Virus Acquisition Research Articles

Vaginal Bacteria and Proinflammatory Host Immune Mediators as Biomarkers of Human Immunodeficiency Virus Acquisition Risk Among African Women.

Few investigations have assessed contributions of both vaginal bacteria and proinflammatory immune mediators to human immunodeficiency virus (HIV) acquisition risk in a prospective cohort. We conducted a nested case-control study of African women who participated in a randomized placebo-controlled trial of daily oral versus vaginal tenofovir-based preexposure prophylaxis for HIV infection. Vaginal concentrations of 23 bacterial taxa and 16 immune mediators were measured. Relationships between individual bacterial concentrations or immune mediators and HIV risk were analyzed using generalized estimating equations in a multivariable model. Factor analysis assessed relationships between combinations of bacterial taxa, immune mediators, and HIV acquisition risk. We identified 177 HIV pre-seroconversion visits from 150 women who acquired HIV and 531 visits from 436 women who remained HIV uninfected. Fourteen bacterial taxa and 6 proinflammatory cytokines and chemokines were individually associated with greater HIV risk after adjusting for confounders. Women with all 14 taxa versus <14 taxa (adjusted odds ratio [aOR], 4.45 [95% confidence interval {CI}, 2.20-8.98]; P < .001) or all 6 immune mediators versus <6 mediators (aOR, 1.77 [95% CI, 1.24-2.52]; P < .001) had greater risk for HIV acquisition. Factor analysis demonstrated that a bacterial factor comprised of 14 high-risk bacterial taxa (aOR, 1.57 [95% CI, 1.27-1.93]; P < 0.001) and the interferon gamma-induced protein 10 (highest quartile: aOR, 3.19 [95% CI, 1.32-7.72]; P = 0.002) contributed to the highest HIV risk. Bacterial and host biomarkers for predicting HIV acquisition risk identify women at greatest risk for HIV infection and can focus prevention efforts.

Assessing the Potential of Tortistilus (Hemiptera: Membracidae) from Northern California Vineyards as Vector Candidates of Grapevine Red Blotch Virus.

Ceresini treehoppers are present in northern California vineyard ecosystems, including the closely related Spissistilus and Tortistilus (Hemiptera: Membracidae). These membracids are not direct pests of wine grapes, but S. festinus is a vector of grapevine red blotch virus (GRBV). No information is available on the ability of Tortistilus spp. to transmit GRBV. In this study, Tortistilus were collected on yellow panel cards across 102 vineyard sites and surrounding areas in Napa Valley, California, USA in 2021-2023. Specimens were morphotyped, sexed and tested for GRBV ingestion and acquisition by multiplex PCR or qPCR. Phylogenetic analysis of the partial sequence of mt-COI and ITS gene fragments of a subset of 40 Tortistilus specimens revealed clustering in a monophyletic clade with T. wickhami with the former barcode sequence. Only 6% (48/758) of the T. wickhami tested positive for GRBV, but none of the heads with salivary glands (0%, 0/50) of the dissected specimens tested positive for GRBV, indicating no virus acquisition. In contrast, half of the dissected heads with salivary glands of S. festinus (52%, 12/23), from the same collection vineyard sites, tested positive for GRBV. Together, our findings confirmed the presence of T. wickhami in northern California vineyards and suggested a dubious role of this treehopper as a vector of GRBV.

EBV Reactivation and Disease in Allogeneic Hematopoietic Stem Cell Transplant (HSCT) Recipients and Its Impact on HSCT Outcomes.

The acquisition or reactivation of Epstein-Barr virus (EBV) after allogeneic Hematopoietic Stem Cell Transplant (HSCT) can be associated with complications including the development of post-transplant lymphoproliferative disorder (PTLD), which is associated with significant morbidity and mortality. A number of risk factors for PTLD have been defined, including T-cell depletion, and approaches to monitoring EBV, especially in high-risk patients, with the use of preemptive therapy upon viral activation have been described. Newer therapies for the preemption or treatment of PTLD, such as EBV-specific cytotoxic T-cells, hold promise. Further studies to help define risks, diagnosis, and treatment of EBV-related complications are needed in this at-risk population.

