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Public Health

Vetted resources and information on current public health events.

Priority Pathogens

NIAID Emerging Infectious Diseases/Pathogens

NIAID’s pathogen priority list is periodically reviewed and is subject to revision in conjunction with our federal partners, including the U.S. Department of Homeland Security, which determines threat assessments, and the Centers for Disease Control and Prevention, which is responsible for responding to emerging pathogen threats in the United States.

Category A Pathogens

Are those organisms/biological agents that pose the highest risk to national security, because they:

  • Can be easily disseminated or transmitted from person to person
  • Result in high mortality rates and have the potential for major public health impact
  • Might cause public panic and social disruption
  • Require special action for public health preparedness

Examples of Category A priority pathogens:

  • Anthrax (Bacillus anthracis)
  • Botulism (Clostridium botulinum toxin)
  • Plague (Yersinia pestis)
  • Smallpox (Variola Virus)
  • Viral Hemorrhagic Fevers (including Ebolavirus and Marburg Virus)

Category B Pathogens

Are the second highest priority organisms/biological agents, because they:

  • Are moderately easy to disseminate
  • Result in moderate morbidity rates and low mortality rates
  • Require specific enhancements for diagnostic capacity and enhanced disease surveillance

Examples of Category B  priority pathogens:

  • Food and waterborne pathogens (including E.coli, Salmonella, Listeria)
  • Hepatitis A
  • West Nile Virus
  • Zika Virus

Category C Pathogens

Are the third highest priority and include emerging pathogens that could be engineered for mass dissemination in the future due to:

  • Availability
  • Ease of production and dissemination
  • Potential for high morbidity and mortality rates and major health impact

Examples of Category C priority pathogens:

  • Hantaviruses (including Nipah and Hendra viruses)
  • Tuberculosis
  • Influenza Virus
  • Severe acute respiratory syndrome associated coronaviruses (including SARS and MERS)
  • Antimicrobial resistance

One Health Approach to Zoonotic Disease

What is One Health?

One Health is a collaborative, multisectoral, and transdisciplinary approach — working at the local, regional, national, and global levels — with the goal of achieving optimal health outcomes recognizing the interconnection between people, animals, plants, and their shared environment.

One Health is an approach that recognizes that the health of people is closely connected to the health of animals and our shared environment. One Health is not new, but it has become more important in recent years. This is because many factors have changed interactions between people, animals, plants, and our environment.

These changes have led to the spread of existing or known (endemic) and new or emerging zoonotic diseases, which are diseases that can spread between animals and people. Every year, millions of people and animals around the world are affected by zoonotic diseases.

U.S. Federal Coordination with One Health

The CDC uses a One Health approach by involving experts in human, animal, environmental health, and other relevant disciplines and sectors in monitoring and controlling public health threats and to learn about how diseases spread among people, animals, plants, and the environment. The CDC works closely with the US Department of Agriculture (USDA), the Department of the Interior (DOI), and other federal agencies to exchange information and coordinate One Health activities across the US government.

In 2017, CDC, USDA, and DOI organized a One Health Zoonotic Disease Prioritization (OHZDP) workshop to further joint efforts to address zoonotic disease challenges in the United States. Participants in the workshop identified eight zoonotic diseases of greatest national concern:

  • Zoonotic influenza
  • Salmonellosis
  • West Nile
  • Plague
  • Emerging coronaviruses (such as SARS and MERS, and as of 2020, COVID-19)
  • Rabies
  • Brucellosis
  • Lyme disease

Following this workshop, the House Appropriations Committee Report that accompanied the 2021 Omnibus Appropriations Bill directed CDC to create a national One Health framework to combat the threat of zoonotic diseases and advance emergency preparedness in the United States. The bill also directs the development of a federal One Health coordination mechanism to strengthen One Health collaboration related to prevention, detection, control, and response for zoonotic diseases and related One Health work across the federal government. CDC, USDA, and DOI are currently working together and with other federal partners to create both the framework and the coordination mechanism at the federal level.

