About

Justin Remais, PhD, is a Professor and Chair of the Division of Environmental Health Sciences at the University of California, Berkeley. He is also an affiliated faculty member of the Energy and Resources Group at UC Berkeley. His professional contact information includes an email and phone number, and his office is located at Berkeley Way West, Office 5301. The page primarily lists members of the Remais Lab, including postdoctoral fellows, graduate students, and previous lab members, but does not provide detailed information about his research focus, background, or key contributions.

Research topics

• Medicine
• Environmental health
• Pathology
• Immunology
• Ecology
• Internal medicine
• Intensive care medicine
• Biology

Selected publications

• Epidemiology of Aspergillosis Diagnoses in US Adults Using a National EHR Database, 2013–2023

  Open Forum Infectious Diseases · 2026-02-25

  articleOpen accessSenior author

  Background: Aspergillosis is a fungal infection associated with rising hospitalizations and substantial morbidity and mortality. In the United States, data remain fragmented due to the absence of centralized surveillance. This study aimed to evaluate demographic, geographic, and temporal trends in aspergillosis diagnoses across the United States and evaluate changes in those patterns following the emergence of COVID-19. Methods: We conducted a retrospective cohort study using electronic health record data from 142 US healthcare systems (Oracle Health), including adults aged ≥18 years who received care between 2013 and 2023. The cohort included over 76 million patients and 127 million person-years. Aspergillosis prevalence was calculated using post-stratification weights. Adjusted prevalence ratios (aPRs) were estimated via quasi-Poisson and Bayesian spatiotemporal regression. COVID-19-related shifts were evaluated using estimated marginal means. Results: From 2013 to 2023, aspergillosis prevalence increased by 5% annually, peaking in 2022. Rhode Island had the highest state-level aPR; Utah the lowest. Diagnosis was higher among males (aPR 1.37), older adults (≥65 years vs 18-24 years: aPR 4.95), and urban residents (rural aPR 0.86). Following the emergence of COVID-19, prevalence increased disproportionately among Hispanic or Latino patients and several racial minority groups. A nonsignificant upward trend was also observed among rural residents. Conclusions: This study provides a comprehensive national assessment of aspergillosis diagnosis patterns in the United States, revealing rising prevalence and shifts in affected populations following the emergence of COVID-19. These findings may aid earlier clinical recognition, especially among groups not traditionally considered high-risk, and support efforts to expand diagnostic access and improve fungal disease surveillance.

  PublisherDOI

• Regional Increases in Incidence of Coccidioidomycosis (Valley Fever) — Arizona, 2005–2022

  MMWR Morbidity and Mortality Weekly Report · 2026-02-19 · 1 citations

  articleOpen access

  Incidence of coccidioidomycosis (Valley fever), a fungal infection caused by inhalation of Coccidioides species spores, has increased substantially across the southwestern United States in association with increasing aridity, warming temperatures, and precipitation volatility.Arizona and California report >95% of U.S. coccidioidomycosis cases, and incidence in Arizona has increased statewide.Patterns within Arizona's distinct climatological regions have not been characterized, especially in regions outside the known zone of persistently high levels of disease occurrence (hyperendemicity) in the southwest Sonoran Desert region.In this study, surveillance data reported to the Arizona Department of Health Services since 2005 were used to calculate coccidioidomycosis incidence within six ecological regions.During 2005-2022, annual incidence approximately doubled in Arizona, with >95% of cases reported from the Sonoran Desert region.Although the Plateaus and Mojave Desert regions (in the northern parts of the state) reported <1.5% of Arizona cases during this period, these regions experienced the highest relative increases in incidence from the 2005-2007 period to the 2020-2022 period.During 2020-2022, coccidioidomycosis incidence in the Plateaus region was 6.61 times the incidence during 2005-2007 (95% CI = 4.22-10.30),and in the Mojave Desert region, incidence was 4.50 times that during 2005-2007 (95% CI = 3.45-5.89).The Plateau and Mojave regions also reported the highest relative increases in incidence from the 2014-2016 period to the 2020-2022 period.Large relative incidence increases in northern regions, including cooler and wetter regions generally considered less suitable for Coccidioides species establishment and transmission, necessitate targeted public health messaging in these areas and support ongoing investigation into the causes of these increases.* Based on the earliest date among the following: symptom onset, specimen collected for laboratory testing, laboratory test results finalized for a specimen, diagnosis, case reported to the county, entered into the Medical Electronic Disease Surveillance Intelligence System (MEDSIS), reported to ADHS, or submitted to the state.Event date definitions are outlined in Arizona Department of Health Services' User Training Guide | MEDSIS.