A plant virus differentially alters DNA methylation in two cryptic species of a hemipteran vector

Epigenetic patterns including DNA methylation are known to vary between distantly related species, but it is not clear how these patterns differ at an intraspecific level. The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Aleyrodidae; Hemiptera), encompasses several cryptic species. These cryptic species possess highly similar genomes but exhibit substantial biological and physiological differences. B. tabaci cryptic species are invasive, highly polyphagous, and transmit an array of plant infecting single stranded DNA viruses (ssDNA) –begomoviruses. In this study, DNA methylation patterns around genes and genomic features of two prominent B. tabaci cryptic species were investigated following acquisition of a monopartite ssDNA virus –tomato yellow curl virus. The cryptic species investigated included: B (also known as Middle East Asia Minor 1) and Q (also known as Mediterranean). Genomic features, such as promoters, gene bodies, and transposable elements were assessed for methylation levels in both B and Q cryptic species. Despite overall similar trends, both cryptic species showed differences in methylation levels between these genomic features. Virus induced differentially methylated regions were associated with predominantly distinct genes in B and Q cryptic species. All differentially methylated regions were assessed for differential gene expression and alternative splicing events with and without virus acquisition. DNA methylation levels were found to have a negative correlation with differential gene expression in both B and Q cryptic species. The differentially expressed genes were further grouped into hyper- and hypomethylated clusters. These clusters included genes with implications for virus-vector interactions including immune functions and xenobiotics’ detoxification. The observed DNA methylation pattern differences within each cryptic species could, in part, explain some of the biological and physiological differences between them.

PET/CT Targeted Tissue Sampling Reveals Intravenously Administered HGN194 IgG1 Affects HIV Distribution after Rectal Exposure.

Neutralizing monoclonal antibodies hold great potential for prevention of human immunodeficiency virus (HIV) acquisition. IgG is the most abundant antibody in human serum, has a long half-life, and potent effector functions, making it a prime candidate for an HIV prevention therapeutic. We combined Positron Emission Tomography imaging and fluorescent microscopy of 64Cu-labeled, photoactivatable-green fluorescent protein HIV (PA-GFP-BaL) and fluorescently labeled HGN194 IgG1 to determine whether intravenously instilled IgG influences viral interaction with mucosal barriers and viral penetration in colorectal tissue 2 h after rectal viral challenge. Our results show that IgG1 did not alter the number of virions found throughout the colon or viral penetration into the epithelium of the rectum or descending colon. A minor increase in virions was observed in the transverse colon of IgG1 treated animals. Overall, the number of viral particles found in the mesenteric lymph nodes was low. However, IgG1 administration resulted in a significant reduction of virions found in mesenteric lymph nodes. Taken together, our results show that HGN194 IgG1 does not prevent virions from penetrating into the colorectal mucosa but may perturb HIV virion access to the lymphatic system.

Untangling the role of the microbiome across the stages of HIV disease.

The primate microbiome consists of bacteria, eukaryotes, and viruses that dynamically shape and respond to host health and disease. Understanding how the symbiotic relationship between the host and microbiome responds to HIV has implications for therapeutic design. Advances in microbiome identification technologies have expanded our ability to identify constituents of the microbiome and to infer their functional capacity. The dual use of these technologies and animal models has allowed interrogation into the role of the microbiome in lentiviral acquisition, vaccine efficacy, and the response to antiretrovirals. Lessons learned from such studies are now being harnessed to design microbiome-based interventions. Previous studies considering the role of the microbiome in people living with HIV largely described viral acquisition as an intrusion on the host:microbiome interface. Re-framing this view to consider HIV as a novel, albeit unwelcome, component of the microbiome may better inform the research and development of pre and postexposure prophylaxes.

Oral HPV infection clearance and acquisition after nonavalent vaccination in men who have sex with men and transgender women: a prospective analysis.

Oral HPV infection is the main risk factor for the development of oropharyngeal carcinoma. Men who have sex with men (MSM), especially if living with HIV (PLWH), are at increased risk of infection and consequently of cancer development. Aim of this study is to evaluate the impact of nonavalent vaccine on oral HPV infection in a cohort of MSM and transgender women (TGW). This prospective study included all MSM and TGW who started nonavalent HPV vaccination from May 2019 to September 2021. Oral rinse was collected before each vaccine administration and after six months of follow up. Descriptive statistics were used. Kaplan Meier probability curves and Cox regression models for HPV acquisition and clearance were calculated. The analysis included 211 individuals (202 MSM and 9 TGW). PLWH were 138 (65.4%). Baseline oral rinse was positive in 30 subjects (14.2%). Positivity rate did not change over time (p = 0.742), even when restricting the analysis only to high-risk genotypes (p = 0.575) and to genotypes covered by vaccine (p = 0.894). The risk to acquire HPV infection was 12.8% at one year and 33.4% at two years after vaccination. The probability to clear the infection was 67.6% at one year and 87.9% at two years. HIV infection had no impact on vaccine efficacy. Age above 45 years was the only factor associated to HPV acquisition (aHR 4.06, 95% CI 1.03-15.98, p = 0.045). Prevalence of oral HPV infection was higher in PLWH, but HIV had no impact on viral clearance or acquisition after vaccination.

