Dengue Hemorrhagic Syndrome Symptoms, Causes and Treatment

As a medical professional in India, you must be an expert in the symptoms, causes, diagnosis, management and treatment of Dengue. Dengue is a viral infection that spreads from mosquitoes to people and is a common occurrence in tropical and subtropical climates. The most common symptoms are high fever, headache, body aches, nausea and rash. 

Read this blog post carefully about Dengue Hemorrhagic Syndrome Symptoms, Causes and Treatment till the end if you want to elevate your microbiology preparation for NEET PG exam. 

Dengue fever is a mosquito-borne disease that affects tropical and subtropical regions of the world. A high temperature and flu-like symptoms are brought on by mild dengue fever. The severe variety of dengue fever, also known as dengue hemorrhagic fever, can result in severe bleeding, a sharp drop in blood pressure (shock), and even death.

Each year, dengue infections affect millions of people globally. Southeast Asia, the islands of the western Pacific, Latin America, and Africa are where dengue fever is most prevalent. Localised occurrences of the illness have been reported in Europe and the southern United States, among other new locations.

Epidemiological Determinants

Agent

• Flavivirus - 1, 2, 3, 4 serotypes
• No cross-immunity among serotypes
• Recovery from one serotype can only give immunity to that serotype in particular.

Vector – 

• Aedes Mosquito
  • Aedes aegypti - It is comparatively less aggressive and it is Discordant feeder that is it needs more than 1 feed.
  • Aedes albopictus - It is More aggressive and it is Concordant feeder that is 1 feed is enough

Features of Aedes aegypti 

• Hunchback appearance
• White stripes on black body
• Artificial collection of water
• Flight range - 100 meters
• Eggs - Single and cigar-shaped
• Larvae - Siphon tube
• Reservoir of infection: Man and mosquito
• Transmission cycle: Man-mosquito-man
• Incubation period: 3 to 10 days

Host factors 

All ages

• Birth genders
• Children have a milder disease than adults.

Environmental factors 

Humidity - 60 to 80%

• Temperature - 16 to 30 C

Also Read: HELMINTHOLOGY : Structure, Classification, Growth, and Development : NEET PG Microbiology

Symptoms of Dengue

A dengue infection frequently goes undetected in many people.

When symptoms do appear, they frequently start four to ten days after being bitten by an infected mosquito and can be confused for other ailments, like the flu. The symptoms of dengue include:

• Break bone fever - Classical dengue fever
• Retro orbital pain
• Arthralgia
• Myalgia
• Bimodal presentation of fever - It Peaks on day 1-2 and Resurges on day 5-6. Recovery occurs  within 7-10 days.
• Recovery within 7-10 days.
• Dengue fever + hemorrhagic manifestations (bleeding from any orifice)
• Rash: Maculopapular/ rubelliform 
• Lab diagnosis
  • 20% increase in hematocrit
  • Thrombocytopenia (platelet count <100000)
• Clinical diagnosis
  • Tourniquet test (>10 petechiae/ sq inch area)

Dengue Shock Syndrome

In  a severe case of dengue, blood vessels may leak fluid into body, resulting in symptoms including breathing difficulties, low blood pressure, and abdominal pain. Additionally, it could cause bleeding, liver damage, confusion, and cardiac problem. This condition is known as  Dengue shock syndrome or  dengue hemorrhagic fever. In this condition we can find the following findings:

• Pulse pressure - <90
• Blood pressure - <80 mmHg

Diagnosis of Dengue

Dengue fever can be challenging to diagnose since its signs and symptoms are similar to those of other illnesses such chikungunya, the Zika virus, malaria, and typhoid fever.

Your medical and travel histories will probably be questioned by your doctor. Include all pertinent information about your international travels, such as the dates and locations you visited as well as any possible mosquito encounters.

Additionally, your doctor might take a blood sample to be examined in a lab for signs of a dengue virus infection.

Within 1to 5 days the NS antigen test is done whereas if it is more than 5 days then we go for  IgM ELISA.

Treatment of Dengue

There are no specialised dengue antiviral medications. Supportive care recommendations include telling patients to drink plenty of water and steer clear of aspirin, aspirin-containing medications, and other non-steroidal anti-inflammatory drugs (like ibuprofen) due to their anticoagulant qualities. Whereas we can provide patient treatment according to symptoms:

Symptomatic treatment 

• IV fluid resuscitation
  • Crystalloids preferred.
  • Initial - 0.9% Normal saline
  • Maintenance - Ringer lactate

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Prevention and Control of Dengue

Dengue can be prevented by taking few of the methods mentioned below:

Larval Surveillance 

• Sampling unit: Houses or premises searches for water-holding containers.
  • House index: Number of houses positive for aedes larvae/ Number of houses searched.
  • Container index: Number of containers positive/ Number of containers checked.
  • Breteau index: Number of containers positive for larva or pupa/ Number of houses checked.
  • Aedes Aegypti Index 
    • Other name: House index
    • Percentage of houses and their premises showing actual breeding of aedes aegypti larvae.
    • Should not be >1%
    • Airports and seaports in endemic areas should be kept at least 400m around their premises free from the breeding of Aedes aegypti.

Vector Control of Dengue

Integrated vector management 

• Anti adult measures
• Anti larval measures
• Personal protection

Vaccine

1st dengue vaccine - Dengvaxia (CYD-TDV. It is for Age group of 9-45 years. It is Not used in India on a routine basis.

And that is everything you need to know about Dengue for your Microbiology preparation. For more interesting and informative blog posts like this, download the PrepLadder App and keep following our blog.