Household Transmission of Mpox to Children and Adolescents, California, 2022.

BACKGROUND: In California, the 2022 mpox outbreak cumulated 5572 cases, 20% of US cases, as of November 28, 2022; 0.3% of cases were among children <16 years old. The secondary attack rate (SAR) for children sharing households with infected adults is unknown. METHODS: A line list of pediatric mpox household contacts aged <16 years reported through August 31, 2022 was created. It included demographic and clinical information on the contacts. Pediatric contact lists were crossmatched with the state vaccination database to identify those who received postexposure prophylaxis (PEP) with the JYNNEOS vaccine. RESULTS: We identified 129 pediatric household contacts with median age of 7 years (range, 0-15 years). Among 18 symptomatic contacts, 12 (66.7%) underwent mpox testing; 5 (41.2%) were confirmed cases, 6 (50%) were negative, and 1 (0.8%) had an indeterminate result. Six symptomatic children were not tested for mpox (33.3%). Overall, 6 infected contacts were identified, resulting in a SAR of 4.7% (6 of 129). The majority of pediatric household contacts and 4 of 6 infected children identified as Hispanic/Latino. Only 18 children (14%) reported receiving PEP. CONCLUSIONS: The SAR was overall low among pediatric household contacts; none had severe disease. This may be underestimated given low testing rates.

COVID-19, HIV, and Syphilis Contact Tracing: What Have We Learned and Where Are We Headed?

ABSTRACT: Contact tracing is a core public health intervention for a range of communicable diseases, in which the primary goal is to interrupt disease transmission and decrease morbidity. In this article, we present lessons learned from COVID-19, HIV, and syphilis in San Francisco to illustrate factors that shape the effectiveness of contact tracing programs and to highlight the value of investing in a robust disease intervention workforce with capacity to pivot rapidly in response to a range of emerging disease trends and outbreak response needs.

Contact-Tracing Outcomes Among Household Contacts of Fully Vaccinated Coronavirus Disease 2019 (COVID-19) Patients: San Francisco, California, 29 January-2 July 2021.

BACKGROUND: The extent to which vaccinated persons diagnosed with coronavirus disease 2019 (COVID-19) can transmit to other vaccinated and unvaccinated persons is unclear. METHODS: Using data from the San Francisco Department of Public Health, this report describes outcomes of household contact tracing during 29 January-2 July 2021, where fully vaccinated patients with COVID-19 were the index case in the household. RESULTS: Among 248 fully vaccinated patients with breakthrough infections, 203 (82%) were symptomatic and 105 were identified as the index patient within their household. Among 179 named household contacts, 71 (40%) contacts tested, over half (56%) were fully vaccinated and the secondary attack rate was 28%. Overall transmission from a symptomatic fully vaccinated patient with breakthrough infection to household contacts was suspected in 14 of 105 (13%) of households. Viral genomic sequencing of samples from 44% of fully vaccinated patients showed that 82% of those sequenced were infected by a variant of concern or interest and 77% by a variant carrying mutation(s) associated with resistance to neutralizing antibodies. CONCLUSIONS: Transmission from fully vaccinated symptomatic index patients to vaccinated and unvaccinated household contacts can occur. Indoor face masking and timely testing of all household contacts should be considered when a household member receives a positive test result in order to identify and interrupt transmission chains.

Prioritizing COVID-19 Contact Tracing During a Surge Using Chatbot Technology.

When COVID-19 cases surge, identifying ways to improve the efficiency of contact tracing and prioritize vulnerable communities for isolation and quarantine support services is critical. During a fall 2020 COVID-19 resurgence in San Francisco, California, prioritization of telephone-based case investigation by zip code and using a chatbot to screen for case participants who needed isolation support reduced the number of case participants who would have been assigned for a telephone interview by 31.5% and likely contributed to 87.5% of Latinx case participants being successfully interviewed. (Am J Public Health. 2022;112(1):43-47. https://doi.org/10.2105/AJPH.2021.306563).