High burden of viruses and bacterial pathobionts drives heightened nasal innate immunity in children.

Studies during the COVID-19 pandemic showed that children had heightened nasal innate immune responses compared with adults. To evaluate the role of nasal viruses and bacteria in driving these responses, we performed cytokine profiling and comprehensive, symptom-agnostic testing for respiratory viruses and bacterial pathobionts in nasopharyngeal samples from children tested for SARS-CoV-2 in 2021-22 (n = 467). Respiratory viruses and/or pathobionts were highly prevalent (82% of symptomatic and 30% asymptomatic children; 90 and 49% for children <5 years). Virus detection and load correlated with the nasal interferon response biomarker CXCL10, and the previously reported discrepancy between SARS-CoV-2 viral load and nasal interferon response was explained by viral coinfections. Bacterial pathobionts correlated with a distinct proinflammatory response with elevated IL-1β and TNF but not CXCL10. Furthermore, paired samples from healthy 1-year-olds collected 1-2 wk apart revealed frequent respiratory virus acquisition or clearance, with mucosal immunophenotype changing in parallel. These findings reveal that frequent, dynamic host-pathogen interactions drive nasal innate immune activation in children.

Doxycycline Prophylaxis to Prevent Sexually Transmitted Infections in Women

(Abstracted from N Engl J Med 2024;389:2331–2340) Around the globe, bacterial sexually transmitted infections (STIs) are increasing, with 374 million estimated annual infections of Chlamydia trachomatis, Neisseria gonorrhoeae, and Treponema pallidum. The burden of STI sequelae is disproportionately endured by women, with resulting effects such as chronic pain, pelvic inflammatory disease, ectopic pregnancy, infertility, pregnancy/fetal complications, and increased risk of human immunodeficiency virus (HIV) acquisition.

Innate protection against intrarectal SIV acquisition by a live SHIV vaccine.

Identifying immune correlates of protection is a major challenge in AIDS vaccine development. Anti-Envelope antibodies have been considered critical for protection against SIV/HIV (SHIV) acquisition. Here, we evaluated the efficacy of an SHIV vaccine against SIVmac251 challenge, where the role of antibody was excluded, as there was no cross-reactivity between SIV and SHIV envelope antibodies. After 8 low-dose intrarectal challenges with SIVmac251, 12 SHIV-vaccinated animals demonstrated efficacy, compared with 6 naive controls, suggesting protection was achieved in the absence of anti-envelope antibodies. Interestingly, CD8+ T cells (and some NK cells) were not essential for preventing viral acquisition, as none of the CD8-depleted macaques were infected by SIVmac251 challenges. Initial investigation of protective innate immunity revealed that protected animals had elevated pathways related to platelet aggregation/activation and reduced pathways related to interferon and responses to virus. Moreover, higher expression of platelet factor 4 on circulating platelet-leukocyte aggregates was associated with reduced viral acquisition. Our data highlighted the importance of innate immunity, identified mechanisms, and may provide opportunities for novel HIV vaccines or therapeutic strategy development.

Characterization and Determinants of Long-Term Immune Recovery Under Suppressive Antiretroviral Therapy.

