a short survey about symptoms and specimen preference. Specimens were tested for SARS-CoV-2 by means of real-time reverse-transcription polymerase chain reaction (rRT-PCR); viral culture was performed on a subset of specimens positive by rRT-PCR. The sensitivity of SS and ANS for SARS-CoV-2 detection by rRT-PCR was measured against that of NPS. Subgroup analyses included test outcomes by symptom status and culture results.

RESULTS

Sensitivity for SARS-CoV-2 detection by rRT-PCR appeared higher for SS than for ANS (85% vs 80%) and higher among symptomatic participants than among those without symptoms (94% vs 29% for SS; 87% vs 50% for ANS). Among participants with culture-positive SARS-CoV-2 by any specimen type, the sensitivities of SS and ANS by rRT-PCR were 94% and 100%, respectively. SS and ANS were equally preferred by participants; most would undergo NPS collection again despite this method's being the least preferred.

CONCLUSIONS

SS were slightly more sensitive than ANS for SARS-CoV-2 detection with rRT-PCR. With both SS and ANS, SARS-CoV-2 was reliably detected among participants with symptoms. Self-collected SS and ANS offer practical advantages, are preferred by patients, and might be most useful for testing people with coronavirus disease 2019 symptoms.

Bartonella Seroreactivity Among Persons Experiencing Homelessness During an Outbreak of Bartonella quintana in Denver, Colorado, 2020

During a recent outbreak of Bartonella quintana disease in Denver, 15% of 241 persons experiencing homelessness who presented for severe acute respiratory syndrome coronavirus 2 testing were seroreactive for Bartonella. Improved recognition of B quintana disease and prevention of louse infestation are critical for this vulnerable population.

Emergency Department Visits for Tick Bites - United States, January 2017-December 2019

The incidence of tickborne diseases in the United States is increasing; reported cases more than doubled from >22,000 in 2004 to >48,000 in 2016 (1). Ticks are responsible for approximately 95% of all locally acquired vectorborne diseases reported by states and the District of Columbia, with Lyme disease accounting for >80% of those cases (2). After a tick bite, persons might seek care at an emergency department (ED) for tick removal and to receive postexposure prophylaxis, which has been shown to effectively prevent Lyme disease when taken within 72 hours of a high-risk bite (3). Using data from CDC's National Syndromic Surveillance Program (NSSP), investigators examined ED tick bite visits during January 2017-December 2019 by sex, age group, U.S. region, and seasonality. During this 36-month period, 149,364 ED tick bite visits were identified. Mean cumulative incidence was 49 ED tick bite visits per 100,000 ED visits overall; incidence was highest in the Northeast (110 per 100,000 ED visits). The seasonal distribution of ED tick bite visits was bimodal: the larger peak occurred during the spring and early summer, and the smaller peak occurred in the fall. This pattern aligns with the seasonality of a known and abundant human-biter, the blacklegged tick, Ixodes scapularis (4). Compared with other age groups, pediatric patients aged 0-9 years accounted for the highest number and incidence of ED tick bite visits; incidence was higher among male patients than among females. Tick bites are not monitored by current surveillance systems because a tick bite is an event that in and of itself is not a reportable condition to health departments. Syndromic surveillance of ED tick bite visits can provide timely information that might predict temporal and geographic risk for exposure to tickborne diseases and guide actionable public health messaging such as avoiding tick habitats, wearing repellent consistently when outdoors, and performing regular tick checks during times of increased tick bite risk.

Shelter Characteristics, Infection Prevention Practices, and Universal Testing for SARS-CoV-2 at Homeless Shelters in 7 US Urban Areas

Objectives. To examine shelter characteristics and infection prevention practices in relation to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection point prevalence during universal testing at homeless shelters in the United States.Methods. SARS-CoV-2 testing was offered to clients and staff at homeless shelters, irrespective of symptoms. Site assessments were conducted from March 30 to June 1, 2020, to collect information on shelter characteristics and infection prevention practices. We assessed the association between SARS-CoV-2 infection prevalence and shelter characteristics, including 20 infection prevention practices by using crude risk ratios (RRs) and exact unconditional 95% confidence intervals (CIs).Results. Site assessments and SARS-CoV-2 testing results were reported for 63 homeless shelters in 7 US urban areas. Median infection prevalence was 2.9% (range = 0%-71.4%). Shelters implementing head-to-toe sleeping and excluding symptomatic staff from working were less likely to have high infection prevalence (RR = 0.5; 95% CI = 0.3, 0.8; and RR = 0.5; 95% CI = 0.4, 0.6; respectively); shelters with medical services available were less likely to have very high infection prevalence (RR = 0.5; 95% CI = 0.2, 1.0).Conclusions. Sleeping arrangements and staffing policies are modifiable factors that might be associated with SARS-CoV-2 infection prevalence in homeless shelters. Shelters should follow recommended practices to reduce the risk of SARS-CoV-2 transmission.

