Common ColdCommon Cold Most common infectionMost common infection Caused by group of viruses called: Caused by group of viruses called: * Rhinoviruses – * Rhinoviruses – RNA RNA virusesviruses Virus infects the cells of the Virus infects the cells of the

Respiratory tractRespiratory tract Other viruses that may cause a cold Other viruses that may cause a cold

are:are: * Adenovirus* Adenovirus * Coronavirus* Coronavirus * Influenza A and B* Influenza A and B

Virus is spread by droplets from nose Virus is spread by droplets from nose and throatand throat

from coughs, sneezing or direct contactfrom coughs, sneezing or direct contact Person may feel sick from 2 – 4 daysPerson may feel sick from 2 – 4 days There is no cure or vaccines for coldThere is no cure or vaccines for cold Treatment of a cold includes relieving Treatment of a cold includes relieving the symptoms:the symptoms: * Grandma’s chicken soup* Grandma’s chicken soup * Aspirin* Aspirin * Throat lozenges* Throat lozenges

Known as the “Known as the “FLUFLU”” Highly Highly contagiouscontagious infection infection In the respiratory tract:In the respiratory tract: * Nose* Nose * Lungs* Lungs Named by the proteins on Named by the proteins on the surface of the virus:the surface of the virus: HH = = HHaemagglutininaemagglutinin NN = = NNeuraminidaseeuraminidase

H5N1 Type/strain of Influenza A Called “Avian” flu Most wild ducks are the natural carries of the virus How did it end up infecting humans?..........

When poultry, such as chickens and turkeys became infected The virus is found in chicken droppings…….

Farmers needs to wash their hands

H1N1H1N1:: Influenza AInfluenza A Normally only infects pigs, but…Normally only infects pigs, but… The virus is able to mutate as it travels The virus is able to mutate as it travels

from hostfrom host to host for years……..to host for years…….. Then, if it happens to infect a Then, if it happens to infect a human host, it can mutate……human host, it can mutate…… This is not good! Why?................This is not good! Why?................ Once it mutates in the human host then Once it mutates in the human host then

it can be it can be transmitted from one person to another transmitted from one person to another and and

our our immune system immune system can’t fightcan’t fight the the virus offvirus off

Bird flu remains a threat:Bird flu remains a threat: (AFP) – Mar 24, 2010 “Bird flu outbreaks that have killed seven people in several countries so far this year show the virus remains a threat to humans”

“Last week, a three-year-old Vietnamese girl stricken with the virus died of severe lung infection, authorities there said.”

“Fatality rate for humans infected with bird flu remains high at 59 percent”

Luckily, Luckily, we can’twe can’t get the get the virus by eating cooked virus by eating cooked chicken or eggschicken or eggs It It has nothas not been proven that been proven that the virus can be spread from person to the virus can be spread from person to personperson

Most common in Most common in AsiaAsia and and IndonesiaIndonesia No cases have been seen in No cases have been seen in USAUSA or or North AmericaNorth America At present time there is At present time there is no affective no affective vaccine vaccine against H5N1. WHY?.......against H5N1. WHY?....... Regular Flu vaccine doesn’t workRegular Flu vaccine doesn’t work

Known as the Known as the “Spanish Flu”“Spanish Flu” Killed close to Killed close to 50 million 50 million people people worldwideworldwide That’s more than the That’s more than the Black Death Black Death Bubonic PlagueBubonic Plague from 1347 to 1351from 1347 to 1351 An estimated An estimated 675,000675,000 Americans died Americans died during the pandemicduring the pandemic What is aWhat is a “Pandemic” “Pandemic” ?...........?........... When an infectious disease When an infectious disease spreads worldwidespreads worldwide

Origin of the Origin of the Spanish Flu Spanish Flu is not knownis not known Interestingly it killed healthy adults, not Interestingly it killed healthy adults, not

the usual the usual population such as:population such as: * Young children* Young children * Elderly* Elderly * The Sick * The Sick WHY?..............WHY?.............. Do to their healthy, Do to their healthy, strong immune strong immune

systemsystem, the , the the system overreacted to the virus the system overreacted to the virus destroying destroying

healthy tissues and organs as wellhealthy tissues and organs as well

Some Scientists believe that the Some Scientists believe that the H1N1 H1N1 virus of virus of today is the mutated version of thetoday is the mutated version of the 1918 Flu 1918 Flu virusvirus

