emerging infectious disease

Emerging Infectious Dieases

August 31st, 2016P. Damronglerd MD

Outlines

• Definition• Zika virus• Ebola virus• MERS

Definition

WHO• An emerging disease is one that has appeared

in a population for the first time, • Or that may have existed previously but is

rapidly increasing in incidence or geographic range

= Re-emerging disease

Example of Emerging Diseases

ZIKA VIRUS

Epidemiology

• Family Flaviviridae• Genus Flavivirus• Mosquito-transmitted virus

– Aedes genus, mainly Aedes aegypti in tropical regions– Usually bite during the day, peaking during early

morning and late afternoon/evening– Same mosquito that transmits dengue, chikungunya

and yellow fever

• Sexual transmission of Zika virus is also possible

Curr Opin Infect Dis. 2016 Aug 4. DOI: 10.1097/QCO.0000000000000301

TImeline

http://www.who.int/emergencies/zika-virus/zika_timeline1000.jpg

Clinical Features

• 80% = asymptomatic• Mild symptom and self-

limiting• Low grade fever & short

term

• Some cases reported – High fever up to 40oC– Lymphadenopathy– Severe abdominal pain– Thrombocytopenia– Enantema– Hematoma


Common Signs and Symptoms


Neurological & Congenital Syndrome

• Guillan-Barré syndrome• Meningoencephalitis• Acute myelitis• Encephalopathy• Microcephaly

Situation

• As of 3 August 2016, 68 countries and territories have reported evidence of mosquito-borne Zika virus transmission since 2007

• 65 of these countries and territories have reported evidence of mosquito-borne Zikavirus transmission since 2015

http://www.who.int/emergencies/zika-virus/situation-report/4-august-2016/en/

Distribution of Zika Virus, 2013-2016


Countries and Territories Reporting Mosquito-borne Zika Virus Transmission


Microcephaly and/or CNS Malformation Cases Potentially Associated Report


Guillain-Barré Syndrome (GBS) Potentially Associated Report


Laboratory Diagnosis

• Can be detected in blood (plasma, serum), CSF, urine, saliva, breast milk, semen, vaginal secretion, amniotic fluid, tissues

• Viral genome: conventional or real-time RT-PCR

• Serology (anti-ZIKV IgM or IgG): ELISA, immunofluorescence, plaque-reduction test (PRNT)


Treatment

• Usually mild and requires no specific treatment

• Should get plenty of rest, drink enough fluids, and treat pain and fever with common medicines

• If symptoms worsen medical care and advice

• Currently no vaccine available

http://www.who.int/mediacentre/factsheets/zika/en/

คาแนะนาดานสขภาพสาหรบนกกฬาและเจาหนาทในการแขงขน

กฬาโอลมปก ครงท 31 ณ เมองรโอ เด จาเนโร สาธารณรฐบราซล

กอนการเดนทาง

1. ผ เดนทางหญงควรคมกาเนดปองกนการตงครรภ กอนการเดนทาง 3

เดอน และในระหวางทอยในสาธารณรฐบราซล จนกระทงเดนทาง

กลบออกมาแลวอยางนอย 3 เดอน

2. หญงตงครรภควรงดการเดนทางไปสาธารณรฐบราซล

http://beid.ddc.moph.go.th/beid_2014/th/diseases/2078



ระหวางทอยในสาธารณรฐบราซล

1. ปองกนตนเองไมใหถกยงกด โดยการใชสารเคมฉด/พน/ทาตามเสอผาและรางกาย สวมเสอผาปกปดรางกายมดชดและสวมใสเสอผาทมสออน อาศยอยในหองปรบอากาศ ทปดประต ปดหนาตาง หากไมม ควรนอนในมงเคลอบสารกาจดยง

2. หลกเลยงการเดนทางเขาไปในพนททมความแออด มนาชนแฉะ เพอลดความเสยงตอการถกยงกด

3. ผ เดนทางทงชายและหญง ควรงดการมเพศสมพนธ หรอมเพศสมพนธอยางปลอดภยโดยใชถงยางอนามยและคมกาเนดอยางเครงครด

