Priority Pathogens

Overview

This novel coronavirus emerged in late 2019 and caused a global pandemic with unprecedented impact. It has infected over 760 million people and caused roughly 6.9 million reported deaths worldwide as of 2023, making it one of the deadliest outbreaks in modern history.

Impact

• Public Health: Global health crisis with millions of cases and deaths
• Healthcare: Strained healthcare systems worldwide
• Economy: Major economic disruptions and recessions
• Society: Changes in social behavior and public gatherings
• Travel: Severe restrictions on international travel
• Mortality: Over 6.9 million reported deaths (2023)

Overview

Filoviridae is a family of filamentous, enveloped, negative-sense RNA viruses that includes some of the most virulent human pathogens known. The most notable members are Ebola virus and Marburg virus, which cause severe hemorrhagic fevers with extremely high mortality rates. The name "filo" comes from the Latin word for "thread" or "filament," referring to their distinctive filamentous structure.

Filoviridae has been designated as a prototype pathogen family for pandemic preparedness research by the National Institute of Allergy and Infectious Diseases (NIAID). As part of the NIAID-funded Research and Development of Vaccines and Monoclonal Antibodies for Pandemic Preparedness (ReVAMPP) project, this viral family was prioritized due to its significant potential for causing outbreaks and public health emergencies. NIAID selected virus families of concern with insufficient research, inadequate medical countermeasures, and low to moderate historical support.

Impact

• Human Health: Causes severe hemorrhagic fevers with mortality rates ranging from 25% to 90%
• Outbreaks: Multiple outbreaks in Africa with the largest occurring in West Africa (2014-2016)
• Healthcare Systems: Outbreaks can overwhelm local healthcare systems and require international response
• Biosecurity: Classified as biosafety level 4 pathogens requiring maximum containment
• Research: Significant focus on vaccine and therapeutic development
• Zoonotic Potential: Natural reservoir believed to be certain bat species

Overview

Tuberculosis (TB) is a centuries-old pathogen that remains one of the leading causes of infectious death globally. In 2021 alone, an estimated 10.6 million people fell ill with TB and 1.6 million died from it, a toll only recently eclipsed by COVID-19. Drug-resistant TB strains are an increasing concern, with ~450,000 new cases of rifampicin-resistant TB in 2021.

Impact

• Public Health: Leading cause of infectious death globally
• Healthcare: Significant burden on healthcare systems
• Mortality: 1.6 million deaths in 2021
• Drug Resistance: ~450,000 new cases of rifampicin-resistant TB annually
• HIV Synergy: Increased risk in HIV-positive individuals

Overview

Aspergillus molds are ubiquitous in the environment and cause a range of diseases, from allergies to deadly invasive infections. A. fumigatus is the most common cause of invasive aspergillosis in immunosuppressed patients.

Impact

• Public Health: ~1.5 million deaths annually from serious fungal diseases, including invasive aspergillosis
• Mortality: Invasive pulmonary aspergillosis has ~50% mortality even with treatment
• Geography: Global distribution with significant impact in healthcare settings
• Antifungal Resistance: Emerging resistance complicates treatment
• Toxins: A. flavus produces aflatoxin, contributing to liver cancer risk

Overview

Candidozyma auris (formerly Candida auris) is an emerging multidrug-resistant fungus that has caused hospital outbreaks worldwide. Identified in 2009, it has spread to dozens of countries and is difficult to eradicate in healthcare settings.

Impact

• Public Health: Rapidly increasing cases globally
• Healthcare: Major infection control challenge in hospitals
• Mortality: Over 1 in 3 patients with bloodstream infection die
• Drug Resistance: Often resistant to multiple antifungal drugs
• Growth: U.S. infections jumped from 173 in 2017 to 2,377 in 2022

Overview

Coccidioides posadasii causes coccidioidomycosis, known as Valley Fever, a respiratory disease endemic in the arid Americas (southwestern US, parts of Latin America). Infection is acquired by inhaling airborne fungal spores from soil.

Impact

• Public Health: Significant impact in endemic areas
• Geography: Endemic in southwestern US and parts of Latin America
• Severity: Can lead to severe pneumonia or disseminated disease
• Growth: California cases tripled from 2014 to 2018 (7,000-9,000 cases annually)
• Climate Impact: Range and incidence expanding due to climate change

Overview

Cryptococcus neoformans is a leading cause of deadly meningitis in immunocompromised individuals, especially those with advanced HIV/AIDS. It causes an estimated ~220,000 new cases of cryptococcal meningitis each year, resulting in about 181,000 deaths – roughly 15% of all AIDS-related deaths globally.