Also, interestingly enough, it was not the virus Also, interestingly enough, it was not the virus itself that caused so many deaths, BUT?..........itself that caused so many deaths, BUT?.......... A secondary A secondary bacterial infection bacterial infection in the LUNGS!!!in the LUNGS!!! In the In the past 300 years past 300 years there have been two there have been two

otherother Flu pandemics:Flu pandemics: 1. 1. The Asian Flu of 1957The Asian Flu of 1957 2.2. The Hong Kong Flu of 1968The Hong Kong Flu of 1968

The word “The word “herpeinherpein” comes ” comes from Greek word “from Greek word “to creepto creep”” There are more that There are more that 100100 herpes viruses but only herpes viruses but only 88 infect human host infect human host Most adults worldwide are Most adults worldwide are infected infected

DNADNA virus virus “ “HiddenHidden” virus” virus Once infected, it is your buddy for Once infected, it is your buddy for LIFE!!!LIFE!!!

HSV – 1HSV – 1 HSV – 2HSV – 2 HSV-1HSV-1 infects the cells in the mouth, infects the cells in the mouth, skin and cornea of the eyeskin and cornea of the eye HIGHLY CONTAGIOUS - HIGHLY CONTAGIOUS - by by direct contactdirect contact Cause cold sores and severe Cause cold sores and severe blistering of the skinblistering of the skin HSV- 2HSV- 2 is type of STD – also is type of STD – also Highly Highly

contagiouscontagious

Causes 2 distinct diseases: Chicken pox –Varicella * Common in children * In adults it is very serious * Virus remains dormant or “Hidden” in nerve cells of spinal cord

Shingles – Herpes zoster * Common in adults * Reactivation of Chicken pox virus * Virus becomes “Active” again

EBVEBVCauses Causes MononucleosisMononucleosis or the “ or the “Kissing Kissing

DiseaseDisease””Transmitted in saliva from person to Transmitted in saliva from person to

personpersonVirus infects cells in the mouthVirus infects cells in the mouthNext, virus infects B – cellsNext, virus infects B – cells * Type of * Type of whitewhite blood cells blood cells * Virus “* Virus “HidesHides” in B – cells” in B – cells More than More than 90% 90% of people become of people become

infectedinfected Can cause Cancer:Can cause Cancer: * Burkitt’s Lymphoma - cancer of B-cells* Burkitt’s Lymphoma - cancer of B-cells * Nasophyrangeal CA – nose and throat* Nasophyrangeal CA – nose and throat

66 strains of Hepatitis virus: strains of Hepatitis virus: * A B C D E and F* A B C D E and F Only Only 33 can make us sick: can make us sick: * * A B and CA B and C Infects the LiverInfects the Liver Each type/strain is transmitted Each type/strain is transmitted

differently:differently: * Contaminated food or water* Contaminated food or water * Blood* Blood * Sexually /STD* Sexually /STD Causes Causes JaundiceJaundice – yellowing of skin – yellowing of skin

and eyesand eyes

HVAHVA Type of Type of RNARNA virus virus More common in developing More common in developing countries with poor sanitationcountries with poor sanitation Highly contagious – found in fecesHighly contagious – found in feces Spreads by eating and drinking Spreads by eating and drinking contaminated food and watercontaminated food and water Children have mild or no symptomsChildren have mild or no symptoms * They develop life - long immunity* They develop life - long immunity 75 %75 % of adults develop of adults develop jaundicejaundice

HVBHVB DNA DNA virusvirus Close to 400 million are infected world - Close to 400 million are infected world -

widewide Spread by contaminated blood by drug Spread by contaminated blood by drug

usersusers sharing needlessharing needles Body fluids - STDBody fluids - STD Health care workersHealth care workers 90%90% of people recover of people recover But…… But…… 10% 10% of people develop of people develop chronic hepatitischronic hepatitis

HVCHVC RNA RNA virusvirus Mainly spread via Mainly spread via contaminated bloodcontaminated blood 75% 75% of infected people develop Chronic of infected people develop Chronic HepatitisHepatitis Only Only 50% 50% of people with chronic hepatitisof people with chronic hepatitis recoverrecover There is no vaccine for There is no vaccine for HVCHVC Luckily, There is vaccine for Luckily, There is vaccine for HVAHVA and and

HVBHVB