Current U.S. Outbreaks of Concerning Diseases

Increase in Invasive Serogroup Y Meningococcal Disease in the United States

Distributed via the CDC Health Alert Network
March 28, 2024, 1:30 PM ET

The Centers for Disease Control and Prevention (CDC) is issuing this Health Alert Network (HAN) Health Advisory to alert healthcare providers to an increase in invasive meningococcal disease, mainly attributable to Neisseria meningitidis serogroup Y (Figure). In 2023, 422 cases were reported in the United States, the highest annual number of cases reported since 2014. As of March 25, 2024, 143 cases have been reported to CDC for the current calendar year, an increase of 62 cases over the 81 reported as of this date in 2023. A specific meningococcal strain, sequence type (ST) 1466, is responsible for most (101 of 148, 68%) serogroup Y cases with available sequence type data that were reported across the United States in 2023. Cases caused by this strain are disproportionately occurring in people ages 30–60 years (65%), Black or African American people (63%), and people with HIV (15%). In addition, most cases of invasive meningococcal disease caused by ST-1466 in 2023 had a clinical presentation other than meningitis: 64% presented with bacteremia, and at least 4% presented with septic arthritis. Of 94 patients with known outcomes, 17 (18%) died; this case-fatality rate is higher than the historical case-fatality rate of 11% reported for serogroup Y cases in 2017–2021.

Recommendations for Healthcare Providers
  • Maintain a heightened suspicion for invasive meningococcal disease and start immediate antibiotic treatment for persons with suspected meningococcal disease. Blood and cerebrospinal fluid (CSF) cultures are indicated for patients with suspected meningococcal disease.
  • Recognize that invasive meningococcal disease may affect people of any age or demographic group.
    • Current increases in disease are disproportionately affecting people ages 30–60 years, Black or African American people, and people with HIV.
  • Be aware that patients with invasive meningococcal disease may present with bloodstream infection or septic arthritis and without symptoms typical of meningitis (e.g., headache, stiff neck).
  • Ensure that all people recommended for meningococcal vaccination are up to date for meningococcal vaccines.
    • All 11–12 year-olds should receive a MenACWY vaccine. Since protection wanes, CDC recommends a booster dose at age 16 years.
    • For people at increased risk due to medical conditions (e.g., with HIV), recommended vaccination includes a 2-dose primary MenACWY series with booster doses every 3–5 years, depending on age.
  • Immediately notify state, tribal, local, or territorial health departments about any suspect or confirmed cases of invasive meningococcal disease.
  • Consult with your state or local health department for any questions about meningococcal disease treatment or contact prophylaxis, including any changes based on local meningococcal resistance patterns.
Recommendations for the Public
  • Seek medical attention immediately if you or your child develops symptoms of meningococcal disease:
    • Symptoms of meningitis may include fever, headache, stiff neck, nausea, vomiting, photophobia, or altered mental status.
    • Symptoms of meningococcal bloodstream infection may include fever and chills, fatigue, vomiting, cold hands and feet, severe aches and pains, rapid breathing, diarrhea, or, in later stages, a dark purple rash.
    • While symptoms of meningococcal disease can at first be nonspecific, they worsen rapidly, and the disease can become life-threatening within hours.
  • Talk to your healthcare provider about meningococcal vaccines that may be recommended for you and your household or family members, including any recommended booster doses.
What is Meningococcal Disease?

Meningococcal Disease is caused by the bacterium Neisseria meningitidis. It is a rare but severe illness with a case-fatality rate of 10–15% even with appropriate antibiotic treatment.

The two most common types of meningococcal infections are meningitis and septicemia. Both of these types of infections are very serious and can be deadly in a matter of hours.

Meningococcal meningitis

Doctors call meningitis caused by the bacteria Neisseria meningitidis meningococcal meningitis. When someone has meningococcal meningitis, the bacteria infect the lining of the brain and spinal cord and cause swelling.

The most common symptoms include:

  • Fever
  • Headache
  • Stiff neck

Other additional symptoms that are often present:

  • Nausea
  • Vomiting
  • Photophobia (eyes being more sensitive to light)
  • Altered mental status (confusion
Meningococcal septicemia (aka meningococcemia)

Doctors call septicemia (a bloodstream infection) caused by Neisseria meningitidis meningococcal septicemia or meningococcemia. When someone has meningococcal septicemia, the bacteria enter the bloodstream and multiply, damaging the walls of the blood vessels. This causes bleeding into the skin and organs.

