emerging diseases and travel related illnesses

Emerging Diseases and Travel related illnessesAmornphat Kitro, M.D. Department of Community Medicine. Faculty of MedicineChiang Mai [email protected]

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Outline• Emerging disease

• Coronavirus 2019• SARS• MERS• Ebola

• Travel related illness• High altitude• Jet lag• Cruise ship travel• Cave related illness

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FACULY OF MEDICINE CHIANG MAI UNIVERSITY

Definition

• Emerging VS Re-emerging• Newly emerging: diseases

that have been discovered in the human host or a population for the first time• Re-emerging: infectious

diseases that reappear, more pathogenic form and in rapidly increasing incidence or new geographic locations after apparent control or eradication

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Department of Community Medicine

Chiang Mai University

Infectious disease that has appeared in the population for the first time, or that may have exited previously but in rapidly

increasing incidence or geographic range

History of outbreak

communicable disease act, B.E

2558 (2015)

แนวทางการรายงานโรคตดิต่ออันตรายและโรคตดิต่อ

ที5ต้องเฝ้าระวังตามพระราชบัญญัตโิรคตดิต่อ พ.ศ. ABBC

Coronavirus outbreak• Corona=crown

• Identified in • Avain• Mammals: bat, camels, dogs, masked palm civets

• Emerging disease• SARS-CoV, 2002-2003• MERS-OcV, 2012 (Novel Coronavirus 2012)• SARS-CoV-2, Dec 2019

• Pneumonia of unknown ethiology in Wuhan• 2019-novel coronavirus (2019-nCoV)• Severe acute respiratory syndrome coronavirus-2

(SARS-CoV-2)• COVID-19

COVID-19• Zoonosis

• Bat: natural reservoir• Palm civet: intermediate host

• Incubation: 2-14 days • mean 5.2 days, 95% CI 4.1-7.0

days)• Could be long as 24 days (rare

case)• Reproductive number (R0) =

2.2 (range up to 6.6)• Case fatality rate

• Supportive treatment ± Flavipiravir

Reproductive Number (R0)Disease Transmission Reproductive NumberMeasles Airborne 12 – 18Pertussis Airborne/droplet 12 – 17Diphtheria Airborne/droplet 6 – 7Smallpox Contact 5 – 7Polio Food & water vehicle (fecal-oral route) 5 – 7Rubella Airborne/droplet 5 – 7Mumps Airborne/droplet 4 – 7HIV Sexual contact 2 – 5SARS Airborne/droplet 2 – 5Influenza H1N1 pdm Airborne/droplet 1.5 - 2

Herd Immunity

Herd immunity = 1 – (1/R0)

Transmission

DropletsCoronavirus

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FACULTY OF MEDICINE CHIANG MAI UNIVERSITY

Transmission

Contact

Reservoir host

S protein bind to ACE2 receptor: quick spreading of virus

Transmission and chain of transmissionWhich character has the highest risk of getting an

infection?

1. 2. 3. 4.

Symptoms and when to be worried?

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≥37.5 COr 99.5 F

Respiratory symptoms

- History of travel or live in Mainland China within 14 days or- History of contact with animals or admitted in a hospital in a country with outbreak or- History of close contact with a laboratory confirmed Coronavirus 2019 patient or- Patient with unexplained pneumonia with history of close contact with suspected

patient

Household contact

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Family members, relatives who take care of the confirmed case

Live in the same household with a confirmed case

Transportation

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Patient with symptoms can spread Coronavirus

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Workplace and community

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Student, colleagues and closed friend

Live in the same community and contact with respiratory secretion of the patient

Severe Acute Respiratory Syndrome (SARS)

• 1st reported in Asia

• 8,098 people worldwide became sick and 774 died

• Currently, no known SARS trasmission anywhere in the world

• Droplet transmission• Incubation: 2-7 days (up to 10)

• Symptoms: high fever (>38.0 °C), headache, body ache, mild respiratory symptoms with dry cough, diarrhea, pneumonia

Middle East Respiratory Syndrome Coronavirus (MERS-CoV)

• 1st case was reported from Middle East

• Novel Coronavirus 2012• Superspreader: Korea

• Transmission: camel to human, human to human

• Incubation: 2-14 days

• Symptoms: fever, URI, GI pneumonia, ARDS

• Case fatality 30-40%• Supportive treatment ±

ribavirin

May not show any signs of infectionShed viral through- Nasal & eye discharge

milk and urine- Raw organ and meat

Nasopharyngel Swab and Troat/oropharyngeal swabOr Nasopharyngeal aspiration Or Tracheal aspirate

Super spreader

an individual who is more

likely to infect others,

compared with a typical infected

person

Patient under investigation (PUI)• Respiratory infection (cough,

runny nose, sorethroat) with a history of travel from countries in or near the Arabian Peninsula within 14 days with • Symptomatic patient with

fever (38 Celsius) or • contact with camel or • Close contact with a

confirmed MERS case while the case was ill

• Probable case • Screening gene: up E

detected

• Confirm case• Gene ORF 1a and ORF 1b

detected • Or RdRp gene or N gene

detected (nucleotide sequencing)

