Children: Early Swim Lessons May Reduce Drowning

The idea might seem obvious, but some safety experts have raised concerns that teaching young children to swim may put them at higher risk by diminishing their natural fear of water or making their caregivers overconfident. The American Academy of Pediatrics, for example, recommends swimming lessons for children 5 and up but has not taken a position on lessons for younger children because not enough was known about their effect, the researchers note.

The study, which appears in The Archives of Pediatric & Adolescent Medicine, looked at drowning deaths of people ages 1 to 19 in six states over two years. Researchers compared the swimming experience of the victims with that of similarly aged children in the same county.

Led by Dr. Ruth A. Brenner of the National Institute of Child Health and Human Development, they found that swimming lessons did not increase the drowning risk for younger children and, in fact, seemed to decrease it.

But the authors cautioned that swimming lessons alone “will not prevent drowning and that even the most proficient swimmers can drown.”

Reverse Triage Increases Hospital Beds During Disaster

By Todd Neale, Staff Writer, MedPage Today
Published: April 08, 2009
Reviewed by Dori F. Zaleznik, MD; Associate Clinical Professor of Medicine, Harvard Medical School, Boston.

LITTLE FALLS, N.J., April 8 -- Discharging noncritical patients appears to be an effective way to increase a hospital's capacity for emergency admissions during a public disaster, researchers found.

Explain to interested patients that this study examined the potential impact of discharging noncritical patients during a hypothetical disaster for freeing up hospital bed space.

In three hospitals in a single health system in Maryland, so-called reverse triage contributed to 50%, 55%, and 59% of the creation of surge capacity during a hypothetical disaster of short duration, Gabor Kelen, M.D., of Johns Hopkins in Baltimore, and colleagues reported online in Disaster Medicine and Public Health Preparedness.

"Making hospital beds available for victims of a mass emergency may be easier than once thought," Dr. Kelen said. "Reverse triage . . . can significantly increase surge capacity without a corresponding increase in resources."

Hospitals in the U.S. are expected to function without outside help for up to four days during a disaster.

But the researchers cited concerns about their ability to absorb large numbers of casualties. So they set out to explore how the reverse triage of low-risk patients during the first 96 hours of a hypothetical disaster would affect surge capacity.

Within a single health system in Maryland, they canvassed inpatient units for 19 weeks at a 1,017-bed inner-city university hospital, a 355-bed teaching hospital in a working class neighborhood, and a 260-bed community hospital in a mostly wealthy county.

Nurseries, pediatric units, and ICUs were excluded.

Any patients who did not require any critical intervention -- used as a proxy for a consequential medical event -- within four days of the hypothetical disaster were deemed suitable for early discharge.

Critical interventions ranged from CPR and defibrillation, major surgery, and dialysis to blood transfusion and lumbar puncture.

Of 3,491 total patients, 44% qualified for early discharge (40% at the university hospital, 47% at the teaching hospital, and 59% at the community hospital).

After accounting for normal patient discharges and full use of staffed and unstaffed beds, the researchers estimated gross surge capacity -- beds available for disaster victims only -- at 77%, 95%, and 103% for the three hospitals, respectively.

After further accounting for normal emergency but nondisaster-related admissions, the net surge capacity was 66%, 71%, and 81%, respectively.

Reverse triage accounted for the bulk of the surge bed creation at each hospital, with additional contributions from unused licensed beds, routine discharge, and unused staffed beds.

"Reverse triage offers an important new approach in the creation of surge capacity, requiring no substantial resource increment," the researchers said.

Most of the surge capacity would have been available within 24 to 48 hours in an actual disaster situation.

And, the researchers said, "an even larger percentage of patients could be safely sent home or avoid admission, should the concept of hospital at home be available during a disaster."

They acknowledged that the study did not provide a method for predicting in advance which patients are unlikely to require a critical intervention in the coming days, "but it does show that if a system predicting risk can be harnessed, it would be a powerful tool."

The findings might not apply to a longer-term disaster, such as an influenza outbreak, they said.

The study was funded in part by the Agency for Healthcare Research and Quality and by a Department of Homeland Security Center of Excellence Grant.

The authors made no financial disclosures.
Primary source: Disaster Medicine and Public Health Preparedness
Source reference:
Kelen G, et al "Creation of surge capacity by early discharge of hospitalized patients at low risk for untoward events" Disaster Med Public Health Prep 2009; DOI: 10.1097/DMP.0b013e3181a5e7cd.

