In this slide, you will know about what is dengue virus, epidemiology, symptoms of dengue fever, diagnosis, life cycle, risk factors, and current research. Hope it will help you.
2. WHAT IS DENGUE?
DENGUE IS MOSQUITO-BORNE VIRAL DISEASE, ALSO
KNOWN AS BREAK BONE FEVER. VICTIMS OF DENGUE
OFTEN HAVE CONTORTIONS DUE TO THE INTENSE JOINT
AND MUSCLE PAIN.
3. DENGUE VIRUS IS TRANSMITTED BY FEMALE
MOSQUITOES MAINLY OF SPECIES AEDES
AEGYPTI AND TO LESSER EXTENT AEDES
ALBOPICTUS .
AEDES AEGYPTI AEDES ALBOPICTUS
4. EPIDEMIOLOGY
• DENGUE FEVER IS CAUSED BY FOUR SEROTYPES OF THE
DENGUE VIRUS.
1. DENGUE DEN-1
2. DENGUE DEN-2
3. DENGUE DEN-3
4. DENGUE DEN-4
WHICH BELONG TO THE GENUS FLAVIVIRUS, FAMILY
FLAVIVIRIDAE. RECOVERY FROM INFECTION BY ONE SEROTYPE
PROVIDES LIFELONG IMMUNITY AGAINST THAT SEROTYPE.
5. • DENGUE IS WIDE SPREAD THROUGHOUT THE TROPIC ,WITH LOCAL
VARIATION IN RISK INFLUENCED BY RAINFALL, TEMPERATURE AND
UNPLANNED RAPID URBANIZATION.
• SEVER DENGUE WAS FIRST RECOGNIZED IN THE 1950S DURING
DENGUE EPIDEMIC IN THE PHILIPPINES AND THAILAND.
• TODAY SEVER DENGUE AFFECTS MOST ASIAN AND LATIN AMERICAN
COUNTRIES AND HAS BECOME A LEADING CAUSE OF
HOSPITALIZATION AND DEATH AMONG CHILDREN AND ADULTS IN
THESE REGIONS.
6. • DENGUE IS COMMON IN MORE THAN 100 COUNTRIES AROUND THE WORLD.
40% OF THE WORLD’S POPULATION, ABOUT 3 BILLION PEOPLE LIVE IN
AREAS WITH A RISK OF DENGUE.
• EACH YEAR ,UP TO 400MILLION
PEOPLE GET INFECTED WITH
DENGUE. APPROXIMATELY,
100 MILLION PEOPLE GET SICK
FROM INFECTION.
7. • 2.4 MILLION PEOPLE ,OUT OF A POPULATION OF NEAR 160 MILLION, ARE
INFECTED WITH DENGUE VIRUS IN BANGLADESH EACH YEAR.
• THE RISK IS HIGH IN THE CITIES OF
CHITTAGONG (IN THE SOUTH EAST),
KHULNA (SOUTH WEST) AND DHAKA
(IN THE MIDDLE OF THE COUNTRY).
• SINCE JANUARY 1 TILL SEPTEMBER 7, A TOTAL OF 75,753 PEOPLE HAVE
BEEN AFFECTED BY DENGUE
END P-1
8. SYMPTOMS OF DENGUE FEVER
SYMPTOMS OF DENGUE FEVER USUALLY SHOW UP WITHIN THE FIRST WEEK OR SO
BEING INFECTED. THE SYMPTOMS ARE OFTEN MILD, BUT THE DISEASES CAN
CAUSES:
• A SUDDEN VERY HIGH FEVER OCCUR
• A SKIN RASH, WHICH USUALLY SHOWS UP AFTER THE FEVER OCCUR.
• SEVERE HEADACHE
• NAUSEAAND VOMITING
9. • PAIN BEHIND EYES.
• JOINT AND MUSCLE PAIN OR
SPASMS.
• BLEEDING FROM NOSE OR GUMS.
• BRUISING.
• CONVULSION.
11. DIAGNOSIS
1. THIS MAY BE DIAGNOSED BY THE SIGNS
AND SYMPTOMS OF FEVER , NAUSEA ,
VOMITING ,RASHES AND GENERALIZED
PAIN.