Decreased Time From Human Immunodeficiency Virus Diagnosis to Care, Antiretroviral Therapy Initiation, and Virologic Suppression during the Citywide RAPID Initiative in San Francisco.

BACKGROUND: Early virologic suppression (VS) after human immunodeficiency virus (HIV) infection improves individual health outcomes and decreases onward transmission. In San Francisco, immediate antiretroviral therapy (ART) at HIV diagnosis was piloted in 2013-2014 and expanded citywide in 2015 in a rapid start initiative to link all new diagnoses to care within 5 days and start ART at the first care visit. METHODS: HIV providers and linkage navigators were trained on a rapid start protocol with sites caring for vulnerable populations prioritized. Dates of HIV diagnosis, first care visit, ART initiation, and VS were abstracted from the San Francisco Department of Public Health HIV surveillance registry. RESULTS: During 2013-2017, among 1354 new HIV diagnoses in San Francisco, median days from diagnosis to first VS decreased from 145 to 76 (48%; P < .0001) and from first care visit to ART initiation decreased from 28 to 1 (96%; P < .0001). By 2017, 28% of new diagnoses had a rapid start, which was independently associated with Latinx ethnicity (AOR, 1.73; 95% CI, 1.15-2.60) and recent year of diagnosis (2017; AOR, 16.84; 95% CI, 8.03-35.33). Persons with a rapid ART start were more likely to be virologically suppressed within 12 months of diagnosis than those with a non-rapid start (RR, 1.17; 95% CI, 1.10-1.24). CONCLUSIONS: During a multisector initiative to optimize ART initiation, median time from diagnosis to VS decreased by nearly half. Immediate ART at care initiation was achieved across many, but not all, populations, and was associated with improved suppression rates.

Lessons From Mass-Testing for Coronavirus Disease 2019 in Long-Term Care Facilities for the Elderly in San Francisco.

Coronavirus disease 2019 can cause significant mortality in the elderly in long-term care facilities (LTCF). We describe 4 LTCF outbreaks where mass testing identified a high proportion of asymptomatic infections (4%-41% in healthcare workers and 20%-75% in residents), indicating that symptom-based screening alone is insufficient for monitoring for COVID-19 transmission.

Unnamed Partners From Syphilis Partner Services Interviews, 7 Jurisdictions.

BACKGROUND: Reducing transmission depends on the percentage of infected partners treated; if many are missed, impact on transmission will be low. Traditional partner services metrics evaluate the number of partners found and treated. We estimated the proportion of partners of syphilis patients not locatable for intervention. METHODS: We reviewed records of early syphilis cases (primary, secondary, early latent) reported in 2015 to 2017 in 7 jurisdictions (Florida, Louisiana, Michigan, North Carolina, Virginia, New York City, and San Francisco). Among interviewed syphilis patients, we determined the proportion who reported named partners (with locating information), reported unnamed partners (no locating information), and did not report partners. For patients with no reported partners, we estimated their range of unreported partners to be between one and the average number of partners for patients who reported partners. RESULTS: Among 29,719 syphilis patients, 23,613 (80%) were interviewed and 18,581 (63%) reported 84,224 sex partners (average, 4.5; 20,853 [25%] named and 63,371 [75%] unnamed). An estimated 11,138 to 54,521 partners were unreported. Thus, 74,509 to 117,892 (of 95,362-138,745) partners were not reached by partner services (78%-85%). Among interviewed patients, 71% reported ≥1 unnamed partner or reported no partners; this proportion was higher for men who reported sex with men (75%) compared with men who reported sex with women only (65%) and women (44%). CONCLUSIONS: Approximately 80% of sex partners were either unnamed or unreported. Partner services may be less successful at interrupting transmission in networks for men who reported sex with men where a higher proportion of partners are unnamed or unreported.

Extrapolating Sentinel Surveillance Information to Estimate National COVID Hospital Admission Rates: A Bayesian Modeling Approach.