April is STD Awareness Month

April is STD Awareness Month, an annual observance to raise awareness about the impact of sexually transmitted diseases (STDs) on the health of Americans and the importance of individuals discussing sexual health with their healthcare providers and, if sexually active, their partners.

STDs are a major public health issue:

CDC estimates that there are approximately 19 million new cases of STDs each year in the United States, almost half of them among young people ages 15 to 24.
STDs have an economic impact: direct medical costs associated with STDs in the United States are estimated at $15.9 billion annually.
Vaccines offer protection against two common sexually transmitted viral infections: hepatitis B and Human Papillomavirus (HPV). CDC recommends their use for people at risk.

While serious health threats from STDs cross racial and ethnic lines, disparities persist at too high a level.
Higher rates of the most commonly reported STDs persist among African-Americans and Hispanics when compared to whites.
Most STDs have been associated with increased risk of HIV transmission.

Vitamin D Pills May Prevent Fractures in Older Adults

March 31, 2009
Vital Signs
By NICHOLAS BAKALAR

Vitamin D supplements may help prevent fractures in people over 65, provided they take enough of the right kind. A new review of clinical trials appears to show a strong dose-dependent effect for vitamin D in lowering the risk for nonvertebral fractures in the elderly.

The lead author of the analysis, Heike A. Bischoff-Ferrari, a professor of medicine at the University of Zurich, said that “vitamin D in a high enough dose is not only beneficial in the frail older population, but it also works in those still living at home and able to take care of themselves.”

The researchers, writing in the March 23 issue of The Archives of Internal Medicine, reviewed 12 randomized trials that together included more than 65,000 subjects. Doses under 400 international units a day had no discernible effect, but for doses larger than that, the pooled data showed a 20 percent reduction in the risk for all nonvertebral fractures, and an 18 percent reduction for broken hips.

The type of vitamin D made a difference. The effect of vitamin D3 was significant, with a 23 percent risk reduction, but there was no significant reduction with vitamin D2. The authors suggest that D3 is more effective in maintaining blood levels of 25-hydroxyvitamin D, the active form that the supplement takes in the body.

Heart Muscle Renewed Over Lifetime, Study Finds

In a finding that may open new approaches to treating heart disease, Swedish scientists have succeeded in measuring a highly controversial property of the human heart: the rate at which its muscle cells are renewed during a person’s lifetime.

Tests of nuclear weapons in the atmosphere, which lasted until 1963, generated a radioactive form of carbon, carbon-14. The carbon-14 in carbon dioxide is breathed in by plants, turned into glucose (see equation) and enters the human diet. In the body, the carbon-14 is incorporated into new DNA, and once a new cell is made, its DNA does not change. The level of carbon-14 in the atmosphere has dropped each year since 1963 (see graph), so the exact amount in a cell marks the year the cell was born. From a cell's birth date, researchers can calculate how quickly different tissues such as the intestine, brain and heart are renewed.

Dr. Jonas Frisén of the Karolinska Institute in Stockholm.
The finding upturns what has long been conventional wisdom: that the heart cannot produce new muscle cells and so people die with the same heart they were born with.

About 1 percent of the heart muscle cells are replaced every year at age 25, and that rate gradually falls to less than half a percent per year by age 75, concluded a team of researchers led by Dr. Jonas Frisen of the Karolinska Institute in Stockholm. The upshot is that about half of the heart’s muscle cells are exchanged in the course of a normal lifetime, the Swedish group calculates. Its results are to be published Friday in the journal Science.

“I think this will be one of the most important papers in cardiovascular medicine in years,” said Dr. Charles Murry, a heart researcher at the University of Washington in Seattle. “It helps settle a longstanding controversy about whether the human heart has any ability to regenerate itself.”

If the heart can generate new muscle cells, researchers can hope to develop drugs that might accelerate the process, since the heart fails to replace cells that are killed in a heart attack.

The dogma that the heart cannot generate new muscle cells has been challenged since 1987 by a somewhat lonely skeptic, Dr. Piero Anversa, now of the Harvard Medical School. Dr. Anversa maintains that heart muscle cells are renewed so fast that a person dying at age 80 has replaced the heart four times over. Many other researchers have doubted this assertion.

