Zoonotic Diseases in US 2025
Zoonotic diseases continue to represent a significant public health challenge across the United States in 2025, affecting thousands of Americans annually through various transmission pathways from animals to humans. These infectious diseases, which naturally spread between vertebrate animals and people, encompass a diverse range of pathogens including bacteria, viruses, parasites, and fungi. The landscape of zoonotic disease surveillance in the United States has evolved substantially, with federal agencies including the Centers for Disease Control and Prevention, the U.S. Department of Agriculture, and the Department of the Interior collaborating through the U.S. One Health Coordination Unit established in January 2024 to address these complex health threats comprehensively.
The epidemiological patterns observed throughout 2025 reveal both persistent endemic challenges and emerging threats that demand coordinated public health responses. From vector-borne illnesses transmitted by ticks and mosquitoes to foodborne pathogens acquired through contaminated animal products, zoonotic diseases affect diverse populations across rural and urban settings. The economic burden associated with these infections extends beyond direct healthcare costs to include productivity losses, outbreak response expenditures, and long-term disability expenses. Understanding the current statistical landscape of zoonotic disease incidence in the United States provides essential insights for prevention strategies, resource allocation, and policy development aimed at protecting both human and animal health through integrated surveillance and response systems.
Key Zoonotic Disease Facts and Statistics in the US 2025
| Zoonotic Disease Category | Key Statistic | Significance |
|---|---|---|
| Lyme Disease Cases | 476,000 estimated annual cases | Most common vector-borne disease in US |
| West Nile Virus | 2,000+ cases reported in 2025 | Leading cause of mosquito-borne disease |
| Rabies Deaths | 6 human deaths in 12 months | Highest annual toll in recent years |
| Plague Cases | 7 average annual cases | Persists in western US states |
| Hantavirus Infections | 864 total cases since 1993 | 35% fatality rate nationwide |
| Salmonella Infections | 1.35 million annual cases | Most common foodborne zoonotic pathogen |
| Campylobacter Infections | 1.3 million annual cases | Second most frequent foodborne illness |
| Q Fever Cases | 178-215 acute cases yearly | Underreported by factor of 12-14 |
| Brucellosis Cases | 80-140 annual reports | Occupational exposure disease |
| Foodborne Outbreaks | 160+ multistate events in 2024 | 10 million illnesses from six pathogens |
Data sources: CDC National Notifiable Diseases Surveillance System, CDC Emerging Infectious Diseases journal, CDC FoodNet surveillance, CDC Hantavirus surveillance program, CDC Vector-Borne Disease reports 2024-2025
The statistical landscape of zoonotic diseases in the United States during 2025 demonstrates the pervasive nature of animal-to-human disease transmission across multiple ecological niches and geographic regions. Lyme disease emerges as the predominant vector-borne threat with an estimated 476,000 actual infections occurring annually, though only approximately 89,000 cases receive official confirmation through surveillance systems. This substantial underreporting pattern reflects diagnostic challenges, limited healthcare access in endemic areas, and the nonspecific presentation of early-stage infections. West Nile virus maintains its position as the leading mosquito-borne illness affecting Americans, with over 2,000 confirmed cases documented in 2025 including 1,404 neuroinvasive presentations that carry significant morbidity risks. The rabies mortality statistics for the past twelve months reveal a concerning trend with 6 documented human deaths, representing an elevation above historical averages and highlighting ongoing challenges in post-exposure prophylaxis access and public awareness regarding mammalian bite risks.
Foodborne zoonotic pathogens account for the largest absolute number of illnesses annually, with Salmonella causing approximately 1.35 million infections and Campylobacter responsible for 1.3 million cases each year across the United States. These bacterial infections primarily originate from contaminated poultry, unpasteurized dairy products, and produce exposed to animal waste, generating substantial healthcare costs and productivity losses. The surveillance data for 2024-2025 documented over 160 multistate outbreak investigations coordinated by federal agencies, revealing persistent vulnerabilities in food production, processing, and handling systems. Less common but equally significant zoonotic threats include hantavirus pulmonary syndrome, which maintains a devastating 35% case-fatality rate among the 864 documented infections since surveillance began in 1993, and Q fever, which epidemiological studies suggest experiences underreporting by factors ranging from 12 to 14, indicating actual disease burdens far exceeding official statistics. These comprehensive statistics underscore the multifaceted nature of zoonotic disease challenges facing public health systems throughout 2025.