Ebola Hemorrhagic Fever

• Ebola river, Democratic Republic of Congo

• Case fatality rate: 50% (25-90%)• Transmission: fruit bat to human,

human-to-human• Incubation: 2-21 days

• Outbreak• Past outbreak 2014-2016 (Guinea,

Liberia, Sierra Leone)• Current: DR Congo

Ring vaccination

a strategy to inhibit the spread of a disease by vaccinating only those who are most likely to be infected

High altitude illness

Definition

Oxygenation at different height• As altitude increases – gases exert less pressure - the hypoxia that occurs with higher altitudes• The percentage of oxygen remains the same with changes in altitude

How can we explain the cause of hypoxia?Mixture of non-reacting gases, the total pressure exerted is equal to the sum of the partial pressure of the individual gases• Example

• Oxygen at sea levelO2 = 21% and PO2 =21% x 760 mmHg = 159.22 mmHg

• Oxygen at 8,000 feetO2 = 21% and PO2 =21% x 565 mmHg = 118.65 mmHg

Dalton’s law

Pathophysiology

Physiologic change

Acclimatization by organ system

Acclimatization VS adaptation

Ascent risk associated with underlying medical conditions

Risk Category for AMS

High altitude illness (HAI)

• Acute mountain sickness (AMS)• High altitude cerebral edema (HACE)• High altitude pulmonary edema (HAPE)

Acute mountain sickness (AMS)• Onset 2-12 hours after arriving to the

altitude

• Symptoms• throbbing headache• loss of appetite, nausea or vomiting• Fatigue• Dizziness• Sleep disturbance

• Resolve within 12-48 hours of acclimatization

High altitude cerebral edema (HACE)• Symptoms develop after AMS

• Ataxia (most common)• Alteration of conscious: confusion,

lethargy• papilledema

• Should rule out alternative diagnosis

High Altitude Pulmonary edema (HAPE)Symptoms

• Dry cough à productive cough (pink frosty sputum)

• Dyspnea on exertion or at rest

Signs• Worsening tachycardia• Prominent P2, RV heaving, rales in

both lungs

2018 Lake Louse

acute mountain

sickness score

Recommended medication dosing to

prevent and treat altitude

illness

Acetazolamide prophylaxis • 125 mg every 12 hours

• Start 24 hr before ascent and continue for at least 48 hr after arrival to the highest altitude

• Avoid in patient who allergic to sulfa group• Side effect

• Increase urination• Paresthesia of the fingers and toes• Altered taste of carbonated beverages

Tips for acclimatization

• Gradual ascent

• Using prophylatic medication

• Avoid alcohol for the first 48 hours

• Mild exercise for the first 48 hours

• Have high altitude exposure (>2,750m) for ≥ 2 nights within 30 days before trip

• Provide rest day during trekking

Jet lagMismatch between a person’s circadian rhythms and the time of day in the new time zone.

Risk for travelers Travel >3 time zones

Circadian rhythms

Clinical Presentation

• Poor sleep• Difficulty initiating sleep (after

eastward flights)• Fractionated sleep• Early awakening (after westward

flights)

• Poor performance (physical, mental)

• Negative feeling• GI disturbance

• Fatigue• Factors that impact severity of jet lag

• Age• Direction of travel• Number of time zones crossed• Individuals

Treatment • Light

• Diet• smaller meals before

and during the flight• Caffeine: help daytime

sleepiness• Avoid alcohol

• Hypnotic medication• Temazepam, Zolpidem,

Zopiclone: reduce sleep loss (not help resynchronized circadian rhythms, caution use during flight time

• Melatonin• Melatonin : Direct effect

on internal clock and alter circadian rhythm• Dose 2-5 mg is generally

recommended• Ramelteon: melatonin

receptor agonist• Take before nocturnal

sleep in the new time zone

Cruise ship Travel

• Crowded, semi-enclosed environments on board

• Person-to-person, food-borne, vector-borne (port visit)

• Medical limitation• Vary on ship size, itinerary, length of cruise• ambulatory care

What kind of illnesses can be found during cruise ship travel?

• 3-11%: urgent/emergency

• 95%: treated and managed onboard

• 5%: require evacuation and shoreside consultation

• respiratory illness (19-29%)

• Seasickness (10-25%)

• Injuries (slips, falls) (12-18%)• Gastrointestinal (9-10%)

• Vector-borne• Death (cardiovascular-0.6 to 9.8

deaths per million passenger-nights)

GI illness

• Salmonella

• ETEC

• E.coli

• Shigella

• Clostridium perfringens

• Cyclospora cayetanensis

• Norovirus

Respiratory illnesses

• Influenza

• Legionnaire

Vaccine-preventable disease

• Meningococcal• Measles• Rubella• Varicella

Cave related illness

Absence of sunlightConstancy of temperatureCave fauna: bats, rodents,birds, reptiles, arthropods

Disease from cave

• Histoplasma capsulatum

• Marburg Hemorrhagic fever

• Rabies• Leptospirosis

• Tick borne relapsing fever• Envenomatous animal

Q&A

Department of Community MedicineChiang Mai University

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Thank you

Department of Community MedicineChiang Mai University

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emerging diseases and travel related illnesses

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