Monkeypox
Encyclopedia
Monkeypox also known as cockpox is an exotic infectious disease
caused by the monkeypox virus
. The disease was first identified in laboratory monkey
s, hence its name, but in its natural state it seems to infect rodent
s more often than primate
s. The disease is most prevalent in Central
and West Africa
, but an outbreak occurred also in the United States
in 2003.
Human monkeypox is a zoonotic viral
disease that occurs primarily in remote villages of Central and West Africa
in proximity to tropical rainforest
s where there is more frequent contact with infected animals. Monkeypox is usually transmitted to humans from rodent
s, pets, and primate
s through contact with the animal's blood
or through a bite. Human monkeypox can be difficult to distinguish clinically from smallpox
(to which it is closely related) and chickenpox
(to which it is not).
s (Cricetomys sp.), dormice (Graphiurus
sp.) and African squirrels (Heliosciurus, Funisciurus) have all been implicated as reservoirs of the virus. The use of these animals as food may be an important source of transmission to humans.
Monkeypox as a disease in humans was first associated with an illness in the Democratic Republic of the Congo
(formerly Zaire), in the town of Basankusu
, Équateur
Province, in 1970. A second outbreak of human illness was identified in DRC/Zaire
in 1996–1997. In 2003, a small outbreak of human monkeypox in the United States
occurred among owners of pet prairie dog
s. The outbreak originated from Villa Park IL, outside of Chicago, when a exotic animal dealer kept young prairie dogs in close proximity to an infected Gambian pouched rat (Cricetomys gambianus) recently imported from West Africa. Seventy-three people were reportedly infected, of which there were no fatalities.
A second African focus of infection has been discovered in Sudan
. No infected patients died.
, although it is often milder. Unlike smallpox, monkeypox t is assumed that vaccination
against smallpox would provide protection against human monkeypox infection considering that they are closely related viruses and the vaccine protects animals from experimental lethal monkeypox challenge. This has not been conclusively demonstrated in humans because routine smallpox vaccination was discontinued following the apparent eradication of smallpox and due to safety concerns with the vaccine. Limited person-to-person spread of infection has been reported in disease-endemic areas in Africa. Case-fatality ratios in Africa have ranged from 1% to 10%.
Centers for Disease Control and Prevention
(CDC) recommends that persons investigating monkeypox outbreaks and involved in caring for infected individuals or animals should receive a smallpox vaccination to protect against monkeypox. Persons who have had close or intimate contact with individuals or animals confirmed to have monkeypox should also be vaccinated. The people who have been infected can be vaccinated up to 14 days after exposure. CDC does not recommend preexposure vaccination for unexposed veterinarian
s, veterinary staff, or animal control officers, unless such persons are involved in field investigations.
This film, produced by INCEF for distribution in communities prone to infection, describes the nature of the illness and how best to confront it.
(44 cases), Indiana
(24), Illinois
(19), Ohio
(4), Kansas
(1), Missouri
(1), and New Jersey
(1). Analysis of the first 53 cases showed that 50 had contact with prairie dogs that were purchased from Phil's Pocket Pets of Villa Park, Illinois
. Electron microscopy and serologic studies were used to confirm that the disease was human monkeypox.
The onset of the illness among the patients in the United States began in early May 2003. Patients typically experienced a prodrome
consisting of fever, headaches, myalgia
s, chills, and drenching sweats. Roughly one-third of patients had nonproductive cough. This prodromal phase was followed 1–10 days later by the development of a papular rash that typically progressed through stages of vesiculation, pustulation, umbilication, and crusting. In some patients, early lesions had become ulcerated. Rash distribution and lesions occurred on head, trunk, and extremities; many of the patients had initial and satellite lesions on palms, soles, and extremities. Rashes were generalized in some patients. After onset of the rash, patients generally manifested rash lesions in different stages. All patients reported direct or close contact with prairie dogs, most of which were sick. Illness in prairie dogs was frequently reported as beginning with a blepharoconjunctivitis
, progressing to presence of nodular lesions in some cases. Some prairie dogs died from the illness, while others reportedly recovered.
Infectious disease
Infectious diseases, also known as communicable diseases, contagious diseases or transmissible diseases comprise clinically evident illness resulting from the infection, presence and growth of pathogenic biological agents in an individual host organism...
caused by the monkeypox virus
Monkeypox virus
Monkeypox virus is the virus that causes the disease monkeypox in both humans and animals. It was first identified in 1958 as a pathogen of crab-eating macaque monkeys being used as laboratory animals. The crab-eating macaque is often used for neurological experiments...