4. หากมอาการไข หรอรสกไมสบาย ใหแจงผจดการทม หรอแพทยประจาทมทนท




หลงการเดนทาง

• เกบปสสาวะทนททกลบมาถง เพอรบการดแลทเหมาะสม และปองกนการแพรกระจายของเชอไวรสซกาทดานควบคมโรค สนามบนสวรรณภม และเกบปสสาวะซาอกครง หลงการเดนทางกลบแลว 1 สปดาห (ถาได)

• ผ เดนทางกลบมาทงชายและหญง ควรงดการมเพศสมพนธ หรอมเพศสมพนธอยางปลอดภยโดยใชถงยางอนามย และคมกาเนดอยางเครงครด ตอเนองอยางนอย 3 เดอน หากหญงพบวาตงครรภ หรอชายทมอาการไข หรอผน ใหรบพบแพทยทนท และแจงประวตการเดนทาง

• ผ เดนทางมาจากประเทศทมการระบาดของโรคตดเชอไวรสซกา รวมถงเมองรโอ เด จาเนโร สาธารณรฐบราซล ใหงดบรจาคโลหตเปนเวลา 4 สปดาหนบตงแตวนทเดนทางออกมา


EBOLA VIRUS

http://apps.who.int/iris/bitstream/10665/208883/1/ebolasitrep_10Jun2016_eng.pdf?ua=1

Ebola

• Ebola virus disease (EVD), formerly known as Ebola haemorrhagic fever

• First appeared in 1976 in 2 simultaneous outbreaks, in Nzara, Sudan, and in Yambuku, Democratic Republic of Congo

• Severe fatal illness

• Case fatality rate of up to 90%

http://www.who.int

• Genus Ebolavirus is 1 of 3 members of the Filoviridaefamily (filovirus), along with genus Marburgvirus and genus Cuevavirus. Genus Ebolavirus comprises 5 distinct species:

– Bundibugyo ebolavirus (BDBV)– Sudan ebolavirus (SUDV)– Zaire ebolavirus (EBOV)– Taï Forest ebolavirus (TAFV)– Reston ebolavirus (RESTV)

Ebola

http://www.who.int

Transmission

• Virus is transmitted to people from wild animals and spreads in the human population through human-to-human transmission

• Infection has been documented through the handling of infected chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found ill or dead or in the rainforest

http://www.who.int

Transmission

• Transmitted by direct contact with the blood, body fluids and tissues of infected animals or people

• Men who have recovered from the disease can still transmit the virus through their semen for up to 7 weeks after recovery from illness

http://www.who.int

Signs and Symptoms

• Sudden onset of fever, intense weakness, muscle pain, headache and sore throat

• Followed by vomiting, diarrhoea, rash, impaired kidney and liver function

• In some cases, both internal and external bleeding

Incubation period is 2 to 21 days

http://www.who.int

Diagnosis

• Diagnosed definitively in a laboratory through several types of tests:

– Antibody-capture enzyme-linked immunosorbent assay (ELISA)

– Antigen detection tests– Serum neutralization test– Reverse transcriptase polymerase chain reaction (RT-PCR)

assay– Electron microscopy– Virus isolation by cell culture

http://www.who.int

Ebola 2014

http://www.who.int

Treatment

• Supportive care-rehydration with oral or intravenous fluids- and treatment of specific symptoms, improves survival

• There is as yet no proven treatment available for EVD

• Potential treatments including blood products, immune therapies and drug therapies are currently being evaluated

• No licensed vaccines are available yet, but 2 potential vaccines are undergoing human safety testing

http://www.who.int/mediacentre/factsheets/fs103/en/

WHO Situation Report, June 10th, 2016

• Ebola in West Africa was lifted on 29 March 2016

• Confirmed cases = 28,616 • Probable and suspected cases have been

reported in Guinea, Liberia and Sierra Leone, with 11,310 deaths

• Latest cluster = prefectures of N’Zerekore and Macenta in south-eastern Guinea, Monrovia in Liberia


WHO Situation Report, June 10th, 2016

• In Guinea, the last case tested negative for Ebola virus for the second time on 19 April – Guinea declared an end to Ebola virus

transmission on 1 June

• On 9 June the World Health Organization (WHO) declared the end of the most recent outbreak of EVD in Liberia– This follows 42 days since the last case tested

negative for the second time on 28 April


The First Case 60-year-old Saudi man who was admitted to a private hospital in Jeddah on June 13, 2012 • Fever, cough, expectoration,

and shortness of breath• Died 11 days later from

progressive respiratory failure

• Human Coronavirus Erasmus Medical Center (HCoV-EMC)