  PublisherOA PDFDOI

• Urban soils along the Kern River and Los Gatos Creek are hotspots for <i>Coccidioides</i> in the San Joaquin Valley of California

  bioRxiv (Cold Spring Harbor Laboratory) · 2026-01-16

  articleOpen access

  Abstract Coccidioidomycosis (Valley fever) is acquired through inhalation of spores produced by fungi in the genus Coccidioides . Coccidioides is commonly detected in, and cultivated from, the lung tissue of native rodents and the soils within their burrows. Coccidioidomycosis is acquired by exposure to environmentally produced spores and is not spread between hosts. Thus, determining the location of rodent burrows with soils harboring Coccidioides will be critical for understanding coccidioidomycosis incidence and modelling how Coccidioides distributions will be affected by global change. Coccidioides is readily detected in rodent burrows on undisturbed land, has not been detected on agricultural land, and is unstudied on urban land. To test the hypothesis that Coccidioides is in urban soil, we sampled rodent burrow soils from the banks of two water ways, the Kern River and Los Gatos Creek, which transect two cities, Bakersfield and Coalinga, in the San Joaquin Valley of California. To test the hypothesis that Coccidioides would not be detected at higher elevations, we extended our sampling of rodent burrows along waterways into the mountains of California. From 1178 soil and settled dust samples, we find that Coccidioides is found in urban riparian environments in Bakersfield and Coalinga, on riparian land on the floor of the San Joaquin Valley but not at higher elevations and is negatively correlated with modeled soil moisture. Coccidioides shows significant co-occurrence patterns with animal-associated fungal taxa, but no broader relationships with the greater fungal community. Our results warrant caution when excavating urban rodent burrows in the region. Author Summary Coccidioidomycosis, or Valley fever, is caused by a fungus that primarily infects people when its spores become airborne and are inhaled. Although the fungus is found in the burrows of rodents, its presence in cities has been unclear. We investigated whether urban environments in California’s San Joaquin Valley, an area with high Valley fever incidence, harbor the fungus. By sampling more than a thousand soils and settled dust samples along riparian areas (waterways and adjacent environments) in Bakersfield and Coalinga, we found that the fungus that causes Valley fever, Coccidioides, occurs in urban riparian zones. The fungus was restricted to low elevations and was more likely to be detected in drier soils. We also compared positive and negative soils using DNA-based surveys of fungi. While the broader fungal community showed no strong relationship to Coccidioides , several species tied to animal activity were more common in positive samples, supporting a link to rodent hosts. These findings show that urban waterways can serve as habitat for Coccidioides . Because these areas lie within major population centers, identifying and avoiding disturbance of rodent burrows may reduce exposure risk, and future models of Valley fever should account for riparian corridors and local ecological conditions.

  PublisherOA PDFDOI

• A comparative analysis estimating aspergillosis and histoplasmosis encounters among inpatients in the United States using multi-regional electronic health record and National Discharge Data, 2014-2020