Lyme Disease Statistics in the US 2025
| Lyme Disease Metric | 2023-2025 Data | Geographic Distribution |
|---|---|---|
| Reported Cases (2023) | 89,000+ cases | 14 high-incidence states |
| Estimated Actual Cases | 476,000 annual infections | Northeast and Upper Midwest |
| Reporting Gap | 5.3x underreporting factor | Nationwide surveillance limitation |
| High-Incidence States | 14 states account for 95% | Pennsylvania, New York, New Jersey lead |
| Primary Vector | Blacklegged tick (Ixodes scapularis) | Expanding geographic range |
| Seasonal Peak | May through August | Corresponds to nymphal tick activity |
| Age Groups Affected | Bimodal distribution 5-9 and 45-54 years | Higher rates in children and older adults |
| Economic Cost | Estimated $1 billion+ annually | Healthcare and productivity losses |
| Prevention Method | Tick checks within 24 hours | 70-90% transmission risk reduction |
| Long-term Complications | 10-20% develop post-treatment symptoms | Persistent arthralgia, fatigue, cognitive issues |
Data source: CDC Lyme Disease Surveillance Program, National Notifiable Diseases Surveillance System 2023-2025
Lyme disease represents the most prevalent vector-borne infectious disease throughout the United States in 2025, with epidemiological surveillance systems documenting over 89,000 confirmed and probable cases in the most recent complete reporting year of 2023. However, comprehensive epidemiological modeling conducted by the Centers for Disease Control and Prevention reveals that actual disease incidence substantially exceeds reported figures, with an estimated 476,000 Americans contracting Lyme disease annually. This dramatic underreporting phenomenon stems from multiple factors including diagnostic limitations of current serological testing methodologies, inconsistent clinical recognition of early-stage presentations, and incomplete reporting compliance across healthcare facilities nationwide. The geographic concentration of Lyme disease remains heavily skewed toward the northeastern and upper midwestern regions, with 14 high-incidence states accounting for approximately 95% of all reported cases, led by Pennsylvania, New York, and New Jersey which consistently report the highest absolute case numbers.
The transmission dynamics of Lyme disease follow distinct seasonal patterns aligned with blacklegged tick (Ixodes scapularis) life cycle stages, with peak human infection rates occurring between May and August when nymphal ticks actively quest for blood meals in wooded and grassy environments. Age-specific incidence data demonstrates a characteristic bimodal distribution with elevated rates observed among children aged 5-9 years who frequently engage in outdoor activities in tick habitat and adults aged 45-54 years involved in recreational or occupational woodland exposures. The economic burden associated with Lyme disease in the United States exceeds $1 billion annually when accounting for direct medical costs, long-term treatment expenses for persistent symptoms, and productivity losses from missed work days. Prevention strategies emphasizing prompt tick removal within 24 hours of attachment can reduce transmission risk by 70-90%, yet public awareness and consistent implementation of protective behaviors remain suboptimal across endemic regions. Approximately 10-20% of treated patients develop post-treatment Lyme disease syndrome characterized by persistent arthralgia, profound fatigue, and cognitive difficulties that may persist for months or years beyond initial infection, representing a significant source of chronic morbidity that challenges both patients and healthcare providers throughout 2025.