Cell turnover rates can easily be measured in animals by making their cells radioactive and seeing how fast they are replaced. Such an experiment, called pulse-labeling, could not ethically be done in people. But Dr. Frisen realized several years ago that nuclear weapons tested in the atmosphere until 1963 had in fact labeled the cells of the entire world’s population.

The nuclear blasts generated a radioactive form of carbon known as carbon-14. The amount of carbon-14 in the atmosphere has gradually diminished since 1963, when above-ground tests were banned, as it has been incorporated into plants and animals or diffused into the oceans.

In the body, carbon-14 in the diet gets into the DNA of new cells and stays unchanged for the life of the cell. Because the level of carbon-14 in the atmosphere falls each year, the amount of carbon-14 in the DNA can serve to indicate the cell’s birth date, Dr. Frisen found.

Four years ago he used his new method to assess the turnover rate of various tissues in the body, concluding that the average age of the cells in an adult’s body might be as young as 7 to 10 years. But there is a wide range of ages — from the rapidly turning over cells of the blood and gut to the mostly permanent cells of the brain.

Dr. Frisen has successfully applied his method to the heart muscle cells, but had to navigate a series of technical obstacles created by the special behavior of the cells. Many have two nuclei, instead of the usual one, and within these double nuclei the DNA may be duplicated again. “I was really impressed at the level of rigor they put into this analysis,” Dr. Murry said, calling it a “scientific tour de force.”

The finding that heart muscle cells do regenerate, though at a considerably slower rate than Dr. Anversa predicted, is a “reasonable conclusion to a hotly contested issue,” Dr. Murry said. “Anversa went out on a limb, and I think he was partly right.”

Dr. Loren Field, a heart expert at the Indiana University School of Medicine, said he had found that heart muscle cells regenerated in mice at the same rate that Dr. Frisen had found in people. Despite the controversy created by Dr. Anversa’s claims, there has long been agreement that there is a low but detectable rate of cell renewal in the heart, Dr. Field said. The goal now, in his view, is “to try to tickle the system to enhance it.”

Dr. Anversa, for his part, said he was “ecstatic” at Dr. Frisen’s confirmation of his view that the heart could generate new muscle cells, but suggested that the new measurements might have underestimated the rate at which new cells are formed. Since heart muscle cells contract 70 times a minute, they seem likely to need renewing more often than Dr. Frisen’s measurements suggest, he said. “Now let’s discuss the magnitude of the process, and that will let us think about how we can apply this concept to heart failure,” Dr. Anversa said.

Dr. Frisen said he did not agree that the rate of regeneration had been underestimated. He said it would now be worth trying to understand how the regeneration of heart muscle cells was regulated.

A zebrafish, for instance, can regenerate large regions of its heart after injury, and possibly a similar response could be induced in people. It could also be that the heart does generate many new muscle cells after a heart attack but that the cells fail to establish themselves. Drugs that kept any such new cells alive could be helpful, Dr. Frisen said.

Fewer Sugary Drinks Key to Weight Loss

Cutting down on sodas, other sweet beverages may work better than eating less, study finds

HealthDay
Thursday, April 2, 2009

THURSDAY, April 2 (HealthDay News) -- When it comes to losing weight, cutting back on the calories in sugar-sweetened drinks, rather than food, may be most important.

So say researchers who found that cutting back on calories from sugary beverages -- by only one serving per day -- accounted for nearly two-and-a-half pounds of lost weight over 18 months.

"Weight loss from liquid calories is greater than loss of calorie intake from solid food," concluded lead researcher Dr. Liwei Chen, an assistant professor of epidemiology at the School of Public Health at the LSU Health Science Center in New Orleans.

One reason for this is that the body is able to self-regulate its intake of solid food. For example, if you eat too much solid food at lunch, you'll tend to eat less at dinner. But the same self-regulation is not there for what you drink, experts say. Your body does not adjust to liquid calories, so over time, you gain more weight, Chen explained.

"If you reduce your intake of beverages, particularly sugar-containing beverages, it's a simple but easy way to help you maintain your weight," Chen said. "You can avoid additional weight gain, or if you are on a diet, it's an easy, simple way to help you achieve your goals," Chen added.

One dietitian said the finding wasn't so surprising.