Diagnosis, Treatment, and Prevention Practices for Lyme Disease by Clinicians, United States, 2013-2015

OBJECTIVES

Although tick-borne diseases account for a large number of health care visits in the United States, clinical practices for tick bite and Lyme disease treatment and prevention are not well understood. The objective of this study was to better understand factors associated with clinical practices related to tick bites and Lyme disease.

METHODS

In 2013-2015, questions about tick-bite evaluation, Lyme disease diagnosis and treatment, appropriate use of Lyme disease testing, and tick-bite prevention were included in Porter Novelli's DocStyles survey, a nationally representative annual web-based survey of health care providers. We performed analyses of responses by provider license type and state-level incidence (high or low) of Lyme disease in 2019.

RESULTS

A total of 4517 providers were surveyed across the 3 study years. Overall, 80.9% of providers reported that they had evaluated at least 1 patient for a tick bite, 47.6% had diagnosed at least 1 patient with Lyme disease, and 61.9% had treated at least 1 patient for Lyme disease in the previous year. Providers from states with a high incidence of Lyme disease saw more patients for tick bites and Lyme disease than providers from states with a low incidence of Lyme disease. Few providers correctly chose Lyme disease testing as clinically useful in the hypothetical case of a patient from a state with a high incidence of Lyme disease with an arthritic knee (36.0%) or with new-onset atrioventricular block (39.5%), and respondents across all provider types incorrectly chose testing when not clinically indicated. Most providers (69.7%) reported routinely recommending tick-bite prevention methods to patients.

CONCLUSIONS

Many providers evaluate patients for tick bites and treat patients for Lyme disease, but knowledge about appropriate testing is low. Providers may benefit from tailored education about appropriate Lyme disease diagnosis, testing, and effective tick-bite prevention.

Use of Commercial Claims Data for Evaluating Trends in Lyme Disease Diagnoses, United States, 2010-2018

We evaluated MarketScan, a large commercial insurance claims database, for its potential use as a stable and consistent source of information on Lyme disease diagnoses in the United States. The age, sex, and geographic composition of the enrolled population during 2010-2018 remained proportionally stable, despite fluctuations in the number of enrollees. Annual incidence of Lyme disease diagnoses per 100,000 enrollees ranged from 49 to 88, ≈6-8 times higher than that observed for cases reported through notifiable disease surveillance. Age and sex distributions among Lyme disease diagnoses in MarketScan were similar to those of cases reported through surveillance, but proportionally more diagnoses occurred outside of peak summer months, among female enrollees, and outside high-incidence states. Misdiagnoses, particularly in low-incidence states, may account for some of the observed epidemiologic differences. Commercial claims provide a stable data source to monitor trends in Lyme disease diagnoses, but certain important characteristics warrant further investigation.

1428. Lyme Disease Treatment in the United States: Prescribing Patterns from a Nationwide Commercial Insurance Database, 2016-2018

Background

Lyme disease (LD) is the most common vector-borne disease in the United States and is a significant public health problem. The use of non-standard antibiotic treatment regimens for LD has been associated with adverse effects; however, the overall landscape of treatment has not been described previously. We aimed to describe real-world antibiotic prescribing patterns for LD.

Methods

We performed a retrospective analysis of the MarketScan commercial claims database of outpatient encounters from 2016-2018 in the United States. We identified all individuals with a visit that included an LD diagnosis code and a prescription within 30 days of the visit for one or more of 12 antibiotics that may be prescribed for LD. We then categorized each individual as having received either standard or non-standard treatment during the two-year period. Standard treatment was defined as treatment with a first, second or third-line antibiotic for LD, for no longer than 30 days, and for no more than two episodes during the study period. Descriptive and multivariable analyses were performed to compare characteristics of people who received standard vs non-standard treatment for LD.