Infect Drug Resist. 2014 Nov 3;7:281-7

The Second Case and Afterward• Qatar, a 49-year-old man, was

diagnosed in September 2012 with the novel coronavirus

• He was transported to the United Kingdom for intensive care

• The isolated viruses from the Saudi and the Qatari cases were 99.5% identical

• Majority of cases (>80%) have been reported from Saudi Arabia

• Since then 1333 cases have been reported from 26 countries


MERS 2012

http://www.who.int/csr/disease/coronavirus_infections/mers-2012-2015-global-situation-2015-06-26.png?ua=1

Phylogeny

• Enveloped RNA virus• Subfamily Coronavirinae• Novel virus is a representative

of a new, yet-to-be-established species in lineage C of the genus Betacoronavirus

J Virol. 2013 Jul; 87: 7790–7792

Symptom• Range of presentation

– Asymptomatic– Mild respiratory symptoms – Severe acute respiratory disease – Death (36%)

• Typical presentation: – Fever, cough and shortness of breath– Pneumonia is a common finding, but not always present

• Gastrointestinal symptoms, including diarrhoea, have also been reported

• The virus appears to cause more severe disease in older people, people with weakened immune systems, and those with chronic diseases such as cancer, chronic lung disease and diabetes.

http://www.who.int/mediacentre/factsheets/mers-cov/en/

Transmission

• Sporadic (community-onset)• Intra-familial transmission• Health-care-related transmission


MERS 2013


Studypopulations

Number of cases

Median age (range)

Male : female ratio

Asymptomatic (%)

Severe case(%)

Fatality rate(%)

Saudi Arabia, May 2013

23 56 (24–94) 2.8:1 0 100 65

Saudi Arabia Sept 2012 - June 2013

47 NA 3.3:1 0 100 60

9 countries, Mar 2012 -Sept 2013

133 NA 1.5:1 13.5 86.5 45

9 countries, Sept 2012 -Oct2013

161 50 (14-94) 1.8:1 11.1 63.4 -

Saudi Arabia, April - June 2014

402 46 (0.75-94) 1.4:1 28.6 44.5 28.3

Saudi Arabia, May 2013 - Feb 2014

113 41 (0.25-89) 1.3:1 28.9 NA 30


MERS 2014


Korea

St. Mary Hospital (37)Asian Medical Center (1)Yoel Lin Hospital (1)

Samsung Hospital (59

Treatment and Prevention

• No vaccine or specific treatment is currently available• Treatment is supportive and based on the patient’s clinical

condition– Cysteine protease inhibitor K11777 targeting cathepsin-

mediated cell entry1

– Oral ribavirin (dose based on calculated creatinine clearance, for 8-10 days) and subcutaneous pegylated interferon alfa-2a (180 μg per week for 2 weeks)2

• 14 (70%) of 20 patients in the treatment group had survived after 14 days, compared with seven (29%) of 24 in the comparator group (p=0·004)

1 Antiviral Res. 2015 Feb 7;116C:76-842 Lancet Infect Dis. 2015 Jan 15;211:13

WHO update and clarification on recent MERS cases reported by the Kingdom of Saudi Arabia

• Between 19-22 June 2016, WHO published 3 reports on the Disease Outbreak News (DON) describing 25 cases of Middle East Respiratory Syndrome (MERS)

• 24 of the cases contacted with a probable, single index case who was diagnosed with MERS in a hospital in Riyadh City, Riyadh Region

• The 22 June 2016 DON reported that the index case had died

http://www.who.int/emergencies/mers-cov/saudi-arabia-update/en/

WHO update and clarification on recent MERS cases reported by the Kingdom of Saudi Arabia

• As of 22 June 2016 twenty-four (24) contacts have tested positive for MERS including twenty (20) healthcare contacts and three (3) household contacts

• In addition, one case has been diagnosed in a household contact of a hospital patient who was diagnosed with the disease after exposure to the probable index case

• Twenty (20) of the twenty-four (24) have not exhibited any MERS symptoms


Cumulative Cases

• Globally since September 2012 WHO has been notified of over 1,700 laboratory-confirmed cases of infection with MERS, in 27 countries, including more than 600 related deaths


emerging infectious disease

Health & Medicine