Influenza/ Flu

Y.12 Donghyun Ko & Joonhyuk Hyun

Influenza(Flu)

• The flu which is also called influenza is an infectious respiratory disease caused by influenza viruses that  infect the nose, throat, and lungs. It can cause mild to severe illness, and at times can lead to death.

Types of Influenza(Flu) Viruses (3 types)

The flu is caused by influenza virus types A, B, and C. Both type A and type B flu viruses are responsible for the seasonal outbreaks of flu.

• Type A Flu Virus: Type A flu or influenza A viruses are capable of infecting animals, although it is more common for people to suffer the ailments associated with this type of flu. Wild birds commonly act as the hosts for this flu virus. Type A flu virus is constantly changing and is generally responsible for the large flu epidemics. The influenza A2 virus (and other variants of influenza) is spread by people who are already infected. The most common flu hot spots are those surfaces that an infected person has touched and rooms where he has been recently, especially areas where he has been sneezing.

• Type B Flu Virus: Unlike type A flu viruses, type B flu is found only in humans. Type B flu may cause a less severe reaction than type A flu virus, but occasionally, type B flu can still be extremely harmful. Influenza type B viruses are not classified by subtype and do not cause pandemics.
• Type C Flu Virus: Influenza C viruses are also found in people. They are, however, milder than either type A or B. People generally do not become very ill from the influenza type C viruses. Type C flu viruses do not cause epidemics.

Fig 2. Types of Influenza Virus Table (http://www.keyword-suggestions.com/aW5mbHVlbnphIHR5cGUgYg/)

*Segmented genome: “Genome of a virus divided into segments, each of which encodes one or more ORFs. Segmented genomes are commonly found in RNA viruses. A segmented genome facilitates genetic re-assortment among different viral strains, when present in the same cell, providing a source of variation for the virus.” (http://medical-dictionary.thefreedictionary.com/segmented+genome )

*Amantadine: “A drug used especially as the hydrochloride C10H17N·HCl to prevent infection (as by an influenza virus) by interfering with virus penetration into host cells.” (https://www.merriam-webster.com/dictionary/amantadine )

*Rimantadine: “A synthetic antiviral drug that is chemically related to amantadine and is administered orally in the form of its hydrochloride C12H21N·HCl in the prevention and treatment of influenza A.” (https://www.merriam-webster.com/medical/rimantadine )

*Zanamivir: “An antiviral drug C12H20N4O7 administered by oral inhalation in the treatment of influenza A and B.” (https://www.merriam-webster.com/medical/zanamivir )

*Glycoprotein: “A conjugated protein in which the non-protein group is a carbohydrate.” (https://www.merriam-webster.com/dictionary/glycoprotein )

Signs/ symptoms of Flu

• Fever or feeling feverish/chills.
• Cough
• Sore throat
• Runny or stuffy nose
• Muscle or body aches
• Headaches
• Fatigue

How Flu Spreads

• Spread of flu viruses is mainly caused by droplets made when people with flu cough, sneeze or talk. These droplets can land in the mouths or noses of other people who are nearby. Less often, touching a surface or object that has flu virus on it and then touching their own mouth, eyes or possibly their nose might also cause infection of flu viruses.

Incubation Period & Period of Infectiousness

• Typical incubation period of influenza is 1~4 days. Patients with flu may be able to spread the flu to other people before they realize they are sick, as well as while they are sick. Most healthy adults may be able to infect others beginning 1 day before symptoms of flu develop and up to 5 to 7 days after becoming sick. On the one hand, young children and people with weakened immune systems, might be able to infect others for an even longer time than of healthy adults.

Complications of Flu

• Bacterial pneumonia
• Ear infections
• Sinus infections
• Dehydration
• Worsening of chronic medical conditions (e.g. congestive heart failure, asthma, or diabetes)

People at High Risk from Flu

• Anyone can get the flu (even healthy people), and serious problems related to the flu can happen at any age, but some people are at high risk of developing serious flu-related complications if they get sick. This includes people 65 years and older, people of any age with certain chronic medical conditions (such as asthma, diabetes, or heart disease), pregnant women, and young children.

Diagnosis of Flu

• It is very difficult to distinguish the flu from other viral or bacterial causes of respiratory illnesses on the basis of symptoms alone. There are tests available to diagnose flu.

Treatment

• Get plenty of rest
• Drink plenty of water and avoid drinking alcohol + smoking
• Aspirin or ibuprofen can help to treat fever, headaches, and muscle aches associated with the flu.                (Aspirin is not to be used to treat flu-like symptom in children)
• You can also take antiviral drugs, depending upon the duration of illness and severity of symptoms.

Precaution for Flu

• The first and most important step of the precaution of flu is to get a flu vaccination each year. CDC(Centers for Disease Control and Prevention) also recommends everyday preventive actions such as staying away from people who are sick, frequent handwashing and covering coughs and sneezes to help slow the spread of germs that cause respiratory (nose, throat, and lungs) illnesses, like flu.

