Recent Viral Epidemic and Pandemic Diseases

Recent viral epidemic and pandemic diseases:

Monkeypox: Viral Epidemic and Pandemic Diseases

• Monkeypox is caused by the monkeypox virus, a member of the Orthopoxvirus genus in the family Poxviridae.
• Monkeypox is usually a self-limited disease with symptoms lasting from 2 to 4 weeks. Severe cases can occur. In recent times, the case fatality ratio has been around 3–6%.
• Monkeypox is transmitted to humans through close contact with an infected person or animal, or with material contaminated with the virus.
• Monkeypox virus is transmitted from one person to another by close contact with lesions, body fluids, respiratory droplets and contaminated materials such as bedding.
• Monkeypox is a viral zoonotic disease that occurs primarily in tropical rainforest areas of central and west Africa and is occasionally exported to other regions.
• An antiviral agent developed for the treatment of smallpox has also been licensed for the treatment of monkeypox.
• The clinical presentation of monkeypox resembles that of smallpox, a related orthopoxvirus infection which was declared eradicated worldwide in 1980. Monkeypox is less contagious than smallpox and causes less severe illness.
• Monkeypox typically presents clinically with fever, rash and swollen lymph nodes and may lead to a range of medical complications.
• Vaccines used during the smallpox eradication programme also provided protection against monkeypox.

• The WHO declared monkeypox a global health emergency.
• The rare designation means the WHO now views the outbreak as a significant enough threat to global health that a coordinated international response is needed.
• The WHO last issued a global health emergency in January 2020 in response to the Covid-19 outbreak.
• Europe is the epicenter of the outbreak. Right now, men who have sex with men are the community at highest risk.
• The WHO chief said the global risk is moderate, but the threat is high in Europe.

Corona Virus: Viral Epidemic and Pandemic Diseases

• The new, or “novel” coronavirus, now called COVID-19, had not previously detected before the outbreak was reported in Wuhan, China in December 2019.
• Symptoms: Acute onset of fever, cough, and difficulty in breathing.
• More severe for older people and people with pre-existing medical conditions(such as diabetes and heart disease). i.e for low immunity people.
• COVID-19 is declared a Pandemic by WHO on March 11. 
• The COVID-19 virus spreads primarily through droplets of saliva or discharge from the nose when an infected person coughs or sneezes, so it’s important that you also practice respiratory etiquette (for example, by coughing into a flexed elbow).

SARS Virus: Viral Epidemic and Pandemic Diseases

• First detected in Guangdong province of southern China in Nov 2002. SARS-COV virus identified in 2003.
• Around the world, 8,098 people became sick from SARS and 774 died.
• It transformed from Bats to Civet Cats and from Civet Cats to Humans.
• Initial symptoms are flu-like symptoms and may include fever, muscle pain, lethargy, cough, sore throat, and shortness of breath.

Ebola Virus: Viral Epidemic and Pandemic Diseases

• Ebola virus disease (EVD), formerly known as Ebola hemorrhagic(means bleeding) fever, is a severe, often fatal illness affecting humans and other primates.
• The virus is transmitted to people from wild animals (such as fruit bats, porcupines and non-human primates) and then spreads in the human population through direct contact with the blood, secretions, organs or other bodily fluids of infected people, and with surfaces and materials (e.g. bedding, clothing) contaminated with these fluids.
• The virus was first discovered in 1976, but the major outbreak in 2014-16.
• Starting in Guinea and then moving across land borders to Sierra Leone and Liberia.

Previous Year’s Questions Of UPSC On Human Diseases

Zika Virus: Viral Epidemic and Pandemic Diseases

• Zika virus is a mosquito-borne flavivirus that was first identified in Uganda in 1947 in monkeys.
• It was later identified in humans in 1952 in Uganda and the United Republic of Tanzania.
• Zika virus disease is caused by a virus transmitted primarily by Aedes mosquitoes, which bite during the day.
• Zika virus infection during pregnancy can cause infants to be born with microcephaly and other congenital malformations, known as congenital Zika syndrome.
• Infection with Zika virus is also associated with other complications of pregnancy including preterm birth and miscarriage.
• In October 2015, Brazil reported an association between Zika virus infection and microcephaly.
• Microcephaly
  • Microcephaly is a condition where a baby is born with a small head or the head stops growing after birth.
  • Microcephaly is a rare condition. One baby in several thousand is born with microcephaly.
  • Babies born with microcephaly may develop convulsions and suffer physical and learning disabilities as they grow older.
  • There is no specific treatment for microcephaly.