Rabies Surveillance Data in the US 2025
| Rabies Indicator | 2024-2025 Statistics | Context and Trends |
|---|---|---|
| Human Deaths (12 months) | 6 documented fatalities | Highest annual total in recent years |
| Average Annual Deaths | Fewer than 10 deaths | Long-term average since 2000 |
| Animal Cases Annually | Approximately 4,000 cases | Wildlife reservoir maintenance |
| Primary Animal Reservoirs | Raccoons, skunks, bats, foxes | Geographic variation by species |
| Post-Exposure Prophylaxis | Nearly 100% effective when timely | Critical intervention for exposed individuals |
| Bat Exposures | Leading source of human rabies | Often unrecognized bite events |
| Domestic Animal Vaccination | Core requirement for dogs and cats | Primary prevention strategy |
| Incubation Period Range | 3 weeks to several months | Variable based on bite location |
| Case Fatality Rate | Nearly 100% once symptomatic | Almost universally fatal without treatment |
| Prevention Cost-Effectiveness | Post-exposure prophylaxis $3,000-7,000 | Far lower than treatment attempt costs |
Data source: CDC Rabies Surveillance in the United States 2024-2025, National Notifiable Diseases Surveillance System
Rabies surveillance data from the 2024-2025 reporting period reveals a concerning elevation in human mortality, with 6 documented deaths attributed to rabies virus infection over the preceding twelve months, representing the highest annual fatality count observed in recent surveillance years. This increase above the long-term average of fewer than 10 annual deaths nationwide highlights ongoing challenges in ensuring universal awareness of rabies risks and timely access to post-exposure prophylaxis following potential exposures. The overwhelming majority of these fatal cases involve delayed or absent medical intervention following unrecognized or underestimated animal contact events, particularly bat exposures where bite wounds may be imperceptible and victims remain unaware of potential virus transmission. Wildlife reservoirs maintain endemic rabies circulation throughout the United States with approximately 4,000 animal cases documented annually, predominantly affecting raccoons in eastern states, skunks across the central regions, bats nationwide, and foxes in southwestern territories.
The epidemiological significance of rabies in 2025 extends beyond raw case numbers to encompass the disease’s virtually 100% case-fatality rate once clinical symptoms manifest, making it among the deadliest infectious diseases known to medical science. Post-exposure prophylaxis administered promptly following suspected rabies exposures achieves nearly 100% effectiveness in preventing disease development, yet requires timely recognition of exposure risks and immediate medical consultation for assessment and treatment initiation. Bat-associated rabies cases predominate among recent human infections in the United States, as these animals can inflict minor bite wounds that escape victim notice, leading to delayed or absent prophylaxis and subsequent fatal outcomes. The incubation period for rabies typically ranges from 3 weeks to several months, though cases with incubation periods exceeding one year have been documented, creating diagnostic and prevention challenges when exposure histories remain unclear. Domestic animal vaccination programs represent the cornerstone of rabies prevention strategy, with core vaccination requirements for dogs and cats effectively eliminating canine rabies variant circulation in the United States and dramatically reducing human exposure risks from companion animals throughout 2025.
West Nile Virus Cases in the US 2025
| West Nile Virus Metric | 2025 Data | Clinical Significance |
|---|---|---|
| Total Cases (2025) | Over 2,000 infections | Provisional data through December 2025 |
| Neuroinvasive Cases | 1,404 severe presentations | Meningitis, encephalitis, acute flaccid paralysis |
| Case Fatality Rate | 3-15% among hospitalized | Higher mortality in elderly patients |
| Asymptomatic Infections | Approximately 80% of infections | Most infections produce no symptoms |
| Peak Transmission Season | July through September | Corresponds to mosquito population peaks |
| Primary Vector | Culex species mosquitoes | Widespread across continental US |
| High-Risk Populations | Adults over 60 years | Age-related severe disease risk |
| Geographic Distribution | Nationwide with state variation | Highest incidence in western states |
| Long-term Sequelae | Up to 50% of neuro cases | Persistent fatigue, cognitive deficits, weakness |
| Prevention Strategy | Mosquito bite avoidance, DEET repellents | No human vaccine available |
Data source: CDC ArboNET Surveillance System 2025, CDC West Nile Virus Activity Reports
West Nile virus maintains its status as the predominant mosquito-borne disease affecting Americans throughout 2025, with surveillance systems documenting over 2,000 confirmed cases nationwide as provisional data reporting continues through December. Among these infections, 1,404 cases presented as neuroinvasive disease manifestations including meningitis, encephalitis, or acute flaccid paralysis, representing the most severe clinical presentations associated with substantial morbidity and mortality risks. The case-fatality rate for hospitalized West Nile virus patients ranges from 3-15% depending on disease severity and patient demographic characteristics, with elderly individuals over 60 years experiencing disproportionately elevated mortality risks and higher rates of permanent neurological sequelae. Epidemiological studies indicate that approximately 80% of West Nile virus infections remain asymptomatic, with affected individuals never developing clinical manifestations requiring medical attention, suggesting actual infection rates far exceed documented case counts throughout the 2025 transmission season.
