A May 8, 2026 CDC Health Alert Network advisory flagged an Andes hantavirus cluster aboard the MV Hondius cruise ship; federal agencies airlifted 17 American passengers to Offutt Air Force Base in Omaha, Nebraska for evaluation and care (CDC media release, May 8, 2026; Contagion Live, May 11, 2026). Days later, the Illinois Department of Public Health confirmed a domestically acquired Sin Nombre hantavirus case in Winnebago County. The two events drove the most-read rodent-disease US headlines of the month.
US hantavirus is not a Black-disparity story. Hantavirus pulmonary syndrome cases have concentrated in the Western states since the disease became reportable in 1993 per CDC hantavirus surveillance; Black Americans are not the disproportionately affected demographic for this disease.
The rat-borne disease US Black urban families should understand is leptospirosis, a bacterial infection that infected rats shed in urine into standing water and contaminated soil. US national surveillance documented 1,053 confirmed and probable leptospirosis cases across 34 jurisdictions between 2014 and 2020, an annual incidence of 0.48 per 100,000 population, with 85 percent of cases hospitalized and a 10 percent case-fatality rate (Atherstone et al., PLoS Neglected Tropical Diseases 2025; PMID 40845049).
The same Atherstone et al. paper (PMC12413079) documents the federal data gap that makes a US Black-specific leptospirosis disparity structurally invisible: only 202 of the 1,053 cases, 19 percent, had both race and ethnicity reported. Verbatim from the paper: "Missing and unknown data on race, ethnicity, and occupation limit the ability to identify and estimate disparities, make recommendations to improve early diagnosis and treatment, and develop prevention recommendations."
Rats shed Leptospira in urine; humans pick it up through flood water and contaminated soil
Leptospirosis is caused by Leptospira bacteria, shed in the urine of infected rats and other mammals. Humans pick up the infection through contact with contaminated water or soil after flooding, through cuts and abraded skin, or through mucous membrane exposure. The acute illness presents with fever, jaundice, calf and lower-back pain, headache, and vomiting. The severe form, Weil disease, includes acute kidney injury and pulmonary hemorrhage. The CDC estimates about 1 million cases globally per year with roughly 60,000 deaths (CDC leptospirosis general information).
The clearest evidence base for leptospirosis as a structural-housing-quality disease comes from Salvador, Brazil. A community cross-sectional study of 3,171 slum residents documented overall Leptospira antibody prevalence of 15.4 percent with a 95 percent confidence interval of 14.0 to 16.8 (Reis et al., PLoS Neglected Tropical Diseases 2008; PMC2292260). An increase of one US dollar per day in per capita household income was associated with an 11 percent decrease in infection risk, 95 percent confidence interval 5 to 18 percent. The paper documented low income and Black race as independent risk factors for seropositivity (1.25 prevalence ratio, 95 percent CI 1.03 to 1.50). Residence in flood-risk regions with open sewers, proximity to accumulated refuse, sighting rats, and presence of chickens were each environmental risk factors with prevalence ratios between 1.26 and 1.43. The Brazilian racial classification system is not directly comparable to US categories; the editorially transferable finding is the structural relationship between leptospirosis exposure and the housing-quality and sanitation-infrastructure and accumulated-refuse and flood-risk-region cluster, not the prevalence number.
Why US Black urban families face elevated leptospirosis exposure
A 2021 case-control study from the same Yale and Fiocruz research program extended the framework to the specific housing-quality features that predict leptospirosis risk independently of patient race (Costa et al., PLoS Neglected Tropical Diseases 2021; PMID 33657101). Peridomiciliar rodent burrows raised the odds of infection over three-fold (odds ratio 3.30). Rat feces 2.86. Rat runs 2.57. Households bordering abandoned houses 2.48. Unplastered walls 2.22. The predictive score the authors built and validated reached an area under the curve of 0.70 in development and 0.71 in validation.
The five housing-quality features documented in Costa 2021 (peridomiciliar burrows, rat feces, rat runs, bordering abandoned houses, unplastered walls) are the proximal exposures. In the US urban context, those features cluster disproportionately in Black tenant housing. The HUD American Housing Survey has historically documented elevated rodent-infestation rates in Black tenant housing; the 2023 AHS race-stratified rodent-infestation tabulation is the highest-priority anchor for current US disparities and is access-blocked through standard interactive query paths as of mid-May 2026. We carry the structural finding forward and will publish an Updated: addendum when the 2023 figures are retrievable through HUD media relations or direct AHS Table Creator output.
