West Nile Fever
West Nile virus
Disease Outbreaks
West Nile Virus Vaccines
Bird Diseases
Culex
Culicidae
West Nile fever--a reemerging mosquito-borne viral disease in Europe. (1/1137)
West Nile virus causes sporadic cases and outbreaks of human and equine disease in Europe (western Mediterranean and southern Russia in 1962-64, Belarus and Ukraine in the 1970s and 1980s, Romania in 1996-97, Czechland in 1997, and Italy in 1998). Environmental factors, including human activities, that enhance population densities of vector mosquitoes (heavy rains followed by floods, irrigation, higher than usual temperature, or formation of ecologic niches that enable mass breeding of mosquitoes) could increase the incidence of West Nile fever. (+info)Entomologic and avian investigations of an epidemic of West Nile fever in Romania in 1996, with serologic and molecular characterization of a virus isolate from mosquitoes. (2/1137)
Between July and October 1996, a West Nile (WN) fever epidemic occurred in the southern plain and Danube Valley of Romania and in the capital city of Bucharest, resulting in hundreds of neurologic cases and 17 fatalities. In early October 1996, entomologic and avian investigations of the epidemic were conducted in the city of Bucharest and nearby rural areas. Thirty (41%) of 73 domestic fowl sampled had neutralizing antibody to WN virus, including 5 of 13 ducks (38%), 1 of 1 goose, 19 of 52 chickens (37%), 1 of 1 peahen, and 4 of 6 turkeys (67%). Seroprevalence in domestic fowl (27%, or 7 of 26) from the urban Bucharest site was not significantly different (P = 0.08, by Fisher's exact test) than rates at three rural sites (50%, or 23 of 46). Serum collected from one of 12 Passeriformes, an Erithacus rubecula, was positive for neutralizing antibody to WN virus. A total of 5,577 mosquitoes representing seven taxa were collected. Culex pipiens pipiens accounted for 96% of the mosquitoes collected. A single virus isolate, RO97-50, was obtained from a pool of 30 Cx. p. pipiens females aspirated from the walls and ceiling of a blockhouse located near the center of Bucharest, resulting in a minimum infection rate of 0.19 per 1,000. Antisera prepared against RO97-50 failed to distinguish among RO97-50, WN virus strain Eg101, and Kunjin (KUN) virus strain MRM16. A 2,323-basepair DNA fragment of the envelope (E) glycoprotein gene from RO97-50 and a Romanian WN virus strain obtained from a human cerebrospinal fluid sample, RO96-1030, were sequenced. Phylogenetic analyses of 23 WN virus strains and one KUN virus strain using the amino acid and nucleotide sequences for a small portion of the E gene suggest the existence of two large lineages of viruses. Bootstrap analysis of the nucleotide alignment indicated strong support (95%) for a lineage composed of WN virus strains from northern Africa, including isolates from Egypt and Algeria, and west, central, and east Africa, all of the European isolates, those from France and Romania, an Israeli isolate, and an isolate of KUN virus from Australia. The nucleotide sequence of RO97-50 was identical to the sequence of a WN virus isolate obtained from Cx. neavei mosquitoes from Senegal and Cx. univittatus mosquitoes from Kenya. The phylogenetic analyses were compatible with the introduction of virus into Romania by birds migrating from sub-Saharan Africa, to northern Africa, and into southern Europe. (+info)Update: West Nile-like viral encephalitis--New York, 1999. (3/1137)
The outbreak of human arboviral encephalitis attributable to a mosquito-transmitted West Nile-like virus (WNLV) continues to wane in the Northeast. As of October 5, the number of laboratory-positive cases had increased to 50 (27 confirmed and 23 probable), including five deaths. The increase in cases is mainly a result of completed retesting with West Nile virus antigen of specimens previously tested with the related St. Louis encephalitis virus antigen and to intensive retrospective case finding in the ongoing epidemiologic investigations. (+info)Outbreak of West Nile-like viral encephalitis--New York, 1999. (4/1137)
An outbreak of arboviral encephalitis was first recognized in New York City in late August and has since been identified in neighboring counties in New York state. Although initially attributed to St. Louis encephalitis (SLE) virus based on positive serologic findings in cerebrospinal fluid (CSF) and serum samples using a virus-specific IgM-capture enzyme-linked immunosorbent assay (ELISA), the cause of the outbreak has been confirmed as a West Nile-like virus based on the identification of virus in human, avian, and mosquito samples. (+info)Isolation of West Nile virus from mosquitoes, crows, and a Cooper's hawk in Connecticut. (5/1137)