The study "supports what many have suspected -- liquid calories don't satisfy," said Connie Diekman, director of university nutrition at Washington University in St. Louis. "In addition, the identification that [sugar-sweetened beverages] can impact weight gain more than other liquids is an important message as Americans continue to work to lower their calories."

And if you get thirsty? "Drink water," Chen said.

The report was published in the April 1 issue of the American Journal of Clinical Nutrition.

For the study, researchers studied the diets of 810 adults 25 to 79 years old who participated in the Lifestyle Interventions for Blood Pressure Control (PREMIER) trial. People in the trial, which lasted 18 months, were randomly assigned to one of three groups: advice about lowering blood pressure; lifestyle intervention (including dieting advice and exercise to lower blood pressure); or lifestyle intervention plus a specific diet that was rich in fruits and vegetables.

In the current study, researchers specifically looked at the weight of the participants and the beverages they drank. People in PREMIER had their weight measured at six and 18 months and were quizzed about their diet by unannounced phone interviews.

Beverages were placed into seven categories: sugar-sweetened beverages (including soft drinks, fruit drinks, fruit punch, or high-calorie beverages sweetened with sugar); diet drinks such as diet soda and other diet drinks that were artificially sweetened; milk (including whole milk, 2 percent milk, 1 percent and skim); 100 percent fruit and vegetable juice; coffee and tea with sugar; coffee and tea without sugar; alcoholic beverages.

The researchers found that sugar-sweetened drinks accounted for 37 percent of all the liquid calories people in the study consumed. Among beverages, sugar-sweetened beverages were the only type of beverage type significantly associated with weight change at both the 6 and 18 months, the researchers noted.

Drinking fewer sugary drinks was more important than eating less for losing weight, the researchers found. In fact, drinking one less serving of a soft drink was associated with just over one pound of weight loss at six months and an additional weight loss of more than 1.4 pounds at 18 months.

Diekman said the findings are a reminder that little things mean a lot when it comes to weight loss.

"If one small diet change can trigger a one-half- to one-pound weight loss in six months, adding other small changes or boosting activity even 15 minutes a day could make 'healthy' more attainable," she said. "As a registered dietitian, this study indicates to me that helping people make gradual changes will help them comfortably achieve a healthier weight."

Consuming liquid calories has increased along with the obesity epidemic, Chen's group noted. In earlier studies, researchers found that 75 percent of U.S. adults could be overweight or obese by 2015, and they tied drinking sugar-sweetened beverages to the obesity epidemic.

In 2006, the nation's major soft drink companies agreed to limit the sale of sodas in U.S. schools. That deal was brokered by the Alliance for a Healthier Generation, a joint effort of the American Heart Association and the President William J. Clinton Foundation.

What to Do if You Have a Potential Rabies Exposure

Rabies is a medical urgency not an emergency, but decisions must not be delayed. Any wounds should be immediately washed and medical attention from a health care professional should be sought for any trauma due to an animal attack before considering the need for rabies vaccination.

The need for rabies vaccination should be evaluated under the advisement of your physician and/or a state or local health department official. Decisions to start vaccination, known as postexposure prophylaxis (PEP), will be based on your type of exposure, the animal you were exposed to, as well as laboratory and surveillance information for the area where the exposure occurred.

What Were You Exposed To?
Rabies virus is transmitted through specific bodily excretions and tissue. Saliva and Brain/Nervous tissue are considered infectious materials that can transmit rabies virus. If contact with either of these has occurred the type of exposure should be evaluated to determine if PEP is necessary.

Contact such as petting or handling an animal, or contact with blood, urine or feces does not constitute an exposure, and therefore no postexposure prophylaxis is needed in these situations.

Rabies virus becomes noninfectious by desiccation and ultraviolet irradiation. Different environmental conditions affect the rate at which the virus becomes inactive, but in general, if the material containing the virus is dry, the virus can be considered noninfectious.

What Type of Exposure Occurred?
Rabies is transmitted only when the virus is introduced into a bite wound, open cuts in skin, or onto mucous membranes (such as the mouth or eyes).

When an exposure has occurred, the likelihood of rabies infection varies with the nature and extent of that exposure. Under most circumstances, two categories of exposure -- bite and nonbite -- should be considered.

Bite
Any penetration of the skin by teeth constitutes a bite exposure. All bites, regardless of body site, represent a potential risk of rabies transmission, but that risk varies with the species of biting animal, the anatomic site of the bite, and the severity of the wound.