Impact

• Public Health: Leading cause of meningitis in immunocompromised individuals
• Healthcare: Significant burden on healthcare systems
• Mortality: ~181,000 deaths annually
• HIV Impact: Major cause of AIDS-related deaths
• Geography: Highest burden in sub-Saharan Africa

Overview

Flaviviridae is a family of positive-sense, single-stranded RNA viruses that includes numerous important human pathogens. Notable members include dengue virus, Zika virus, yellow fever virus, West Nile virus, and hepatitis C virus. Many flaviviruses are arthropod-borne (arboviruses), primarily transmitted by mosquitoes or ticks, while others like hepatitis C are transmitted through blood and other body fluids.

Flaviviridae has been designated as a prototype pathogen family for pandemic preparedness research by the National Institute of Allergy and Infectious Diseases (NIAID). As part of the NIAID-funded Research and Development of Vaccines and Monoclonal Antibodies for Pandemic Preparedness (ReVAMPP) project, this viral family was prioritized due to its significant potential for causing outbreaks and public health emergencies. NIAID selected virus families of concern with insufficient research, inadequate medical countermeasures, and low to moderate historical support.

Impact

• Human Health: Causes a wide range of diseases from mild febrile illness to severe hemorrhagic fever, encephalitis, and chronic liver disease
• Geographic Distribution: Worldwide, with many members endemic to tropical and subtropical regions
• Vectors: Many members transmitted by mosquitoes (Aedes and Culex species) or ticks
• Emerging Threats: Several members have caused major outbreaks in recent decades (Zika, dengue, West Nile)
• Economic: Significant healthcare costs and productivity losses
• Chronic Disease: Hepatitis C is a leading cause of liver cirrhosis and cancer worldwide

Overview

Histoplasma capsulatum is a soil-based fungus (often associated with bird or bat droppings) that causes histoplasmosis when its spores are inhaled. It is endemic in parts of North America (Ohio/Mississippi River valleys), Latin America, Asia, and Africa.

Impact

• Geography: Endemic in multiple continents
• Severity: Can cause acute pulmonary infection or disseminated disease
• HIV Impact: Major cause of death in HIV-positive patients
• Mortality: 50-80% mortality in AIDS-associated cases without proper therapy
• Treatment: Requires antifungal therapy like liposomal amphotericin B

Overview

Paramyxoviridae is a family of enveloped, negative-sense RNA viruses that includes several significant human and animal pathogens. Notable members include measles virus, mumps virus, respiratory syncytial virus (RSV), parainfluenza viruses, and the highly virulent Nipah and Hendra viruses. These viruses are responsible for a range of respiratory and systemic diseases in humans and animals.

Paramyxoviridae has been designated as a prototype pathogen family for pandemic preparedness research by the National Institute of Allergy and Infectious Diseases (NIAID). As part of the NIAID-funded Research and Development of Vaccines and Monoclonal Antibodies for Pandemic Preparedness (ReVAMPP) project, this viral family was prioritized due to its significant potential for causing outbreaks and public health emergencies. NIAID selected virus families of concern with insufficient research, inadequate medical countermeasures, and low to moderate historical support.

Impact

• Human Health: Causes widespread respiratory illnesses, childhood diseases, and emerging zoonotic infections
• Vaccination: Several members are targets of routine childhood vaccination programs
• Mortality: Measles remains a leading cause of vaccine-preventable childhood mortality globally
• Emerging Threats: Nipah and Hendra viruses have high mortality rates and pandemic potential
• Economic: Significant healthcare costs associated with respiratory infections
• Public Health: Requires ongoing surveillance and vaccination campaigns

Overview

Plasmodium falciparum causes the most lethal form of malaria, a disease that remains a massive global burden especially in sub-Saharan Africa. In 2021, there were over 247 million malaria cases worldwide and about 619,000 deaths, mostly in young children.

