1. CEEZAD Home
  2. »News and Events
  3. »properties
  4. »2018 Pathogen of the Month

Center of Excellence for Emerging and Zoonotic Animal Diseases

Pathogen of the Month



September pathogen of the month:



What is it?

Plague is a bacterial disease transmitted by the fleas that infest on rodents. For most of the past century, plague in the United States has chiefly been found in rural and semi-rural areas of the West where many types of rodents can be found.

Many types of animals can be infected by plague. Wild carnivores can be infected by eating other infected animals. Such plagues can become epizootic, infecting humans.

History of plague

Plague has a notorious medical history dating back to ancient times. The first recorded pandemic, the Justinian plague, began in 541 and over the next two centuries was estimated to have killed 25 million people. The Black Death or Great Plague began in China in 1334 and spread through Europe, claiming an estimated 60 percent of the European population. The most recent major spread of plague broke out in China in the 1860s and spread across the world by rats aboard steamships. It causes an estimated 10 million deaths.

What is the current status?

The accompanying map shows the distribution of bubonic plague cases since 1976. A cat in Wyoming was recently confirmed to have been infected with plague. The case comes a little over a year after the plague was found in prairie dogs in the Thunder Basin National Grassland.

The last confirmed case in a human in Wyoming was in 2008, according to a department press release. Overall, there have been just 6 cases of plague in humans in Wyoming since 1978, according to the department. The United States overall averages 7 human cases a year.

"Plague is a serious bacterial infection that can be deadly for pets and for people if not treated as soon as possible with antibiotics," Alexia Harrist, state health officer and epidemiologist, said in a statement. "The disease can be transmitted to humans from ill animals and by fleas coming from infected animals."

Worldwide, Plague epidemics have occurred in Africa, Asia, and South America. Most human cases since the 1990s have occurred in Africa. Almost all of the cases reported in the last 20 years have occurred among people living in small towns and villages or agricultural areas rather than in larger towns and cities.


How serious can it be?

The Centers For Disease Control says Plague is a very serious illness, but is treatable with commonly available antibiotics. The earlier a patient seeks medical care and receives treatment that is appropriate for plague, the better their chances are of a full recovery.


The CDC lists several basic steps to minimize one’s risk of being exposed to Plague: These include: Reduce rodent habitat around your home, work place, and recreational areas; wear gloves if you are handling or skinning potentially infected animals to prevent contact between your skin and the plague bacteria; use repellent if you think you could be exposed to rodent fleas during activities such as camping, hiking, or working outdoors; keep fleas off of your pets by applying flea control products. Animals that roam freely are more likely to come in contact with plague infected animals or fleas and could bring them into homes; do not allow dogs or cats that roam free in endemic areas to sleep on your bed.



Source: Centers for Disease Control.


August pathogen of the month:


(The most common cause of gastroenteritis)


What is it?

Norovirus is a highly contagious virus known for its tendency to spread quickly in densely populated areas, as well as through contaminated food. Since it has a reputation for moving freely in areas with large numbers of confined people, it is informally known as a “cruise ship virus,” although it is also common in college dorms and restaurants. However, it is also known to be able to spread quickly via water – in such settings as swimming pools, making it a particular threat in summer. Symptoms include vomiting, diarrhea, and other gastrointestinal symptoms. Norovirus can live in water for several months or possibly even years, the Centers for Disease Control has said -- and lakes and ponds can pose a particular risk, since they're not treated with germ-killing chlorine.

The Centers for Disease control estimates that norovirus causes 19 to 21 million cases of acute gastroenteritis annually, contributing to as many as 71,000 hospitalizations and up to 800 deaths in the United States alone. The case fatality rate worldwide is about 7 persons per 100,000.

What is the current status?

Two recent outbreaks in the United States have thrust norovirus into the news. A July outbreak in Maine sickened nearly 100 people who visited a beach and swam in a lake in the town of Bridgton or had contact with others who had done so. Several people became ill after caring for someone who'd been at that beach and got sick -- even though they hadn't been to the beach themselves. That makes sense, say health officials, since norovirus can also spread through direct contact with infected people.

