Health & Safety
Rodent-Borne Diseases: What McAllen Homeowners Should Know
Rodents can spread disease through droppings, urine, saliva, bites, and indirectly through fleas, ticks, and mites, according to the CDC. Here is what that actually means for each disease, and why exclusion is the real prevention.
This page provides general educational information about rodent-associated diseases for pest control awareness purposes. It is not medical advice and should not be used to diagnose or treat any condition. If you have symptoms following possible rodent exposure, contact a medical provider directly.
Hantavirus
What It Is: A viral illness that can cause severe respiratory disease. In the United States, it is primarily associated with deer mice and related native rodent species rather than the common house mouse or Norway rat.
How Rodents Contribute: Deer mice are the primary reservoir species in Texas. They can carry and shed the virus without appearing sick themselves.
Exposure Routes: Hantavirus spreads when dried rodent droppings, urine, or nesting material get disturbed and release airborne particles that are then inhaled, most often in enclosed, poorly ventilated spaces like attics, sheds, and cabins that have sat closed up for a while. It is not spread through rodent bites in the way some other diseases are.
General Warning Signs: Early symptoms resemble the flu: fever, fatigue, and muscle aches, typically appearing one to eight weeks after exposure. Symptoms can progress and become serious, which is why any flu-like illness following a known rodent exposure should be mentioned to a medical provider.
Prevention: Ventilate a space before cleaning it, and never sweep or vacuum dry droppings. Wet the area with disinfectant first. See our full hantavirus and exclusion guide for the complete safe-cleanup process.
Leptospirosis
What It Is: A bacterial infection caused by Leptospira bacteria, which can infect both humans and animals.
How Rodents Contribute: Rodents, particularly Norway rats, are a recognized carrier of Leptospira and shed the bacteria in their urine.
Exposure Routes: Infection typically occurs through contact with water, soil, or food contaminated with infected rodent urine, particularly when it reaches broken skin, eyes, nose, or mouth. Flooding or standing water after heavy rain, common in South Texas, can increase exposure risk in affected areas.
General Warning Signs: Symptoms can include fever, headache, chills, muscle aches, and in some cases more severe complications. Symptoms can resemble several other illnesses, which is part of why a known rodent exposure is worth mentioning to a doctor if you become ill.
Prevention: Avoid contact with standing water or soil that may be contaminated with rodent urine, and use gloves when cleaning areas with known rodent activity. Sealing entry points reduces the rodent population contributing urine to a property in the first place.
Salmonellosis
What It Is: An infection caused by Salmonella bacteria, most commonly associated with food poisoning.
How Rodents Contribute: Rodents can carry salmonella and spread it through their droppings, particularly when they travel across kitchen counters, stored food, or food preparation surfaces.
Exposure Routes: Exposure typically happens through eating food or touching surfaces contaminated with rodent droppings, then transferring the bacteria to the mouth. This is why any kitchen or pantry activity is taken seriously, even from a small number of droppings.
General Warning Signs: Symptoms typically include diarrhea, fever, and stomach cramps, usually developing within a few days of exposure.
Prevention: Store food in sealed containers rather than original packaging, disinfect any surface where droppings are found, and seal entry points that give rodents kitchen access in the first place.
Rat-Bite Fever
What It Is: A bacterial infection that can result from a rat bite or scratch, or less commonly from contaminated food or water.
How Rodents Contribute: Rats can carry the responsible bacteria in their mouths without appearing sick, and transmit it through a bite, scratch, or contact with their droppings or secretions.
Exposure Routes: The most direct route is a bite or scratch from an infected rat, which is one of the clearest reasons not to handle live or dead rodents without protection. Contaminated food or water is a less common route.
General Warning Signs: Symptoms can include fever, rash, and joint pain, typically developing within a few days to a few weeks after exposure.
Prevention: Never handle rodents, alive or dead, with bare hands. Use gloves and proper disposal methods, and seek professional removal rather than DIY handling when possible. See our dead rodent removal page for safe handling of a rodent that has already died.