The COVID-19-Associated Hospitalization Surveillance Network (COVID-NET) was established in March 2020 to monitor trends in hospitalizations associated with SARS-CoV-2 infection. COVID-NET is a geographically diverse population-based surveillance system for laboratory-confirmed COVID-19-associated hospitalizations with a combined catchment area covering approximately 10% of the US population. Data collected in COVID-NET includes monthly counts of hospitalizations for persons with confirmed SARS-CoV-2 infection who reside within the defined catchment area. A Bayesian modeling approach is proposed to estimate US national COVID-associated hospital admission rates based on information reported in the COVID-NET system. A key component of the approach is the ability to estimate uncertainty resulting from extrapolation of hospitalization rates observed within COVID-NET to the US population. In addition, the proposed model enables estimation of other contributors to uncertainty including temporal dependence among reported COVID-NET admission counts, the impact of unmeasured site-specific factors, and the frequency and accuracy of testing for SARS-CoV-2 infection. Based on the proposed model, an estimated 6.3 million (95% uncertainty interval (UI) 5.4-7.3 million) COVID-19-associated hospital admissions occurred in the United States from September 2020 through December 2023. Between April 2020 and December 2023, model-based monthly admission rate estimates ranged from a minimum of 1 per 10,000 population (95% UI 0.7-1.2) in June of 2023 to a highest monthly level of 16 per 10,000 (95% UI 13-19) in January 2022.

Klebsiella pneumoniae K1 liver abscess and septic endophthalmitis in a U.S. resident.

Klebsiella pneumoniae K1 is a major agent of hepatic abscess with metastatic disease in East Asia, with sporadic reports originating elsewhere. We report a case of abscess complicated by septic endophthalmitis caused by a wzyAKpK1-positive Klebsiella strain in a U.S. resident, raising concern for global emergence.

Public Health Detailing on Sexual Health Care in San Francisco: Learnings From Real-World Implementation.

OBJECTIVES: Public health detailing is an intervention in which a public health professional visits health care providers to educate them about evidence-based approaches to improve health. The San Francisco Department of Public Health conducted a public health detailing program from 2016 to 2018 to improve sexual health care and preexposure prophylaxis services in the city. METHODS: We conducted a mixed-methods study to understand the implementation of detailing and explore examples of changes to clinicians' clinical behaviors. We surveyed 203 clinicians, conducted 60-minute qualitative interviews with 7 clinicians and 4 detailers, and analyzed tracking forms. We used descriptive statistics to assess associations in the surveys. We used qualitative thematic analysis to understand facilitators and barriers to detailing and identify ways to improve the process and identify its potential benefits. RESULTS: In interviews, both clinicians and detailers had a favorable view of detailing as a tool to connect health department expertise to clinicians. Detailers cited challenges such as limited clinic time, provider turnover, and policies that limit their access to clinicians. These challenges may attenuate the real-world benefits of detailing. Clinicians offered examples of how detailing altered their behaviors, such as taking sexual health histories, building knowledge and confidence about sexual health, and using health department services. Matched surveys (n = 21) showed preliminary changes to prescribing preexposure prophylaxis. CONCLUSIONS: Public health detailing is a promising approach to increase clinicians' knowledge and confidence to offer sexual health care services, build buy-in, and support connection to health departments. Detailing programs require sufficient investment and staff support to build lasting and collaborative relationships between clinicians and public health departments and to assess the impact of the intervention.

San Francisco's Citywide COVID-19 Response: Strategies to Reduce COVID-19 Severity and Health Disparities, March 2020 Through May 2022.

San Francisco implemented one of the most intensive, comprehensive, multipronged COVID-19 pandemic responses in the United States using 4 core strategies: (1) aggressive mitigation measures to protect populations at risk for severe disease, (2) prioritization of resources in neighborhoods highly affected by COVID-19, (3) timely and adaptive data-driven policy making, and (4) leveraging of partnerships and public trust. We collected data to describe programmatic and population-level outcomes. The excess all-cause mortality rate in 2020 in San Francisco was half that seen in 2019 in California as a whole (8% vs 16%). In almost all age and race and ethnicity groups, excess mortality from COVID-19 was lower in San Francisco than in California overall, with markedly diminished excess mortality among people aged >65 years. The COVID-19 response in San Francisco highlights crucial lessons, particularly the importance of community responsiveness, joint planning, and collective action, to inform future pandemic response and advance health equity.

