This is the Presentation Delivered by Dr. Farah Tanveer (MD) Consultant Infectious Diseases in Qarshi University Lahore Campus.

1. Dengue
DR. FARAH TANVEER, MD, FACP
Diplomate American Board of Infectious
Diseases
Consultant Infectious Diseases at Expert Consult
Clinic of Lahore

2. Introduction
• Dengue virus
• Female mosquitoes mainly of the species Aedes aegypti and, to a lesser
extent, Ae. albopictus.
• Tropical and sub-tropical climates worldwide.
• Both species have been closely associated with human dwellings due to their
breeding preference for clean water domestic habitats.
• Day-time feeder; peak biting periods are early in the morning and in the evening
before suns
• Four serotypes of the virus that cause dengue (DENV-1, DENV-2, DENV-3 and
DENV-4).

3. • First isolated in 1943 after an outbreak in Japan.
• Before 1970, only 9 countries had experienced severe dengue epidemics.
• The disease is now endemic in more than 100 countries.
• The Americas, South-East Asia and Western Pacific regions are the most seriously
affected, with Asia representing ~70% of the global burden of disease.

4. Transmission
• Transmitted to humans due to the bites of infected
female mosquitoes, primarily the Aedes
aegypti mosquito
• After feeding on an DENV-infected person, the virus
replicates in the mosquito midgut, before it
disseminates to secondary tissues, including the
salivary glands.
• The time it takes from ingesting the virus to actual
transmission to a new host is 8-12 days.
• Once infectious, the mosquito is capable of
transmitting virus for the rest of its life.

5. Transmission
• Human-to-mosquito transmission can occur up
to 2 days before someone shows symptoms of
the illness, up to 2 days after the fever has
resolved .
• Maternal transmission has been reported.
Perinatally infected neonates typically become
ill during the first week of life.
• Rare cases of transmission via blood products
and organ donation have been recorded.

6. WHO
Classification
Dengue ( with or
without warning signs)
Severe Dengue

7. Clinical
Manifestations
Incubation period- 5-7 days
Disease spectrum varies from
Asymptomatic (~ 70%) to mild
illness (~25%) to severe ( 1 in
20) illness which can be fatal.

8. FEBRILE PHASE- 2-7 days

9. Skin
Manifestations
Maculopapular or macular confluent rash with islands of
skin sparing. The rash typically begins on day 3 and persists
2-3 days

10. Laboratory Findings
Leukopenia ( decrease from 2-10 days, lowest on day 5)
Thrombocytopenia (decrease from 3-10 days, sharp decrease on day 4-6)
Hyponatremia
Elevated transaminases
Normal ESR

11. Warning Signs
• Severe abdominal pain
• Persistent vomiting ( at least 3 episodes/
24 hours)
• Rapid breathing
• Bleeding gums or nose
• Fatigue/ restlessness/ drowsiness
• Blood in vomit or stool
• Red spots or patches on skin
• Cold, clammy skin
• Progressive Increase in hematocrit

12. Severe
Dengue/
Critical
phase
• About 1 in 20 people who get sick with dengue will
develop severe dengue.
• If you have had dengue in the past, you are more
likely to develop severe dengue.
• Infants and pregnant women are at higher risk for
developing severe dengue.
• Placental transfer of maternal IgG against dengue
virus (from a previous maternal infection) may
increase risk for severe dengue among infants
infected at 6–12 months of age, when the
protective effect of antibody wanes.

13. Severe Dengue/ Critical phase
3-7 days after illness onset and
within 24-48 hours of fever
resolution
Substantial plasma leakage as a
result of a marked increase in
vascular permeability.
Pleural effusions leading to
respiratory distress, ascites,
hypoproteinemia, or
hemoconcentration.
Patients may appear to be well
despite early signs of shock.
However, once hypotension
develops, systolic blood pressure
rapidly declines, and irreversible
shock and death may ensue
despite resuscitation.
Severe hemorrhagic manifestations
Organ impairment ( e.g elevated
transaminases >1000 IU/L),
impaired consciousness or heart
impairment.

14. Convalescent Phase
As plasma leakage subsides, the patient begins to reabsorb extravasated intravenous fluids
and pleural and abdominal effusions.
As a patient’s well-being improves, hemodynamic status stabilizes (although he or she may
manifest bradycardia), and diuresis ensues. The patient’s hematocrit stabilizes or may fall
because of the dilutional effect of the reabsorbed fluid, and the white cell count usually
starts to rise, followed by a recovery of platelet count.
The convalescent-phase rash may desquamate and be pruritic.

15. Diagnosis
Diagnostic Test
≤7 Days After Symptom
Onset
>7 Days Post Symptom
Onset
Specimen Types
Molecular Tests ✓ —
Serum, plasma, whole
blood, cerebrospinal
fluid*
Dengue Virus Antigen
Detection (NS1)
✓ — Serum
Serologic Tests ✓ ✓
Serum, cerebrospinal
fluid*
Tissue Tests ✓ ✓ Fixed tissue

16. IgM antibodies are
detectable 4-5 days
after onset of
symptoms and remain
detectable for about 3
months. The presence
of IgM is indicative of a
recent DENV infection.
IgG antibody levels
take longer to develop
and remains in the
body for years. The
presence of IgG is
indicative of a past
infection.

