Other Zoonotic Agents Toolbox

This CDC reference is updated regularly and includes links to general information about Andes Virus, clinical overview, clinician brief for Hantavirus Pulmonary Syndrome, public health guidance, FAQs, etc.

New World screwworm (NWS) infestation occurs when NWS fly larvae (Cochliomyia hominivorax) infest the tissue or flesh of warm-blooded animals. In places where the flies are present, people can also become infested.

Rich SN, Hinckley AF, Earley A, Petersen JM, Mead PS, Kugeler KJ
Tularemia is a rare nationally notifiable zoonosis, caused by the tier-1 select agent Francisella tularensis, that has been reported from all U.S. states except Hawaii. 

As of 18 May: 10 cases (8 lab-confirmed), 3 deaths. No confirmed U.S. Andes virus cases. Clinical laboratories advised to handle specimens from suspected HPS patients under BSL-2 enhanced precautions (Class II BSC, respirator). Andes virus is NOT a U.S. Select Agent, but laboratory directors should review biosafety risk assessments for specimen processing. Serology (IgM/IgG ELISA) and RT-PCR are diagnostic methods of choice; CDC DHCPP available for testing support.

This CDC reference is updated regularly and includes links to general information about Andes Virus, clinical overview, clinician brief for Hantavirus Pulmonary Syndrome, public health guidance, FAQs, etc.

As of February 17, 2026, Central America and Mexico have reported more than 153,000 NWS cases in animals and over 1,300 cases in people.

CDC is issuing this Health Alert Network (HAN) Health Advisory to share information and notify clinicians, public health authorities, and the public about recent New World screwworm (NWS) animal cases in the Mexican state of Tamaulipas, which shares a border with the U.S. state of Texas.

New World screwworm (NWS) infestation occurs when NWS fly larvae (Cochliomyia hominivorax) infest the tissue or flesh of warm-blooded animals. In places where the flies are present, people can also become infested.

Rabies is a viral disease that infects mammals and has an almost 100% fatality rate if postexposure prophylaxis is not administered before symptom onset. Outbreaks among cattle are rare but have been reported. Steer-to-steer transmission could not be ruled out.

In February 2025, CDC confirmed a fatal rabies case in a patient who had received a transplanted kidney from a deceased donor with undiagnosed rabies. Three cornea recipients from the same donor underwent graft removal, received PEP, and remained asymptomatic.

Stein SR, Beron AJ, Nelson KM, et al.
Movement of wildlife has facilitated the spread of non-bat rabies virus variants into new geographic areas of the United States, with major implications for human health.

Cavallone IN, et al.
 CDC recommendations to health care providers and preparedness personnel regarding treatment and postexposure prophylaxis (PEP) of tularemia. Because F. tularensis has a low infectious inoculum, it is classified as a potential bioterrorism agent that could infect thousands of persons if intentionally released.