The transmission ecology of West Nile virus in the United States centers on Culex species mosquitoes that acquire the virus through blood meals from infected bird populations and subsequently transmit the pathogen to humans and other mammalian hosts during feeding events. Peak transmission activity occurs between July and September when mosquito populations reach maximum abundance and viral amplification in avian reservoirs achieves highest levels, driving elevated human infection risks during late summer and early autumn months. Geographic distribution of West Nile virus activity spans the continental United States with state-specific variation in annual incidence rates, though western states consistently report higher case counts reflecting favorable climatic conditions for vector populations and viral transmission efficiency. Among patients who survive severe neuroinvasive disease, approximately 50% experience long-term neurological complications including persistent fatigue, cognitive deficits, muscle weakness, and movement disorders that may persist for months or years beyond acute infection. Prevention strategies in 2025 emphasize mosquito bite avoidance through protective clothing, insect repellents containing DEET or picaridin, elimination of standing water breeding sites, and indoor confinement during peak mosquito activity hours, as no licensed human vaccine exists for West Nile virus prophylaxis despite ongoing research and development efforts.
Plague Epidemiology in the US 2025
| Plague Statistic | Current Data | Epidemiological Context |
|---|---|---|
| Average Annual Cases | 7 human infections | Range 0-17 cases per year |
| Geographic Distribution | Western United States exclusively | New Mexico, Arizona, Colorado lead |
| Case Types | 80%+ bubonic plague | Remaining cases septicemic or pneumonic |
| Primary Animal Reservoir | Ground squirrels, prairie dogs, rats | Flea-mediated transmission |
| Human Mortality Rate | 10-15% with treatment | Nearly 100% untreated pneumonic |
| Age Range Affected | Infants to 96 years | 50% of cases ages 12-45 |
| Seasonal Pattern | May through August peak | Historical data shows expanding season |
| Early-Season 2024 Case | January 2024 Oregon case | Earliest recorded in state history |
| Treatment Effectiveness | High success with prompt antibiotics | Streptomycin, gentamicin, doxycycline |
| Prevention Priority | Flea control on pets, rodent avoidance | DEET repellents for outdoor activities |
Data source: CDC Plague Surveillance Program 2024-2025, State Health Department Reports
Plague remains an endemic zoonotic disease in the western United States throughout 2025, with surveillance data indicating an average of 7 human cases reported annually, though yearly totals demonstrate considerable variation ranging from zero to 17 cases depending on environmental conditions, rodent population dynamics, and human exposure patterns. The geographic distribution of plague cases concentrates heavily in New Mexico, Arizona, and Colorado, accounting for the majority of infections, with additional sporadic cases occurring in California, southern Oregon, and far western Nevada where suitable rodent reservoirs and flea vectors maintain endemic transmission cycles. Bubonic plague represents over 80% of documented human cases in the United States, characterized by painful swollen lymph nodes called buboes that develop near the site of infected flea bites, while the remaining cases present as septicemic plague affecting the bloodstream or pneumonic plague involving the lungs, the latter representing the most dangerous and contagious form.
The epidemiology of plague in 2025 reveals concerning evidence of potential seasonal expansion, highlighted by an January 2024 human case in Oregon that represented the earliest calendar date of plague diagnosis in that state’s recorded history, possibly indicating shifting seasonality patterns related to climate influences on flea activity and rodent population cycles. Historically, plague transmission peaks during May through August when flea populations reach maximum abundance and outdoor human activities increase exposure opportunities, yet recent epidemiological patterns suggest that warming trends may extend the active transmission season beyond traditional temporal boundaries. The age distribution of plague cases spans from infants to individuals 96 years old, with approximately 50% of cases occurring among persons aged 12-45 years, likely reflecting increased outdoor recreational and occupational exposures in this demographic group. Mortality rates for treated plague cases range from 10-15%, demonstrating the effectiveness of prompt antibiotic therapy with agents including streptomycin, gentamicin, or doxycycline, while untreated pneumonic plague carries a case-fatality rate approaching 100%, underscoring the critical importance of rapid diagnosis and treatment initiation. Prevention strategies emphasize flea control measures for domestic pets, avoidance of sick or dead rodents and their burrows, use of DEET-containing insect repellents during outdoor activities in endemic areas, and prompt veterinary care for pets showing signs of illness in plague-endemic regions throughout 2025.
