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The presence of avian botulism is extremely hard to detect before an outbreak. Frequent surveillance of sites at risk is needed for early detection of the disease in order to take action and remove carcasses. Vaccines are also developed, but they are expected to have limited effectiveness in stemming outbreaks in wild waterbird populations. However may be effective in reducing mortality for endangered island waterfowl and small non-migratory wild populations. Field tests are needed.
Previous methods of diagnosis included HI, complement fixation, neutralization tests, and injecting the serum of infected individuals into mice. However, new research has introduced more efficient methods to diagnose KFDV. These methods include: nested RT-PCR, TaqMan-based real-time RT-PCR, and immunoglobin M antibodies detection by ELISA. The two methods involving PCR are able to function by attaching a primer to the NS-5 gene which is highly conserved among the genus to which KFDV belongs. The last method allows for the detections of anti-KFDV antibodies in patients.
Preliminary diagnosis is often based on the patient's clinical symptoms, places and dates of travel (if patient is from a nonendemic country or area), activities, and epidemiologic history of the location where infection occurred. A recent history of mosquito bites and an acute febrile illness associated with neurologic signs and symptoms should cause clinical suspicion of WNV.
Diagnosis of West Nile virus infections is generally accomplished by serologic testing of blood serum or cerebrospinal fluid (CSF), which is obtained via a lumbar puncture. Initial screening could be done using the ELISA technique detecting immunoglobulins in the sera of the tested individuals.
Typical findings of WNV infection include lymphocytic pleocytosis, elevated protein level, reference glucose and lactic acid levels, and no erythrocytes.
Definitive diagnosis of WNV is obtained through detection of virus-specific antibody IgM and neutralizing antibodies. Cases of West Nile virus meningitis and encephalitis that have been serologically confirmed produce similar degrees of CSF pleocytosis and are often associated with substantial CSF neutrophilia.
Specimens collected within eight days following onset of illness may not test positive for West Nile IgM, and testing should be repeated. A positive test for West Nile IgG in the absence of a positive West Nile IgM is indicative of a previous flavavirus infection and is not by itself evidence of an acute West Nile virus infection.
If cases of suspected West Nile virus infection, sera should be collected on both the acute and
convalescent phases of the illness. Convalescent specimens should be collected 2–3 weeks after acute specimens.
It is common in serologic testing for cross-reactions to occur among flaviviruses such as dengue virus (DENV) and tick-borne encephalitis virus; this necessitates caution when evaluating serologic results of flaviviral infections.
Four FDA-cleared WNV IgM ELISA kits are commercially available from different manufacturers in the U.S., each of these kits is indicated for use on serum to aid in the presumptive laboratory diagnosis of WNV infection in patients with clinical symptoms of meningitis or encephalitis. Positive WNV test results obtained via use of these kits should be confirmed by additional testing at a state health department laboratory or CDC.
In fatal cases, nucleic acid amplification, histopathology with immunohistochemistry, and virus culture of autopsy tissues can also be useful. Only a few state laboratories or other specialized laboratories, including those at CDC, are capable of doing this specialized testing.
A number of various diseases may present with symptoms similar to those caused by a clinical West Nile virus infection. Those causing neuroinvasive disease symptoms include the enterovirus infection and bacterial meningitis. Accounting for differential diagnoses is a crucial step in the definitive diagnosis of WNV infection. Consideration of a differential diagnosis is required when a patient presents with unexplained febrile illness, extreme headache, encephalitis or meningitis. Diagnostic and serologic laboratory testing using polymerase chain reaction (PCR) testing and viral culture of CSF to identify the specific pathogen causing the symptoms, is the only currently available means of differentiating between causes of encephalitis and meningitis.
The disease can be prevented in horses with the use of vaccinations. These vaccinations are usually given together with vaccinations for other diseases, most commonly WEE, VEE, and tetanus. Most vaccinations for EEE consist of the killed virus. For humans there is no vaccine for EEE so prevention involves reducing the risk of exposure. Using repellent, wearing protective clothing, and reducing the amount of standing water is the best means for prevention
The botulinum neurotoxin is lethal because it causes paralysis. Field identification involves locating birds showing flaccidity in the legs, wings and neck, as well as the presence of protuberant nictitating membrane. The presence of several dozen, or even hundreds, of fresh waterbird carcasses is the stereotypical sign an outbreak has occurred. In this case the specimens need to be taken to disease laboratory to determine the cause of mortality. Most commonly, detection of "C. botulinum" in carcasses during lab work is accomplished through analysis of polymerase chain reactions (PCR) and is often the most successful method.