We developed a robust characterization of immune recovery trajectories in people living with HIV on antiretroviral treatment (ART) and relate our findings to epidemiological risk factors and bacterial pneumonia. Using data from the Swiss HIV Cohort Study and the Zurich Primary HIV Infection Cohort Study (n = 5907), we analyzed the long-term trajectories of CD4 cell and CD8 cell counts and their ratio in people living with HIV on ART for at least 8 years by fitting nonlinear mixed-effects models. The determinants of long-term immune recovery were investigated using generalized additive models. In addition, prediction accuracy of the modeled trajectories and their impact on the fit of a model for bacterial pneumonia was assessed. Overall, our population showed good immune recovery (median plateau [interquartile range]-CD4: 718 [555-900] cells/μL, CD8: 709 [547-893] cells/μL, CD4/CD8: 1.01 [0.76-1.37]). The following factors were predictive of recovery: age, sex, nadir/zenith value, pre-ART HIV-1 viral load, hepatitis C, ethnicity, acquisition risk, and timing of ART initiation. The fitted models proved to be an accurate and efficient way of predicting future CD4 and CD8 cell recovery dynamics: Compared with carrying forward the last observation, mean squared errors of the fitted values were lower by 1.3%-18.3% across outcomes. When modeling future episodes of bacterial pneumonia, using predictors derived from the recovery dynamics improved most model fits. We described and validated a method to characterize individual immune recovery trajectories of people living with HIV on suppressive ART. These trajectories accurately predict long-term immune recovery and the occurrence of bacterial pneumonia.

Facilitators, Barriers, and Opportunities to Implementing Sexual History Screening and Human Immunodeficiency Virus Pre-Exposure Prophylaxis at a Federally Qualified Health Center.

Sexual history screening (SHS) is recommended to determine risk for acquisition of human immunodeficiency virus (HIV) and eligibility for pre-exposure prophylaxis (PrEP). SHS and PrEP are underutilized, sequential screening, and prevention practices. This study aimed to understand factors impacting the implementation of SHS and PrEP at a multi-site federally qualified health center (FQHC) in Connecticut. Guided by the Consolidated Framework for Implementation Research, semistructured interviews were conducted on Zoom with primary care providers (PCPs), medical assistants, clinical leadership, and PrEP navigators. Convenience and purposive sampling took place via email until thematic saturation was achieved. Thematic analysis was conducted. Twenty-two participants were interviewed for this study. PCPs lacked knowledge and reported limited or no use of SHS to determine patients' level of HIV risk, which may explain why most PCPs relied on patients to request PrEP. While PCPs perceived organizational support to prescribe PrEP, clinical staff were unaware of structural resources. Lastly, participants described a vertical trajectory of influence from external sources (policies and insurance) to time allocated to appointments that limits their ability to implement SHS and PrEP, further complicated by the electronic health record and disparities in structural resources across clinical sites. This study provides foundational evidence for future research on implementation strategies to improve HIV prevention through universal, comprehensive SHS to identify patients for PrEP. Overcoming barriers to SHS and PrEP, particularly in clinical settings such as FQHCs that care for vulnerable populations, may improve identification, prevention, and treatment of HIV and aid in ending the HIV epidemic.

Prevalence of HIV, HBV and HCV among livestock merchants and slaughterhouse workers in Ibadan, Nigeria.

Most studies on viral infections among livestock handlers have focused on occupational exposure from inadvertent contact with infected animals. Consequently, little emphasis is given to the effect of their lifestyle on the acquisition of other blood-borne viruses. To determine the prevalence and assess risk factors for HIV, HBV and HCV infections among livestock handlers in Ibadan, Nigeria. Blood samples were collected from 265 livestock handlers between October 2016 to April 2017 in Ibadan. The samples were tested for the presence of antibodies to HIV and HCV; and surface antigen to HBV using ELISA. Structured questionnaire was administered to collect information on risk factors associated with the transmission of these viruses. Data analysis was carried out using Chi-square test and logistic regression to determine the association between risk factors and predictors of infection (p < 0.05). Of 265 participants, 11 (4.2%), 29 (10.9%) and 13 (4.9%) individuals tested positive for HIV, HBV and HCV infections respectively. Two (0.8%) of the participants were coinfected with HIV and HBV while 1(0.4%) was coinfected with both HBV and HCV. Individuals who travelled frequently in the course of Livestock trades had a higher rate of HIV infection. A high Infection with HIV, HBV and HCV is common among the study participants. There is a need for continued surveillance and awareness creation on preventive measures against these viruses.

Leadership styles on job satisfaction and security among healthcare workers during the COVID-19 pandemic.