Hantavirus Pulmonary Syndrome Statistics in the US 2025
| Hantavirus Indicator | Surveillance Data | Public Health Significance |
|---|---|---|
| Total Cases Since 1993 | 864 documented infections | Comprehensive surveillance period |
| Case-Fatality Rate | 35% overall mortality | Among highest for infectious diseases |
| Geographic Concentration | 96% west of Mississippi River | Four Corners region most affected |
| Top Three States | New Mexico (122), Colorado (119), Arizona (86) | Cumulative cases 1993-2022 |
| Recent Annual Average | 20-40 cases yearly | Significant year-to-year variation |
| New Mexico 2025 Cases | 7 confirmed cases | Santa Fe, Taos, McKinley, Bernalillo counties |
| Primary Rodent Reservoir | Deer mice (Peromyscus maniculatus) | 15% carriage rate |
| Transmission Route | Inhalation of aerosolized rodent excreta | No human-to-human transmission |
| Incubation Period | 2-4 weeks (range to 8 weeks) | Delayed symptom onset |
| High-Risk Activities | Cleaning rodent-infested structures | Spring cabin opening, storage area cleaning |
Data source: CDC Hantavirus Surveillance Program 2025, National Notifiable Diseases Surveillance System, State Health Department Reports
Hantavirus pulmonary syndrome continues to pose a significant mortality threat throughout the western United States in 2025, with comprehensive surveillance data documenting 864 laboratory-confirmed cases since the disease first received recognition during the 1993 Four Corners outbreak and subsequent establishment of national surveillance systems. The case-fatality rate for hantavirus pulmonary syndrome stands at 35%, placing it among the deadliest infectious diseases affecting Americans and far exceeding mortality rates associated with most other endemic zoonotic pathogens. Geographic analysis of case distribution reveals overwhelming concentration in western states, with 96% of documented infections occurring west of the Mississippi River and the Four Corners region encompassing portions of New Mexico, Arizona, Colorado, and Utah representing the area of highest endemic activity. Cumulative case counts since surveillance initiation identify New Mexico with 122 cases, Colorado with 119 cases, and Arizona with 86 cases as the three states bearing the greatest disease burdens, reflecting optimal ecological conditions for deer mouse populations and human exposure opportunities.
Recent surveillance data from 2025 indicates that New Mexico has documented 7 confirmed hantavirus pulmonary syndrome cases during the current year affecting residents of Santa Fe, Taos, McKinley, and Bernalillo counties, maintaining the state’s historical pattern as the epicenter of hantavirus activity in the United States. The primary reservoir species for Sin Nombre virus, the predominant hantavirus strain causing human disease domestically, is the deer mouse (Peromyscus maniculatus), with approximately 15% of these rodents carrying the virus in endemic regions and shedding viral particles in their urine, feces, and saliva. Human infection occurs through inhalation of aerosolized virus particles when contaminated dust becomes airborne during activities such as cleaning rodent-infested structures, opening cabins or storage buildings after winter closure periods, or sweeping areas contaminated with rodent excreta. The incubation period for hantavirus pulmonary syndrome typically ranges from 2-4 weeks following exposure, though cases with incubation periods extending to 8 weeks have been documented, creating diagnostic challenges when exposure histories remain unclear or remote in time. Prevention strategies emphasize proper rodent exclusion from human dwellings, wet cleaning methods using disinfectants rather than sweeping or vacuuming in rodent-contaminated areas, ventilation of enclosed spaces before entry, use of respirators when cleaning heavily infested areas, and prompt medical evaluation for individuals developing fever and respiratory symptoms following recognized rodent exposures throughout 2025.