Symptoms may include:

  • Fever and chills
  • Fatigue (feeling tired)
  • Vomiting
  • Cold hands and feet
  • Severe aches or pain in the muscles, joints, chest, or abdomen (belly)
  • Rapid breathing
  • Diarrhea
  • In the later stages, a dark purple rash

CDC Signs and Symptoms of Meningococcal Disease

Locally Acquired Cases of Malaria in Florida, Texas, and Maryland
CDC Malaria Notice: August 22, 2023

CDC is collaborating with three state health departments on an investigation of seven locally acquired cases of Plasmodium vivax (P. vivax) malaria in Sarasota County, FL, one case of P.vivax in Cameron County, TX, and one case of P. falciparum malaria in a Maryland resident who lives in the National Capital Region. There is no evidence to suggest that the cases in the three states are related. All patients were promptly treated at area hospitals and are recovering.

Most malaria cases diagnosed in the United States are imported, usually by persons who travel to countries where malaria is endemic (regularly occurring). However, locally acquired mosquito-transmitted malaria cases can occur, as Anopheles mosquito vectors exist throughout the United States. In 2003 there were 8 cases of locally acquired P. vivax malaria identified in Palm Beach County, FL.

Florida, Texas, and Maryland have been engaging in additional surveillance activities and mitigation efforts to reduce the possibility of additional local transmission. CDC is coordinating with, and providing technical assistance to, state and local officials.

The risk of locally acquired malaria is very low in the United States. Malaria is primarily spread by mosquitoes. If you have traveled to an area where malaria occurs and develop fever, chills, headache, body aches, and fatigue, seek medical care urgently and tell your healthcare provider that you have traveled.

Maryland Department of Health announces positive case of locally acquired malaria
Press Release: August 18, 2023

The Maryland Department of Health has confirmed and reported a positive case of locally acquired malaria in a Maryland resident who lives in the National Capital Region. The individual was hospitalized and is now recovering. They did not travel recently outside of the United States or to other U.S. states with recent locally acquired malaria cases. 

“Malaria was once common in the United States, including in Maryland, but we have not seen a case in Maryland that was not related to travel in over 40 years,” said Maryland Department of Health Secretary Laura Herrera Scott. “We are taking this very seriously and will work with local and federal health officials to investigate this case.”

Malaria is a mosquito-borne disease caused by a parasite. More than 2,000 cases of malaria are reported annually in the U.S., according to the Centers for Disease Control and Prevention, with most cases occurring in people returning from international travel. Maryland typically reports around 200 travel-related malaria cases each year, and the Maryland Department of Health investigates each case for cause and risk. 

Symptoms of malaria usually appear 7 to 30 days after an infective bite and include high fever, chills, body aches, diarrhea and vomiting. 

“Malaria can be very dangerous and even fatal if it is not treated, but early treatment reduces the chances of complications,” said Deputy Secretary for Public Health Services Dr. Nilesh Kalyanaraman. “We urge the public to take precautions against mosquito bites, and if you develop symptoms after traveling abroad, seek urgent medical care.”

The risk to the public for locally acquired mosquito-transmitted malaria remains very low, according to the Centers for Disease Control and Prevention. However, Marylanders can take these precautions to prevent mosquito bites or travel-related malaria:

  • Use insect repellent containing DEET on exposed skin.

  • If weather and heat allow, wear loose-fitting, long sleeved clothing.

  • Keep windows and doors closed or covered with screens to keep mosquitoes out of your house.

  • Empty standing water at least once a week to prevent mosquitoes from laying eggs.

  • Repair broken screening on windows, doors, porches, and patios. 

  • Before you travel, learn about the health risks and precautions for malaria and other diseases for your destination.

  • If you are planning to travel abroad, check with your health care provider for current recommendations on prescription medications to prevent malaria.

  • If you have traveled to an area where malaria transmission occurs more often, and you develop fever, chills, headache, body aches, and fatigue, seek urgent medical care and tell your health care provider that you have traveled. 

Florida health department reports 2 more malaria cases in Sarasota County
Sarasota Herald-Tribune | July 6, 2023

The Florida Department of Health reported an additional two cases of locally acquired malaria in Sarasota County, bringing the county’s total to six cases.

Sarasota and Manatee counties have been under a mosquito-borne illness alert since June 19. County and health officials are encouraging residents to protect themselves from mosquitoes, including by applying bug spray, avoiding areas with large mosquito populations and wearing long-sleeved shirts and long pants at nighttime.  

