A Comprehensive Course on Dengue-Screening, Diagnosis and Management | CME Learning Center | CME Learning Overview

COURSE CURRICULUM

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

Rule of 20.

Other hemorrhagic fever
- Petechiae positive
- Rash, evidence of bleeding
- Ebola virus, marble virus, lassa virus, yellow fever virus, crimean congo hemorrhagic virus, hantavirus
- 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