Nipah Virus: Viral Epidemic and Pandemic Diseases

• Nipah virus is a zoonotic virus (it is transmitted from animals to humans) and can also be transmitted through contaminated food or directly between people.
• Fruit bats are the natural host of the Nipah virus.
• There is no treatment or vaccine available for either people or animals.
• The primary treatment for humans is supportive care.
• NiV can lead to acute respiratory distress, encephalitis, and/or seizures, and can progress to coma within 24 to 48 hours.
• The mortality rate is estimated at between 40 and 75 percent.
• The virus can also cause severe disease in animals such as pigs, resulting in significant economic losses for farmers.
• In 2018, Niv Positive was found in Kerala.
• Nipah virus was first recognized in 1999 during an outbreak among pig farmers in, Malaysia.
• The disease has also been identified periodically in eastern India.

Influenza Virus: Viral Epidemic and Pandemic Diseases

• There are four types of influenza viruses: types A, B, C, and D.
• Influenza C viruses can infect both humans and pigs but infections are generally mild and are rarely reported.
• Influenza D viruses primarily affect cattle only.
• Influenza A and B viruses circulate and cause seasonal epidemics of disease.
• Only influenza type A viruses are known to have caused pandemics.
• Humans can be infected with avian, swine, and other zoonotic influenza viruses, such as – avian influenza virus subtypes A(H5N1), A(H7N9), and A(H9N2) and –swine influenza virus subtypes A(H1N1), A(H1N2) and A(H3N2).

Chikungunya: Viral Epidemic and Pandemic Diseases

• Mosquito-borne viral disease.
• First recognized in 1952 during an outbreak in southern Tanzania.
• Chikungunya means: to become contorted, i.e sufferers have severe joint pain.
• It is transmitted to humans by the bites of infected female mosquitoes.
• Most commonly, the mosquitoes are Aedes aegypti and Aedes albopictus.
• These two species can also transmit other mosquito-borne viruses including dengue.
• They bite throughout daylight hours.

Dengue: Viral Epidemic and Pandemic Diseases

• Dengue virus is transmitted by female mosquitoes mainly of the species Aedes aegypti and, to a lesser extent, Ae. albopictus. These mosquitoes are also vectors of chikungunya, yellow fever, and Zika viruses.
• Dengue is widespread throughout the tropics, with local variations in risk influenced by rainfall, temperature, relative humidity and unplanned rapid urbanization.
• In 2020, dengue continues to affect several countries, with reports of increases in the numbers of cases in Bangladesh, Brazil, Cook Islands, Ecuador, India, Indonesia, Maldives, Mauritania, Mayotte (Fr), Nepal, Singapore, Sri Lanka, Sudan, Thailand, Timor-Leste and Yemen.

MERS-CoV: Viral Epidemic and Pandemic Diseases

• MERS-CoV: Middle East respiratory syndrome coronavirus
• Since September 2012, WHO has been notified of 2494 laboratory-confirmed cases of infection with MERS-CoV.
• The majority of these cases were reported from Saudi Arabia.

Hendra virus infection: Viral Epidemic and Pandemic Diseases

• The natural host of the virus has been identified as being fruit bats – the first recorded outbreak of the disease was in the Brisbane suburb of Hendra, Australia, in 1994.
• As of July 2016, 53 disease incidents involving over 70 horses have been reported

Yellow Fever: Viral Epidemic and Pandemic Diseases

• Yellow fever is an acute viral hemorrhagic disease transmitted by infected mosquitoes(Aedes aegypti).
• The “yellow” in the name refers to jaundice that affects some patients. •Symptoms of yellow fever include fever, headache, jaundice, muscle pain, nausea, vomiting, and fatigue.
• The virus is endemic in tropical areas of Africa and Central and South America.
• Yellow fever is prevented by an extremely effective vaccine, which is safe and affordable.
• Good supportive treatment in hospitals improves survival rates. There is currently no specific anti-viral drug for yellow fever.

Small Pox: Viral Epidemic and Pandemic Diseases

• Belongs to the orthopoxvirus family.
• The last known natural case was in Somalia in 1977.
• It was declared eradicated in 1980 following a global immunization campaign led by the WHO.
• Transmitted from person to person via infective droplets during close contact.

Difference Between Pandemic, Endemic And Epidemic Disease

Also, refer to,

• Different Types Of Covid-19 Testing
• Different Types of Immunity
• Important MCQs On Diseases
• MCQs on Virus