Question

Which of the following would NOT be considered an emerging disease? a. Ebola hemorrhagic fever b. West Nile virus fever/encephalitis c. Zika virus disease d. Tuberculosis

Short answer

d. Tuberculosis

Step-by-step solution

Define Emerging Disease

Emerging diseases are infections that have recently appeared within a population or those whose incidence or geographic range is rapidly increasing or threatens to increase in the near future.

Identify Emerging Diseases in Options

Determine if the given diseases (a, b, c, and d) fit the definition of an emerging disease.

Analyze Option a

Ebola hemorrhagic fever first appeared in 1976 and has had periodic outbreaks with increased incidence. Hence, it is considered an emerging disease.

Analyze Option b

West Nile virus fever/encephalitis was first detected in the United States in 1999 and has since spread rapidly, classifying it as an emerging disease.

Analyze Option c

Zika virus disease gained international attention for its rapid spread and association with birth defects around 2015, thus qualifying it as an emerging disease.

Analyze Option d

Tuberculosis has been known for centuries and is not a new or increasing threat. Therefore, it does not fit the criteria of an emerging disease.

Conclusion

From the analysis of each option, determine which disease is NOT considered an emerging disease.

Key concepts

Ebola hemorrhagic fever

Ebola hemorrhagic fever is a severe, often fatal illness in humans caused by the Ebola virus. The virus is transmitted to people from wild animals and spreads through human-to-human transmission. The initial outbreak was recorded in 1976 in Central Africa near the Ebola River.
The disease's symptoms include sudden onset of fever, intense weakness, muscle pain, headache, and sore throat, followed by vomiting, diarrhea, rash, impaired kidney and liver function, and in some cases, both internal and external bleeding. Due to its high fatality rate and periodic outbreaks, Ebola hemorrhagic fever is classified as an emerging disease.

• Transmission: Begins through contact with the bodily fluids of infected animals and continues human-to-human via direct contact with bodily fluids of infected patients.
• Prevention: Protective gear for healthcare workers, sterilization of medical equipment, and avoiding contact with infected individuals.
• Treatment: Primarily supportive care, including hydration, pain management, and treating secondary infections.

West Nile virus fever

West Nile virus fever is another emerging disease that first appeared in the United States in 1999. This virus is primarily transmitted to humans through the bite of an infected mosquito.
The majority of people infected with the West Nile virus show no symptoms, but some may develop mild symptoms such as fever, headache, body aches, skin rash, and swollen lymph glands. In severe cases, the infection can cause encephalitis or meningitis, characterized by high fever, neck stiffness, stupor, disorientation, coma, tremors, seizures, and paralysis.

• Mosquito-borne Disease: It relies heavily on the presence of mosquitoes for spread.
• Prevention: Use of insect repellents, wearing protective clothing, and removing standing water where mosquitoes breed.
• Treatment: There is no specific vaccine or antiviral treatment. Care is supportive, aimed at relieving symptoms.

Zika virus disease

Zika virus disease gained significant attention around 2015 due to its rapid spread and its serious impact on fetuses. The virus is primarily spread through the bite of an infected Aedes mosquito, the same type that transmits dengue and chikungunya viruses.
Symptoms of Zika virus disease often include mild fever, rash, conjunctivitis, muscle and joint pain, malaise, and headache. Importantly, Zika virus infection during pregnancy can cause infants to be born with microcephaly and other congenital abnormalities. It can also lead to increased cases of Guillain-Barré syndrome, a rare neurological disorder that can lead to paralysis.

• Transmission: Mainly mosquito bites, but it can also be transmitted through sexual contact, blood transfusion, and from mother to fetus.
• Prevention: Protection against mosquito bites and screening of blood products for Zika virus.
• Treatment: No specific treatment or vaccine; supportive care to alleviate symptoms.

Tuberculosis diagnosis

Tuberculosis (TB) is not considered an emerging disease, as it has been known for centuries. TB is caused by the bacterium Mycobacterium tuberculosis and primarily affects the lungs, but it can also affect other parts of the body.
People with active TB can spread the bacteria through the air when they cough or sneeze. Symptoms of active TB include prolonged coughing, chest pain, coughing up blood, weakness, weight loss, fever, and night sweats.

• Diagnosis Methods:
  1. Tuberculin Skin Test (TST): A small amount of tuberculin is injected under the skin, and the injection site is checked after 48-72 hours for any reaction.
  2. Interferon-Gamma Release Assays (IGRAs): Blood tests that measure the immune response to TB antigens.
  3. Chest X-Rays: Used to detect changes in the lungs.
  4. Sputum Test: Microscopic examination and culture of sputum samples to identify TB bacteria.
• Prevention: BCG vaccine, screening, treatment of latent TB infection, and improved ventilation in living spaces.
• Treatment: Typically involves a 6-9 month course of antibiotics such as isoniazid, rifampin, ethambutol, and pyrazinamide.