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

Transcription

1 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

2 Chikununya virus Alphavirus First described in 1953 Tanzania Africa to bent over Buka-buka brokenbroken Zika virus Flavivirus First isolated in 1947 in Monkey in Uganda, Africa Human cases in 1952 in Uganda and Tanzania Dengue virus Flavivirus 4 genetically diverse sero-types

3 Chikungunya virus Zika virus

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6 Dengue Disease burden Classification Clinical features and usefulness of warning signs vaccine

7 30 most highly endemic countries

8 Dengue in Singapore Despite vector control, low breeding index, Singapore faces successive waves of dengue epidemic Predominantly adult dengue Increasing recognition of atypical dengue

9 WHO 1997

10 Dengue Fever Dengue Hemorrhagic fever Dengue Shock Syndrome WHO 1997

11 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

12 SEARO 2011

13 Warning signs (7) Persistent vomiting Abd pain / tenderness Mucosal bleeding Clinical fluid accumulation Lethargy-restlessness Enlarged liver >2cm Rapid HCT - Plt WHO 2009

14 WHO 2009 RT-PCR, NS1 IgM IgG serology

15 Dengue management Febrile phase Primary Care Early recognition / suspicion of dengue POCT / rapid combined Ag/Abs Daily monitoring Early recognition of warning signs Secondary Care Hospitalization hospitalisation Adequate trained staff Critical phase Lab support Adequate consumables Tertiary Care ICU Specialized dengue care unit Final Outcome Recovery WHO 2009

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18 Pleural effusion Typically on the Right

19 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

20 Local evidence on utility of warning signs 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

21 Majority had WS 1 day prior to onset of severe illness

22 Age distribution of adult dengue deaths Singapore Fatalities >65 Age group (years) DHF age in 2 o Infection, 1981 Cuba Outbreak Guzman IJID 2002;6:118 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

23 2012

24 Dengvaxia licensed in 5 countries Imperfect but good enough for Singapore? 2016

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26 Take home message - Dengvaxia

27 SAGE Apr 2016

28 Age 45> with seroprevalence more than 70%

29 4 th Oct 2016 Dengvaxia approved in Singapore for use in sero-positive individuals from 12 to 45 years 6 th March 2017 Dengvaxia available in Singapore

30 Sudden onset of fever Severe headache, chills Nausea, vomiting Severe, sometime persistent joint pain Overlapping presentations with dengue Incubation period: 3-7 days (3-12 days)

31 Laboratory diagnosis of Chikungunya

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34 Aug 08 Outbreak R knee swelling

35 J Clin Virol 2010

36 J Clin Virol 2010

37 N = 48 N = TWC neutrophils Total White cells lymphocytes Day of illness Day of illness Neutrophils(%) Lymphocytes(%) N=48 N = 48 Plt count Platelet Hematocrit HB Day of illness Day of illness Hb Haematocrit

38 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

39 Persisting mixed Cryoglobulinemia in Chikungunya infection PLoS Neg Tro Dis 2009;(Feb)3:e374

40 EID Vol 15, No. 2 Feb 2009

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

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

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44 Zika Recent zika virus outbreak in Singapore 2016 Sexual transmission Vertical mother-fetus transmission Congenital abnormalities Neurological complications

45 Generelised rash Red eyes

46 J Infect 2017

47 CDC-CSTE Fever or rash or conjunctivitis or arthralgia WHO Rash + arthralgia or arthritis or nonpurulent conjunctivitis PAHO Rash + 2> fever, arthralgia, myalgia, or non-purulent conjunctivitis ECDC Rash + arthralgia or myalgia or nonpurulent conjunctivitis Singapore Fever and rash plus One > headache, myalgia, arthralgia, non-purulent conjunctivitis

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49 Congenital abnormality

50 Rapid evolution of disease- rapid onset and short plateau phase Approx 1 / 3 needs respiratory assistance Generally favorable outcomes Lancet Feb 2016

51 Geographic region Fever, chill Aches, pain: headache, joint pain, myalgia rash Tick-borne relapsing fever Human granulocytic anaplasmosis Tick-borne encephalitis Q fever

52 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.

53 Lyme Disease Caused by the bacterium Borrelia burgdorferi Transmitted to humans through the bite of infected blacklegged ticks. Early Signs and Symptoms (3 to 30 days after tick bite) Fever, chills, headache, fatigue, muscle and joint aches, and swollen lymph nodes Erythema 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) Later Signs and Symptoms (days to months after tick bite) Severe headaches and neck stiffness Additional EM rashes on other areas of the body Arthritis 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 bones Heart palpitations or an irregular heart beat (Lyme carditis) Episodes of dizziness or shortness of breath Inflammation of the brain and spinal cord Nerve pain Shooting pains, numbness, or tingling in the hands or feet Problems with short-term memory

54 Treatment Early stages oral doxycycline, amoxicillin, cefuroxime Neurological or cardiac forms Iv ceftriaxone or penicillin

55 Tularemia 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 bites Skin contact with infected animals Ingestion of contaminated water Inhalation of contaminated aerosols or agricultural dusts Laboratory exposure

56 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 nodes Glandular Oculoglandular Oropharygeal Pneumonic (most severe form) Typhoidal Mild to life threatening Diagnosis Rare disease, hard to diagnose culture 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.

57 Phew We make it to the end Q & A