  AJE Advances Research in Epidemiology · 2026-04-01

  articleOpen accessSenior author

  Abstract Fungal diseases are an emerging public health threat, yet their epidemiology remains poorly understood due to limited surveillance. Electronic health record (EHR) datasets offer opportunities for studying fungal diseases, but their national representativeness is unclear. We compared inpatient encounters for aspergillosis and histoplasmosis between Oracle EHR Real World Data (OERWD) and the Healthcare Cost and Utilization Project National Inpatient Sample (HCUP NIS), a nationally representative discharge-derived database. We analyzed inpatient encounters from both databases and applied calibration weights to OERWD to improve alignment with national benchmarks. Relative differences (RDs) in encounter counts were compared using Wald tests. Survey-weighted quasibinomial models estimated prevalence and 95% CIs; temporal trends were evaluated with Mann–Kendall tests. Dataset differences were assessed using interaction terms between a dataset indicator and demographic or geographic subgroups. OERWD had fewer total and disease-specific encounters than HCUP NIS. Weighting improved precision, and prevalence estimates did not differ significantly for most strata (31 of 42), indicating broad agreement in demographic and geographic distributions. Both datasets showed higher aspergillosis prevalence in the Pacific division and higher histoplasmosis prevalence in the East South Central division, with males and older adults consistently exhibiting higher prevalence. These findings indicate that, while HCUP NIS is optimal for nationally representative prevalence estimates, weighting EHR-derived data can reproduce key demographic and geographic prevalence patterns observed in national benchmarks. Benchmarking EHR-derived estimates against national standards represents an important step toward establishing their representativeness and supporting future studies leveraging EHR data to investigate fungal disease epidemiology in greater clinical detail.

  PublisherOA PDFDOI

• Use of Dog Serologic Data for Improved Understanding of Coccidioidomycosis: A One Health Approach

  SSRN Electronic Journal · 2025-01-01

  preprintOpen accessSenior author
  PublisherDOI

• Prolonged coccidioidomycosis transmission seasons in a warming California: a Markov state transition model of shifting disease dynamics

  Journal of The Royal Society Interface · 2025-02-01 · 5 citations

  articleOpen accessSenior author

  Coccidioidomycosis, an emerging fungal disease in the southwestern United States, exhibits pronounced seasonal transmission, yet the influence of current and future climate on the timing and duration of transmission seasons remains poorly understood. We developed a distributed-lag Markov state transition model to estimate the effects of temperature and precipitation on the timing of transmission season onset and end, analysing reported coccidioidomycosis cases ( n = 72 125) in California from 2000 to 2023. Using G-computation substitution estimators, we examined how hypothetical changes in seasonal meteorology impact transmission season timing. Transitions from cooler, wetter conditions to hotter, drier conditions were found to significantly accelerate season onset. Dry conditions (10th percentile of precipitation) in the spring shifted season onset an average of 2.8 weeks (95% CI: 0.43–3.58) earlier compared with wet conditions (90th percentile of precipitation). Conversely, transitions back to cooler, wetter conditions hastened season end, with dry autumn conditions extending the season by an average of 0.69 weeks (95% CI: 0.37–1.41) compared with wet conditions. When dry conditions occurred in the spring and autumn, the transmission season extended by 3.70 weeks (95% CI: 1.23–4.22). With prolonged dry seasons expected in California with climate change, our findings suggest this shift will extend the period of elevated coccidioidomycosis risk.

  PublisherOA PDFDOI

• Use of Dog Serologic Data for Improved Understanding of Coccidioidomycosis: A One Health Approach

  The Journal of Infectious Diseases · 2025-04-08 · 2 citations

  articleOpen accessSenior author

  BACKGROUND: Coccidioidomycosis (Valley fever) occurs when animals and humans inhale spores of Coccidioides spp, soil-dwelling fungi of the southwestern United States (US). The spatial epidemiology of coccidioidomycosis is poorly understood due to irregular detection of Coccidioides in soil, disease underdiagnosis, and lack of nationwide mandatory reporting. Data on seroreactivity to Coccidioides among dogs-which are highly susceptible to coccidioidomycosis, widespread across the US, and have limited travel-may strengthen our understanding human disease risk. METHODS: We analyzed serologic test results for 834 899 dogs between 2012 and 2022 from all known diagnostic laboratories conducting serologic testing for anti-Coccidioides antibodies in dogs in the US. We used testing date and county-level location data to estimate spatial and temporal trends in incidence and test positivity for dogs and compared them to human surveillance data. RESULTS: The overall seropositivity rate among tested dogs was 37.6% (313 829/834 899). Average test positivity rates in states with ≥0.5 tests per annum per 10 000 households were 35.4% (Texas) to 74.1% (Montana). For these states, average annual incidence per 10 000 households was as follows: Arizona (86.8), New Mexico (0.89), Nevada (0.78), California (0.75), Montana (0.63), Colorado (0.41), Oregon (0.41), Texas (0.38), Idaho (0.37), Wyoming (0.34), Utah (0.32), and Washington (0.26). Human incidence in California and Arizona between 2012 and 2022 was significantly correlated with dog incidence (ρ = 0.75 and ρ = 0.65, respectively). The distribution of seropositive dogs expanded from 76 of 3144 counties (2.4%) in 2012 to 390 in 2022 (12.4%). CONCLUSIONS: Further investment in human diagnostic infrastructure and provider knowledge may ameliorate significant underrecognition of this emerging fungal disease.