Foodborne Zoonotic Disease Burden in the US 2025
| Foodborne Pathogen | Annual Case Estimates | Key Sources and Impact |
|---|---|---|
| Salmonella Infections | 1.35 million cases annually | Leading bacterial cause, poultry, eggs |
| Campylobacter Infections | 1.3 million cases annually | Raw poultry, unpasteurized dairy |
| E. coli (STEC) Cases | 265,000 infections yearly | Ground beef, leafy greens, raw milk |
| Listeria monocytogenes | 1,600 infections, 260 deaths | Ready-to-eat meats, soft cheeses |
| Total Foodborne Illnesses | 10 million from six pathogens | Includes norovirus, C. perfringens |
| Hospitalizations | 53,300 annually | Severe cases requiring admission |
| Fatalities | 900+ deaths yearly | Predominantly elderly, immunocompromised |
| Multistate Outbreaks 2024 | 160+ investigations | CDC coordination across states |
| Economic Burden | $15.5 billion annually | Healthcare, productivity, outbreak costs |
| Peak Season | June-August (33.1% of cases) | Summer months highest risk period |
Data source: CDC FoodNet Surveillance Program 2025, National Outbreak Reporting System, CDC Foodborne Disease Surveillance 2024-2025
Foodborne zoonotic diseases represent the largest category of animal-to-human disease transmission in the United States throughout 2025, with comprehensive surveillance and modeling studies estimating approximately 10 million illnesses annually attributable to six major pathogens including Salmonella, Campylobacter, Listeria monocytogenes, Shiga toxin-producing Escherichia coli, norovirus, and Clostridium perfringens. Among bacterial zoonotic pathogens, Salmonella infections lead with an estimated 1.35 million cases occurring each year across the United States, primarily transmitted through consumption of contaminated poultry, eggs, raw milk, and produce exposed to animal feces during production or processing. Campylobacter ranks as the second most common foodborne bacterial pathogen with approximately 1.3 million annual infections, predominantly acquired through undercooked poultry consumption, unpasteurized dairy products, or cross-contamination during food preparation involving raw chicken products. The incidence rate for Campylobacter reached 23.4 cases per 100,000 population in 2024, representing an increase from 22.1 cases per 100,000 the previous year and demonstrating ongoing challenges in pathogen control throughout the food production chain.
Listeria monocytogenes, while causing relatively fewer absolute cases with approximately 1,600 infections annually, demonstrates disproportionately high mortality with an estimated 260 deaths each year, reflecting the pathogen’s particular virulence among vulnerable populations including pregnant women, neonates, elderly individuals, and immunocompromised patients. The 2024 surveillance year documented over 160 multistate foodborne outbreak investigations coordinated by the Centers for Disease Control and Prevention, revealing persistent vulnerabilities in food safety systems and highlighting the interconnected nature of modern food distribution networks that enable single contamination events to affect consumers across multiple states simultaneously. Seasonal patterns of foodborne illness demonstrate pronounced summer peaks, with 33.1% of all reported cases occurring during the June through August period in 2024, reflecting the combined effects of elevated ambient temperatures promoting bacterial proliferation, increased outdoor food preparation and consumption activities, and greater fresh produce consumption during summer months. The economic burden associated with foodborne zoonotic diseases in the United States exceeds $15.5 billion annually when accounting for direct medical costs, productivity losses from missed work, outbreak investigation and response expenditures, food industry recall costs, and long-term sequelae management for patients developing chronic complications such as reactive arthritis following Salmonella or Campylobacter infections, hemolytic uremic syndrome following STEC infections, or Guillain-Barré syndrome triggered by Campylobacter infections throughout 2025.
Q Fever Surveillance in the US 2025
| Q Fever Metric | Reported Data | True Disease Burden |
|---|---|---|
| Acute Cases (2019) | 178 reported cases | Most recent complete data year |
| Chronic Cases (2019) | 34 reported cases | 14% of total reported |
| Annual Range 2016-2018 | 164-215 cases | Year-to-year variation |
| Underreporting Factor | 12-14x actual cases | Capture-recapture analysis estimate |
| Estimated True Burden | 6,794+ cases (2000-2012) | Lower bound estimate |
| Seroprevalence US | 3.1% of population | Prior exposure prevalence |
| High-Incidence States | California, Texas, Iowa | 36% of cases from three states |
| Seasonal Peak | April-May highest incidence | Livestock birthing season correlation |
| Primary Transmission | Inhalation of contaminated aerosols | Livestock birthing products high risk |
| High-Risk Occupations | Veterinarians, farmers, meat processors | Occupational exposure predominates |
Data source: CDC Q Fever Surveillance 2019, Rickettsial Zoonoses Branch epidemiological studies, National Notifiable Diseases Surveillance System
Q fever remains a significantly underrecognized and underreported zoonotic disease in the United States throughout 2025, with the most recent complete surveillance data from 2019 documenting 178 acute Q fever cases and 34 chronic cases reported to the Centers for Disease Control and Prevention through the National Notifiable Diseases Surveillance System. However, comprehensive epidemiological analyses employing capture-recapture methodologies and seroprevalence studies indicate that actual Q fever disease burden exceeds reported figures by factors ranging from 12 to 14 times, suggesting that between 2,136 and 2,492 true cases occurred in 2019 alone rather than the 212 officially documented infections. Seroprevalence studies measuring antibodies against Coxiella burnetii, the bacterial causative agent of Q fever, detect evidence of prior infection in 3.1% of the United States population, indicating widespread subclinical or undiagnosed disease transmission occurring throughout endemic regions without generating recognized clinical cases or public health reports.