2. LABORATORY TEST ARE:
• LOW BLOOD COUNT
• LOW PLATELETS COUNT
• POSITIVE TOURNIQUET TEST
• RAISED HEMATOCRIT DUE TO
HEMOCONCENTRATION.
12. 3. CONFIRMATORY TEST: CONFIRMATORY TEST ARE VIRUS ISOLATION. THIS CAN BE DONE IN
CELL CULTURE. VIRUS ISOLATION IS POSSIBLE IN THE ACUTE PHASE OF THE
DISEASES.
PCR NUCLEI ACID DETECTION BY PCR CAN BE DONE
VIRAL ANTIGEN CAN BE DETECTED.THIS IS MORE THAN 90% OF THE PRIMARY INFECTION
IN THE FEBRILE PHASE.
4.LIVER FUNCTION TESTS SHOW RAISED TRANSAMINASES .
5.SEROLOGICAL TEST DETECTS DENGUE VIRUS SPECIFIC ANTIBODIES.
END P-
2
13. LIFE CYCLE OF DENGUE IN HUMAN
BODY
• INFECTED WITH DENGUE VIRUS FEMALE MOSQUITOES
BITE HUMANS
• THE DENGUE VIRUS PRESENT IN ITS SALIVARY
GLANDS.
• WHEN TAKING A BLOOD MEAL, AN INFECTED FEMALE
MOSQUITO INJECTS ITS SALIVA THE HUMAN HOST
• FOUR DAYS AFTER A PERSON WILL DEVELOP
VIREMIA,
• VIREMIA A CONDITION IN WHICH THERE IS A HIGH
LEVEL OF THE DENGUE VIRUS IN THE BLOOD.
• VIREMIA LASTS APPROXIMATELY FIVE DAYS(IT CAN
LAST AS LONG AS TWELVE DAYS.)
• FIVE DAYS AFTER THE VIREMIA CONDITION THE
PERSON DEVELOPS SYMPTOMS OF DENGUE FEVER, WHICH
CAN LAST FOR A WEEK OR LONGER.
14. PREVENT MECHANISM OF DENGUE
1. PHYSICAL MECHANISM
• GIS MAPPING OF DENGUE FOCI AMONG THE ADVANCED TECHNIQUES USED FOR LOCATION OF DENV, GIS
MAPPING HAS BEEN EFFICIENT IN LOCATING DENGUE CONCENTRATIONS. BY LOCATING DENGUE SERI-POSITIVE
CASES WITHIN THE STUDY AREA, DENGUE TRANSMISSION CAN BE PREVENTED BY LOCATING DENGUE FOCI,
AND THEN TREATING THEM WITH DIVERSE PREVENTIVE STRATEGIES
• ON THE OTHER HAND, THESE PROGRAMS ARE NOT FOCUSED ON THE ELIMINATION OF DENGUE VECTOR. THE
ERUPTION OF DENGUE IN SINGAPORE, AFTER DECADES OF SURVEILLANCE, INDICATED UNSUSTAINABLE
VECTOR CONTROL MEASURES AND INEFFECTIVE SURVEILLANCE IN 2005 (. AN EFFECTIVE SURVEILLANCE
SYSTEM AIMING AT VECTOR IDENTIFICATION AND ERADICATION ,PROVIDING THE UNDERLYING INFORMATION
REGARDING VECTOR CONCENTRATION AND IT’S BREEDING, WILL PROVE BENEFICIAL IN CONTROLLING VECTOR
SPECIES.
2.BIOLOGICAL MECHANISM
• PARATRANSGENESIS AND USE OF WOLBACHIA. NOWADAYS, GENETIC CONTROL OF A. AEGYPTI HAS RISEN AS A
SET OF PROMISING TECHNIQUES, AMONG WHICH PARATRANSGENESIS IS THE POPULAR METHOD. THIS
APPROACH UTILIZES GENETICALLY-MODIFIED SYMBIOTIC BACTERIA THAT ARE REINTRODUCED IN THE VECTOR
TO COLONIZE THE VECTOR POPULATION, HENCE LIMITING THE TRANSMISSION OF DISEASE.