The two additional cases were reported the week of June 25-July 1, according to a report released on Thursday. Sarasota County has been experiencing an outbreak of locally acquired malaria, which means that the individuals contracted malaria from mosquitoes in the Sarasota area – not from insects in another country. 

Such locally acquired cases are very rare, as the vast majority of malaria cases in the U.S. are in travelers or other people returning to the country from nations where there is transmission of malaria. The last outbreak of locally acquired malaria in the U.S. was in 2003, when Palm Beach County saw eight such cases.

The first Sarasota County case was reported the week of May 21-27, and the second during the week of June 11-17, according to Florida Department of Health reports. The third and fourth cases were reported the week of June 18-24.  

Locally Acquired Malaria Cases Identified in the United States

Distributed via the CDC Health Alert Network
June 26, 2023, 5:00 PM ET


The Centers for Disease Control and Prevention (CDC) is issuing this Health Alert Network (HAN) Health Advisory to share information and notify clinicians, public health authorities, and the public about:

  1. Identification of locally acquired malaria cases (P. vivax) in two U.S. states (Florida and Texas) within the last 2 months,
  2. Concern for a potential rise in imported malaria cases associated with increased international travel in summer 2023, and
  3. Need to plan for rapid access to IV artesunate, which is the first-line treatment for severe malaria in the United States.

CDC is collaborating with two U.S. state health departments with ongoing investigations of locally acquired mosquito-transmitted Plasmodium vivax malaria cases. There is no evidence to suggest the cases in the two states (Florida and Texas) are related.

In Florida, four cases within close geographic proximity have been identified, and active surveillance for additional cases is ongoing. Mosquito surveillance and control measures have been implemented in the affected area.

In Texas, one case has been identified, and surveillance for additional cases, as well as mosquito surveillance and control, are ongoing. All patients have received treatment and are improving.

Locally acquired mosquito-borne malaria has not occurred in the United States since 2003 when eight cases of locally acquired P. vivax malaria were identified in Palm Beach County, FL . Despite these cases, the risk of locally acquired malaria remains extremely low in the United States. However, Anopheles mosquito vectors, found throughout many regions of the country, are capable of transmitting malaria if they feed on a malaria-infected person. The risk is higher in areas where local climatic conditions allow the Anopheles mosquito to survive during most of or the entire year and where travelers from malaria-endemic areas are found.

In addition to routinely considering malaria as a cause of febrile illness among patients with a history of international travel to areas where malaria is transmitted, clinicians should consider a malaria diagnosis in any person with a fever of unknown origin regardless of their travel history. Clinicians practicing in areas of the United States where locally acquired malaria cases have occurred should follow guidance from their state and local health departments. Prompt diagnosis and treatment of people with malaria can prevent progression to severe disease or death and limit ongoing transmission to local Anopheles mosquitos. Individuals can take steps to prevent mosquito bites and control mosquitos at home to prevent malaria and other mosquito-borne illnesses.

Malaria is a serious and potentially fatal disease transmitted through the bite of an infective female anopheline mosquito. Though rare, malaria can also be transmitted congenitally from mother to fetus or to the neonate at birth, through blood transfusion or organ transplantation, or through unsafe needle-sharing practices. Malaria is caused by any of five species of protozoan parasite of the genus Plasmodium: P. falciparum, P. vivax, P. malariae, P. ovale, and P. knowlesi. Worldwide, more than 240 million cases of malaria occur each year (95% in Africa). Almost all cases of malaria in the United States are imported and occur in people traveling from countries with malaria transmission, many from sub-Saharan Africa and South Asia. Before the COVID-19 pandemic, approximately 2,000 cases of mostly travel-related malaria were diagnosed in the United States each year; approximately 300 people experienced severe disease (most P. falciparum), and 5 to 10 people with malaria died yearly (3). Most imported cases of malaria in the United States are diagnosed during summer and early fall. In 2023, CDC expects summer international travel among U.S. residents will be increasing to pre-COVID-19 pandemic levels (4).