Results

A total of 84,769 prescriptions met criteria for inclusion, written for 45,926 unique patients. The mean duration of prescriptions was 21.4 days (SD 10.8). Most individuals (84.5%) treated for LD received standard treatment during the study period. Female gender (OR 1.5, p< 0.0001) and age 19-45 (p=0.0003) were significantly associated with being prescribed non-standard LD treatment. Treatment in low-incidence states (OR 2.2 compared to high-incidence states, p< 0.0001) and during non-summer months (OR 2.2, p< 0.0001) was more likely to be non-standard.

Age distribution of patients receiving treatment for Lyme disease, by gender and age at first prescription

Seasonality of standard versus non-standard treatment of Lyme disease

Conclusion

In this population of employed, young, and insured patients, young and middle-aged women were at the highest risk of receiving non-standard LD treatment. Treatments prescribed in states with low incidence of LD or during non-summer months were also more likely to be non-standard, a trend which likely reflects misdiagnosis or overtreatment of LD. Future studies are needed to further define prescriber and patient factors associated with non-standard LD treatment and related adverse outcomes.

Disclosures

All Authors: No reported disclosures

LB-12. SARS-CoV-2 RNA and Antibodies among People Experiencing Homelessness and Staying in Shelters or Outdoor Encampments in Denver, Colorado, May-July 2020

Background

The COVID-19 pandemic has disproportionately affected people experiencing homelessness (PEH) residing in shelters. Initial and regular testing of PEH in communities with moderate or substantial SARS-CoV-2 transmission may limit spread in shelters. We analyzed factors associated with positive SARS-CoV-2 RNA and antibody tests for PEH staying in shelters or encampments in Denver, Colorado.

Methods

In May 2020, Denver Public Health collaborated with local leaders to identify 4 homeless shelters and 3 outdoor encampments for voluntary, universal SARS-CoV-2 testing. At each testing event, a short questionnaire including sociodemographic factors and symptoms was administered to PEH who consented to testing. SARS-CoV-2 RNA testing by reverse transcription polymerase chain reaction (RT-PCR) was performed on nasopharyngeal swabs; antibody testing was performed on venous blood samples. PEH reporting a prior positive RT-PCR test were not retested but were eligible for antibody testing. Statistical calculations were performed with an α of 0.05; all tests were two-sided.

Results

From June 2–July 28, 2020, 931 PEH were approached. A total of 863 RT-PCR tests were performed at 14 testing events, and 334 antibody tests were performed at 5 testing events. Overall, 604 and 259 RT-PCR tests were conducted in 4 shelters and 3 encampments, respectively; 189 and 145 antibody tests were conducted in 3 shelters and 2 encampments, respectively. PEH tested in shelters were older, more often men, less often Native American, and less likely to report COVID-19 symptoms than those tested at encampments (Table 1). Overall, 9% of PEH tested in shelters tested positive for SARS-CoV-2 compared to 3% of PEH tested in encampments (p=0.002); 8% of men had positive RT-PCR results compared to 2% of women (p=0.03) (Table 2). PEH tested at shelters had a higher percentage of detectable SARS-CoV-2 antibodies than those tested in encampments (24% vs 8%, p=0.0002; Table 3). Neither RT-PCR nor antibody test results differed significantly by race or ethnicity.

Table 1. Demographics of participants residing in encampments compared with shelters in Denver, Colorado, May-July 2020 (n=931)

Table 2. Comparison of participants testing positive or negative for SARS-CoV-2 RT-PCR* by location and demographics, in Denver, Colorado, May-July 2020

Table 3. Comparison of participants testing positive or negative for antibodies against SARS-CoV-2 by location and demographics in Denver, Colorado, May-July 2020

Conclusion

A greater percentage of PEH tested positive for both SARS-CoV-2 RNA and antibodies at shelters than encampments, suggesting that continued assessment of mitigation strategies in shelters should be a priority.

