Newly Emerging and Re Emerging Diseases An Overview

Newly Emerging and Re. Emerging Diseases: An Overview Benny Cheng Roger Lau Henry Chong

Overview �Introduction and Background �Notable Emerging/Re-emerging diseases �Bioterrorism �Transmission Routes

Introduction �Infectious diseases remain among the leading causes of death worldwide �This occurs because of three reasons: � 1. Emergence of new infectious diseases � 2. Re-emergence of old infectious diseases � 3. Persistence of stubborn infectious diseases

Definition �According to the NIAID: �Emerging Diseases �“Outbreak of previously unknown diseases or known diseases whose incidence in humans has significantly increased in the last two decades” �Re-emerging Diseases �“Known diseases that have reappeared after a significant decline in incidence”

How do they emerge? �Changes in human demographics �Exposure to carriers of the disease �Globalization and trade �Genetic variations and mutations �Human behaviour

Diseases covered �HIV �Hepatitis �HPV �Herpes �Influenza �Avian Influenza �SARS �Marburg Disease �Malaria �Tuberculosis �Trypanosomiasis

HIV & AIDS �Human Immunodeficiency Virus (HIV) – lentivirus �Over time develops into Auto Immunodeficiency Disease (AIDS) �Symptoms – Progressive illness leads to Infections & Cancer �Origin is still a mystery �Closest origin is the Simian Immunodeficiency Virus (SIV) that affects Monkey from Africa

Influence Over the Globe �First diagnosed in 1981 in a group of homosexual men �Until 2010, up to 25 million people have died from AIDS � 2. 7 million people acquired HIV in 2010; total number of 34 million people

Routes of Transmission

Prevention and Treatments �HIV / AIDS ARE PREVENTABLE! �Education �Behaviour Modification �Distribution of Condoms �Clean syringes �Sadly, there is miracle vaccine �Scientists are working on it

Hepatitis �Hepatitis Virus causes a swelling and inflammation of the liver which leads to serious health conditions �Fatigue, jaundice, weight lose �Hepatitis Forms: A, B, C, D, E, G �Most common in Canada: HAV, HBV, HCV

Hepatitis Around the World � 130 -170 million people chronically infected with HCV �Estimated 1. 4 million cases of HAV annually � 2 billion people infected worldwide � 350 million living with chronic infection � 600, 000 people die each year from HBV

Transmission of Hepatitis A, B, C Hepatitis A (HAV) B (HBV) C (HCV) Transmission Contaminated food and water Sexual contact, Blood transfer, Mother to baby at birth Exposure to infectious blood and injection drug use

Prevention and Treatments �Share common risk factors as other infectious diseases (HIV, tuberculosis) �Wash your hands! �Practice safe sex �Do not share personal items that gets in contact with blood �No cure – only therapeutic drugs

Human papillomavirus (HPV) �Virus from the papillomavirus family �One of the most common sexually transmitted infection �Transmitted mainly through sexual activity � 50% of sexually active men/women will have it at some point

Symptoms, Treatment and Prevention �Symptoms/signs �Warts Genital �Cancer Cervical �Treatment and Prevention � 90% of cases taken care of by Immune system �Vaccination �Safe sex

Herpes Simplex Virus �STD caused by viruses HSV-1 or HSV-2 �Transmission from sexual contact � Open sores � Bodily fluid � Skin to skin contact �One in six people will likely be infected �Outbreaks for infected will decrease over the years

Herpes Simplex Virus �STD caused by viruses HSV-1 or HSV-2 �Transmission from sexual contact � Open sores � Bodily fluid � Skin to skin contact �One in six people will likely be infected �Outbreaks for infected will decrease over the years

Dealing with Herpes �Symptoms � Typically ulcers (sores) and blisters � Can be mistaken for insect bites �Treatment � None, but there is medication to prevent outbreaks �Prevention � Abstinence from sex with infected individuals

Stats for HPV and Herpes

Influenza �Acute viral infection by influenza virus �Forms A, B, C �A: H 1 N 1 and H 3 N 2 subtypes currently circulating amongst humans �Zoonosis: transfers between animals and humans �Named H and N – Hemagglutinin and Neuraminidase �Strains of flu named after cities in Asia!?