Clinical manifestations of malaria are non-specific and include fever, chills, headache, myalgias, and fatigue. Nausea, vomiting, and diarrhea may also occur. For most people, symptoms begin 10 days to 4 weeks after infection, although a person may feel ill as early as 7 days or as late as 1 year after infection. If not treated promptly, malaria may progress to severe disease, a life-threatening stage, in which mental status changes, seizures, renal failure, acute respiratory distress syndrome, and coma may occur. Malaria in pregnant people is associated with high risks of both maternal and perinatal morbidity and mortality. P. falciparum and P. knowlesi infections can cause rapidly progressive severe illness or death, while the other species, including P. vivax, are less likely to cause severe disease. Laboratory abnormalities can include anemia, thrombocytopenia, hyperbilirubinemia, and elevated transaminases, varying from normal or mildly altered in uncomplicated disease to very abnormal in severe disease. P. vivax and P. ovale canremaindormant in the liver and such infections require additional treatment; failure to treat the dormant hepatic stages may result in chronic infection, causing relapsing episodes. Relapses may occur after months or even years without symptoms.

Malaria is a medical emergency and should be treated accordingly. Patients suspected of having malaria should be urgently evaluated in a facility that is able to provide rapid diagnosis and treatment, within 24 hours of presentation. Order microscopic examination of thin and thick blood smears, and a rapid diagnostic test (RDT) if available, to diagnose malaria as soon as possible. Artemether-lumefantrine (Coartem®) is the preferred option, if readily available, for the initial treatment of uncomplicated P. falciparum or unknown species of malaria acquired in areas of chloroquine resistance. Atovaquone-proguanil (Malarone®) is another recommended option. P. vivax infections acquired from regions other than Papua New Guinea or Indonesia should initially be treated with chloroquine (or hydroxychloroquine). IV artesunate is the only drug available for treating severe malaria in the United States. Artesunate for InjectionTM, manufactured by Amivas, is approved by the U.S. Food and Drug Administration (FDA) and is commercially available. Hospitals should have a plan for rapidly diagnosing  and treating malaria within 24 hours of presentation. Additional information on diagnosing and treating malaria, including details of treating the dormant liver stages, is available on the CDC website.

What is T. indotineae?

Trichophyton indotineae (T. indotineae) is a novel fungal species from the genus Trichophyton initially discovered on the Indian subcontinent, but in recent years has reached near-epidemic levels on the subcontinent as well as spread across the globe. T. indotineae are often resistant to terbinafine, the primary antifungal treatment used to treat tinea.

T. indotineae infections are highly transmissible and characterized by widespread, inflamed, pruritic plaques on the body, pubic region and adjacent thigh, or the face.

First Reported Case of T. indotineae in the United States

On February 28, 2023, a New York City dermatologist notified public health officials of two patients who had severe tinea that did not improve with oral terbinafine treatment, raising concern for potential T. indotineae infection; these patients shared no epidemiologic links. Skin culture isolates from each patient were previously identified by a clinical laboratory as Trichophyton mentagrophytes and were subsequently forwarded to the Wadsworth Center, New York State Department of Health, for further review and analysis. Sanger sequencing of the internal transcribed spacer region of the ribosomal gene, followed by phylogenetic analysis performed during March 2023, identified the isolates as T. indotineae.

Information for Healthcare Providers

Patient A had no recent international travel history, suggesting potential local U.S. transmission of T. indotineae.

  • Health care providers should consider T. indotineae infection in patients with widespread tinea, particularly when eruptions do not improve with first-line topical antifungal agents or oral terbinafine.
  • Culture-based identification techniques used by most clinical laboratories typically misidentify T. indotineae as T. mentographytes or T. interdigitale; correct identification requires genomic sequencing.
  • Health care providers who suspect T. indotineae infection should contact their state or local public health department for assistance with testing,** which is available at certain public health laboratories and specialized academic and commercial laboratories.
  • Successful treatment using oral itraconazole, a triazole antifungal, has been documented. However, providers should be aware of challenges with itraconazole absorption, which can lead to variable serum drug concentrations; itraconazole’s interactions with other drugs; the need for up to 12 weeks of therapy (3); and the documented emergence of triazole resistance.
  • Antimicrobial stewardship efforts are essential to minimize the misuse and overuse of prescribed and over-the-counter antifungal drugs and corticosteroids. In addition, health care providers can educate patients about strategies to prevent the spread of the dermatophytes that cause tinea.

Source: Caplan AS, Chaturvedi S, Zhu Y, et al. Notes from the Field: First Reported U.S. Cases of Tinea Caused by Trichophyton indotineae — New York City, December 2021–March 2023. MMWR Morb Mortal Wkly Rep 2023;72:536–537.

