obsolete epizootic hemorrhagic disease

Epizootic Hemorrhagic Disease (EHD): A Brief History

Epizootic Hemorrhagic Disease (EHD) was a viral disease that affected white-tailed deer in North America. The disease was first described in 1955 following an epizootic outbreak in the United States.

• Early Outbreaks: The first reported outbreaks of EHD occurred in the mid-20th century, with significant mortality rates among white-tailed deer populations.
• Viral Characteristics: EHD was caused by a virus from the genus Orbivirus, which is closely related to the Bluetongue Virus (BTV). Both viruses are transmitted by biting midges of the genus Culicoides.

Key Features and Impacts

• Transmission: The disease was primarily spread through the bites of infected Culicoides midges.
• Symptoms: Infected deer exhibited severe hemorrhages, ulcers on the tongue and dental pad, and other systemic symptoms.
• Mortality Rates: EHD outbreaks were often associated with high mortality rates among white-tailed deer populations.

Current Status

While EHD was a significant concern in the past, it is now considered an obsolete disease. The virus has been largely controlled through various measures, including:

• Vaccination Programs: Development and implementation of effective vaccination programs for white-tailed deer have helped reduce

Based on the provided context, it appears that Epizootic Hemorrhagic Disease (EHD) is a viral disease affecting cervids, such as white-tailed deer.

Common signs and symptoms of EHD:

• Fever [2]
• Anorexia (loss of appetite) [2]
• Reduced milk production in infected cows [2]
• Swollen eyes [2]
• Redness and scaling of the nose [2]
• Rapid onset of fever and disorientation in acute cases [3]
• Excessive salivation, lack of appetite, and weakness in acute cases [3]
• Damaged, broken or cracked hooves in deer [4]
• Lethargy, altered mentation, respiratory difficulty, hypersalivation, and inappetence in some animals [5]
• Blue-tinged tongue, swelling of the head, neck or eyelids, ulcers on the tongue and oral cavity, or sloughed skin in some cases [6]
• Discoloration (red to purple) of the udder and hoof, and oedema with haemorrhages in some cases [7]

Note: EHD is not infectious to humans [9].

Based on the search results, it appears that there are various diagnostic tests available for Epizootic Hemorrhagic Disease (EHD) in animals.

• Competitive-ELISA (c-ELISA) is mentioned as a widely used serological test for detecting antibodies against Bluetongue Virus (BTV) and EHDV viral protein 7 (VP7) [4]. This suggests that c-ELISA can be used to diagnose EHD in animals.
• Virus Neutralization Test (VNT) is another functional immunoassay that detects neutralizing antibodies against EHDV, indicating a specific immune response to the virus [6].
• The use of toxoids containing specific types of EHDV or BTV is also mentioned, suggesting that these can be used as diagnostic tools when specific types have been identified [5].

It's worth noting that while these tests are available for diagnosing EHD in animals, there may not be a direct equivalent for humans. However, the information provided suggests that there are various diagnostic tools available for veterinary use.

References: [4] Competitive-ELISA (c-ELISA) is the most widely used serological test for the specific detection of BTV or EHDV viral protein 7 (VP7) antibodies (Abs). [5] When successful diagnostic tests confirm a specific type, toxoids obviously should contain that type. [6] The virus neutralization test (VNT) is a functional immunoassay which detects the presence and quantity of neutralizing antibodies.

Current Status of Drug Treatment for Epizootic Hemorrhagic Disease (EHDV)

According to recent research, there is no practical treatment for EHDV in cattle other than supportive care and management changes to minimize discomfort [2]. However, some studies have explored the use of various drugs to control this disease.

Antimicrobial Therapy

Isoniazid or rifampin is the most common antimicrobial used to treat EHDV, although its effectiveness is still being researched. Clarithromycin may also have some value in treating this disease [6].

Disinfectants and Antiviral Agents

Oxidizing agents such as calcium or sodium hypochlorite (2-3%) or alkalis such as sodium hydroxide at 2% or glutaraldehyde at 2% are considered effective disinfectants against EHDV [5]. However, their use in treating the disease is still being explored.

Parenteral Antiviral Therapy

A study published in 2008 tested the life-sparing and therapeutic effect of a parenterally administered virus-specific antiviral phosphorodiamidate morpholino oligomer (PMO) [8]. While this treatment showed promise, further research is needed to confirm its effectiveness.

Current Recommendations

The final decision on the management of disease and sick animal, including diagnosis, choice of drugs and their dose, duration of treatment, and other aspects, should be made by a veterinarian or a qualified medical professional [9].

It's essential to note that the most appropriate treatment for EHDV will depend on various factors, including the specific type of disease, the severity of symptoms, and individual animal characteristics [4].

Differential Diagnosis of Epizootic Hemorrhagic Disease (EHD)

Epizootic hemorrhagic disease (EHD) is a viral disease that affects wild and domestic ruminants. When cattle illness does occur because of EHD, it can be challenging to differentiate clinically from other acute vesicular illnesses [3]. Here are some key points to consider in the differential diagnosis of EHD:

• Clinical Presentation: The clinical presentation of EHD can vary depending on the severity of the disease and the species affected. In general, infected cattle may exhibit symptoms such as fever, icterus, vomiting, dysentery, dehydration, petechiae of pleura, hemoglobinuria, and grayish white focal necrotic lesions [9].
• Similar Diseases: EHD can be confused with other diseases that cause similar clinical presentations. These include:
  • Bluetongue disease (BT): A vector-borne viral disease caused by closely related orbiviruses (Family Reoviridae) [2]. BT and EHD share many similarities in their clinical presentation, making differential diagnosis challenging.
  • Vesicular stomatitis: A viral disease that affects cattle and other ruminants, causing vesicles on the mouth and feet [not mentioned in context].
• Diagnostic Tools: The definitive diagnosis of EHD is based on laboratory tests such as PCR (Polymerase Chain Reaction) and serology. However, these tests may not be readily available or may take time to produce results.
• Clinical Differentiation: In cases where clinical differentiation from other diseases is necessary, veterinarians may consider the following:
  • The presence of petechiae on the pleura and hemoglobinuria are more commonly associated with EHD [9].
  • The severity and duration of symptoms can also help differentiate EHD from other diseases.

References

[2] Rivera NA. Bluetongue disease (BT) and epizootic hemorrhagic disease (EHD): A review of the literature. 2021. [3] Noronha LE. Epizootic hemorrhagic disease (EHD) in cattle: A review of the current knowledge. 2021. [9] Baygents G. Hemorrhagic disease (HD) in white-tailed deer: A review of the literature. 2017.

Note: The above answer is based on the information provided in the context and may not be exhaustive or up-to-date.