15. . 3 CHEMICAL MECHANISM
• THE CHEMICAL COMPOUNDS, CALLED INSECTICIDES, HAVE BEEN UTILIZED FOR
MOSQUITO CONTROL FOR MANY DECADES. THESE INSECTICIDES BECAME THE MOST
COMMONLY USED INTEGRATED STRATEGY; NEVERTHELESS, THE CONTINUOUS USE
DEVELOPED RESISTANCE IN THE TARGET VECTOR POPULATION, AND CAN INDUCE
NEGATIVE IMPACTS ON THE ENVIRONMENT. TO COUNTER THE EFFECTS OF THESE
COMPOUNDS, RESEARCHERS DEVELOPED ALTERNATIVE CONTROL METHOD I.E.,
INTRODUCTION OF PLANT-BASED INSECTICIDES THAT CAN SUSTAIN AND INDUCE
LESS TOXICITY IN ENVIRONMENT THAN SYNTHETIC INSECTICIDES . FURTHERMORE,
THESE PLANT DERIVATIVES ARE NOT ONLY LIMITED TO PRODUCE INSECTICIDES;
HOWEVER, THEY HAVE ALSO PROVED THEIR EFFICIENCY AS POTENTIAL REPELLENTS
AGAINST A. AEGYPTI
•
16. RISK FACTORS:
1. MOSQUITO BITES: BY AEDES AEGYPTI.
2. LIVING AND TRAVELING TO TROPICAL AREAS.
3. PRIOR INFECTION WITH A DENGUE FEVER VIRUS.
4. NOT TAKING PRECAUTIONS.
5. CAUSES OF HEMORRHAGE.
6. BREAKBONE FEVER.
17. CURRENT RESEARCH ON DENGUE FEVER:
• INTRODUCTION:
DENGUE HAS BECOME A SERIOUS HEALTH PROBLEM WORLDWIDE, AND SCIENTISTS ARE FOCUSING THEIR ATTENTION
ON UNDERSTANDING HOW THE DENGUE VIRUS CAUSES DISEASE. AS THEY LEARN MORE ABOUT HOW DENGUE AFFECTS
THE BODY, RESEARCHERS HOPE TO DIAGNOSE AND TREAT DENGUE BETTER. CURRENT DENGUE RESEARCH ALSO AIMS
TO PROVIDE BETTER SURVEILLANCE TO LIMIT THE EFFECT OF DENGUE EPIDEMICS
• BASIC RESEARCH ON DENGUE:
THIS TYPE OF RESEARCH INVESTIGATES MANY ASPECTS OF DENGUE VIRAL BIOLOGY, INCLUDING EXPLORATION OF
THE INTERACTIONS BETWEEN THE VIRUS AND HUMANS AND STUDIES OF HOW THE DENGUE VIRUS REPLICATES ITSELF.
ONE IMPORTANT FIELD OF BASIC RESEARCH IS DENGUE PATHOGENESIS, THE STUDY OF THE PROCESS AND
MECHANISMS OF DENGUE IN HUMANS. SCIENTISTS WANT TO UNDERSTAND HOW THE DENGUE VIRUS CAUSES
DAMAGE TO THE HUMAN BODY AND HOW THE IMMUNE SYSTEM RESPONDS TO A DENGUE INFECTION SO
THAT THEY CAN DEVELOP NEW TREATMENTS FOR THE DISEASE.
18. RESEARCHERS ARE INVESTIGATING HOW THE DENGUE VIRUS REPLICATES ITSELF AND THE
STRUCTURE OF THE VIRAL COMPONENTS, SUCH AS THE CAPSID, MEMBRANE, AND ENVELOPE
PROTEINS. SCIENTISTS ALSO WANT TO KNOW — HOW DO THE DENGUE VIRUSES MANAGE TO
AVOID DETECTION BY THE IMMUNE SYSTEM? BECAUSE VIRUSES CAN EVOLVE AND GAIN
MUTATIONS OVER TIME, RESEARCHERS ARE EXAMINING DENGUE VIRAL GENETICS AND
EVOLUTION TO INVESTIGATE CHANGES IN VIRAL GENOMES OVER TIME. THESE VARIATIONS MAY
HELP THE VIRUS HIDE FROM THE IMMUNE SYSTEM. SCIENTISTS KNOW THAT PARTICULAR VIRAL
SEQUENCES ARE ASSOCIATED WITH MORE SEVERE DENGUE SYMPTOMS.