Outbreak of Extensively Drug-resistant Pseudomonas aeruginosa Associated with Artificial Tears

Distributed via the CDC Health Alert Network
February 1, 2023, 7:00 PM ET


The Centers for Disease Control and Prevention (CDC) is issuing this Health Alert Network (HAN) Health Advisory about infections with an extensively drug-resistant strain of Verona Integron-mediated Metallo-β-lactamase (VIM) and Guiana-Extended Spectrum-β-Lactamase (GES)-producing carbapenem-resistant Pseudomonas aeruginosa (VIM-GES-CRPA) in 12 states. Most patients reported using artificial tears. Patients reported more than 10 different brands of artificial tears, and some patients used multiple brands. The majority of patients who used artificial tears reported using EzriCare Artificial Tears, a preservative-free, over-the-counter product packaged in multidose bottles. CDC laboratory testing identified the presence of the outbreak strain in opened EzriCare bottles with different lot numbers collected from two states. Patients and healthcare providers should immediately discontinue using EzriCare artificial tears pending additional guidance from CDC and the Food and Drug Administration (FDA).


As of January 31, 2023, CDC in partnership with state and local health departments identified 55 case-patients in 12 states (CA, CO, CT, FL, NJ, NM, NY, NV, TX, UT, WA, WI) with VIM-GES-CRPA, a rare strain of extensively drug-resistant P. aeruginosa. Thirty-five patients are linked to four healthcare facility clusters. Dates of specimen collection were from May 2022 to January 2023. Isolates have been identified from clinical cultures of sputum or bronchial wash (13), cornea (11), urine (7), other nonsterile sources (4), blood (2), and from rectal swabs (25) collected for surveillance; some patients had specimens collected from more than one anatomic site. These specimens were collected in both outpatient and inpatient healthcare settings. Patients had a variety of presentations including keratitis, endophthalmitis, respiratory infection, urinary tract infection, and sepsis. Patient outcomes include permanent vision loss resulting from cornea infection, hospitalization, and one death due to systemic infection.

Isolates in this outbreak are sequence type (ST) 1203, harbor blaVIM-80 and blaGES-9 (a combination not previously observed in the United States) and are closely related based on analysis of whole genome sequencing (WGS) data. These isolates are not susceptible to cefepime, ceftazidime, piperacillin-tazobactam, aztreonam, carbapenems, ceftazidime-avibactam, ceftolozane-tazobactam, fluoroquinolones, polymyxins, amikacin, gentamicin, and tobramycin; the subset of isolates that underwent antimicrobial susceptibility testing for cefiderocol were susceptible to this agent.

Review of common exposures revealed that most patients, including most patients with eye infections, used artificial tears prior to identification of VIM-GES-CRPA infection or colonization. Patients reported more than 10 brands of artificial tears, and some patients used multiple brands. The majority of patients who used artificial tears reported using EzriCare Artificial Tears, a preservative-free product dispensed in multidose bottles. This was the only common artificial tears product identified across the four healthcare facility clusters. CDC laboratory testing identified the presence of VIM-GES-CRPA in opened EzriCare Artificial Tears bottles from multiple lots; these bottles were collected from patients with and without eye infections in two states. These product-related VIM-GES-CRPA match the outbreak strain. VIM-GES-CRPA recovered from opened bottles could represent either bacterial contamination during use or during the manufacturing process. Testing of unopened bottles of EzriCare Artificial Tears is ongoing to assist in evaluating for whether contamination may have occurred during manufacturing.

Current Update

As of May 15, 2023, CDC, in partnership with state and local health departments, identified 81 patients in 18 states (CA, CO, CT, DE, FL, IL, NC, NJ, NM, NV, NY, OH, PA, SD, TX, UT, WA, WI) with VIM-GES-CRPA, a rare strain of extensively drug-resistant P. aeruginosa. This represents an increase of 13 patients since the last update. Among these 13 patients, 6 (46%) had specimens collected prior to the February 2, 2023, manufacturer recall of products associated with this outbreak. These cases were confirmed after the recall date due to the time it takes for testing to confirm the outbreak strain and because of retrospective reporting of infections. Of the 7 patients who had specimens collected after the recall, most either resided in long-term care facilities with other known cases or reported use of a recalled brand of artificial tears.