Cats can be protected from H5N1 if they are given a vaccination, as mentioned above. However, it was also found that cats can still shed some of the virus but in low numbers.
If a cat is exhibiting symptoms, they should be put into isolation and kept indoors. Then they should be taken to a vet to get tested for the presence of H5N1. If there is a possibility that the cat has Avian Influenza, then there should be extra care when handling the cat. Some of the precautions include avoiding all direct contact with the cat by wearing gloves, masks, and goggles. Whatever surfaces the cat comes in contact with should be disinfected with standard household cleaners.
They have given tigers an antiviral treatment of Oseltamivir with a dose of 75 mg/60 kg two times a day. The specific dosage was extrapolated from human data, but there hasn't been any data to suggest protection. As with many antiviral treatments, the dosage depends on the species.
Initial diagnosis may be via symptoms, but is usually confirmed via an antigen and antibody test. A PCR-based test is also available. Although any of these tests can confirm psittacosis, false negatives are possible and so a combination of clinical and lab tests is recommended before giving the bird a clean bill of health. It may die within three weeks.
Blood analysis shows leukopenia, thrombocytopenia and moderately elevated liver enzymes. Differential diagnosis must be made with typhus, typhoid and atypical pneumonia by Mycoplasma, Legionella or Q fever. Exposure history is paramount to diagnosis.
Diagnosis involves microbiological cultures from respiratory secretions of patients or serologically with a fourfold or greater increase in antibody titers against "C. psittaci" in blood samples combined with the probable course of the disease. Typical inclusions called "Leventhal-Cole-Lillie bodies" can be seen within macrophages in BAL (bronchoalveolar lavage) fluid. Culture of "C. psittaci" is hazardous and should only be carried out in biosafety laboratories.
The most efficient treatment in breeding flocks or laying hens is individual intramuscular injections of a long-acting tetracycline, with the same antibiotic in drinking water, simultaneously. The mortality and clinical signs will stop within one week, but the bacteria might remain present in the flock.
There is no cure for EEE. Treatment consists of corticosteroids, anticonvulsants, and supportive measures (treating symptoms) such as intravenous fluids, tracheal intubation, and antipyretics. About four percent of humans known to be infected develop symptoms, with a total of about six cases per year in the US. A third of these cases die, and many survivors suffer permanent brain damage.
Initial response to H5N1, a one size fits all recommendation was used for all poultry production systems, though measures for intensively raised birds were not necessarily appropriate for extensively raised birds. When looking at village poultry, it was first assumed that the household was the unit and that flocks did not make contact with other flocks, though more effective measures came into use when the epidemiological unit was the village.
Recommendations also involve restructuring commercial markets to improve biosecurity against avian influenza. Poultry production zoning is used to limit poultry farming to specific areas outside of urban environments while live poultry markets improve biosecurity by limiting the number of traders holding licenses and subjecting producers and traders to more stringent inspections. These recommendations in combination with requirements to fence and house all poultry, and limit free ranging flocks will eventually lead to fewer small commercial producers and backyard producers, costing livelihoods as they are unable to meet the conditions needed to participate.
A summary of reports to the World Organisation for Animal Health in 2005 and 2010 suggest that surveillance and under-reporting in developed and developing countries is still a challenge. Often, donor support can focus on HPAI control alone, while similar diseases such as Newcastle disease, acute fowl cholera, infectious laryngotracheitis, and infectious bursal disease still affect poultry populations. When HPAI tests come back negative, a lack of funded testing for differential diagnoses can leave farmers wondering what killed their birds.
Since traditional production systems require little investment and serve as a safety net for lower income households, prevention and treatment can be seen as less cost effective than letting a few birds die. Effective control not only requires prior agreements to be made with relevant government agencies, such as seen with Indonesia, they must also not unduly threaten food security.
Prophylaxis by vaccination, as well as preventive measures like protective clothing, tick control, and mosquito control are advised. The vaccine for KFDV consists of formalin-inactivated KFDV. The vaccine has a 62.4% effectiveness rate for individuals who receive two doses. For individuals who receive an additional dose, the effectiveness increases to 82.9%. Specific treatments are not available.