Impact

• Public Health: Leading cause of childhood mortality in endemic regions
• Healthcare: Significant economic impacts
• Mortality: ~619,000 deaths annually
• Geography: Highest burden in sub-Saharan Africa
• Economic Impact: Major economic burden in affected regions

Overview

Cryptosporidium is a protozoan parasite that causes diarrheal illness, which can be severe in young children and immunocompromised individuals. It spreads through waterborne transmission, with oocysts that are resistant to chlorine.

Impact

• Public Health: Leading cause of waterborne diarrheal outbreaks in the U.S.
• Child Health: Major contributor to child mortality and malnutrition
• Geography: Global distribution with significant impact in developing regions
• Severity: Can cause chronic, life-threatening diarrhea in immunocompromised individuals
• Treatment: Limited treatment options (nitazoxanide with variable efficacy)

Overview

Hantaviridae is a family of viruses primarily but not exclusively carried by rodents. These viruses can cause severe and sometimes fatal diseases in humans, including Hantavirus Pulmonary Syndrome (HPS) and Hemorrhagic Fever with Renal Syndrome (HFRS). Unlike many other viral families, hantaviruses are not transmitted between humans but are primarily spread through contact with infected rodent urine, droppings, or saliva.

Hantaviridae has been designated as a prototype pathogen family for pandemic preparedness research by the National Institute of Allergy and Infectious Diseases (NIAID). As part of the NIAID-funded Research and Development of Vaccines and Monoclonal Antibodies for Pandemic Preparedness (ReVAMPP) project, this viral family was prioritized due to its significant potential for causing outbreaks and public health emergencies. NIAID selected virus families of concern with insufficient research, inadequate medical countermeasures, and low to moderate historical support.

Impact

• Human Health: Causes severe respiratory disease (HPS) in the Americas and kidney disease (HFRS) in Europe and Asia
• Mortality: HPS has a mortality rate of approximately 38%
• Geographic Distribution: Worldwide, with specific viruses endemic to particular regions
• Reservoir Hosts: Primarily carried by specific rodent species with long-term infections
• Public Health: Requires significant prevention efforts in endemic areas

Overview

Mpox, formerly known as monkeypox, is a viral zoonotic disease caused by the mpox virus. Historically, it caused sporadic outbreaks in Central and West African countries. In 2022, it emerged as a large multinational outbreak, growing from a handful of cases to over 80,000 confirmed cases across more than 100 countries by late 2022. This prompted the WHO to declare a Public Health Emergency.

Impact

• Public Health: Global outbreak with cases in multiple countries
• Healthcare: Increased demand for diagnostic testing and treatment
• Community: Disproportionate impact on certain populations
• Travel: Enhanced screening at international borders
• Mortality: Case-fatality rate <0.1% in non-endemic countries (2022), ~10% in Africa for more virulent clades

Overview

Nairoviridae is a family of arthropod-borne viruses that includes several important human and animal pathogens. The most notable member is Crimean-Congo hemorrhagic fever virus (CCHFV), which causes severe hemorrhagic disease in humans. These viruses are characterized by their segmented, negative-sense RNA genomes and transmission primarily through tick vectors.

Nairoviridae has been designated as a prototype pathogen family for pandemic preparedness research by the National Institute of Allergy and Infectious Diseases (NIAID). As part of the NIAID-funded Research and Development of Vaccines and Monoclonal Antibodies for Pandemic Preparedness (ReVAMPP) project, this viral family was prioritized due to its significant potential for causing outbreaks and public health emergencies. NIAID selected virus families of concern with insufficient research, inadequate medical countermeasures, and low to moderate historical support.

Impact

• Human Health: Crimean-Congo hemorrhagic fever has a high mortality rate (10-40%)
• Geographic Range: Widespread across Africa, the Balkans, Middle East, and Asia
• Vectors: Primarily transmitted by Hyalomma ticks
• Healthcare: Poses significant nosocomial infection risk to healthcare workers
• Public Health: Requires specialized containment facilities for handling

Overview

Togaviridae is a family of enveloped, positive-sense, single-stranded RNA viruses that includes important human and animal pathogens. The family consists of a single genus, Alphavirus, which includes chikungunya virus, Venezuelan equine encephalitis virus, and others. Most alphaviruses are arthropod-borne (arboviruses), primarily transmitted by mosquitoes.