Dates of specimen collection were from May 2022 to April 2023. Patients were initially identified from:

  • cultures of sputum, bronchial wash, or tracheal aspirate (14)
  • sites related to the eye (e.g., cornea, vitreous; 21)
  • urine (13)
  • other nonsterile sources (3)
  • blood (3)
  • ear (1)
  • rectal swabs (26)

Adverse outcomes that were associated with clinical (non-surveillance) cultures and reported to public health include 14 patients with vision loss, an additional 4 patients with enucleation (surgical removal of eyeball), and 4 deaths within 30 days of VIM-GES-CRPA clinical culture collection.

Most patients reported using artificial tears. Patients reported over 10 different brands of artificial tears, and some patients used multiple brands. EzriCare Artificial Tears, a preservative-free, over-the-counter product packaged in multidose bottles, was the brand most commonly reported. This was the only common artificial tears product identified across the four healthcare facility clusters. Laboratory testing by CDC identified the presence of VIM-GES-CRPA in opened EzriCare bottles from multiple lots; these bottles were collected from patients with and without eye infections and from two states. VIM-GES-CRPA recovered from opened products match the outbreak strain. Testing of unopened bottles of EzriCare Artificial Tears by FDA identified bacterial contamination; further characterization of the contaminants is ongoing.

Three products have been voluntarily recalled by their manufacturer, Global Pharma (Chennai, India), in association with this outbreak:

  • EzriCare Artificial Tears
  • Delsam Pharma Artificial Tears
  • Delsam Pharma Artificial Ointment

No other products have been linked to this outbreak. Patients and healthcare providers should immediately stop using and discard EzriCare Artificial Tears, Delsam Pharma Artificial Tears, and Delsam Pharma Artificial Ointment.

Recommendations for Healthcare Providers
  • Immediately discontinue using EzriCare Artificial Tears pending additional guidance from CDC and FDA.
  • Advise patients who used EzriCare Artificial Tears to monitor for signs and symptoms of infection. Perform culture and antimicrobial susceptibility testing when clinically indicated.
  • Healthcare providers treating patients for keratitis or endophthalmitis should ask patients if they have used EzriCare Artificial Tears. Providers should consider performing culture and antimicrobial susceptibility testing to help guide therapy if patients report use of this product.
  • Healthcare providers treating VIM-GES-CRPA infections should consult with a specialist knowledgeable in the treatment of antibiotic-resistant bacteria to determine the best treatment option. VIM-GES-CRPA isolates associated with this outbreak are extensively drug-resistant. Isolates that underwent susceptibility testing at public health laboratories were not susceptible to cefepime, ceftazidime, piperacillin-tazobactam, aztreonam, carbapenems, ceftazidime-avibactam, ceftolozane-tazobactam, fluoroquinolones, polymyxins, amikacin, gentamicin, and tobramycin. A subset of 3 isolates that underwent antimicrobial susceptibility testing for cefiderocol at clinical laboratories or CDC were susceptible to this agent.
  • Place patients infected or colonized with VIM-GES-CRPA and admitted to acute care settings in isolation and use Contact Precautions. For residents of skilled nursing facilities who are infected or colonized with VIM-GES-CRPA, use Enhanced Barrier Precautions if the resident does not have an indication for Contact Precautions.
  • At this time, CDC does not recommend testing patients who have used this product and who are not experiencing any signs or symptoms of infection.
Recommendations for Clinical Laboratories
  • Clinical laboratories that identify P. aeruginosa resistant to imipenem or meropenem are encouraged to perform carbapenem resistance mechanism testing; isolates may also be submitted to the Antimicrobial Resistance Laboratory Network for mechanism testing.
    • Laboratories wishing to apply a more specific definition when identifying isolates that might be related to this cluster for mechanism testing could limit testing to carbapenem-resistant P. aeruginosa that are also resistant to cefepime, ceftazidime, and (if tested) ceftazidime-avibactam and ceftolozane-tazobactam.
  • Clinical laboratories that identify any carbapenem-resistant P. aeruginosa from an ocular specimen or VIM-CRPA from any specimen source should submit the isolate to the Antimicrobial Resistance Laboratory Network for further characterization. Please reach out to your health department’s healthcare-associated infections contact or email for assistance submitting isolates
Recommendations for the Public
  • Discontinue using EzriCare Artificial Tears pending additional guidance from CDC and FDA.
  • If patients were advised to use EzriCare Artificial Tears by their healthcare provider, they should follow up with their healthcare provider for an alternative artificial tears product to use.
  • Patients who used EzriCare Artificial Tears and who have signs or symptoms of an eye infection, such as discharge from the eye, eye pain or discomfort, redness of the eye or eyelid, feeling of something in the eye, increased sensitivity to light, or blurry vision, should seek timely medical care. At this time, CDC does not recommend testing of patients who have used this product and who are not experiencing any signs or symptoms of infection.
U.S. Reported Cases of Pediatric Hepatitis of Uknown Origin
Current Numbers of persons under investigation (PUI): 4011*