West Nile (WN) virus, a mosquito-transmitted virus native to Africa, Asia, and Europe, was isolated from two species of mosquitoes, Culex pipiens and Aedes vexans, and from brain tissues of 28 American crows, Corvus brachyrhynchos, and one Cooper's hawk, Accipiter cooperii, in Connecticut. A portion of the genome of virus isolates from four different hosts was sequenced and analyzed by comparative phylogenetic analysis. Our isolates from Connecticut were similar to one another and most closely related to two WN isolates from Romania (2.8 and 3.6 percent difference). If established in North America, WN virus will likely have severe effects on human health and on the health of populations of birds. (+info)Origin of the West Nile virus responsible for an outbreak of encephalitis in the northeastern United States. (6/1137)
In late summer 1999, an outbreak of human encephalitis occurred in the northeastern United States that was concurrent with extensive mortality in crows (Corvus species) as well as the deaths of several exotic birds at a zoological park in the same area. Complete genome sequencing of a flavivirus isolated from the brain of a dead Chilean flamingo (Phoenicopterus chilensis), together with partial sequence analysis of envelope glycoprotein (E-glycoprotein) genes amplified from several other species including mosquitoes and two fatal human cases, revealed that West Nile (WN) virus circulated in natural transmission cycles and was responsible for the human disease. Antigenic mapping with E-glycoprotein-specific monoclonal antibodies and E-glycoprotein phylogenetic analysis confirmed these viruses as WN. This North American WN virus was most closely related to a WN virus isolated from a dead goose in Israel in 1998. (+info)Continued transmission of West Nile virus to humans in southeastern Romania, 1997-1998. (7/1137)
After an epidemic of West Nile (WN) virus neurologic infections in southeastern Romania in 1996, human and animal surveillance were established to monitor continued transmission of the virus. During 1997 and 1998, neurologic infections were diagnosed serologically as WN encephalitis in 12 of 322 patients in 19 southeastern districts and in 1 of 75 Bucharest patients. In addition, amid a countrywide epidemic of measles, the etiology of the febrile exanthem in 2 of 180 investigated cases was determined serologically to be WN fever; 1 case was complicated by hepatitis. Sentinel chickens placed in Bucharest seroconverted to WN virus during the summer months, indicating their potential value in monitoring transmission. The continued occurrence of sporadic WN infections in southeastern Romania in consecutive years after the 1996 epidemic is consistent with local enzootic transmission of the virus. (+info)An outbreak of West Nile fever among migrants in Kisangani, Democratic Republic of Congo. (8/1137)
In February 1998, an outbreak of acute febrile illness was reported from the Kapalata military camp in Kisangani, the Democratic Republic of Congo. The illness was characterized by an acute onset of fever associated with severe headache, arthralgia, backache, neurologic signs, abdominal pain, and coughing. In 1 individual, hemorrhagic manifestations were observed. The neurologic signs included an altered level of consciousness, convulsions, and coma. Malaria was initially suspected, but the patients showed negative blood films and failed to respond to antimicrobial drugs. A total of 35 sera collected from the military patients in the acute phase were tested for the presence of IgM against vector-borne agents. Serum IgM antibodies against West Nile fever virus were found in 23 patients (66%), against Chikungunya virus in 12 patients (34%), against dengue virus in 1 patient (3%), and against Rickettsia typhi in 1 patient (3%). All sera were negative for IgM antibody against Rift Valley fever virus, Crimean Congo hemorrhagic fever virus, and Sindbis virus. These data suggest that infections with West Nile fever virus have been the main cause of the outbreak. (+info)West Nile Fever is defined as a viral infection primarily transmitted to humans through the bite of infected mosquitoes. The virus responsible for this febrile illness, known as West Nile Virus (WNV), is maintained in nature between mosquito vectors and avian hosts. Although most individuals infected with WNV are asymptomatic, some may develop a mild, flu-like illness characterized by fever, headache, fatigue, body aches, skin rash, and swollen lymph glands. A minority of infected individuals, particularly the elderly and immunocompromised, may progress to severe neurological symptoms such as encephalitis (inflammation of the brain), meningitis (inflammation of the membranes surrounding the brain and spinal cord), or acute flaccid paralysis (sudden weakness in the limbs). The diagnosis is confirmed through laboratory tests, such as serological assays or nucleic acid amplification techniques. Treatment primarily focuses on supportive care, as there are no specific antiviral therapies available for West Nile Fever. Preventive measures include personal protection against mosquito bites and vector control strategies to reduce mosquito populations.