Also in July, a food court illness that sickened 350 people in Kentucky was identified as norovirus. Citing a Lexington-Fayette County Health Department release, the Lexington Herald-Leader reported that test results from those who had gone to the Fayette Mall food court were consistently positive for the very contagious virus.


How serious can it be?

The illness, which is often characterized as “food poisoning” or “stomach flu,” is not usually serious. There is no treatment, but most people get better within one to 2 days.

Even so, persons with a norovirus illness should drink plenty of liquids to replace fluid lost from vomiting and diarrhea. This will help prevent dehydration, which can lead to serious problems. Severe dehydration may require hospitalization for treatment with fluids given through your vein (intravenous or IV fluids).

Watch for signs of dehydration in children who have norovirus illness. Children who are dehydrated may cry with few or no tears and be unusually sleepy or fussy.



The Centers for Disease Control recommends several common-sense steps designed to reduce the risk of being affected by a norovirus. These steps include practicing proper hand-washing, the safe handling and preparation of food, cleaning and disinfecting surfaces and thorough washing of laundry. It also emphasizes that those who are showing symptoms of norovirus should not engage in the preparation of food for others.


Sources: Seattle Pierce County  Health Department; oie.int; Lexington Herald-Leader; Centers for Disease Control.




July pathogen of the month:

Rift Valley Fever

What is it?

Rift Valley Fever (RVF) is a disease of humans and ruminant animals (cattle, buffalo, sheep and goats) caused by a virus that is spread through mosquitoes. It is also spread to humans by direct contact with blood, fluids, or tissues of infected animals.

In animals, Rift Valley Fever can cause severe disease, death and abortions, resulting in serious economic consequences. In humans, symptoms include fever, weakness, back pain, dizziness, and weight loss. People usually recover in two days to one week. However, some people may suffer more severe illness, such as severe bleeding, inflammation and swelling of the brain, or eye disorders. About 1-10% of infected people may have permanent loss of vision. Approximately 2% of people who get RVFV die from the infection.


What is the current status?

A recent outbreak of Rift Valley Fever is causing widespread losses and illnesses in Eastern Africa, notably Tanzania, Rwanda, Kenya and South Africa. In parts of Kenya, where the disease was first identified in 1931, slaughterhouses have been closed for weeks following a recent outbreak. There, 26 human cases have been reported, six of them fatal. A regional meeting of a council on Agriculture and Food Security in Dar es Salaam, Tanzania directed East African nations to address the issue of Rift Valley Fever promptly.


How serious can it be?

                2016 outbreaks in Uganda and Niger identified nearly 350 human cases, 33 of them fatal. In ruminants, losses translate to animals that do not enter into the food chain, and to an increase in abortions resulting in decreases of future generations of animals. Impacts are also measure in decreases to the availability of dairy products. The Centers for Disease control says analysts characterize the potential disruption to the economy of a stricken nation as devastating.


The best prevention steps involve control of the mosquito vector as well as vaccination campaigns.

What’s CEEZAD doing about it?

CEEZAD scientists Juergen Richt, Igor Morozov, and Bonto Fabuary, working in conjunction with USDA research microbiologist Bill Wilson, are engaged in the development of a safe, efficacious and DIVA-compatible vaccine to prevent ruminant animals from developing Rift Valley Fever.


Sources: CDC, CEEZAD.org, World Health Organization, Promedmail.org


June Pathogen of the Month:

Lyme Disease


What is it?Lyme Disease Symptoms

Lyme disease is a chronic, debilitating disease. It could be caused by the bacterium Borrelia burgdorferi and transmitted to humans by the bite of infected blacklegged ticks,although scientists believe its worldwide nature make it possible that other bacterium and/or other vectors could also be involved. That possibility is under study. The riskiest months for Lyme Disease are typically May through September when young ticks are biting. Typical symptoms  include fever, headache, fatigue, and a characteristic skin rash called erythema migrans.

What is the current status?