Disclosures

All Authors: No reported disclosures

1614. Single-Dose Doxycycline as Lyme Disease Post-Exposure Prophylaxis in a National Commercial Insurance Claims Database―the United States, 2014–2017

Background

Approximately 300,000 cases of Lyme disease occur annually in the UNITED STATES, with children aged 5–9 years disproportionately affected. A single dose of doxycycline administered within 72 hours of a high-risk tick bite is recommended for post-exposure prophylaxis (PEP) to prevent Lyme disease in areas of high incidence. However, it is not known how often or for which patients PEP is used. We aimed to describe recent patterns of single-dose doxycycline medication claims in states with high and low Lyme disease incidence, and the associated patient and prescription characteristics in a large national commercial insurance claims database.

Methods

Outpatient medication claims in the IBM Watson Health MarketScan Database®, a large nation-wide database of de-identified insurance claims filed between January 1, 2014–December 31, 2017 were reviewed. Claims of single-dose doxycycline were identified and associated patient demographics and medication characteristics were analyzed.

Results

During 2014–2017, 66,210 medication claims for single-dose doxycycline were filed by 63,112 enrollees; mean annual incidence of receiving at least one single-dose doxycycline prescription was 56 per 100,000 enrollees. Mean patient age was 43 years (IQR 33–56 years); only 8% were for children aged <18 years. About half (46%) were male patients. Most claims (71%) were made by patients residing in the 14 states with high Lyme disease incidence, defined as an average annual incidence of ≥ 10 confirmed Lyme disease cases per 100,000 population. The majority (80%) of medication claims were during the 6 months of peak tick activity (April–July for nymphal ticks and October–November for adult ticks).

Conclusion

Single-dose doxycycline medication claims are common in states with high Lyme disease incidence and are highest during months of peak tick activity, consistent with the assumption that most single-dose doxycycline is used for Lyme disease PEP. Use of single-dose doxycycline to prevent Lyme disease is infrequent in children, despite being a group at high risk for Lyme disease. Efforts to educate pediatric healthcare providers and parents should be made to increase Lyme disease PEP access for children.

Disclosures

All authors: No reported disclosures.

Same-Day HIV Pre-Exposure Prophylaxis (PrEP) Initiation During Drop-in Sexually Transmitted Diseases Clinic Appointments Is a Highly Acceptable, Feasible, and Safe Model that Engages Individuals at Risk for HIV into PrEP Care

Objective

Strategies to increase pre-exposure prophylaxis (PrEP) uptake are needed. We hypothesized that same-day PrEP initiation in a sexually transmitted diseases (STD) clinic would be acceptable, feasible, and safe, and that individuals would engage in ongoing PrEP care.

Method

Individuals aged ≥ 18 years were evaluated for PrEP. Exclusion criteria were HIV, history of renal dysfunction or chronic hepatitis B infection, pregnancy, indications for HIV post-exposure prophylaxis, or positive screen for acute HIV symptoms. One hundred individuals received a free 30-day PrEP starter pack and met with a patient navigator to establish ongoing care. Bivariate analysis and multivariable logistic regression were used to compare individuals who did and did not attend at least 1 PrEP follow-up appointment within 180 days of enrollment. Client satisfaction surveys were given 3 months after enrollment.

Results

The majority (78%) of participants completed at least 1 PrEP follow-up appointment, and 57% attended at least 2 follow-up appointments. After adjusting for race and ethnicity, age, health insurance status, and annual income, only income was associated with follow-up appointment attendance. Each additional $10,000 increase in income was associated with a 1.7-fold increase in the odds of attending a PrEP follow-up appointment (95% confidence interval, 1.07–2.66, P = .02). The majority (54%) of individuals completed the satisfaction survey and all respondents liked the option of same-day PrEP initiation.

Conclusions

Our study suggests STD clinic-based, same-day PrEP initiation is acceptable, feasible, safe, and links a high proportion of individuals into ongoing PrEP care. Additional resources may be needed to support low-income individuals’ retention in care.

Syndromic Surveillance of Emergency Department Visits for Acute Adverse Effects of Marijuana, Tri-County Health Department, Colorado, 2016-2017

OBJECTIVES

In Colorado, legalization of recreational marijuana in 2014 increased public access to marijuana and might also have led to an increase in emergency department (ED) visits. We examined the validity of using syndromic surveillance data to detect marijuana-associated ED visits by comparing the performance of surveillance queries with physician-reviewed medical records.