People who do not regularly come into contact with birds are not at high risk for contracting avian influenza. Those at high risk include poultry farm workers, animal control workers, wildlife biologists, and ornithologists who handle live birds. Organizations with high-risk workers should have an avian influenza response plan in place before any cases have been discovered. Biosecurity of poultry flocks is also important for prevention. Flocks should be isolated from outside birds, especially wild birds, and their waste; vehicles used around the flock should be regularly disinfected and not shared between farms; and birds from slaughter channels should not be returned to the farm.
With proper infection control and use of personal protective equipment (PPE), the chance for infection is low. Protecting the eyes, nose, mouth, and hands is important for prevention because these are the most common ways for the virus to enter the body. Appropriate personal protective equipment includes aprons or coveralls, gloves, boots or boot covers, and a head cover or hair cover. Disposable PPE is recommended. An N-95 respirator and unvented/indirectly vented safety goggles are also part of appropriate PPE. A powered air purifying respirator (PAPR) with hood or helmet and face shield is also an option.
Proper reporting of an isolated case can help to prevent spread. The Centers for Disease Control and Prevention (US) recommendation is that if a worker develops symptoms within 10 days of working with infected poultry or potentially contaminated materials, they should seek care and notify their employer, who should notify public health officials.
For future avian influenza threats, the WHO suggests a 3 phase, 5 part plan.
- Phase: Pre-pandemic
- Reduce opportunities for human infection
- Strengthen the early warning system
- Phase: Emergence of a pandemic virus
- Contain or delay spread at the source
- Phase: Pandemic declared and spreading internationally
- Reduce morbidity, mortality, and social disruption
- Conduct research to guide response measures
Vaccines for poultry have been formulated against several of the avian H5N1 influenza varieties. Control measures for HPAI encourage mass vaccinations of poultry though The World Health Organization has compiled a list of known clinical trials of pandemic influenza prototype vaccines, including those against H5N1. In some countries still at high risk for HPAI spread, there is compulsory strategic vaccination though vaccine supply shortages remain a problem.
Fowl cholera is also called avian cholera, avian pasteurellosis, avian hemorrhagic septicemia.
It is the most common pasteurellosis of poultry. As the causative agent is "Pasteurella multocida", it is considered as a zoonosis.
Adult birds and old chickens are more susceptible. In parental flocks, cocks are far more susceptible than hens.
Besides chickens, the disease also concerns turkeys, ducks, geese, raptors, and canaries. Turkeys are particularly sensitive, with mortality ranging to 65%.
The recognition of this pathological condition is of ever increasing importance for differential diagnosis with avian influenza.
There is no specific treatment for the condition.
Control may rely on boosting bird immunity, preventing group mixing and faecal spreading.
There is currently no specific treatment for the virus. A vaccine is available, but only experimentally. It has not been released to the public due to the risk it poses to already exposed birds.
Therapeutic intervention is limited to treating secondary infections. The individual bird can sometimes recover, but this is rare. If only the feathers are affected and the bird suffers no other symptoms, it can usually experience an acceptable quality of life. But if the bird's beak or nails are affected, veterinarians will recommend euthanasia.
The management of the disease lies thus mostly in prevention. Every new bird that enters a pen with other birds should be quarantined first and be tested for BFDV. Birds which are known carriers should not be introduced into new pens, especially not if those contain young birds.
A cat that is infected with a high dose of the virus can show signs of fever, lethargy, and dyspnea. There have even been recorded cases where a cat has neurological symptoms such as circling or ataxia.
In a case in February 2004, a 2-year-old male cat was panting and convulsing on top of having a fever two days prior to death. This cat also had lesions that were identified as renal congestion, pulmonary congestion, edema, and pneumonia. Upon inspection, the cat also had cerebral congestion, conjunctivitis, and hemorrhaging in the serosae of the intestines.
However, a cat that is infected with a low dose of the virus may not necessarily show symptoms. Though they may be asymptomatic, they can still transfer small amounts of the virus.