  PublisherOA PDFDOI

• Climate warming and urbanization may expand dengue transmission risk in California

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-11-16

  preprintOpen access

  Abstract Background While primarily a disease of tropical and subtropical regions, dengue outbreaks are increasing in non-endemic regions due to environmental change and increasing travel and trade. For these non-endemic regions, estimating the risk of dengue is challenging as transmission is driven by both local environmental conditions and the introduction of viremic travelers. In this study, we aimed to estimate current and future dengue risk in California, USA—a region that has recently experienced its first cases of locally-acquired dengue. Methods We modeled dengue risk as the product of three key components needed for local transmission—vector presence, temperature-suitability for pathogen transmission, and viral introductions via travel-associated cases—estimated using vector and case surveillance, sociodemographic, and environmental data. We estimated risk for locations and months where local transmission was reported in 2023-2024 to define a ‘threshold’ level of risk. We then projected monthly, census tract-level risk under both current conditions and future scenarios of climate warming and urban expansion. Findings Approximately 18.2 million (95% CI: 17.9-18.3) California residents—primarily in the Central Valley and the Los Angeles and San Diego metropolitan areas—currently live in areas where peak monthly dengue risk exceeds levels estimated during observed local transmission. Under moderate scenarios of climate warming and urban expansion, an additional 4.1 million (95% CI: 3.7-4.6) California residents may be at risk by mid-century, with the largest increase in risk estimated for September and for the Sacramento Valley and coastal southern California regions. Outside the summer months and beyond the Central Valley and southern California, current and future risk remains low due to one or more major bottlenecks to transmission. Interpretation Our study identifies the specific regions and months conducive to dengue transmission in the non-endemic setting of California. At present, this covers a substantial portion of the state and is projected to expand under on-going climate warming and urbanization. Our results underscore the need for sustained vector control, and timely detection and management of travel-associated cases. Research in Context Evidence before this study Dengue is considered endemic in over 125 countries and rapidly expanding its range, aided by climate warming, urbanization, and global travel and trade. Estimating transmission risk in newly emerging regions is critical for public health preparedness and depends on both local environmental conditions and the introduction of viremic travelers. We searched PubMed from database inception to May 8, 2025, for articles published in English using search terms “dengue”, “model”, “non-endemic”, and their common textual variants. We identified 75 relevant studies modeling dengue transmission risk in non-endemic settings. However, nearly all were focused on one or two major determinants of transmission (eg, climate, vector population dynamics, or case importations) and/or did not include future projections. We found no studies that developed and validated a model of dengue transmission risk in non-endemic settings that incorporated vector, pathogen, and human suitability factors, and applied this model to project future risk. Added value of this study This study provides a novel approach to model dengue transmission risk in emerging regions that integrates the major factors driving transmission—vector presence, temperature suitability, and travel-associated cases. We apply this model to California—an emerging center of transmission risk in the continental USA—to identify the times and regions where risk exceeds levels observed during recent local transmission. We found that approximately 18.2 million California residents may be at risk based on this threshold, with an additional 4.1 million potentially at risk by mid-century under a moderate scenario of warming and urban expansion. Implications of all the available evidence Our study identifies the hotspots of dengue transmission risk at a fine spatial and temporal resolution (census tract, month) in a highly populous and globally-connected region of emerging dengue risk. These risk estimates, and the regionally-specific bottlenecks to transmission that we identify can inform targeted disease surveillance and prevention strategies. Further, our findings have implications for other emerging regions including the southern USA and southern Europe, suggesting that the risk of local dengue transmission may increase under ongoing climate warming, urbanization, and global travel.