Barriers and Enablers to COVID-19 Vaccination in San Francisco's Spanish-Speaking Population.

Populations at high risk for COVID-19- including Spanish speakers-may face additional barriers to obtaining COVID-19 vaccinations; by understanding their challenges, we can create more equitable vaccine interventions. In this study, we used interviews to identify barriers and enablers to COVID-19 vaccine uptake among participants in the San Francisco Department of Public Health contact tracing program. Data analysis employed Capability, Opportunity, Motivation Behavior model (COM-B) and the Behavior Change Wheel framework as guides to target barriers with interventions and supporting policies. This paper presents data from interviews focused on COVID-19 vaccine uptake that was part of a project to improve COVID-19 preventive behaviors in San Francisco. We completed seventeen interviews between February and May 2021; six (35%) were completed in English and 11 (65%) in Spanish. Barriers to vaccine uptake included an unprepared health system, fear of side effects, limited knowledge, and conflicting information. Behavioral factors influencing vaccine uptake were mainly related to physical opportunity, automatic motivation, and psychological capability. Interventions that could address the most significant number of barriers included education, enablement, and environmental restructuring. Finally, communication and marketing policies that use diverse multi-lingual social media and environmental planning that includes accessible vaccine sites for people with disabilities, literacy barriers, and limited English proficiency could significantly increase vaccination. Public health departments should tailor interventions to high-risk populations by understanding the specific barriers they face. This exploratory study suggests how implementation science can provide frameworks to achieve this.

Evaluating the Impact of Language Concordance on Coronavirus Disease 2019 Contact Tracing Outcomes Among Spanish-Speaking Adults in San Francisco Between June and November 2020.

We evaluated the impact of language concordance-clinician or public health worker fluency in a patient's primary language-on coronavirus disease 2019 (COVID-19) contact tracing outcomes among 2668 Spanish-speaking adults in San Francisco. Language concordance was associated with 20% greater odds of COVID-19 testing and 53% greater odds of support service referrals.

Predominance of antibody-resistant SARS-CoV-2 variants in vaccine breakthrough cases from the San Francisco Bay Area, California.

Associations between vaccine breakthrough cases and infection by different SARS coronavirus 2 (SARS-CoV-2) variants have remained largely unexplored. Here we analysed SARS-CoV-2 whole-genome sequences and viral loads from 1,373 persons with COVID-19 from the San Francisco Bay Area from 1 February to 30 June 2021, of which 125 (9.1%) were vaccine breakthrough infections. Vaccine breakthrough infections were more commonly associated with circulating antibody-resistant variants carrying ≥1 mutation associated with decreased antibody neutralization (L452R/Q, E484K/Q and/or F490S) than infections in unvaccinated individuals (78% versus 48%, P = 1.96 × 10-8). Differences in viral loads were non-significant between unvaccinated and fully vaccinated cases overall (P = 0.99) and according to lineage (P = 0.09-0.78). Symptomatic vaccine breakthrough infections had comparable viral loads (P = 0.64), whereas asymptomatic breakthrough infections had decreased viral loads (P = 0.023) compared with infections in unvaccinated individuals. In 5 cases with serial samples available for serologic analyses, vaccine breakthrough infections were found to be associated with low or undetectable neutralizing antibody levels attributable to an immunocompromised state or infection by an antibody-resistant lineage. Taken together, our results show that vaccine breakthrough infections are overrepresented by antibody-resistant SARS-CoV-2 variants, and that symptomatic breakthrough infections may be as efficient in spreading COVID-19 as unvaccinated infections, regardless of the infecting lineage.

Mobilizing a COVID-19 Contact Tracing Workforce at Warp Speed: A Framework for Successful Program Implementation.