Bites by some animals, such as bats, can inflict minor injury and thus be difficult to detect.

Nonbite
Nonbite exposures from terrestrial animals rarely cause rabies. However, occasional reports of rabies transmission by nonbite exposures suggest that such exposures should be evaluated for possible PEP administration.

The contamination of open wounds, abrasions, mucous membranes, or theoretically, scratches (potentially contaminated with infectious material from a rabid animal) also constitutes a nonbite exposure.

Other contact by itself, such as petting a rabid animal and contact with blood, urine, or feces of a rabid animal, does not constitute an exposure and is not an indication for PEP.

Circumstances of Biting Incident and Vaccination Status of Exposing Animal
An unprovoked attack by an animal is more likely than a provoked attack to indicate that the animal is rabid. Bites inflicted on a person attempting to feed or handle an apparently healthy animal should generally be regarded as provoked.

Other factors to consider when evaluating a potential rabies exposure include the local rabies epidemiology in the area, the biting animal’s history and current health status (e.g., abnormal behavior, signs of illness), and the potential for the animal to be exposed to rabies (e.g., presence of an unexplained wound or history of exposure to a rabid animal).

A currently vaccinated dog, cat, or ferret is unlikely to become infected with rabies.

What kind of animal did you have contact with?
Rabies surveillance in wild animal populations tells us that the type of animal you are exposed to affects your risk of rabies. Knowing the species of animal you were exposed to will affect decisions regarding your treatment.

Additionally, based on what is known about rabies in different species, the animal may be held for observation or immediately tested providing information which will be used to determine if rabies Post Exposure Prophylaxis is necessary.

Animal Type to Postexposure Prophylaxis Table Animal Type Evaluation and Disposition of Animal Postexposure Prophylaxis Recommendations
Dogs, cats, and ferrets Healthy and available for 10 day observation Persons should not begin vaccination unless animal develops clinical signs of rabies
Rabid or suspected rabid Immediately vaccinate
Unknown (escaped) Consult public health officials
Raccoons, skunks, foxes, and most other carnivores; Bats Regarded as rabid unless animal is proven negative by laboratory test Consider immediate vaccination
Livestock, horses, rodents, rabbits and hares, and other mammals Consider individually Consult public health officials.

Bites of squirrels, hamsters, guinea pigs, gerbils, chipmunks, rats, mice, other small rodents, rabbits, and hares almost never require rabies postexposure prophylaxis.

Domestic Dogs, Cats, and Ferrets
The likelihood of rabies in a domestic animal varies by region; hence, the need for postexposure prophylaxis also varies.

In the continental United States, rabies among dogs is reported sporadically in states with enzootic wildlife rabies.

During 2000–2004, more cats than dogs were reported rabid in the United States. The majority of these cases were associated with spillover infection from raccoons in the eastern United States. The large number of rabies-infected cats might be attributed to fewer cat vaccination laws, fewer leash laws, and the roaming habits of cats.

In many developing countries, dogs are the major vector of rabies; exposures to dogs in such countries represent an increased risk of rabies transmission.

Other Domestic Animals
In all instances of exposure to other domestic animal species, the local or state health department should be consulted before a decision is made to euthanize and test the animal or initiate postexposure prophylaxis.

Other Exotic Pet Species
Other exotic mammalian species of animals kept as pets are considered the same as other wildlife species. Consultation should be sought from local or state health departments regarding decisions on postexposure prophylaxis.

Use of rabies vaccines in these species constitutes off-label usage. Vaccination may reduce the risk of rabies in these species, but does not eliminate the risk. Efficacy of rabies vaccines have not been demonstrated in any exotic pet species, and are not licensed for these animals. Furthermore, observation periods are not recommended with these species since virus shedding periods before onset of clinical signs are unknown. Considerations should be made to the housing of the animal, its potential to be exposed to and acquire rabies, and the circumstances of the potential exposure to a human or domestic animal.

In situations where rabies is suspected in an exotic pet species (to which a human or domestic animal exposure has occurred) it is recommended to euthanize and test the animal for rabies.

Bats
Rabid bats have been documented in all 49 continental states (Hawaii is rabies free), and bats are increasingly implicated as important wildlife reservoirs for variants of rabies virus transmitted to humans.