*PUI does not mean this person is a confirmed case. The states and CDC are looking broadly (including hepatitis cases of unknown origin in children under 10 years of age, since October, 2021), so this number may go up or down as CDC and states review medical charts and learn more.

States and Jurisdictions Reporting at Least One Person Under Investigation (47)* as of March 6, 2024

These data were posted on January 3, 2024 and reflect data from October 1, 2021. Reported PUIs are preliminary and subject to change as more data become available. Data will be updated monthly.

These may not be recent cases of hepatitis being reported. To protect patient privacy, numbers for each state will not be released.

Person Under Investigation (PUI): Children <10 years of age with elevated aspartate aminotransferase (AST) or alanine aminotransferase (ALT) (>500 U/L) who have an unknown etiology for their hepatitis (with or without any adenovirus testing results, independent of the results) since October 1, 2021.

Pediatric Hepatitis of Unknown Origin

In October 2021, five pediatric patients with hepatitis (inflammation of the liver) of unknown cause were identified in children at a hospital in Alabama. The children had significant liver illness, including some with liver failure, with no known cause. The five children tested negative for hepatitis A, hepatitis B, and hepatitis C viruses and tested positive for adenovirus, a common virus that typically causes cold- or flu-like illness, or more rarely stomach or intestine problems. An additional review of hospital records later identified four additional patients, all of whom had hepatitis and adenovirus infection.

All of the children were previously healthy and ranged in age from one to six years old at the time of hospitalization. The children were from different parts of the state. No known contact or common exposures were found among the children. None of the children had significant underlying medical conditions.

CDC Investigation

In addition to looking for more cases in Alabama, the CDC issued a notice calling for state and local health departments nationwide to report potential cases. CDC is working with states to support them when patients under investigation are reported and is updating investigation numbers regularly.

Clinical Guidance

A clinical workup for children with acute hepatitis should be done locally per treating clinicians. CDC recommends testing for adenovirus and SARS-CoV-2.

Contact your State Public Health Lab for instructions on where to send specimens.

Pediatric Hepatitis as a Manifestation SARS-CoV-2

Emerging evidence shows that children are at increased risk for acute and long-term liver dysfunction. COVID-19 has been identified as causing hepatitis both during acute SARS-CoV-2 infection as well as a predominant feature of MIS-C. There is also evidence of hepatic manifestations of post-acute COVID conditions (Long COVID) in both adults and children.

A recent case series identified five pediatric patients who recovered from acute COVID-19 infections and later presented with liver injury, including two infants that rapidly progressed to liver transplants and three children (age 8-13) who presented with hepatitis with cholestasis.

These investigations suggest that while acute COVID-19 infections may not be present in these pediatric hepatitis cases, SARS-CoV-2 cannot be ruled out as the causative agent of this condition.

Recently, multiple scientists, clinicians, and epidemiologists are noting that anecdotal reports signal that these cases of pediatric hepatitis increase after COVID-19 infection surges, specifically surges tied to the BA.2 Omicron subvariant. Cases began to increase in spring 2022, several months after the massive surge of BA.2 January-February 2022. Cases decreased again over the summer/fall when BA.4 and BA.5 were circulating, but began rising in December 2022 and are continuing to rise into 2023. This corresponds to the rise of the XBB variant, which is a recombinant of two BA.2 subvariants.

On March 30, 2023 Nature published studies from three different groups that independently provided evidence that infection by adeno-associated virus 2 (AAV2) is linked to this outbreak of acute severe hepatitis in children.


**It is important to note that Adeno-associated virus (AAV-2) can remain in the body of a person infected, hiding in a dormant state called latency. Latent viruses can be "reactivated" back to their active state due to a variety of factors, including certain viral infections. COVID-19 has been identified as one of those viruses that can reactivate latent viruses in the body. This connection needs to be further investigated.

Recent Medical Findings

CDC Disese Outbreak Resources