Insect bites (dengue, Chikungunya, Zika, Tick-Borne Take home message - Dengvaxia. SAGE Apr 2016....

transcript

Insect bites (dengue, Chikungunya, Zika, Tick-Borne)

Prof (Dr) Yee-Sin LEO

Clinical Director Communicable Disease Centre

Director Institute of Infectious Disease and Epidemiology

Tan Tock Seng Hospital

July 2017 – Medicine Review Course

Chikununya virusAlphavirusFirst described in 1953 –Tanzania Africa“to bent over”“Buka-buka” – “broken-broken”

Zika virusFlavivirusFirst isolated in 1947 in Monkey in Uganda, AfricaHuman cases in 1952 in Uganda and Tanzania

Dengue virusFlavivirus4 genetically diverse sero-types

Chikungunya virus

Zika virus

Dengue

• Disease burden

• Classification

• Clinical features and usefulness of warning signs

• vaccine

30 most highly endemic countries

Dengue in Singapore

Despite vector

control, low

breeding index,

Singapore faces

successive waves

of dengue epidemic

Predominantly

adult dengue

Increasing

recognition of

atypical dengue

WHO 1997

Dengue Fever

Dengue Hemorrhagic fever

Dengue Shock Syndrome

Dengue hemorrhagic fever (DHF)

A case must meet all 4 criteria

1. Fever lasting 2-7 days

2. Haemorrhagic tendency shown by positive tourniquet test or spontaneous bleeding

3. Thrombocytopenia (<100K/L)

4. Evidence of plasma leakage shown by either hemoconcentration or development of pleural effusions/ascites, or both

DHF is further classified into 4 severity grades based on presence/absence of shock

WHO 1997

SEARO 2011

WHO 2009

Warning signs (7)

Persistent vomiting

Abd pain / tenderness

Mucosal bleeding

Clinical fluid

accumulation

Lethargy-restlessness

Enlarged liver >2cm

Rapid HCT - Plt

WHO 2009RT-PCR, NS1 IgM IgG serology

Primary Care

• Early recognition / suspicion of dengue

POCT / rapid combined Ag/Abs

Daily monitoring

•Early recognition of warning signs

Febrile phase

Secondary Care Hospitalization

Critical phase

• Adequate trained staff

• Lab support

• Adequate consumables

Tertiary Care ICU

Final Outcome

Recovery

Dengue management

WHO 2009

Specialized dengue care unit

hospitalisation

Pleural effusion

Typically on the Right

34Y Indian man with gum bleeding

Platelet nadir 12

Haematocrit lowest 41, highest 52.6

AST 232 ALT 123

Dengue IgM and IgG positive

US abdomen: ascites

DHF3=DSS1

Presence of warning sign/s are common – particularly mucosal bleeding

Absence of warning sign/s rarely will progress to severe disease

Watch closely patients with 2 or more warning signs

Interval from onset of warning sign/s to severe disease can be short

Local evidence on utility of warning signs

Majority had WS 1 day prior to onset of severe illness

DHF – age in 2o Infection, 1981 Cuba Outbreak

Guzman IJID 2002;6:118

Age distribution of adult dengue deaths Singapore 2004-2008

15-24 25-34 35-44 45-54 55-64 >65

Age group (years)

taliti

Older adults with dengue have more atypical presentations, more organ involvement, more

pre-existing comorbidities, higher mortality, require higher index of suspicion to diagnose,

closer monitoring and careful management

Dengvaxia licensed in 5 countries

Imperfect – but good enough for Singapore?

Take home message - Dengvaxia

SAGE Apr 2016

Age 45> with seroprevalence more

than 70%

4th Oct 2016 Dengvaxia approved in

Singapore for use in sero-positive

individuals from 12 to 45 years

6th March 2017 Dengvaxia available

in Singapore

Sudden onset of fever

Severe headache, chills

Nausea, vomiting

Severe, sometime persistent

joint pain

Incubation period:

3-7 days (3-12

Overlapping presentations

with dengue

Laboratory diagnosis of Chikungunya

Aug 08 Outbreak

R knee swelling

J Clin Virol 2010

202187

176 180 183 190 185208

300325

1 2 3 4 5 6 7 8 9 10 11

Day of illness

N = 48

13.6 14 14.3 14.7 15 15 14.9 14.8 14.8 14.7 14.8

39.9 40.5 41.5 42.9 43.7 43.7 43.4 43.2 43 42.6 42.8

1 2 3 4 5 6 7 8 9 10 11

Day of illness

Hb Haematocrit

N = 48

4.3 4.1 44.5

1 2 3 4 5 6 7 8 9 10 11

Day of illness

N = 48

76.670.6

52.7 50.855.7 56.4 54.9 56.1 55.2 55.9

13.217.4

32 32.526.7 26.6 26.5 27.5 28.5 29.1

1 2 3 4 5 6 7 8 9 10 11

Day of illness

Neutrophils(%) Lymphocytes(%)

Total White cells

Platelet

neutrophils

lymphocytes

Hematocrit

Unusual CHIKV manifestations

• Lalitha Am J Ophthalmol 2007; 144: 552

Uveitis, optic neuritis

– N=37 (IgM=26), unilateral=30, onset from acute mean 33D, resolved 8W-3M

– Initial VA 20/20-20/120 65%, <20/200 19%, hand 6%, treated topical and systemic steroid