West Nile Virus (WNV) is an Flavivirus, which is a type of virus that is spread by mosquitoes. It was first discovered in the West Nile district of Uganda in 1937 and has since been found in many countries throughout the world. WNV can cause a mild to severe illness known as West Nile fever.
Most people who become infected with WNV do not develop any symptoms, but some may experience fever, headache, body aches, joint pain, vomiting, diarrhea, or a rash. In rare cases, the virus can cause serious neurological illnesses such as encephalitis (inflammation of the brain) or meningitis (inflammation of the membranes surrounding the brain and spinal cord). These severe forms of the disease can be fatal, especially in older adults and people with weakened immune systems.
WNV is primarily transmitted to humans through the bite of infected mosquitoes, but it can also be spread through blood transfusions, organ transplants, or from mother to baby during pregnancy, delivery, or breastfeeding. There is no specific treatment for WNV, and most people recover on their own with rest and supportive care. However, hospitalization may be necessary in severe cases. Prevention measures include avoiding mosquito bites by using insect repellent, wearing long sleeves and pants, and staying indoors during peak mosquito activity hours.
A disease outbreak is defined as the occurrence of cases of a disease in excess of what would normally be expected in a given time and place. It may affect a small and localized group or a large number of people spread over a wide area, even internationally. An outbreak may be caused by a new agent, a change in the agent's virulence or host susceptibility, or an increase in the size or density of the host population.
Outbreaks can have significant public health and economic impacts, and require prompt investigation and control measures to prevent further spread of the disease. The investigation typically involves identifying the source of the outbreak, determining the mode of transmission, and implementing measures to interrupt the chain of infection. This may include vaccination, isolation or quarantine, and education of the public about the risks and prevention strategies.
Examples of disease outbreaks include foodborne illnesses linked to contaminated food or water, respiratory infections spread through coughing and sneezing, and mosquito-borne diseases such as Zika virus and West Nile virus. Outbreaks can also occur in healthcare settings, such as hospitals and nursing homes, where vulnerable populations may be at increased risk of infection.
West Nile Virus (WNV) vaccines are immunizations that are designed to protect against the West Nile virus, which is a single-stranded RNA virus that belongs to the family Flaviviridae. The virus is primarily transmitted to humans through the bite of infected mosquitoes, particularly those of the Culex species.
There are currently no licensed WNV vaccines available for human use in the United States or Europe. However, there are several veterinary vaccines that have been developed and approved for use in horses and other animals, such as birds and geese. These vaccines work by stimulating the immune system to produce antibodies against the virus, which can help prevent infection and reduce the severity of symptoms in animals that do become infected.
Human WNV vaccine candidates are in various stages of development and testing. Some of these vaccines use inactivated or weakened forms of the virus, while others use only a portion of the viral protein to stimulate an immune response. While these vaccines have shown promise in clinical trials, further research is needed to determine their safety and effectiveness in larger populations before they can be approved for widespread use.
'Bird diseases' is a broad term that refers to the various medical conditions and infections that can affect avian species. These diseases can be caused by bacteria, viruses, fungi, parasites, or toxic substances and can affect pet birds, wild birds, and poultry. Some common bird diseases include:
1. Avian influenza (bird flu) - a viral infection that can cause respiratory symptoms, decreased appetite, and sudden death in birds.
2. Psittacosis (parrot fever) - a bacterial infection that can cause respiratory symptoms, fever, and lethargy in birds and humans who come into contact with them.
3. Aspergillosis - a fungal infection that can cause respiratory symptoms and weight loss in birds.
4. Candidiasis (thrush) - a fungal infection that can affect the mouth, crop, and other parts of the digestive system in birds.
5. Newcastle disease - a viral infection that can cause respiratory symptoms, neurological signs, and decreased egg production in birds.
6. Salmonellosis - a bacterial infection that can cause diarrhea, lethargy, and decreased appetite in birds and humans who come into contact with them.
7. Trichomoniasis - a parasitic infection that can affect the mouth, crop, and digestive system in birds.
8. Chlamydiosis (psittacosis) - a bacterial infection that can cause respiratory symptoms, lethargy, and decreased appetite in birds and humans who come into contact with them.