Additional Information:

Influenza Pandemic

Fig 3.1. Timeline of influenza pandemic from 1895 to 2015 (http://survivingmodernlife.com/tag/influenza/)

• An Influenza pandemic is an epidemic of an influenza virus that spreads on a worldwide scale and infects a large proportion of the world population

Influenza Pandemic	Date	Deaths	Case Fatality Rate	Subtype of Virus (A type)
Russian Flu	1889-1890	1 million	0.15%	H2N2
Spanish Flu	1918-1920	20-100 million	2%	H1N1
Asian Flu	1957-1958	1-1.5 million	0.13%	H2N2
Hong Kong Flu	1968-1969	0.75-1 million	Less than 0.1%	H3N2
2009 Flu Pandemic	2009-2010	18,000-284,500	0.03%	H1N1

Fig 3.2. Table of Influenza pandemic

Interesting Facts:

To find out more about influenza, click on these links below.

• http://www.goodhousekeeping.com/health/a25049/facts-about-flu/
• http://www.viralnova.com/flu-facts/
• http://facts.randomhistory.com/2009/07/19_flu.html

Bibliography

• https://www.cdc.gov/flu/keyfacts.htm
• http://www.tamiflu.com/hcp/management/cinical-flu-overview

• http://www.webmd.com/cold-and-flu/flu-guide/advanced-reading-types-of-flu-viruses#2
• http://www.webmd.com/cold-and-flu/flu-guide/advanced-reading-types-of-flu-viruses#2
• http://www.keyword-suggestions.com/aW5mbHVlbnphIHR5cGUgYg/

Malaria

What is Malaria?

 

   Malaria is a mosquito-borne disease caused by a parasite. People with malaria often experience fever, chills, and flu-like illness. Left untreated, they may develop severe complications and die. In 2015, an estimated 214 million cases of malaria occurred worldwide and 438,000 people died, mostly children in the African Region. About 1,500 cases of malaria are diagnosed in the United States each year. The vast majority of cases in the United States are in travelers and immigrants returning from countries where malaria transmission occurs, many from sub-Saharan Africa and South Asia.

What are the causes of Malaria?

  Malaria can occur if a mosquito infected with the Plasmodium parasite bites you. An infected mother can also pass the disease to her baby at birth. This is known as congenital malaria. Malaria is transmitted by blood, so it can also be transmitted through:

ü   an organ transplant

ü   A blood transfusion (수혈)

ü   use of shared needles or syringes

What are the symptoms?

   The symptoms of malaria typically develop within 10 days to four weeks following the infection. In some people, symptoms may not develop for several months. Some malarial parasites can enter the body but will be dormant for long periods of time. Common symptoms of malaria include:

ü   shaking chills that can range from moderate to severe

ü   high fever

ü   profuse sweating

ü   headache

ü   nausea

ü   vomiting

ü   diarrhea

ü   anemia

ü   muscle pain

ü   convulsions

ü   coma

ü   bloody stools

Prevalence

Malaria infection is still to be considered a major public health problem in those 106 countries where the risk of contracting the infection with one or more of the Plasmodium species exists. According to estimates from the World Health Organization, over 200 million cases and about 655.000 deaths have occurred in 2010. Estimating the real health and social burden of the disease is a difficult task, because many of the malaria endemic countries have limited diagnostic resources, especially in rural settings where conditions with similar clinical picture may coexist in the same geographical areas. Moreover, asymptomatic parasitaemia may occur in high transmission areas after childhood, when anti-malaria semi-immunity occurs. Malaria endemicity and control activities are very complex issues, that are influenced by factors related to the host, to the parasite, to the vector, to the environment and to the health system capacity to fully implement available anti-malaria weapons such as rapid diagnostic tests, artemisinin-based combination treatment, impregnated bed-nets and insecticide residual spraying while waiting for an effective vaccine to be made available.

Malaria Treatment

  Malaria can be a severe, potentially fatal disease (especially when caused by Plasmodium falciparum) and treatment should be initiated as soon as possible.

Patients who have severe P. falciparum malaria or who cannot take oral medications should be given the treatment by continuous intravenous infusion.

Most drugs used in treatment are active against the parasite forms in the blood (the form that causes disease) and include:

ü   chloroquine

ü   atovaquone-proguanil (Malarone®)

ü   artemether-lumefantrine (Coartem®)

ü   mefloquine (Lariam®)

ü   quinine

ü   quinidine

ü   doxycycline (used in combination with quinine)

ü   clindamycin (used in combination with quinine)

ü   artesunate (not licensed for use in the United States, but available through the CDC malaria hotline)

  In addition, primaquine is active against the dormant parasite liver forms (hypnozoites) and prevents relapses. Primaquine should not be taken by pregnant women or by people who are deficient in G6PD (glucose-6-phosphate dehydrogenase). Patients should not take primaquine until a screening test has excluded G6PD deficiency.

How to treat a patient with malaria depends on:

• The type (species) of the infecting parasite
• The area where the infection was acquired and its drug-resistance status
• The clinical status of the patient
• Any accompanying illness or condition
• Pregnancy
• Drug allergies, or other medications taken by the patient

Bibliography

1.        Autino, B., Noris, A., Russo, R. and Castelli, F. (2017). EPIDEMIOLOGY OF MALARIA IN ENDEMIC AREAS.

2.        Cdc.gov. (2017). CDC - Malaria. [online] Available at: https://www.cdc.gov/malaria/ [Accessed 20 Mar. 2017].

3.        Healthline. (2017). Malaria. [online] Available at: http://www.healthline.com/health/malaria?s_con_rec=false&r=00#Diagnosis4 [Accessed 20 Mar. 2017].