The disease, which is widespread in the northeast and Great Lakes areas, has recently been reported to be spreading in Canada. Although concentrations are heavier in the northeast and Great Lakes areas, Lyme Disease is widespread in the United States during summer months. In 2016, there were more than 36,000 confirmed or suspected cases in all but three states, including 16 confirmed and 23 suspected cases in Kansas. Worldwide, the Lyme Disease Association has identified Lyme Disease in more than 80 countries on every continent except Antarctica (see map).

Lyme Disease MapLyme Disease USA Map

How serious can it be?

Lyme Disease is a serious, acute and chronic, multi-systemic disease that can have long-term consequences for those affected by it. It can attack many tissues, including the heart, colon and nervous system. Even in cases where treatment is successful in relieving symptoms, it is not unusual for that two-to-four week treatment period to be followed by lingering symptoms of fatigue, joint pain or muscle aches, sometimes lasting several months.


The Lyme Disease Association emphasizes use of tick repellents, proper clothing, tick checks and proper tick removal techniques after outdoor activities as the most effective prevention steps.


Sources: CDC, CEEZAD.org, Lyme Disease Association Inc.


May Pathogen of the Month:



What is it? Ebola Virus

The World Health Organization describes Ebola as a severe, often fatal viral disease. Ebola first appeared in 1976 in Africa near the Ebola River, giving the illness its name. Symptoms include the sudden onset of fever fatigue, muscle pain, headache and sore throat. The disease can be difficult to distinguish from other infectious viruses. The virus has also shown some ability to persist and therefore be passed along by patients who have recently recovered from its effects.

What causes its spread?

Ebola is transmitted to humans from wild animals, the most likely source being the fruit bat. Those bats are believed to be the source of infection, transmitting the virus to chimpanzees, gorillas, monkeys, forest antelopes and porcupines, who in turn pass it to humans through close contact with blood, organs, secretions or other bodily fluids. But it can also be spread via human-to-human transmission by direct contact and eventually by sexual contact.

Ebola Virus Path - Human Being

How widespread is it?

The most recent serious outbreak was in 2014-16 in West Africa, its range extending from Guinea to Sierra Leone and Liberia. More than 28,000 cases were reported in those three nations alone with an estimated 11,310 fatalities.

What is CEEZAD doing about it?

The December 2017 edition of Medecine et Sante Tropicale includes an article co-written by Dr. Jean Paul Gonzalez, CEEZAD’s deputy director, on recent developments in the effort to contain Ebola.


Sources: WHO, CEEZAD.org, epainassist.com, NewsnViews.


April Pathogen of the Month:




What is it?   Leishmaniasis-affected Leg

The World Health organization describes leishmaniasis as a disease caused by the protozoan Leishmania parasites transmitted by the bite of infected female phlebotomine sandflies. There are three main forms of leishmaniases – visceral (also known as kala-azar and the most severe form of the disease), cutaneous and mucocutaneous, the most common. The disease affects some of the poorest people on earth, and is associated with malnutrition, population displacement, poor housing, a weak immune system and lack of financial resources.    

What causes its spread?

Leishmaniasis is linked to environmental changes that disturb the ecosystem of the sandfly vectors such as deforestation, building of dams, irrigation schemes, and urbanization.

  Leishmaniasis Map

How widespread is it?

 The WHO estimates that 700,000 to 1 million new cases occur annually, with between 20,000 and 30,000 deaths worldwide.


Have outbreaks occurred recently?

Yes. In March, a medical organization documented about 35,000 cases of infection with leishmaniasis in northern and central Syria. Last year, about 70 cases of visceral leishmaniasis, also known as the black fever, were diagnosed in Syria.

What is CEEZAD doing about it?

The March 2018 edition of the American Journal of Tropical Medical Hygiene included an article co-written by Dr. Jean Paul Gonzalez, CEEZAD’s deputy director, on the causes of leishmaniasis infection in Libya. In the paper’s abstract, the article’s authors report on findings from their screening of sandflies for leishmanial DNA.


Sources: OIE, WHO, CMAJ, Pasteur Institute, Libyan National Center For Disease Control, University of Sabratha, University of Tripoli.


March Pathogen of the Month:



Hantavirus in Brief 

What is it?