  PublisherOA PDFDOI

• Recent and Forecasted Increases in Coccidioidomycosis Incidence Linked to Hydroclimatic Swings, California, USA

  Emerging infectious diseases · 2025-03-18 · 12 citations

  articleOpen access

  In 2023, California reported near-record high coccidioidomycosis cases after a dramatic transition from drought to heavy precipitation. Using an ensemble model, we forecasted 12,244 cases statewide during April 1, 2024-March 31, 2025, a 62% increase over cases reported 2 years before and on par with case counts for 2023.

  PublisherDOI

• Estimating the Exposure–Response Relationship between Fine Mineral Dust Concentration and Coccidioidomycosis Incidence Using Speciated Particulate Matter Data: A Longitudinal Surveillance Study

  Environmental Health Perspectives · 2025-01-01 · 12 citations

  articleOpen access

  BACKGROUND: spp. spores, is an emerging infectious disease that is increasing in incidence throughout the southwestern US. The pathogen is soil-dwelling, and spore dispersal and human exposure are thought to co-occur with airborne mineral dust exposures, yet fundamental exposure-response relationships have not been conclusively estimated. OBJECTIVES: We estimated associations between fine mineral dust concentration and coccidioidomycosis incidence in California from 2000 to 2017 at the census tract level, spatiotemporal heterogeneity in exposure-response, and effect modification by antecedent climate conditions. METHODS: We acquired monthly census tract-level coccidioidomycosis incidence data and modeled fine mineral dust concentrations from 2000 to 2017. We fitted zero-inflated distributed-lag nonlinear models to estimate overall exposure-lag-response relationships and identified factors contributing to heterogeneity in exposure-responses. Using a random-effects meta-analysis approach, we estimated county-specific and pooled exposure-responses for cumulative exposures. RESULTS: (95% CI: 1.04, 1.12)] months before estimated disease onset, with the highest exposures being particularly associated. The cumulative exposure-response relationship varied significantly by county [lowest IRR, western Tulare: 1.05 (95% CI: 0.54, 2.07); highest IRR, San Luis Obispo: 3.01 (95% CI: 2.05, 4.42)]. Season of exposure and prior wet winter were modest effect modifiers. DISCUSSION: Lagged exposures to fine mineral dust were strongly associated with coccidioidomycosis incidence in the endemic regions of California from 2000 to 2017. https://doi.org/10.1289/EHP13875.

  PublisherDOI

Recent grants

• EAGER: Collaborative Research: Rapid Production of Geospatial Network Inputs for Spatially Explicit Epidemiological Modeling of COVID-19 in the USA

  NSF · $50k · 2020–2021

• RAPID: Flood-related pathogen risk models appropriate for low resource settings

  NSF · $50k · 2012–2014

• Integrating epidemiologic and environmental approaches to understand and predict Coccidioides exposure and coccidioidomycosis emergence

  NIH · $4.5M · 2019–2025

• Models for improving surveillance of environmentally-mediated infectious diseases

  NIH · $643k · 2011–2017

• Analytical methods for estimating the joint climatological-social drivers of water quality and supply in contrasting tropical zones: Ecuador and China

  NSF · $2.3M · 2014–2016

Frequent coauthors

• Susanne H. Sokolow

  52 shared

• Giulio A. De Leo

  Stanford University

  50 shared

• Philip A. Collender

  University of California, Berkeley

  39 shared

• Christopher M. Hoover

  38 shared

• Jennifer R. Head

  University of Michigan–Ann Arbor

  35 shared

• Gilles Riveau

  35 shared

• Jason R. Rohr

  University of Notre Dame

  27 shared

• Isabel J. Jones

  27 shared

Labs

• REMAIS LAB @ BERKELEYPI

  Environmental Health Sciences

Education

• PhD, Environmental Health Sciences

  University of California, Berkeley

• MS, Civil and Environmental Engineering

  University of California, Berkeley