17. Treatment
Rest
Stay hydrated
Stay alert about warning signs
Acetaminophen ( Panadol) for
fever. NO Ibuprofen/ aspirin

18. Treatment
Prophylactic platelet transfusions- not beneficial
Transfusion for count <10,000 in nonbleeding cases
and <20,000 in patients with bleeding.
Administration of corticosteroids has no
demonstrated benefit

19. Recurrent Dengue Infection
• Once a person has been infected with one strain, their body will build up an
immunity to only that strain of the virus. This means that a person can become
infected with dengue fever another 3 times in their life.
• Each dengue fever reinfection is much more dangerous than the previous
infection.
• Antibody-dependent enhancement (ADE)

20. Vaccination
• The first dengue vaccine, Dengvaxia® (CYD-TDV) is
a live attenuated vaccine developed by Sanofi
Pasteur was licensed in December 2015 and has
now been approved by regulatory authorities in
~20 countries.
• Use of the CYD-TDV vaccine is targeted for persons
living in endemic areas, 9-45 years of age, who
have had at least 1 episode of dengue virus
infection in the past
• The vaccine manufacturer, Sanofi Pasteur,
announced in 2017 that people who receive the
vaccine and have not been previously infected with
a dengue virus may be at risk of developing severe
dengue if they get dengue after being vaccinated.
• Three doses; each shot is spaced 6 months apart.

21. Prevention
• Stay away from mosquito bites
• Mosquito repellents with DEET (20 %-30%)
• Prevent spread of dengue inside your house
• Mosquitoes that bite the affected family member can go on
to bite and infect others.
• Allow the sick child or family member to rest and sleep
under a bed net or use insect repellant while feverish.
• Kill all mosquitoes in the house and empty containers that
carry water on patios.
• • Place screens on windows and doors to prevent
mosquitoes from entering the house.

24. Monkeypox

25. Introduction
• Monkeypox virus- same family as smallpox
• Discovered in 1958 from monkeys used for research in Denmark
• First human case of monkeypox was recorded in 1970 in the Democratic Republic of the
Congo (DRC).
• Endemic areas: Central and West Africa
• 2 clades of monkeypox virus: the West African clade and the Congo Basin (Central
African) clade.
• First Outbreak in non endemic area: 2003 in USA
• Sporadic epidemics have occurred due to international travel or importing animals from
endemic areas.

26. • Natural history uncertain but African rodents and non-
human primates (like monkeys) may harbor the virus and
infect people

27. 2022
Outbreak
• Since 13 May 2022, cases of monkeypox
have been reported to WHO from non
endemic countries.
• Epidemiological investigations are ongoing,
however, reported cases thus far have no
established travel links to endemic areas.
• West African clade predominant.
• As of May 26, 257 confirmed cases and 120
suspected cases
• No deaths

30. Transmission
• Contact Transmission
Animal to human
Human to human
• Respiratory transmission
• From pregnant mother to her fetus.

32. Clinical Manifestations
Incubation
period:7-14 days (
can range from 5-
21 days)
Fever Headache Muscle aches
Backache
Swollen lymph
nodes
Chills Exhaustion

33. Clinical Manifestations
• RASH
• Within 1 to 3 days after the appearance of fever, the patient develops a rash,
often beginning on the face then spreading to other parts.
• Face ( 95%)
• Palms and soles (75%)
• Can also affect oral mucosa ( 70%), genitalia (30%), conjunctiva (20%) and cornea.

34. Monkeypox rash • Lesions progress through the
following stages before falling off:
• Macules
• Papules
• Vesicles
• Pustules
• Scabs
• Few to thousands in number
• Can coalesce to form large areas
of skin slough off.
• Same stage of development

35. Clinical
Manifestations
Lasts for 2−4 weeks.
Usually, self-limiting .
May be severe in some individuals, such as children,
pregnant women or persons with immune
suppression.
Human infections with the West African clade appear
to cause less severe disease (case fatality rate of 3.6%)
compared to the Congo Basin clade ( case fatality rate
10.6%).

36. Complications
of Monkey
Pox

37. Diagnosis
• Clinical
• Confirmed by PCR 6 days ago

38. Treatment
Most of the cases have mild, self-limiting disease requiring
only supportive measures.
Severe cases may need treatment with antivirals:
Tecovirimat approved in the U.S. for treating smallpox and
oral form in Europe to treat cowpox, monkeypox, and
smallpox.

39. Vaccination

40. Under
Investigation

41. Home Isolation of Patient
• Persons with extensive lesions that cannot be easily covered (excluding facial
lesions), draining/weeping lesions, or respiratory symptoms (e.g., cough, sore
throat, runny nose) should be isolated in a room or area separate from other
family members and pets/ animals when possible.
• Persons with monkeypox should not leave the home except as required for
follow-up medical care.
• No visitors

42. Prevention
Avoid Avoid contact with animals that are sick or that have been found
dead in areas where monkeypox occurs.
Avoid Avoid contact with any materials, such as bedding, that has been
in contact with a sick animal.
Isolate Isolate infected patients from others who could be at risk for
infection.
Practice Practice good hand hygiene after contact with infected animals
or humans.
Use Use personal protective equipment (PPE) when caring for
patients.