Togaviridae has been designated as a prototype pathogen family for pandemic preparedness research by the National Institute of Allergy and Infectious Diseases (NIAID). As part of the NIAID-funded Research and Development of Vaccines and Monoclonal Antibodies for Pandemic Preparedness (ReVAMPP) project, this viral family was prioritized due to its significant potential for causing outbreaks and public health emergencies. NIAID selected virus families of concern with insufficient research, inadequate medical countermeasures, and low to moderate historical support.

Impact

• Human Health: Causes diseases ranging from mild febrile illness to severe encephalitis and arthritis
• Geographic Distribution: Worldwide, with specific viruses endemic to particular regions
• Vectors: Most members transmitted by mosquitoes
• Emerging Threats: Chikungunya has caused major outbreaks across multiple continents in recent decades

Overview

Arenaviridae is a family of viruses that includes several important human pathogens. These viruses are primarily rodent-borne and can cause hemorrhagic fevers in humans. The family name comes from the Latin "arenosus," meaning sandy, which refers to the grainy appearance of virions under electron microscopy due to ribosomes inside the viral particles.

Arenaviridae has been designated as a prototype pathogen family for pandemic preparedness research by the National Institute of Allergy and Infectious Diseases (NIAID). As part of the NIAID-funded Research and Development of Vaccines and Monoclonal Antibodies for Pandemic Preparedness (ReVAMPP) project, this viral family was prioritized due to its significant potential for causing outbreaks and public health emergencies. NIAID selected virus families of concern with insufficient research, inadequate medical countermeasures, and low to moderate historical support.

Impact

• Human Health: Several members cause severe hemorrhagic fevers with high mortality rates
• Endemic Regions: Primarily in South America (Junin, Machupo, Guanarito viruses) and Africa (Lassa virus)
• Transmission: Primarily through contact with infected rodent excreta or person-to-person spread
• Public Health: Significant burden in endemic areas with limited treatment options
• Research: Important models for studying viral hemorrhagic fevers and immune responses

Overview

Avian influenza, commonly known as bird flu, is a highly contagious viral disease that primarily affects birds but can occasionally infect humans. The virus belongs to the influenza A family and is classified into different subtypes based on surface proteins (H and N).

Impact

• Wildlife: Significant mortality in wild bird populations
• Agriculture: Severe economic impacts on poultry industries
• Human Health: While human infections are rare, they can be severe when they occur
• Trade: Restrictions on international poultry trade

Overview

Leishmania donovani complex causes visceral leishmaniasis (VL), the most severe form of leishmaniasis. Transmitted by sandfly bites, it affects poor, rural populations in South Asia, East Africa, and Brazil. WHO and NIAID prioritize VL as a neglected tropical disease, focusing on developing better drugs and vaccines. Despite being geographically limited, VL remains a deadly disease of poverty with high untreated fatality rates.

Impact

• Public Health: ~50,000–90,000 new cases annually worldwide
• Geography: Endemic in South Asia, East Africa, and Brazil
• Mortality: Typically fatal if untreated
• Treatment: Increasing reports of treatment failure in India
• Control: Risk of resurgence if control measures lapse

Overview

Mucorales cause mucormycosis, a severe infection affecting immunocompromised individuals and those with uncontrolled diabetes. These environmental molds can invade blood vessels and cause rapid tissue necrosis in sinuses, lungs, or skin.

Impact

• Public Health: ~46% overall mortality rate, up to 68% in disseminated cases
• Emerging Threat: Major surge during COVID-19 pandemic
• Geography: Global distribution with significant impact during outbreaks
• Treatment: Requires aggressive surgery and antifungals
• Disfigurement: Survivors often suffer significant disfigurement

Overview

Naegleria fowleri is a free-living amoeba that causes Primary Amoebic Meningoencephalitis (PAM), an acute brain infection. It enters the nasal passages during freshwater activities and migrates to the brain.

Impact

• Public Health: Extremely rare but highly fatal (95%+ case fatality rate)
• Geography: Historically in warm freshwater regions, expanding northward
• Severity: Destroys brain tissue, death occurs within days
• Treatment: No reliably effective treatments once symptoms begin
• Climate Impact: Cases potentially increasing with rising global temperatures

Overview

Peribunyaviridae is a family of arthropod-borne viruses (arboviruses) that includes several important human and animal pathogens. These viruses have a tripartite, negative-sense RNA genome and are primarily transmitted by mosquitoes and other arthropod vectors. Notable members include La Crosse virus, California encephalitis virus, and Bunyamwera virus.