The most recent localized US increase the surveillance system has flagged is in New York City. The NYC Department of Health and Mental Hygiene issued Health Alert Network Advisory #10 in 2024 documenting 33 confirmed leptospirosis cases in 2024, up from an average of approximately 3 per year between 2001 and 2020, and 24 cases in 2023. Verbatim figures from the HAN PDF are pending direct retrieval; the triangulated case counts above are documented across Contagion Live, Science (AAAS), and ABC News coverage of the advisory.
The federal surveillance gap forecloses three downstream functions
The 81 percent of US leptospirosis cases without race-and-ethnicity capture is the binding constraint. The Atherstone et al. paper (PMC12413079) disaggregates the missing data: 582 cases (55 percent of 1,053) had missing or unknown race, 366 cases (35 percent) had missing or unknown ethnicity. Race data is more often missing than ethnicity data.
The CDC authors document what the data gap forecloses, in one verbatim sentence with three downstream-policy clauses: "Missing and unknown data on race, ethnicity, and occupation limit the ability to identify and estimate disparities, make recommendations to improve early diagnosis and treatment, and develop prevention recommendations." What the language closes off is concrete. The surveillance system cannot identify disparities. It cannot recommend treatment improvements specific to a population it does not see. It cannot develop targeted prevention recommendations for that population either.
This is the same primitive pattern that runs through the rest of this site's coverage of federal data design. The Sheps Center tracks 153 US rural-hospital closures and conversions since 2010 without a race-stratified overlay, the gap covered in our OBBBA piece on enhanced ACA subsidy rollback. The CDC leptospirosis surveillance reports a national case count and a national incidence and a 19 percent race-capture floor that holds the structural disparity question outside the picture. The shared mechanism is that federal data infrastructure designed for general-population surveillance does not capture the race-stratified outcomes that would let researchers and policymakers identify disparities. The Leptospira-shedding rat does not know the difference, but the policy response does.
CDC surveillance, Yale-Fiocruz, and Camara Jones converge on the structural-housing-quality frame
The named voices on the leptospirosis surveillance gap and the structural-housing-quality framework are concentrated at three institutions. Christine Atherstone, DVM, PhD, and Renee Galloway, DVM, MPH, both at the CDC Bacterial Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, are the lead and senior CDC voices on the US national leptospirosis surveillance dataset. Albert I. Ko, MD, the Raj and Indra Nooyi Professor of Public Health and Professor of Epidemiology (Microbial Diseases) and of Medicine (Infectious Diseases) at the Yale School of Public Health, coordinates the Yale and Fiocruz research program on social marginalization, urban ecology, climate, and the emergence of infectious disease threats in slum communities; he is senior author on the Costa 2021 predictive-score paper and a co-author on the Reis 2008 Salvador slum line of work. Camara P. Jones, MD, PhD, MPH, past president of the American Public Health Association (2016) and a former CDC medical officer who led research on social determinants of health and equity from 2000 to 2014, is the canonical national voice translating environmental and housing exposure from an individual-risk frame to a structural-racism-as-health-determinant frame.
What this evidence does not establish
The Salvador slum literature documents Black race as an independent risk factor for Leptospira seropositivity in a Brazilian context that is not directly transferable to US racial categories. The Costa 2021 housing-quality predictive score is built and validated in urban-slum populations in Brazil; the US extension is at the housing-quality-feature level (rodent burrows, rat feces, rat runs, bordering abandoned houses, unplastered walls), not at the cohort level. The Atherstone 2025 US surveillance paper documents the 81 percent race-and-ethnicity gap that prevents a US Black-specific leptospirosis incidence rate from being computed. The structural argument (housing-quality and urban-rat-density and Black-tenant-housing overlay) holds independently of the surveillance gap, but the demographic disparity number itself is the gap.
What to do this week
Three concrete actions for Black readers and Black families in US urban environments.
First, watch for leptospirosis symptoms after flood, standing-water, or rat-contact exposure: fever, jaundice, calf and lower-back pain, headache, vomiting. The severe-course warning signs are kidney decline, bleeding, and the Weil-disease triad of jaundice plus renal failure plus hemorrhage. Ask the clinician for Leptospira serology specifically if exposed and symptomatic; the CDC notes the disease is under-recognized and under-reported, so the test is rarely first-line unless you name it.