To effectively control the spread of COVID-19, it is essential that all jurisdictions have the capacity to rapidly contact trace all close contacts of each and every case. We describe the early experience in the City and County of San Francisco, where contact tracing capability was rapidly expanded to respond to COVID-19. Important prerequisites to scale up included rapid expansion of the COVID-19 contact tracing workforce, a comprehensive training and onboarding program, and the institution of effective performance management metrics. The San Francisco model for contact tracing, including focusing on rigorous training, recruiting, and partnering with community-based organizations from diverse, affected communities, is an inclusive approach relevant to other jurisdictions and settings.

COVID-19 Susceptibility and Outcomes Among People Living With HIV in San Francisco.

INTRODUCTION: Studies to examine whether HIV predisposes to a higher incidence of COVID-19 or more severe disease are accumulating. Initial studies from New York City suggested more severe disease among people living with HIV (PLWH), but this was during a time when hospitals were over-capacity and health systems stretched. This report presents the incidence and outcomes among PLWH with COVID-19 in San Francisco over the first 6 months of the pandemic. METHODS: Community transmission of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) was first reported in San Francisco on March 5, 2020. This report examines the match of the San Francisco Department of Public Health COVID-19 testing database and the San Francisco Department of Public Health HIV Surveillance case registry from March 24, 2020, to September 3, 2020. RESULTS: Among 4252 COVID-19 tests performed among PLWH, 4.5% (N = 193) were positive for COVID-19, compared with a 3.5% (N = 9626) positivity rate among the 272,555 people without HIV tested for COVID-19 (P < 0.001). The mean age of those infected with HIV/COVID-19 was 48 years (20-76), 38.9% White, 38.3% Latinx, 11.9% Black, and 91.2% were men. Only 54.6% of coinfected PLWH were housed, with the remainder marginally housed. The rate of severe illness with COVID-19 was not increased among PLWH. DISCUSSION: In San Francisco, susceptibility to COVID-19 was increased among PLWH over the first 6 months of the pandemic, although clinical outcomes were similar to those without HIV. Homelessness and higher rates of congregate living situations among PLWH likely accounted for this disparity. Special efforts to house patients with marginal housing during the COVID-19 pandemic are needed.

Acute HIV at the Time of Initiation of Pre-exposure or Post-exposure Prophylaxis: Impact on Drug Resistance and Clinical Outcomes.

BACKGROUND: Initiating pre-exposure or post-exposure prophylaxis (PrEP/PEP) in the setting of undiagnosed acute HIV (AHI) could cause antiretroviral resistance. We sought to characterize clinical outcomes and drug resistance mutations among individuals prescribed PrEP/PEP with undiagnosed AHI at a San Francisco sexually transmitted disease clinic. SETTING: In our PrEP/PEP program, patients are tested for HIV using a point-of-care antibody test. If negative, patients are started on prophylaxis and screened for AHI using pooled HIV RNA (5-10 days turn-around). We used 2-drug PEP until 05/2016. METHODS: We identified patients who had as-yet-undiagnosed AHI on the day of PrEP/PEP start between 2011 and 2018, then used our clinical record and surveillance data to describe HIV resistance and clinical outcomes. RESULTS: Of 1758 PrEP and 2242 PEP starts, there were 7 AHI cases among PrEP users (0.40%) and 6 among PEP users (0.30%). Median times for linkage to HIV care, initiation of HIV treatment, and viral suppression were 7, 12, and 43 days. On initiation of HIV care, 3 patients (23%) were found to have an M184 mutation 7-12 days after starting PrEP/PEP. All 3 had genotyping performed on stored serum available from the date of PrEP/PEP start, each of which demonstrated wild-type virus. All 3 patients achieved durable viral suppression. CONCLUSIONS: Although rare (occurring <0.5% of the time), AHI in the setting of PrEP/2-drug PEP can result in an M184 within days. Even with M184, persons with AHI achieve viral suppression when rapidly linked to care and initiated on antiretroviral therapy. Providers should consider AHI screening when starting PrEP/PEP.

Preventing COVID-19 Transmission in Education Settings.