Hantavirus Pulmonary Syndrome, known more simply as hantavirus, is a severe and potentially fatal respiratory disease in humans. It is carried by rodents, making it a potential threat even to those living in homes. Human-to-human transmission has not yet been reported in the United States, although rare cases of human-to-human transmission have been reported elsewhere.




Where is hantavirus

The Centers For Disease Control has been monitoring hantavirus infections since 1993; to date, more than 700 cases have been reported, 16 of them in Kansas. The virus appears to be more widespread in South America, with individual and small clusters of cases reported in nine nations on that continent. Large outbreaks are rare, but they can be serious. Scientists have listed the mortality rate from hantavirus at 38 per cent. Last year an outbreak in Washington state claimed three lives. Hantavirus extends worldwide and shows different clinical presentations and severities (see map). These presentations include HCPS and HFRS.It is most commonly found in rural areas with abundant forests, fields and farms for the rodent host.

Hantavirus Map


Humans are most at risk when they engage in activities with the potential to put them in contact with rodent urine, droppings, saliva or nesting materials. This can include sweeping and dusting. Opening or cleaning cabins, outbuildings and other structures closed for the winter can also present concerns. Campers and hikers can also be exposed. Hantavirus symptoms include fatigue, fever and muscle pains, particularly in the large muscle groups. These can be accompanied by headaches, dizziness, chills and abdominal pain, nausea, vomiting, and diarrhea.

Are there current outbreaks?

Yes. In January and February the nation of Chile reported five cases of hantavirus infection, one of them fatal.  In February, an Arizona woman contracted a disease subsequently diagnosed as hantavirus. Cases have also recently been reported in New Mexico and Colorado.A 2017 outbreak of Seoul virus infection, a version of hantavirus, was identified in 31 infected ratteries in 11 states, among them Iowa and Colorado. Seventeen human infections were reported.

Sources: CEEZAD; Centers for Disease Control; Reuters



February Pathogen of the Month:

Crimean Congo Hemorrhagic Fever


What is it?Crimean-Congo Hemorrhagic Fever

Crimean Congo hemorrhagic fever is a disease that causes severe bleeding in humans and animals. The virus, which is carried by ticks, kills 10 to 40 percent of its victims. It can also be transmitted to people through direct contact with infected animal blood or tissues. Human-to-human transmission is possible due to close contact with secretions from infected persons. Symptoms include fever, muscle ache, dizziness, neck pain, headache and light sensitivity. Nausea, vomiting and diarrhea also occur.

Distribution Map

Where is Crimean Congo hemorrhagic fever?

CCHF is endemic in Africa, the Balkans, the Middle East, and various Asian countries south ofthe 50th parallel north -- the present geographical limit of the principal tick vector. It has not yet established an ongoing presence in Western Europe, although researchers believe that could happen absent effective control strategies.  The hosts of the CCHF virus include a wide range of wild and domestic animals such as cattle, sheep, and goats. For this reason, animal herders, hunters, livestock workers and slaughterhouse workers are viewed as being particularly at risk.

 Is it a threat to humans?

Very much so. In January of 2018, an outbreak of what is known in Africa as 'Bleeding Eye Fever' killed four and infected dozens in South Sudan, Uganda and other areas of east Africa. In South Sudan, health chiefs warned that the spread could be "catastrophic". Up to 60 people were suspected to be infected, and were undergoing tests by a team from the Sudanese health ministry and the World Health Organization. It is difficult to prevent or control CCHF infection in animals as the tick-animal-tick cycle usually goes unnoticed and the infection in domestic animals is usually not apparent. Furthermore, the tick vectors are numerous and widespread, so tick control with chemicals is only a realistic option for well-managed livestock production facilities. In a possible response to climate change, tick vectors also appear to be moving westward from their historical distributions toward wetter environments.

What is CEEZAD doing about Crimean Congo hemorrhagic fever?

CEEZAD scientists have partnered with and support the research of Dr. Huseyin Yilmaz, a veterinarian at Istanbul Veterinary School in Turkey, whose work includes research into the epidemiology of CCHF.

Sources: World Health Organization, Centers For Disease Control, slideshare.net.