Second, document and report rat infestations through your municipal 311 or public-health portal: NYC 311, Chicago 311 (rat abatement service request), DC 311, Atlanta 311, Philadelphia 311, and the equivalent civic portal in your city. Photo evidence helps. Documentation also helps establish a paper trail if a landlord later disputes that infestation conditions existed.
Third, if you live in HUD-assisted housing (Section 8 Housing Choice Voucher tenant, public-housing tenant, project-based Section 8 tenant), you have the right under the Housing Quality Standards regime to request an HQS inspection through your local Public Housing Agency. Landlords are obligated under HQS to maintain rodent control. The HQS inspection process is underused; tenant-protection rights here are real and enforceable. Start with the HUD Tenant Resources and Rights page and your local PHA's tenant-services line.
Citations
- Reis RB, Ribeiro GS, Felzemburgh RDM, Santana FS, Mohr S, Melendez AXTO, Queiroz A, Santos AC, Ravines RR, Tassinari WS, Carvalho MS, Reis MG, Ko AI. Impact of Environment and Social Gradient on Leptospira Infection in Urban Slums. PLoS Neglected Tropical Diseases. 2008. PMC2292260.
- Costa F, Zeppelini CG, Ribeiro GS, Santos N, Reis RB, Martins RD, Hagan JE, Childs JE, Vinetz JM, Diggle PJ, Ko AI. Household rat infestation in urban slum populations: Development and validation of a predictive score for leptospirosis. PLoS Neglected Tropical Diseases. 2021. PMID 33657101.
- Atherstone C, Galloway R, Schafer I, Artus A, et al. Epidemiological, temporal, and geographic trends of leptospirosis in the United States, 2014-2020. PLoS Neglected Tropical Diseases. 2025 Aug 22;19(8):e0013427. PMID 40845049. PMC12413079.
- CDC. Leptospirosis. https://www.cdc.gov/leptospirosis/index.html.
- NYC Department of Health and Mental Hygiene. Health Alert Network Advisory #10, 2024. Triangulated case counts via Contagion Live, Science (AAAS), and ABC News coverage. Direct PDF retrieval pending.
- HUD. American Housing Survey 2023. Race-stratified rodent-infestation tabulation. https://www.census.gov/programs-surveys/ahs/data/2023.html. Direct interactive-query tabulation pending.
- Yale School of Public Health faculty profile, Albert I. Ko, MD. https://ysph.yale.edu/profile/albert-ko/.
- American Public Health Association. APHA Past Presidents. https://www.apha.org/about-apha/executive-board-and-staff/apha-executive-board/apha-past-presidents. Camara P. Jones, MD, PhD, MPH listed as 2016 president.
- Sheps Center for Health Services Research, UNC Chapel Hill. Rural Hospital Closures Data. https://www.shepscenter.unc.edu/programs-projects/rural-health/rural-hospital-closures/. 153 closures and conversions since 2010, current as of May 19, 2026.
- CDC Health Alert Network. Archive. https://www.cdc.gov/han/php/notices/index.html. May 2026 Andes hantavirus cruise-ship advisory: institutional anchor; direct advisory permalink restructured-site-restricted at the time of writing.
- CDC. Media release: CDC provides update on hantavirus outbreak linked to M/V Hondius cruise ship. May 8, 2026. https://www.cdc.gov/media/releases/2026/2026-cdc-provides-update-on-hantavirus-outbreak-linked-to-m-v-hondius-cruise-ship.html. Federal-primary anchor for the May 8 advisory date and the Offutt Air Force Base destination.
- Andes hantavirus repatriation, MV Hondius. Contagion Live, May 11, 2026. https://www.contagionlive.com/view/u-s-coordinates-medical-repatriation-of-passengers-from-cruise-ship-hantavirus-exposure.
- Illinois Department of Public Health. Hantavirus information page. https://www.illinois.gov/topics-services/diseases-and-conditions/diseases-a-z-list/diseases/hantavirus.html. Institutional anchor for the May 2026 Winnebago County Sin Nombre case.
- CDC Hantavirus general information. https://www.cdc.gov/hantavirus/index.html.