The geographic distribution of reported Q fever cases demonstrates concentration in western and Great Plains states where livestock production predominates, with California, Texas, and Iowa collectively accounting for 36% of nationally reported infections, reflecting elevated exposure opportunities among agricultural workers, veterinarians, and individuals living in proximity to cattle, sheep, and goat operations. Temporal patterns of Q fever incidence reveal distinct seasonal peaks during April and May, corresponding precisely to the spring birthing season for domestic ruminants when infectious Coxiella burnetii organisms achieve maximum concentrations in placental tissues, amniotic fluids, and birth products from infected animals. The primary transmission route involves inhalation of contaminated aerosols containing viable bacteria that can survive in environmental conditions for extended periods and remain infectious across substantial distances when transported by prevailing winds from livestock facilities. High-risk occupational groups for Q fever acquisition include veterinarians providing obstetric services to livestock, farmers and ranchers managing birthing animals, meat processing workers handling reproductive tissues, and laboratory personnel manipulating Coxiella burnetii cultures or infected animal specimens. Chronic Q fever develops in fewer than 5% of acutely infected individuals but carries significant morbidity through endocarditis affecting damaged heart valves, vascular infections of aneurysms or vascular grafts, and chronic hepatitis that may persist for years without appropriate antimicrobial therapy combining doxycycline and hydroxychloroquine for 18 months or longer in 2025.
Brucellosis Incidence in the US 2025
| Brucellosis Indicator | Current Statistics | Transmission and Risk Factors |
|---|---|---|
| Annual Case Range | 80-140 reported cases | Relatively rare in United States |
| Primary Transmission | Unpasteurized dairy consumption | Raw milk, fresh cheese from endemic areas |
| Occupational Cases | Veterinarians, slaughterhouse workers | Direct animal contact, tissue exposure |
| Geographic Sources | International travel-associated | Endemic in Mexico, Mediterranean, Middle East |
| Domestic Animal Reservoir | Cattle, bison, swine, dogs | Eradication programs reduced prevalence |
| Incubation Period | 1-4 weeks typical | May extend to several months |
| Clinical Presentation | Undulant fever, arthralgia, hepatosplenomegaly | Nonspecific symptoms delay diagnosis |
| Chronic Complications | Endocarditis, spondylitis, neurobrucellosis | Untreated mortality 2% |
| Treatment Duration | 6-8 weeks combination therapy | Doxycycline plus rifampin or streptomycin |
| Laboratory Diagnosis | Blood culture, serology | Specialized biosafety requirements |
Data source: CDC Brucellosis Surveillance Program 2024-2025, National Notifiable Diseases Surveillance System
Brucellosis maintains a relatively low but persistent presence in the United States during 2025, with annual case reports typically ranging between 80 and 140 documented infections, reflecting the success of decades-long animal eradication programs that have dramatically reduced Brucella species prevalence in domestic livestock populations compared to historical baseline periods. The primary transmission pathway for human brucellosis cases in the contemporary United States involves consumption of unpasteurized dairy products including raw milk and fresh cheeses, particularly items imported from or consumed during travel to brucellosis-endemic regions including Mexico, Mediterranean countries, the Middle East, and parts of Central Asia where livestock infection rates remain elevated and dairy pasteurization practices vary.
Disclaimer: The data research report we present here is based on information found from various sources. We are not liable for any financial loss, errors, or damages of any kind that may result from the use of the information herein. We acknowledge that though we try to report accurately, we cannot verify the absolute facts of everything that has been represented.