The influenza vaccine is recommended by the World Health Organization and United States Centers for Disease Control and Prevention for high-risk groups, such as children, the elderly, health care workers, and people who have chronic illnesses such as asthma, diabetes, heart disease, or are immuno-compromised among others. In healthy adults it is modestly effective in decreasing the amount of influenza-like symptoms in a population. Evidence is supportive of a decreased rate of influenza in children over the age of two. In those with chronic obstructive pulmonary disease vaccination reduces exacerbations, it is not clear if it reduces asthma exacerbations. Evidence supports a lower rate of influenza-like illness in many groups who are immunocompromised such as those with: HIV/AIDS, cancer, and post organ transplant. In those at high risk immunization may reduce the risk of heart disease. Whether immunizing health care workers affects patient outcomes is controversial with some reviews finding insufficient evidence and others finding tentative evidence.
Due to the high mutation rate of the virus, a particular influenza vaccine usually confers protection for no more than a few years. Every year, the World Health Organization predicts which strains of the virus are most likely to be circulating in the next year (see Historical annual reformulations of the influenza vaccine), allowing pharmaceutical companies to develop vaccines that will provide the best immunity against these strains. The vaccine is reformulated each season for a few specific flu strains but does not include all the strains active in the world during that season. It takes about six months for the manufacturers to formulate and produce the millions of doses required to deal with the seasonal epidemics; occasionally, a new or overlooked strain becomes prominent during that time. It is also possible to get infected just before vaccination and get sick with the strain that the vaccine is supposed to prevent, as the vaccine takes about two weeks to become effective.
Vaccines can cause the immune system to react as if the body were actually being infected, and general infection symptoms (many cold and flu symptoms are just general infection symptoms) can appear, though these symptoms are usually not as severe or long-lasting as influenza. The most dangerous adverse effect is a severe allergic reaction to either the virus material itself or residues from the hen eggs used to grow the influenza; however, these reactions are extremely rare.
The cost-effectiveness of seasonal influenza vaccination has been widely evaluated for different groups and in different settings. It has generally been found to be a cost-effective intervention, especially in children and the elderly, however the results of economic evaluations of influenza vaccination have often been found to be dependent on key assumptions.
The majority of MVEV infections are sub-clinical, i.e. do not produce disease symptoms, although some people may experience a mild form of the disease with symptoms such as fever, headaches, nausea and vomiting and only a very small number of these cases go on to develop MVE. In fact, serological surveys which measure the level of anti-MVEV antibodies within the population estimate that only 1 in 800-1000 of all infections result in clinical disease.
The incubation period following exposure to the virus is around 1 to 4 weeks. Following infection, a person will have lifelong immunity to the virus. When a patient appears to show MVE symptoms and has been in an MVE-endemic area during the wet season, when outbreaks usually occur, MVE infection must be confirmed by laboratory diagnosis, usually by detection of a significant rise of MVE-specific antibodies in the patient's serum.
Of those who contract MVE, one-quarter die from the disease.
Sylvatic plague is most commonly found in prairie dog colonies; the flea that feeds on prairie dogs (and other mammals) serves as the vector for transmission to the new host.
Sylvatic plague is an infectious bacterial disease caused by the bacterium "Yersinia pestis" that primarily affects rodents such as prairie dogs. It is the same bacterium that causes bubonic and pneumonic plague in humans. Sylvatic, or sylvan, means 'occurring in wildlife,' and refers specifically to the form of plague in rural wildlife. Urban plague refers to the form in urban wildlife.
It is primarily transmitted among wildlife through flea bites and contact with infected tissue or fluids. Sylvatic plague is most commonly found in prairie dog colonies and some mustelids like the black-footed ferret.
The scientific study of the genetics of MVEV has been facilitated by the construction and manipulation of an infectious cDNA clone of the virus.
In sheep, the disease is also called the "circling disease". The most obvious signs for the veterinarians are neurological, especially lateral deviation of the neck and head.
Kemerovo tickborne viral fever is an aparalytic febrile illness accompanied by meningism following tick-bite. The causative agent is a zoonotic Orbivirus first described in 1963 in western Siberia by Mikhail Chumakov and coworkers. The virus has some 23 serotypes, and can occur in coinfections with other Orbiviruses and tick-transmitted encephalitis viruses, complicating the course of illness. Rodents and birds are the primary vertebrate hosts of the virus; "Ixodes persulcatus" ticks are a vector of the virus. Kemerovo and related viruses may be translocated distances in the environment by migratory birds.