These viruses are remarkably ecologically diverse, having been identified on every continent except Antarctica. They interact with a wide range of arthropod and vertebrate hosts, demonstrating significant adaptability. Clinical outcomes from peribunyavirus infections vary widely, from subclinical cases to fatal disease. In mammals, these viruses often target specific organs or cell types. An important characteristic of peribunyaviruses is their ability to undergo genetic reassortment both in laboratory settings and in nature, with such reassortment events being linked to outbreaks of human disease, particularly within the Orthobunyavirus genus.

Peribunyaviridae has been designated as a prototype pathogen family for pandemic preparedness research by the National Institute of Allergy and Infectious Diseases (NIAID). As part of the NIAID-funded Research and Development of Vaccines and Monoclonal Antibodies for Pandemic Preparedness (ReVAMPP) project, this viral family was prioritized due to its significant potential for causing outbreaks and public health emergencies. NIAID selected virus families of concern with insufficient research, inadequate medical countermeasures, and low to moderate historical support.

Impact

• Human Health: May cause encephalitis, particularly in children (La Crosse virus)
• Geographic Distribution: Worldwide, with specific viruses endemic to particular regions
• Vectors: Primarily transmitted by mosquitoes
• Seasonality: Outbreaks typically occur during mosquito season
• Agriculture: Some members cause significant disease in livestock
• Public Health: Requires vector control measures in endemic areas

Overview

Phenuiviridae is a family of segmented, negative-strand RNA viruses that includes several important human and animal pathogens. The most notable member is Rift Valley fever virus, which causes significant disease in both livestock and humans. These viruses are primarily transmitted by arthropod vectors, especially mosquitoes and ticks.

Phenuivirids are remarkably diverse ecologically, infecting a wide range of hosts including humans, livestock, birds, crustaceans, plants, and fungi. Many are found in arthropods, which may serve as either unique hosts or biological vectors for transmission to other organisms. The family includes significant pathogens affecting human health, livestock production, seafood industries, and agricultural crops.

Phenuiviridae has been designated as a prototype pathogen family for pandemic preparedness research by the National Institute of Allergy and Infectious Diseases (NIAID). As part of the NIAID-funded Research and Development of Vaccines and Monoclonal Antibodies for Pandemic Preparedness (ReVAMPP) project, this viral family was prioritized due to its significant potential for causing outbreaks and public health emergencies. NIAID selected virus families of concern with insufficient research, inadequate medical countermeasures, and low to moderate historical support.

Impact

• Human Health: Causes febrile illness and occasionally severe complications like hemorrhagic fever or encephalitis
• Agriculture: Significant impact on livestock with high mortality in young animals and abortion in pregnant animals
• Economic: Major economic losses in affected agricultural regions
• Geographic Distribution: Primarily Africa, with recent spread to Arabian Peninsula
• Vectors: Transmitted by multiple mosquito species
• Public Health: Potential for epidemics when environmental conditions favor vector populations

Overview

Picornaviridae is a family of small, non-enveloped viruses with positive-sense, single-stranded RNA genomes. This diverse family includes many significant human and animal pathogens, including poliovirus, rhinoviruses (common cold), enteroviruses, hepatitis A virus, and foot-and-mouth disease virus. The name "picorna" comes from "pico" (small) and "RNA," reflecting their tiny size and RNA genome. Most picornaviruses for which the natural hosts have been identified are specific for one, or a very few host species. Transmission by arthropod vectors is not known, although EMCV has been isolated from mosquitoes and ticks, and poliovirus from flies; therefore mechanical transmission may be possible.

Picornaviridae has been designated as a prototype pathogen family for pandemic preparedness research by the National Institute of Allergy and Infectious Diseases (NIAID). As part of the NIAID-funded Research and Development of Vaccines and Monoclonal Antibodies for Pandemic Preparedness (ReVAMPP) project, this viral family was prioritized due to its significant potential for causing outbreaks and public health emergencies. NIAID selected virus families of concern with insufficient research, inadequate medical countermeasures, and low to moderate historical support.

Impact

• Human Health: Causes a wide range of diseases from mild respiratory infections to severe neurological conditions
• Agriculture: Foot-and-mouth disease has devastating impacts on livestock industries
• Public Health: Several members require ongoing surveillance and vaccination programs
• Neurological Disease: Some enteroviruses cause paralysis, meningitis, and encephalitis