OBJECTIVES: In fall 2020, community hubs opened in San Francisco, California, to support vulnerable groups of students in remote learning. Our objectives were to (1) describe adherence to coronavirus disease 2019 (COVID-19) mitigation policies in these urban, low-income educational settings; (2) assess associations between policy adherence and in-hub COVID-19 transmission; and (3) identify barriers to and facilitators of adherence. METHODS: We conducted a mixed-methods study from November 2020 to February 2021. We obtained COVID-19 case data from the San Francisco Department of Public Health, conducted field observations to observe adherence to COVID-19 mitigation policies, and surveyed hub leaders about barriers to and facilitators of adherence. We summarized quantitative data using descriptive statistics and qualitative data using thematic content analysis. RESULTS: A total of 1738 children were enrolled in 85 hubs (39% Hispanic, 29% Black). We observed 54 hubs (n = 1175 observations of children and 295 observations of adults). There was high community-based COVID-19 incidence (2.9-41.2 cases per 100 000 residents per day), with 36 cases in hubs and only 1 case of hub-based transmission (adult to adult). Sixty-seven percent of children and 99% of adults were masked. Fifty-five percent of children and 48% of adults were distanced ≥6 ft. Facilitators of mitigation policies included the following: for masking, reminders, adequate supplies, and "unmasking zones"; for distancing, reminders and distanced seating. CONCLUSIONS: We directly observed COVID-19 mitigation in educational settings, and we found variable adherence. However, with promotion of multiple policies, there was minimal COVID-19 transmission (despite high community incidence). We detail potential strategies for increasing adherence to COVID-19 mitigation.

The SARS-CoV-2 pandemic: the race to trace: contact tracing scale-up in San Francisco-early lessons learned.

In order to effectively control spread of coronavirus 2019 (COVID-19), it is essential that jurisdictions have the capacity to rapidly trace close contacts of each and every case. Best practice guidance on how to implement such programs is urgently needed. We describe the early experience in the City and County of San Francisco (CCSF), where the City's Department of Health expanded contact tracing capability in anticipation of changes in San Francisco's 'shelter in place' order between April and June 2020. Important prerequisites to successful scale-up included a rapid expansion of the COVID-19 response workforce, expansion of testing capability, and other containment resources. San Francisco's scale-up offers a model for how other jurisdictions can rapidly mobilize a workforce. We underscore the importance of an efficient digital case management system, effective training, and expansion of supportive service programs for those in quarantine or isolation, and metrics to ensure continuous performance improvement.

The COVID-19 Symptom to Isolation Cascade in a Latinx Community: A Call to Action.

BACKGROUND: Rapid coronavirus disease 2019 (COVID-19) diagnosis and isolation of infectious persons are critical to stopping forward transmission, and the care cascade framework can identify gaps in the COVID-19 response. METHODS: We described a COVID-19 symptom to isolation cascade and barriers among symptomatic persons who tested polymerase chain reaction positive for severe acute respiratory disease coronavirus 2 (SARS-CoV-2) at a low-barrier testing site serving a low-income Latinx community in San Francisco. Steps in the cascade are defined as days from symptom onset to test, test to result, and result to counseling on self-isolation. We examined SARS-CoV-2 cycle threshold (Ct) values to assess the likelihood of infectiousness on the day of testing and during missed isolation days. RESULTS: Among 145 persons, 97% were Latinx and 81% had an income of <$50 000. The median time from symptom onset to isolation (interquartile range [IQR]) was 7 (5-10) days, leaving a median (IQR) of 3 (0-6) days of isolation. Eighty-three percent had moderate to high levels of virus (Ct <33), but by disclosure 23% were out of their isolation period. The longest intervals were symptom onset to test (median [IQR], 4 [2-9] days) and test to results notification (median [IQR], 3 [2-4] days). Access to a test site was the most common barrier to testing, and food and income loss was the most common barrier to isolation. CONCLUSIONS: Over half of the 10-day isolation period passed by the time of disclosure, and over a fifth of people were likely outside the window of infectiousness by the time they received results. Improvements in test access and turnaround time, plus support for isolation, are needed for epidemic control of SARS-CoV-2 in highly impacted communities.