METHODS

We developed queries of combinations of marijuana-specific International Classification of Diseases, Tenth Revision (ICD-10) diagnostic codes or keywords. We applied these queries to ED visit data submitted through the Electronic Surveillance System for the Early Notification of Community-Based Epidemics (ESSENCE) syndromic surveillance system at 3 hospitals during 2016-2017. One physician reviewed the medical records of ED visits identified by ≥1 query and calculated the positive predictive value (PPV) of each query. We defined cases of acute adverse effects of marijuana (AAEM) as determined by the ED provider's clinical impression during the visit.

RESULTS

Of 44 942 total ED visits, ESSENCE queries detected 453 (1%) as potential AAEM cases; a review of 422 (93%) medical records identified 188 (45%) true AAEM cases. Queries using ICD-10 diagnostic codes or keywords in the triage note identified all true AAEM cases; PPV varied by hospital from 36% to 64%. Of the 188 true AAEM cases, 109 (58%) were among men and 178 (95%) reported intentional use of marijuana. Compared with noncases of AAEM, cases were significantly more likely to be among non-Colorado residents than among Colorado residents and were significantly more likely to report edible marijuana use rather than smoked marijuana use ( P < .001).

CONCLUSIONS

ICD-10 diagnostic codes and triage note keyword queries in ESSENCE, validated by medical record review, can be used to track ED visits for AAEM.

Delayed initiation of antiretroviral therapy among HIV-discordant couples in Kenya

Timely initiation of antiretroviral therapy (ART) is particularly important for HIV-discordant couples because viral suppression greatly reduces the risk of transmission to the uninfected partner. To identify issues and concerns related to ART initiation among HIV-discordant couples, we recruited a subset of discordant couples participating in a longitudinal study in Nairobi to participate in in-depth interviews and focus group discussions about ART. Our results suggest that partners in HIV-discordant relationships discuss starting ART, yet most are not aware that ART can decrease the risk of HIV transmission. In addition, their concerns about ART initiation include side effects, sustaining an appropriate level of drug treatment, HIV/AIDS-related stigma, medical/biological issues, psychological barriers, misconceptions about the medications, the inconvenience of being on therapy, and lack of social support. Understanding and addressing these barriers to ART initiation among discordant couples is critical to advancing the HIV "treatment as prevention" agenda.

Surgical alternatives to the Fontan procedure incorporating a hypoplastic right ventricle

BACKGROUND

Frequently the definitive operation for patients with a right ventricle (RV) that is too small to support full cardiac output is a modified Fontan operation. However, other surgical options exist that incorporate a small RV in the atriopulmonary pathway when biventricular repair is not feasible because of RV or tricuspid valve hypoplasia. The risks and benefits of these options have not been well defined.

METHODS AND RESULTS

Between 1988 and 1993, 8 patients (6 with pulmonary atresia and intact ventricular septum and 2 with tricuspid valve stenosis and RV hypoplasia) underwent a cavopulmonary connection, which allowed right atrial blood to flow either to the pulmonary artery via the RV or directly via the cavopulmonary anastomosis. Age at surgery ranged from 1.5 to 9 years. The proximal right pulmonary artery was ligated in 5 patients, and the atrial septal defect was closed during the same procedure in 7 of the 8 patients. The echocardiographic right ventricular-left ventricular volume ratio ranged from 9% to 25%, and tricuspid valve z-scores ranged from 0 to -4. There were no deaths at a median follow-up of 24 months (range, 7 to 61 months). Mild exertional limitation was evident in only one patient. Postoperative echocardiograms demonstrated pulsatile systolic flow across the RV outflow tract in 5 patients and low-velocity diastolic-systolic flow in a sixth patient with extreme tricuspid valve hypoplasia. At postoperative cardiac catheterization (6 patients) right atrial mean pressures ranged from 7 to 13 mm Hg and mixed venous saturations from 62% to 70%.

CONCLUSIONS

Right atrial decompression via a superior vena cava-to-pulmonary artery anastomosis allows incorporation of a small RV into the pulmonary circulation and closure of the atrial septum, with excellent results to date.

Axially symmetric geodesic lenses

A procedure was developed and used to obtain the optimal shape of corrected aspheric geodesic lenses for F-numbers ranging from 3 to 15. This optimization procedure allows the (constant) refractive index, lens radius, and focal length to be used as independent design parameters. Results of the increase in size of the first diffraction spot and shift in the focal plane caused by perturbations in a lens's shape have been included for several lenses with F-numbers between 3 and 10.