Statistics �Seasonal influenza occurs yearly duing autumn and winter � 3 -5 million cases of severe illness and 250, 000 -500, 000 deaths �More severe and peaks more often in tropical areas �H 1 N 1 outbreak in Mexico in 2009 � 2000 -8000 Canadians die annually

Symptoms �Onset of high fever �Dry cough �Headache �Sore throat �Severe illness and deaths amongst people at high risk (children under the age of two and people chronically ill)

Transmission, Prevention, Treatment �By contact and airborne by sneezing, coughing �Common in schools and health facilities �How to Prevent it? �Cover your mouth to sneeze �Vaccination

Avian Influenza (H 5 N 1) �Avian Flu or Bird Flu �Flu Infection in birds, can mutate to infect humans �Not easily transmitted to humans � 1997: First discovered in Hong Kong in poultry �Wide Scope

Impact and Symptoms �Statistics �As of 2011, 562 cases and 329 deaths worldwide �Over 60% of infected die (WHO) �Symptoms �Affects lower respiratory tract in humans �Viral pneumonia � Fever, cough, sore throat, muscle aches, breathing problems

Treatment and Future Outlook �Treatment �Oseltamivir �Concerns �History of influenza has shown high mutation rates and pandemics throughout the 20 th century �Mutates into new viruses or mixtures into new subtypes

SARS �Severe Acute Respiratory Syndrome �Member of Coronavirus �Coughing and sneezing spread infected droplets through surface contact or an aerosol �Able to live on hands and tissues for up to 6 hours

SARS �Statistics �First appearance: November 2002, China �According to WHO: 251 cases in Canada, over 5000 in China, 8000+ cases worldwide �Killed 44 in Toronto, 750+ deaths worldwide �Epidemic officially ended in July 2003

SARS

Symptoms and Treatment �Symptoms � Cough � Difficulty breathing � Chills and shaking � Fever (Over 38 °C) � Headaches � Muscle Pains �Treatment � Antiviral medication, ventilation support

Prevention �Quarantine �Screening �Hand Hygiene �Cover mouth/nose when sneezing �Masks can help

Marburg Haemorrhagic Fever �Virus from Filoviridae Family �Elongated filaments �First outbreak in 1967 in 2 locations: Marburg, Germany and Belgrade, former Yugslovia �Outbreaks occurred in Angola, Congo, Kenya, and South Africa �Origin: possibly African Fruit Bats or Green Monkeys

Symptoms, Prevention & Treatment �Early stage: �High fever, severe watery diarrhea �“Ghost-like visage” �Late stage: �Severe haemorrhagic manifestations all over the body �Any Treatments? �No vaccine �Supplementary therapies and replace lost blood

Malaria �Infectious disease from Plasmodium �Typically transmitted by carrier mosquitoes �Most common in underdeveloped countries �Usually near the equator �Estimated between 708 000 and 1 003 000 deaths in 2008 (by WHO)

Symptoms, Treatment and Prevention �Symptoms �Fever and elevated temperatures �Sweating and weakness �Kidney failure �Acute respiratory distress syndrome �Treatment and Prevention �Chloroquine, Mefloquine, Doxycycline, Malarone �Mosquito repellent and mosquito nets

Tuberculosis �Infections caused by Mycobacterium tuberculosis �Can be present as � Latent TB Infection � TB disease �Antibiotic Resistant strains are emerging � Multi-drug resistant strains immune to � Isonaizid and Rifampicin

Symptoms, Treatment, Transmission �Symptoms � Can be asymptomatic (latent) � Chest pains � Coughing up blood � Weakness/fatigue �Treatment � Antibiotics �Transmission � Aerosol

Statistics �Nearly one third of the world is infected �TB results in about 2 million deaths yearly �About 9 million people will become infected �TB is one of the main causes of death for HIV infected

Tuberculosis

Trypanosomiasis �African Trypanosomiasis: Sleeping disease �Occurs through the bite of an infected tsetse fly �A re-emerging disease: most recent epidemic in 2008 in Uganda �Over 500, 000 people affected in Africa

Types �Trypanosoma brucei gambiense �Affects the majority of people Symptoms: Passive until advanced stages �Trypanosoma brucei rhodiense �Acute form Symptoms: Rapidly affects neurological system �Also, Chagas Disease: Affects Latin America

Diagnosis and Treatment �Diagnosis: 1. Screening and serological tests 2. Diagnosis for the presence of the parasite 3. Staging to determine the state of disease progression, involving lumbar puncture �Treatment �Two stages: � Stage 1: Pentadimine, suramin � Stage 2: Melarsoprol, Eflornithine � Without treatment, it can be fatal

Bioterrorism �Viruses and bacteria deliberately released to cause illness or death �Agents are usually spread through air, water or food �Response requires cooperation between public health authorities and law enforcement �Real-time Outbreak Disease Surveillance (RODS) in the USA

Categorization �Category A – high-priority agents �Anthrax (2001) �Small pox �Category B – second highest priority �E coli O 157: H 7 �Clostridium perfringens toxin �Category C – third highest priority �SARS �H 1 N 1 �HIV/AIDS

Other Routes of Transmissions �In the 21 st century there are multiple factors: �Economic development and land use �Human demographic and behaviours �International travel and globalization �Balance between human civilizations and microbial speces in nature �Adv of microbes: multiplies and mutates in minutes �Adv of humans: intelligence and will to implement and invent vaccinations