Hospitals employ many social workers, whose tasks are complicated and arduous. Quality of life assessments by healthcare professionals (HCWs) are essential for better healthcare and skillful health service delivery. HCWs have been under tremendous mental and psychological strain and at high risk of virus acquisition since the COVID-19 pandemic outbreak. This study evaluated public hospital efficiency issues and remedies in the Kingdom of Saudi Arabia. The study examined leadership styles and job satisfaction among Saudi Arabian healthcare workers (HCWs). Between September 1 and December 31, 2021, a descriptive cross-sectional investigation was conducted. During the COVID-19 pandemic, a verified web-based survey reached the appropriate sample and data was collected. A web-based self-administered survey collected demographic data, leadership style using Multifactor Leadership Questionnaire Form 6-S (MLQ-6S), and health care employee satisfaction (SEHC) from HCWs. Leadership styles affected HCW job satisfaction, according to this study. Individual concern, idealized influence, contingent compensation, and inspiring motivation were negatively correlated with work satisfaction ratings. Creating a special training programme for new leaders should cover leadership styles and approaches, the skills needed to foster a productive workplace with high-quality care, and the creation of motivated work opportunities that can boost worker engagement and satisfaction.

Preventing breast milk HIV transmission using broadly neutralizing monoclonal antibodies: One size does not fit all.

Key messages Passive immunoprophylaxis with broadly neutralizing monoclonal antibodies (bNAbs) could be a game changer in the prevention of human immunodeficiency virus (HIV) acquisition. The prevailing view is that available resources should be focused on identifying a fixed combination of at least three bNAbs for universal use in therapeutic and preventive protocols, regardless of target populations or routes of transmission. HIV transmission through breastfeeding is unique: it involves free viral particles and cell‐associated virus from breast milk and, in the case of acute/recent maternal infection, a viral population with restricted Env diversity. HIV transmission through breastfeeding in high incidence/prevalence areas could potentially be eliminated by subcutaneous administration to all newborns of one or two long‐acting bNAbs with extended breadth, high potency, and effector properties (ADCC, phagocytosis) against circulating HIV strains.

Passionfruit severe leaf distortion virus: Expanded host range, response of Passiflora spp. plants to infection and transmission by Bemisia tabaciMEAM1

AbstractPassionfruit severe leaf distortion virus (PSLDV) is a begomovirus transmitted by Bemisia tabaci Middle East‐Asia Minor 1 (MEAM1), associated with severe disease in passion flowers. This study aimed to evaluate the reaction of plants of different species of Passiflora to infection with PSLDV, expand the known host range of the virus and determine the minimum virus acquisition and inoculation access periods and the time of virus retention by B. tabaci MEAM1. Plants of Passiflora cincinnata, P. mucronata and P. malacophylla were not infected with PSLDV through transmission with B. tabaci MEAM1. When healthy plants of these species were fork grafted onto PSLDV‐infected plants of P. edulis, only plants of P. malacophylla remained uninfected and the virus was not detected by PCR, suggesting immunity to this begomovirus. Plants of Datura stramonium, Nicotiana benthamiana, N. clevelandii, N. tabacum ‘Xanthi’, Solanum lycopersicum (tomato cv. Compack) and several varieties of Manihot esculenta (cassava cvs IAC 118‐96, IAC 6‐01, Paranavaí, IAC 576, IAC 90 and IAC 14) were susceptible to infection with PSLDV through transmission with B. tabaci MEAM1. Adults of B. tabaci MEAM1 acquired PSLDV after 1 h of feeding on PSLDV‐infected plants of D. stramonium. They transmitted the virus to healthy plants after feeding on these plants for 1 h, although with low transmission rates. The retention time of PSLDV in the vector was 14 days.

D-Limonene Affects the Feeding Behavior and the Acquisition and Transmission of Tomato Yellow Leaf Curl Virus by Bemisia tabaci.

Bemisia tabaci (Gennadius) is an important invasive pest transmitting plant viruses that are maintained through a plant-insect-plant cycle. Tomato yellow leaf curl virus (TYLCV) can be transmitted in a persistent manner by B. tabaci, which causes great losses to global agricultural production. From an environmentally friendly, sustainable, and efficient point of view, in this study, we explored the function of d-limonene in reducing the acquisition and transmission of TYLCV by B. tabaci as a repellent volatile. D-limonene increased the duration of non-feeding waves and reduced the duration of phloem feeding in non-viruliferous and viruliferous whiteflies by the Electrical Penetration Graph technique (EPG). Additionally, after treatment with d-limonene, the acquisition and transmission rate of TYLCV was reduced. Furthermore, BtabOBP3 was determined as the molecular target for recognizing d-limonene by real-time quantitative PCR (RT-qPCR), fluorescence competitive binding assays, and molecular docking. These results confirmed that d-limonene is an important functional volatile which showed a potential contribution against viral infections with potential implications for developing effective TYLCV control strategies.