Murine (Flea-Borne) Typhus
What It Is: Also called murine typhus or endemic typhus, a bacterial illness caused by Rickettsia typhi. According to the CDC, most U.S. cases occur in Texas, California, and Hawaii, which makes it genuinely relevant to South Texas specifically, not just a general risk.
How Rodents Contribute: Rats are the traditional primary host for the infected fleas that spread this disease, though the CDC notes opossums and free-roaming cats can also serve as hosts for infected fleas in some U.S. regions, including Texas.
Exposure Routes: Murine typhus spreads through contact with infected fleas, either through a flea bite or when infected flea feces contact broken skin, the eyes, nose, or mouth. It is not spread directly from a rodent bite.
General Warning Signs: Symptoms typically begin 7 to 14 days after exposure and can include fever, chills, headache, body aches, nausea, and a rash that often starts on the trunk of the body around day five of illness.
Prevention: Controlling rat populations and the fleas they carry is the primary prevention method, since no vaccine exists. This means both rodent exclusion and general yard maintenance, clearing brush and debris where fleas and their hosts can live, matter together.
Lymphocytic Choriomeningitis (LCMV)
What It Is: A viral infection caused by lymphocytic choriomeningitis virus (LCMV), a member of the arenavirus family.
How Rodents Contribute: The house mouse is the primary natural host. The CDC notes an estimated 5 percent of house mice in the United States carry LCMV, and infected mice can shed the virus for life without showing any signs of illness themselves.
Exposure Routes: Exposure occurs through contact with fresh urine, droppings, saliva, or nesting material from an infected mouse, particularly when it reaches broken skin, the eyes, nose, or mouth, or through inhaling contaminated dust. A bite from an infected rodent is also a possible route.
General Warning Signs: Most healthy people have no symptoms or mild flu-like symptoms, including fever and fatigue, typically starting one to two weeks after exposure. Pregnant individuals and people with weakened immune systems are at higher risk for more serious illness, which is worth mentioning to a doctor given a known exposure.
Prevention: Because house mice are the primary host, standard mouse exclusion and sealing is the main prevention method. Avoid sweeping or vacuuming areas with mouse droppings without ventilating and wetting the area first, the same precaution used for other rodent-borne illnesses.
The Common Thread
Why Exclusion Matters More Than Any Single Precaution
Every disease on this page traces back to the same root cause: rodents present on a property. Careful cleanup and basic hygiene reduce risk after the fact, but the only way to prevent exposure at the source is to seal the entry points a rodent would use to get in, so there is nothing to accumulate droppings, urine, or fleas on your property in the first place. This is the same principle behind everything else we do. See our rodent exclusion page for how that process actually works.
Questions
Rodent-Borne Diseases: FAQs
Which of these diseases is most relevant to McAllen and South Texas specifically?
Murine typhus is worth particular attention here, since the CDC notes most U.S. cases occur in Texas, California, and Hawaii. Hantavirus risk is also relevant on rural and semi-rural properties where deer mice are more common.
Can I get one of these diseases just from seeing a rodent, without touching anything?
No. Every disease on this page requires some form of contact, whether that is a bite, contact with droppings or urine, a flea bite, or inhaling airborne particles from disturbed material. Simply seeing a rodent does not transmit disease.
Are these diseases common, or is this overly cautious information?
Most are considered uncommon to rare in general, but the CDC and state health departments track them specifically because rodent exposure is a known, ongoing risk factor. The precautions on this page are standard pest control guidance, not an unusual level of caution.
Does professional pest control reduce disease risk, or just the rodent population?
Both. Removing existing rodents and sealing entry points reduces the population contributing droppings, urine, and fleas to a property, which is the underlying source of exposure risk for every disease covered here.
Should I be more careful about hantavirus than the other diseases on this list?
Hantavirus carries a higher severity profile than several of the others, which is why our dedicated hantavirus page goes into more depth on safe cleanup specifically. That said, all of the precautions on this page are worth following regardless of which disease is the concern.
For species identification, prevention, and pricing guides beyond disease risk, see our full rodent control resources hub.
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