Recent data suggest that transmission of rabies virus can occur from minor, seemingly unimportant, or unrecognized bites from bats. Human and domestic animal contact with bats should be minimized, and bats should never be handled by untrained and unvaccinated persons or be kept as pets.

In all instances of potential human exposures involving bats, the bat in question should be safely collected, if possible, and submitted for rabies diagnosis. Rabies postexposure prophylaxis is recommended for all persons with bite, scratch, or mucous membrane exposure to a bat, unless the bat is available for testing and is negative for evidence of rabies.

Postexposure prophylaxis should be considered when direct contact between a human and a bat has occurred, unless the exposed person can be certain a bite, scratch, or mucous membrane exposure did not occur.

In instances in which a bat is found indoors and there is no history of bat-human contact, the likely effectiveness of postexposure prophylaxis must be balanced against the low risk such exposures appear to present. Postexposure prophylaxis can be considered for persons who were in the same room as a bat and who might be unaware that a bite or direct contact had occurred (e.g., a sleeping person awakens to find a bat in the room or an adult witnesses a bat in the room with a previously unattended child, mentally disabled person, or intoxicated person) and rabies cannot be ruled out by testing the bat. Postexposure prophylaxis would not be warranted for other household members.

Wild Terrestrial Carnivores (Raccoons, Skunks and Foxes)
Raccoons, skunks, foxes, and coyotes are the terrestrial animals most often infected with rabies in the United States. All bites by such wildlife must be considered a possible exposure to the rabies virus.

Postexposure prophylaxis should be initiated as soon as possible following exposure to such wildlife unless the animal has already been tested and determined not to be rabid. If postexposure prophylaxis has been initiated and subsequent testing shows that the exposing animal was not rabid, postexposure prophylaxis can be discontinued.

Signs of rabies among wildlife cannot be interpreted reliably; therefore, any such animal that exposes a person should be euthanized as soon as possible (without unnecessary damage to the head) and the brain should be submitted for rabies testing. If the results of testing are negative, the saliva can be assumed to contain no virus, and the person exposed does not require postexposure prophylaxis.

Other Wild Animals
Small rodents (e.g., squirrels, hamsters, guinea pigs, gerbils, chipmunks, rats, and mice) and lagomorphs (including rabbits and hares) are almost never found to be infected with rabies and have not been known to transmit rabies to humans. From 1990 through 1996, in areas of the country where raccoon rabies was enzootic, woodchucks (groundhogs) accounted for 93% of the 371 cases of rabies among rodents reported to CDC.

In all cases involving rodents, the state or local health department should be consulted before a decision is made to initiate postexposure prophylaxis.

The offspring of wild animals crossbred to domestic dogs and cats (wild animal hybrids) are considered wild animals by the National Association of State and Public Health Veterinarians (NASPHV) and the Council of State and Territorial Epidemiologists (CSTE). Wild animals and wild animal hybrids should not be kept as pets. In instances where wild or hybrid animals are suspected of rabies they should be euthanized and tested for rabies.

Human exposure situations involving animals maintained in United States Department of Agriculture-licensed research facilities or accredited zoological parks should be evaluated on a case-by-case basis.

Availability of the Animal for Observation or Rabies Testing
A healthy domestic dog, cat, or ferret that bites a person should be confined and observed for 10 days.

Any illness in the animal during the confinement period or before release should be evaluated by a veterinarian and reported immediately to the local public health department.

If signs suggestive of rabies develop, postexposure prophylaxis should be initiated. The animal should be euthanized and its head removed and shipped, under refrigeration, for examination by a qualified laboratory.

If the biting animal is stray or unwanted, it should either be confined and observed for 10 days or be euthanized immediately and submitted for rabies examination.

Skunks, raccoons, foxes and bats that bite humans should be euthanized and tested as soon as possible. The length of time between rabies virus appearing in the saliva and onset of symptoms is unknown for these animals and holding them for observation is not acceptable.

After exposure to wildlife in which rabies is suspected, prophylaxis is warranted in most circumstances. Because the period of rabies virus shedding in wild animal hybrids is unknown, these animals should be euthanized and tested rather than confined and observed when they bite humans.

Vaccination should be discontinued if tests of the involved animal are negative for rabies infection.

Content Source: National Center for Zoonotic, Vector-Borne, & Enteric Diseases (ZVED)