Correlates of Rotavirus Vaccine Shedding and Seroconversion in a US Cohort of Healthy Infants.

Rotavirus is a leading cause of severe pediatric gastroenteritis; 2 highly effective vaccines are used in the United States (US). We aimed to identify correlates of immune response to rotavirus vaccination in a US cohort. Pediatric Respiratory and Enteric Virus Acquisition and Immunogenesis Longitudinal (PREVAIL) is a birth cohort of 245 mother-child pairs enrolled in 2017-2018 and followed for 2 years. Infant stool samples and symptom information were collected weekly. Shedding was defined as reverse-transcription polymerase chain reaction detection of rotavirus vaccine virus in stools collected 4-28 days after dose 1. Seroconversion was defined as a 3-fold rise in immunoglobulin A between the 6-week and 6-month blood draws. Correlates were analyzed using generalized estimating equations and logistic regression. Prevaccination immunoglobulin G (IgG) (odds ratio [OR], 0.84 [95% confidence interval {CI}, .75-.94] per 100-unit increase) was negatively associated with shedding. Shedding was also less likely among infants with a single-nucleotide polymorphism inactivating FUT2 antigen secretion ("nonsecretors") with nonsecretor mothers, versus all other combinations (OR, 0.37 [95% CI, .16-.83]). Of 141 infants with data, 105 (74%) seroconverted; 78 (77%) had shed vaccine virus following dose 1. Prevaccination IgG and secretor status were significantly associated with seroconversion. Neither shedding nor seroconversion significantly differed by vaccine product. In this US cohort, prevaccination IgG and maternal and infant secretor status were associated with rotavirus vaccine response.

Preference of Pentalonia nigronervosa for infected banana plants tends to reverse after Banana bunchy top virus acquisition

Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae) is the vector of the Banana Bunchy Top Virus (BBTV), the most serious viral disease of banana (Musa spp.) in the world. Before acquiring the virus, the vector is more attracted to infected banana plants in response to the increased emissions of volatile organic compounds (VOCs). Here, we test the hypothesis that BBTV acquisition directly modifies the preference of P. nigronervosa for infected banana plants, and that the change in preference results from the alteration of the organs linked to the VOC detection or to the behaviour of the vector. We found that the preference of P. nigronervosa for infected banana plants reverses after virus acquisition in dessert banana, while it remains similar between healthy and infected banana plants before and after the acquisition of BBTV. At the same time, aphids reared on infected bananas had smaller forewing areas and hind tibia length than aphids reared on healthy bananas, although the number of secondary rhinaria on the antennae was lower on dessert banana-reared aphids than plantain-reared aphids, this was not affected by the infection status of the aphid. These results support the "vector manipulation hypothesis—VMH" of pathogens to promote their spread. They have implications for the BBTV management.

Overestimation of Severe Acute Respiratory Syndrome Coronavirus 2 Household Transmission in Settings of High Community Transmission: Insights From an Informal Settlement Community in Salvador, Brazil.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant has spread globally. However, the contribution of community versus household transmission to the overall risk of infection remains unclear. Between November 2021 and March 2022, we conducted an active case-finding study in an urban informal settlement with biweekly visits across 1174 households with 3364 residents. Individuals displaying coronavirus disease 2019 (COVID-19)-related symptoms were identified, interviewed along with household contacts, and defined as index and secondary cases based on reverse-transcription polymerase chain reaction (RT-PCR) and symptom onset. In 61 households, we detected a total of 94 RT-PCR-positive cases. Of 69 sequenced samples, 67 cases (97.1%) were attributed to the Omicron BA.1* variant. Among 35 of their households, the secondary attack rate was 50.0% (95% confidence interval [CI], 37.0%-63.0%). Women (relative risk [RR], 1.6 [95% CI, .9-2.7]), older individuals (median difference, 15 [95% CI, 2-21] years), and those reporting symptoms (RR, 1.73 [95% CI, 1.0-3.0]) had a significantly increased risk for SARS-CoV-2 secondary infection. Genomic analysis revealed substantial acquisition of viruses from the community even among households with other SARS-CoV-2 infections. After excluding community acquisition, we estimated a household secondary attack rate of 24.2% (95% CI, 11.9%-40.9%). These findings underscore the ongoing risk of community acquisition of SARS-CoV-2 among households with current infections. The observed high attack rate necessitates swift booster vaccination, rapid testing availability, and therapeutic options to mitigate the severe outcomes of COVID-19.