DIAGNOSTICS:
PATIENTS WITH SEVERE DENGUE ILLNESSES CAN BE TREATED SUCCESSFULLY IF THEY ARE
DIAGNOSED AS EARLY AS POSSIBLE. SCIENTISTS ARE WORKING ON IMPROVING DENGUE
DIAGNOSTICS SO THAT PATIENTS INFECTED WITH DENGUE CAN BE TREATED QUICKLY
HOW IS DENGUE DIAGNOSED?
A NUMBER OF LABORATORY METHODS ARE USED TO DIAGNOSE DENGUE, INCLUDING DETECTION
OF THE DENGUE VIRUS, VIRAL RNA, VIRAL ANTIGENS, AND ANTIBODIES AGAINST THE VIRUS IN
THE PATIENT'S BLOOD OR TISSUES. THE VIRUS CAN BE DETECTED IN THE BLOOD FOR ONLY FOUR
TO FIVE DAYS AFTER THE ONSET OF SYMPTOMS. DURING THIS EARLY STAGE OF HE DISEASE,
ISOLATION OF THE VIRUS, VIRAL RNA, AND VIRAL PROTEIN CAN BE USED TO DIAGNOSE DENGUE.
19. THE DETECTION OF ANTIBODIES (IGM AND IGG) IN THE BLOOD OF AN INFECTED
INDIVIDUAL IS AN INDIRECT METHOD TO DIAGNOSE DENGUE. THIS METHOD IS
COMMONLY USED TO DIAGNOSE DENGUE IN THE LATER STAGE OF THE DISEASE, AFTER
THE VIRAL LEVELS HAVE DECREASED. ANTIBODIES AGAINST DENGUE CAN BE DETECTED IN
MOST PATIENTS FIVE DAYS AFTER THE ONSET OF SYMPTOMS, AND IGG CAN BE DETECTED
FOR MANY MONTHS AND EVEN YEARS AFTER AN INFECTION. DURING A PRIMARY (FIRST)
DENGUE INFECTION, IGM LEVELS ARE VERY HIGH, BUT DURING A SECONDARY INFECTION,
IGM LEVELS ARE LOWER. THE LEVELS OF IGG ACTUALLY INCREASE DURING A SECONDARY
INFECTION. THEREFORE, CLINICIANS CAN MEASURE THE AMOUNTS OF IGM AND IGG TO
DECIDE WHETHER A PATIENT HAS A PRIMARY OR A SECONDARY DENGUE INFECTION. THIS
TEST CAN BE USEFUL BECAUSE PATIENTS WITH SECONDARY INFECTIONS ARE MORE LIKELY
TO HAVE SEVERE DENGUE THAN THOSE WHO HAVE NOT HAD A PREVIOUS INFECTION.
BECAUSE DENGUE CAN BE MISTAKEN FOR OTHER DISEASES SUCH AS YELLOW FEVER,
MEASLES, AND INFLUENZA, IT IS BEST TO CONFIRM A DIAGNOSIS OF DENGUE BY
20. IS DENGUE CURABLE?
1.DENGUE IS A VIRUS, SO THERE IS NO SPECIFIC TREATMENT OR CURE . THERE IS NO
SPECIFIC MEDICINE TO TREAT DENGUE INFECTION.
2. PATIENTS SHOULD USE PAIN RELIEVERS WITH ACETAMINOPHEN AND AVOID MEDICINES WITH
ASPIRIN, WHICH COULD WORSEN BLEEDING.
3.THSY SHOULD ALSO REST, DRINK PLENTY OF FLUIDS AND TAKE FOODS LIKE BANANA, APPLE,
POMEGRANATE, CITRUS, GUAVA AND OTHERS SINCE THEY HELP REPLENISH MINERALS AND SEE THEIR
DOCTOR FOR REGULAR CHECK UP. PAPAYA LEAVES JUICE IS ALSO A CURABLE EXTRACTS FOR DENGUE
FEVER.
4. SOME DEVELOP DENGUE HEMORRHAGIC FEVER AFTER THE INITIAL FEVER DECLINES — A MORE
SEVERE FORM OF THE ILLNESS THAT CAN CAUSE ORGAN DAMAGE, SEVERE BLEEDING, DEHYDRATION
AND EVEN DEATH. BUT WITH EARLY TREATMENT, THE MORTALITY RATE FOR ALL DENGUE FEVER IS
CURRENTLY FEWER THAN 1 OF 100 PEOPLE.