9. Coccidiosis - a parasitic infection that can affect the digestive system in birds.
10. Mycobacteriosis (avian tuberculosis) - a bacterial infection that can cause chronic weight loss, respiratory symptoms, and skin lesions in birds.
It is important to note that some bird diseases can be transmitted to humans and other animals, so it is essential to practice good hygiene when handling birds or their droppings. If you suspect your bird may be sick, it is best to consult with a veterinarian who specializes in avian medicine.
Fever, also known as pyrexia or febrile response, is a common medical sign characterized by an elevation in core body temperature above the normal range of 36.5-37.5°C (97.7-99.5°F) due to a dysregulation of the body's thermoregulatory system. It is often a response to an infection, inflammation, or other underlying medical conditions, and it serves as a part of the immune system's effort to combat the invading pathogens or to repair damaged tissues.
Fevers can be classified based on their magnitude:
* Low-grade fever: 37.5-38°C (99.5-100.4°F)
* Moderate fever: 38-39°C (100.4-102.2°F)
* High-grade or severe fever: above 39°C (102.2°F)
It is important to note that a single elevated temperature reading does not necessarily indicate the presence of a fever, as body temperature can fluctuate throughout the day and can be influenced by various factors such as physical activity, environmental conditions, and the menstrual cycle in females. The diagnosis of fever typically requires the confirmation of an elevated core body temperature on at least two occasions or a consistently high temperature over a period of time.
While fevers are generally considered beneficial in fighting off infections and promoting recovery, extremely high temperatures or prolonged febrile states may necessitate medical intervention to prevent potential complications such as dehydration, seizures, or damage to vital organs.
'Culex' is a genus of mosquitoes that includes many species that are vectors for various diseases, such as West Nile virus, filariasis, and avian malaria. They are often referred to as "house mosquitoes" because they are commonly found in urban environments. These mosquitoes typically lay their eggs in standing water and have a cosmopolitan distribution, being found on all continents except Antarctica. The life cycle of Culex mosquitoes includes four stages: egg, larva, pupa, and adult. Both male and female adults feed on nectar, but only females require blood meals to lay eggs.
'Culicidae' is the biological family that includes all species of mosquitoes. It consists of three subfamilies: Anophelinae, Culicinae, and Toxorhynchitinae. Mosquitoes are small, midge-like flies that are known for their ability to transmit various diseases to humans and other animals, such as malaria, yellow fever, dengue fever, and Zika virus. The medical importance of Culicidae comes from the fact that only female mosquitoes require blood meals to lay eggs, and during this process, they can transmit pathogens between hosts.
I understand you are asking for a medical definition of "Horse Diseases." However, it's important to note that there isn't a specific medical field dedicated to horse diseases as we typically categorize medical fields by human diseases and conditions. Veterinary medicine is the field responsible for studying, diagnosing, and treating diseases in animals, including horses.
Here's a general definition of 'Horse Diseases':
Horse diseases are health issues or medical conditions that affect equine species, particularly horses. These diseases can be caused by various factors such as bacterial, viral, fungal, or parasitic infections; genetic predispositions; environmental factors; and metabolic disorders. Examples of horse diseases include Strangles (Streptococcus equi), Equine Influenza, Equine Herpesvirus, West Nile Virus, Rabies, Potomac Horse Fever, Lyme Disease, and internal or external parasites like worms and ticks. Additionally, horses can suffer from musculoskeletal disorders such as arthritis, laminitis, and various injuries. Regular veterinary care, preventative measures, and proper management are crucial for maintaining horse health and preventing diseases.
I am not aware of a medical definition for the term "birds." Birds are a group of warm-blooded vertebrates constituting the class Aves, characterized by feathers, toothless beaked jaws, the laying of hard-shelled eggs, and lightweight but strong skeletons. Some birds, such as pigeons and chickens, have been used in medical research, but the term "birds" itself does not have a specific medical definition.
Flavivirus is a genus of viruses in the family Flaviviridae. They are enveloped, single-stranded, positive-sense RNA viruses that are primarily transmitted by arthropod vectors such as mosquitoes and ticks. Many flaviviruses cause significant disease in humans, including dengue fever, yellow fever, Japanese encephalitis, West Nile fever, and Zika fever. The name "flavivirus" is derived from the Latin word for "yellow," referring to the yellow fever virus, which was one of the first members of this genus to be discovered.