Dengue has assumed endemic proportions and every year causes 50 million infections worldwide. No therapeutic agents exist for dengue treatment and the key to management is early screening as well as timely and judicious supportive management including fluid management and close monitoring. We bring to you a comprehensive course on dengue covering all aspects of the dengue infection including screening, diagnosis, clinical tests, management and public health approaches in treating as well as preventing the epidemic of dengue.
MODULES
We bring to you 7 modules which will talk about all aspects of dengue fever.
Dengue fever has assumed epidemic proportions.
Dengue, Zika, Chikungunya-related to Aedes mosquito.
50% of world’s population now at risk
No immunity.
Aedes mosquito freely moving.
It requires fresh water
Past 10 years, no of dengue cases has been increasing
Mosquito borne viral infection
Female mosquito bites
Two species: Aedes aegypti, Aedes albopictus
Also transmits zika virus, chikungunya and yellow fever
Flaviviurs, 4 different strains
DENV1
DENV2
DENV3
DENV4
DENV2 and DENV4 are more dangerous
First infection may be not serious, but second is
2006: 15, 000 cases were reported in Delhi [epidemic]
Dengue mosquito is an indoor mosquito
Day biter
Flies lower in the air
It can grow anywhere, from small containers to large water bodies (tank, cooler, small cup)
Virus can transmit through the eggs
Eggs can remain alive throughout the year
Southern part: throughout the year
Northern India: April-November
After virus incubation of 4 to 10 days, an infective virus can transmit for the rest of its life.
Infected asymptomatic or symptomatic patients are the main carriers
Become the public health detective
Infected patients can transmit infection up to 4-5 days; sometimes up to 12 days
Public Health Message:
Destroy the breeding of the mosquito wherever it is found
Image of a building free from mosquito
Febrile phase
High fever <38.5 degree C
Associated headache, myalgia, arthralgia
Transient macular rash
Lasts 3-7 days
Critical Phase
Observe, complications may occur, if not detected may lead to complications
Around the time when the fever starts subsiding
Day 3 to 7
Lasts for 24-48 hours
Occurs only in small proportion of patients
Plasma leakage, tend to bleeding, shock and organ impairment
Rule of 20
20 ml per Kg body weight of body fluid, to be continued till the patient passes urine
Convalescent Phase
Recovery phase
Plasma leakage and hemorrhage resolve
Vital signs are stabilizing
Accumulated fluids (pleural fluid, pericardial fluid, ascites are subsiding)
An additional rash, a confluent erythematous eruption with small islands of unaffected skin that is often pruritic may appear
Within 1-2 days of effervescence
Recovery phase lasts 2 to 4 days
Some patients, especially adults, may have profound fatigue
No fever, Itching and rash indicates patient has already recovered or recovering
Suspect dengue with typical features of dengue fevers
Headache
Nausea
Vomiting
Retro-orbital pain
Myalgia, arthralgia, rash
Hemorrhagic manifestation-positive tourniquet test and
Tests needed
Hemogram
CBC
If TLC count is low, the patient has a viral fever
If tourniquet test is positive, patient has viral hemorrhagic fever
If retro-orbital pain is there, the patient has dengue
If the patient
In chikungunya, severe joint pain and TLC or platelet count may not reduce
In Zika, conjunctivitis may also be present
Limit tests to be done for dengue
Pulse rate
Low pulse rate may mean typhoid fever
High pulse rate may be associated with leakage, internal bleeding or hemorrhagic fever
High pulse rate more than 20, may be a sign of leakage
Blood pressure
Systolic and diastolic
Sudden fall in systolic blood pressure more than 20 mm Hg, it may indicate a leakage
Difference between systolic and diastolic blood pressure of less than 20 indicates leakage, intravascular dehydration
Positive tourniquet test
Checking microvascular fragility
How to do a tourniquet test?
Inflate a blood pressure cuff on the arm to midway between systolic and diastolic blood pressure for 5 minutes
Release the pressure for 1 minute and the skin below the cuff is examined for finding of petechae
More than 10 petechiae in 1 sq. inch means positive tourniquet test
If it is more than 20 it is highly suggestive of dengue fever
Check List
Pulse rate
Systolic and diastolic pressure
Tourniquet test
NS1 antigen test
Recommended if patient has fever between 1 to 7 days
Sensitivity can exceed 90% in primary infection
In secondary cases, sensitivity reduces to 60%
IgG and IgM
Can be positive as early as 4 days
Seroconversion
If IgM positive
Between paired acute and convalescent phase specimens
Day 1
Day 10 to 14
4 fold rise in antibody titers –dengue confirmed
IgM
Recent infection
IgG
o Previous infection
NS1, IgG and IgM positive
Secondary infection
ELISA
Rapid test
Prevention from mosquito bites
Dengue-daytime; others-throughout the day
Indexed case and clinically diagnosed case
First case in the city suggests mosquito breeding has started; there will be large numbers of asymptomatic cases, 50 meters all around find mosquito breeding and try to eliminate the mosquitoes
Dengue is a notifiable disease
Notify all cases- suspected and confirmed
Image of bottle cap of any soft drink; image of underground or rooftop water tank
Rub dry all utensils containing water
Change the water collection, dry rub them
Else eggs can stay on the walls of the surface and remain alive for a year
Image of public health professionals looking for mosquitoes
Follow the mosquito elimination process in the state
Images of temephos tablets, kerosene and gambusia fish in ponds
Ghar to bula raha hai, katwayega toh nahi? If an image can be searched!
Breeding of mosquitoes in hospitals can be detrimental
Infected mosquitoes can bite people with comorbid conditions
Wear clothes that completely cover
Use a repellant with 20-30%DEET or 20% picaridin on exposed skin
Wear neutral colored (such as light grey) clothing
Window screens, insecticide treated bed nets, mosquito repellant coils and vaporisers
Prevent spread of infection
Vaccines are not available in India
Vaccinations are always effective after the first infection has occurred
Multi organ system illness accompanied by hemorrhage
In monsoon season, typical features of headache with peri orbital pain- it will be dengue
Chikungunya
Severe joint pain
Less abdominal pain
Less mucopenia
On flexion, my pain reduces
Zika
Associated conjunctivitis
Malaria
Fever associated with chills and rigors
Typhoid
Persistent fever
Bradycardia
Abdominal pain
Rash
Leptospirosis (especially in Maharashtra)
Rigors
Myalgia
Conjunctival suffocation
Headache
Acute HIV infection
Only if there is history of recent unprotected sexual contact with unknown status of a person
Fever with lymphadenopathy
Sore throat
Rash
Myalgia
Arthralgia
Headache
May have painful muco-cutaneous ulcerations and meningitis
Viral hepatitis
Fever subsides, jaundice appears
Sepsis
Fever with chills and rigors
Tachycardia
Altered mental status
Liver abscess
Fever with and without chills and rigors
Thump test in right hepatic area, patient will writhe in pain
Rickettsial infection, Typhus fever
Headache
Fever
Myalgia
Solitary or multiple scars with regional lymphadenopathy and rash
INSTRUCTORS
Dr.KK Aggarwal
Cardiology
Recipient of Padma Shri, Vishwa Hindi Samman, National Science Communication Award and Dr B C Roy National Award, Dr Aggarwal is a physician, cardiologist, spiritual writer and motivational speaker. He was the Past President of the Indian Medical Association and President of Heart Care Foundation of India. He was also the Editor in Chief of the IJCP Group, Medtalks and eMediNexus