. The disease was first identified in laboratory monkey
Monkey
A monkey is a primate, either an Old World monkey or a New World monkey. There are about 260 known living species of monkey. Many are arboreal, although there are species that live primarily on the ground, such as baboons. Monkeys are generally considered to be intelligent. Unlike apes, monkeys...
s, hence its name, but in its natural state it seems to infect rodent
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
s more often than primate
Primate
A primate is a mammal of the order Primates , which contains prosimians and simians. Primates arose from ancestors that lived in the trees of tropical forests; many primate characteristics represent adaptations to life in this challenging three-dimensional environment...
s. The disease is most prevalent in Central
Central Africa
Central Africa is a core region of the African continent which includes Burundi, the Central African Republic, Chad, the Democratic Republic of the Congo, and Rwanda....
and West Africa
West Africa
West Africa or Western Africa is the westernmost region of the African continent. Geopolitically, the UN definition of Western Africa includes the following 16 countries and an area of approximately 5 million square km:-Flags of West Africa:...
, but an outbreak occurred also in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
in 2003.
Human monkeypox is a zoonotic viral
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
disease that occurs primarily in remote villages of Central and West Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
in proximity to tropical rainforest
Tropical rainforest
A tropical rainforest is an ecosystem type that occurs roughly within the latitudes 28 degrees north or south of the equator . This ecosystem experiences high average temperatures and a significant amount of rainfall...
s where there is more frequent contact with infected animals. Monkeypox is usually transmitted to humans from rodent
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
s, pets, and primate
Primate
A primate is a mammal of the order Primates , which contains prosimians and simians. Primates arose from ancestors that lived in the trees of tropical forests; many primate characteristics represent adaptations to life in this challenging three-dimensional environment...
s through contact with the animal's blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
or through a bite. Human monkeypox can be difficult to distinguish clinically from smallpox
Smallpox
Smallpox was an infectious disease unique to humans, caused by either of two virus variants, Variola major and Variola minor. The disease is also known by the Latin names Variola or Variola vera, which is a derivative of the Latin varius, meaning "spotted", or varus, meaning "pimple"...
(to which it is closely related) and chickenpox
Chickenpox
Chickenpox or chicken pox is a highly contagious illness caused by primary infection with varicella zoster virus . It usually starts with vesicular skin rash mainly on the body and head rather than at the periphery and becomes itchy, raw pockmarks, which mostly heal without scarring...
(to which it is not).
Epidemiology
In addition to monkeys, giant pouched ratGiant pouched rat
The giant pouched rats of sub-Saharan Africa are large muroid rodents. Their head and body length ranges from 25–45 cm with scaly tails ranging from 36–46 cm...
s (Cricetomys sp.), dormice (Graphiurus
Graphiurus
The African dormice, Graphiurus, are a genus of dormouse that live throughout sub-Saharan Africa in a variety of habitats. They are very agile climbers and have bushy tails...
sp.) and African squirrels (Heliosciurus, Funisciurus) have all been implicated as reservoirs of the virus. The use of these animals as food may be an important source of transmission to humans.
Monkeypox as a disease in humans was first associated with an illness in the Democratic Republic of the Congo
Democratic Republic of the Congo
The Democratic Republic of the Congo is a state located in Central Africa. It is the second largest country in Africa by area and the eleventh largest in the world...
(formerly Zaire), in the town of Basankusu
Basankusu
Basankusu is a town in Équateur Province, Democratic Republic of the Congo. It is the main town and administrative centre of the Territory of Basankusu. It boasts an airport, covered and open markets, a hospital and two recently installed cellphone networks....
, Équateur
Équateur
Équateur is one of the ten provinces of the Democratic Republic of Congo. It is in the north of the country, and bordered the Republic of the Congo to the west, the Central African Republic to the north, to the east the Orientale province, and to the south the Kasai-Oriental, Kasai-Occidental, and...
Province, in 1970. A second outbreak of human illness was identified in DRC/Zaire
Democratic Republic of the Congo
The Democratic Republic of the Congo is a state located in Central Africa. It is the second largest country in Africa by area and the eleventh largest in the world...
in 1996–1997. In 2003, a small outbreak of human monkeypox in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
occurred among owners of pet prairie dog
Prairie dog
Prairie dogs are burrowing rodents native to the grasslands of North America. There are five different species of prairie dogs: black-tailed, white-tailed, Gunnison's, Utah and Mexican prairie dogs. They are a type of ground squirrel, found in the United States, Canada and Mexico...
s. The outbreak originated from Villa Park IL, outside of Chicago, when a exotic animal dealer kept young prairie dogs in close proximity to an infected Gambian pouched rat (Cricetomys gambianus) recently imported from West Africa. Seventy-three people were reportedly infected, of which there were no fatalities.
A second African focus of infection has been discovered in Sudan
Sudan
Sudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the...
. No infected patients died.
Monkeypox disease in animals
The symptoms of a sick animal include: listlessness, ocular and nasal discharges, coughing, hair loss sometimes accompanied by painful scabs, and pneumonia. Look for nodules similar to mosquito bites and inflammation of the lymph glands.Symptoms and course
In humans, monkeypox is similar to smallpoxSmallpox
Smallpox was an infectious disease unique to humans, caused by either of two virus variants, Variola major and Variola minor. The disease is also known by the Latin names Variola or Variola vera, which is a derivative of the Latin varius, meaning "spotted", or varus, meaning "pimple"...