• Mittal Arch Ophthalmol 2007; 125: 1381

Optic neuritis

– N=14 (IgM), unilateral 64%, onset from acute mean 11D, all but 4 improved

– Initial VA 6/6-6/12 16%, 6/18-6/60 26%, <6/60 58%, treated systemic steroid

• Singh Epidemiol Infect 2008; 136: 1277

Flaccid paralysis

– Andaman Islands, n=4, IgM,, responded to steroid

• Wielanek Neurology 2007; 69: 2105

Gullian-Barre syndrome

N=3, IgM=3, PCR=1

Persisting mixed Cryoglobulinemia in Chikungunya

infection

PLoS Neg Tro Dis 2009;(Feb)3:e374

EID Vol 15, No. 2 Feb 2009

Inamadar A et al Int. J Derm 208;47:154-9

pigmentation

Inamadar A et al Int. J Derm 208;47:154-9

• Recent zika virus outbreak in Singapore – 2016

• Sexual transmission

• Vertical mother-fetus transmission

• Congenital abnormalities

• Neurological complications

Red eyes

Generelised rash

J Infect 2017

CDC-CSTE

Fever or rash or conjunctivitis or

arthralgia

Rash + arthralgia or arthritis or non-

purulent conjunctivitis

Rash + 2> fever, arthralgia, myalgia, or

non-purulent conjunctivitis

Rash + arthralgia or myalgia or non-

purulent conjunctivitis

Singapore

Fever and rash plus

One > headache, myalgia, arthralgia,

non-purulent conjunctivitis

Congenital abnormality

Rapid evolution of disease- rapid onset and short plateau phase

Approx 1 / 3 needs respiratory assistance

Generally favorable outcomes

Lancet Feb 2016

https://www.cdc.gov/ticks/symptoms.html

Geographic region

Fever, chillAches, pain: headache, joint pain, myalgiarash

Tick-borne relapsing feverHuman granulocytic anaplasmosisTick-borne encephalitis Q fever

How to remove a tick

Never crush a tick with your fingers

Avoid folklore remedies such as "painting" the tick with nail polish or petroleum jelly, or using heat to make the tick detach from the skin

Use fine-tipped tweezers to grasp the tick as close to the skin's surface as possible.

Pull upward with steady, even pressure.

Don't twist or jerk the tick; this can cause the mouth-parts to break off and remain in the skin. If this happens, remove the mouth-parts with tweezers. If you are unable to remove the mouth easily with clean tweezers, leave it alone and let the skin heal.

After removing the tick, thoroughly clean the bite area and your hands with rubbing alcohol, an iodine scrub, or soap and water.https://www.cdc.gov/ticks/removing_a_tick.html

Caused by the bacterium BorreliaburgdorferiTransmitted to humans through the bite of infected blacklegged ticks.

Lyme Disease

Later Signs and Symptoms (days to months after tick bite)Severe headaches and neck stiffnessAdditional EM rashes on other areas of the bodyArthritis with severe joint pain and swelling, particularly the knees and other large joints.Facial palsy (loss of muscle tone or droop on one or both sides of the face)Intermittent pain in tendons, muscles, joints, and bonesHeart palpitations or an irregular heart beat (Lyme carditis)Episodes of dizziness or shortness of breathInflammation of the brain and spinal cordNerve painShooting pains, numbness, or tingling in the hands or feetProblems with short-term memory

Early Signs and Symptoms (3 to 30 days after tick bite)Fever, chills, headache, fatigue, muscle and joint aches, and swollen lymph nodesErythema migrans (EM) rash (70-80%):At the site of a tick bite after a delay of 3 to 30 days (average is about 7 days)

Treatment

Early stages – oral doxycycline, amoxicillin, cefuroxime

Neurological or cardiac formsIv ceftriaxone or penicillin

https://www.cdc.gov/lyme/treatment/index.html

Disease of animals and humans Caused by the bacterium Francisella tularensis. Rabbits, hares, and rodents often die in large numbers during outbreaks.

Humans can become infected through several routes:Tick and deer fly bitesSkin contact with infected animalsIngestion of contaminated waterInhalation of contaminated aerosols or agricultural dustsLaboratory exposure

Tularemia

Signs and symptoms

Several forms (depending on the route of entry), high fever presence in all

Ulceroglandular – most common form, at the site of tick bite , swollen lymph nodesGlandularOculoglandularOropharygealPneumonic (most severe form)Typhoidal

Mild to life threatening

Diagnosis

Rare disease, hard to diagnoseculture

Treatment

streptomycin, gentamicin, doxycycline, ciprofloxacin. Usually lasts 10 to 21 days depending on the stage of illness and the medication used.

Although symptoms may last for several weeks, most patients completely recover.

https://www.cdc.gov/tularemia/diagnosistreatment/index.html

Phew……We make it to the end

Insect bites (dengue, Chikungunya, Zika, Tick-Borne Take home message - Dengvaxia. SAGE Apr 2016....

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