, although it is often milder. Unlike smallpox, monkeypox t is assumed that vaccination
Vaccination
Vaccination is the administration of antigenic material to stimulate the immune system of an individual to develop adaptive immunity to a disease. Vaccines can prevent or ameliorate the effects of infection by many pathogens...
against smallpox would provide protection against human monkeypox infection considering that they are closely related viruses and the vaccine protects animals from experimental lethal monkeypox challenge. This has not been conclusively demonstrated in humans because routine smallpox vaccination was discontinued following the apparent eradication of smallpox and due to safety concerns with the vaccine. Limited person-to-person spread of infection has been reported in disease-endemic areas in Africa. Case-fatality ratios in Africa have ranged from 1% to 10%.
Prevention and treatment
Currently, there is no proven, safe treatment for monkeypox. Smallpox vaccine has been reported to reduce the risk of monkeypox among previously vaccinated persons in Africa. The United StatesUnited States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
Centers for Disease Control and Prevention
Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...
(CDC) recommends that persons investigating monkeypox outbreaks and involved in caring for infected individuals or animals should receive a smallpox vaccination to protect against monkeypox. Persons who have had close or intimate contact with individuals or animals confirmed to have monkeypox should also be vaccinated. The people who have been infected can be vaccinated up to 14 days after exposure. CDC does not recommend preexposure vaccination for unexposed veterinarian
Veterinarian
A veterinary physician, colloquially called a vet, shortened from veterinarian or veterinary surgeon , is a professional who treats disease, disorder and injury in animals....
s, veterinary staff, or animal control officers, unless such persons are involved in field investigations.
This film, produced by INCEF for distribution in communities prone to infection, describes the nature of the illness and how best to confront it.
2003 U.S. outbreak
Through June 18, 2003, there were 93 cases of monkeypox in the United States including WisconsinWisconsin
Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...
(44 cases), Indiana
Indiana
Indiana is a US state, admitted to the United States as the 19th on December 11, 1816. It is located in the Midwestern United States and Great Lakes Region. With 6,483,802 residents, the state is ranked 15th in population and 16th in population density. Indiana is ranked 38th in land area and is...
(24), Illinois
Illinois
Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...
(19), Ohio
Ohio
Ohio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...
(4), Kansas
Kansas
Kansas is a US state located in the Midwestern United States. It is named after the Kansas River which flows through it, which in turn was named after the Kansa Native American tribe, which inhabited the area. The tribe's name is often said to mean "people of the wind" or "people of the south...
(1), Missouri
Missouri
Missouri is a US state located in the Midwestern United States, bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. With a 2010 population of 5,988,927, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. It...
(1), and New Jersey
New Jersey
New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...
(1). Analysis of the first 53 cases showed that 50 had contact with prairie dogs that were purchased from Phil's Pocket Pets of Villa Park, Illinois
Villa Park, Illinois
Villa Park is a suburb of Chicago in DuPage County, Illinois. The population was 22,075 at the 2000 census. A special census in 2003 set the population at 22,517...
. Electron microscopy and serologic studies were used to confirm that the disease was human monkeypox.
The onset of the illness among the patients in the United States began in early May 2003. Patients typically experienced a prodrome
Prodrome
In medicine, a prodrome is an early symptom that might indicate the start of a disease before specific symptoms occur. It is derived from the Greek word prodromos or precursor...
consisting of fever, headaches, myalgia
Myalgia
Myalgia means "muscle pain" and is a symptom of many diseases and disorders. The most common causes are the overuse or over-stretching of a muscle or group of muscles. Myalgia without a traumatic history is often due to viral infections...
s, chills, and drenching sweats. Roughly one-third of patients had nonproductive cough. This prodromal phase was followed 1–10 days later by the development of a papular rash that typically progressed through stages of vesiculation, pustulation, umbilication, and crusting. In some patients, early lesions had become ulcerated. Rash distribution and lesions occurred on head, trunk, and extremities; many of the patients had initial and satellite lesions on palms, soles, and extremities. Rashes were generalized in some patients. After onset of the rash, patients generally manifested rash lesions in different stages. All patients reported direct or close contact with prairie dogs, most of which were sick. Illness in prairie dogs was frequently reported as beginning with a blepharoconjunctivitis
Conjunctivitis
Conjunctivitis refers to inflammation of the conjunctiva...
, progressing to presence of nodular lesions in some cases. Some prairie dogs died from the illness, while others reportedly recovered.
External links
- CDC - Monkeypox Fact Sheet
- CDC Questions and Answers About Monkeypox
- CDC - Human Monkeypox -- Kasai Oriental, Zaire, 1996-1997
- CDC - Outbreak of Human Monkeypox, Democratic Republic of Congo, 1996 to 1997
- CDC Preliminary Report: Multistate Outbreak of Monkeypox in Persons Exposed to Pet Prairie Dogs
- INCEF education project to reduce Monkeypox transmission
- National Library of Medicine - Monkeypox virus
- Virology.net Picturebook: Monkeypox