Viral Encephalitis

Viral Hemorrhagic Fever

Viral Zoonosis

Rift Valley Fever

In Saudi Arabia and Yemen –2000

غبس عجذ اللطف جوجىم. د

ملخ الطت والعلىم الطجخ

جبهعخ الولل عجذ العشش ثجذح

(م2000-10)هـ 7-1421

Yellow Fever

Dengue Fever

Ebola

Arboviruses

( Arthropod-Borne Viruses )

- Mosquitoes,

- ticks,

- sandflies

Examples of Arthropod Vectors

Aedes AegytiAssorted Ticks

Phlebotmine SandflyCulex Mosquito

Viral Encephalitis

Viral Hemorrhagic Fever

• Other viral Syndromes(Arthralgia, Rash, Pulmonary Syndromes,

etc.)

Arboviruses

• more than 400 isolated

• ~ 100 human pathogens

Arboviruses

Members of the Following Families :

• Togaviruses (genus Alphaviruses)

• Flaviviruses

• Bunyaviruses

• Reoviruses (genus Orbiviruses)

Additional Hemorrhagic Fever

Viruses :

• Arenaviruses

• Filoviruses

Zoonotic Viral Infections Not Transmitted

by Arthropods (Direct Contact with

Animals, person-to-person, nosocomial,

etc.)

Arboviruses

Members of the Following Families :

• Togaviruses (genus Alphaviruses)

• Flaviviruses

• Bunyaviruses

• Reoviruses (genus Orbiviruses)

Note :

Rubella virus belongs to the

• Togaviruses (genus Rubivirus)

but is not transmitted by insects

• What does Rubella virus cause?

• How is it transmitted?

• Rift Valley Fever

Arboviruses

• 1902 Walter Reed discovered

the cause of yellow fever, the

first human virus to be

described. He proved mosquito

transmission

Yellow fever :

• One of the great plagues of

mankind.

• Epidemics in the 17th, 18th, 19th,

and 20th century

• 1937 Theiler developed the

17D vaccine (live-attenuated)

Objectives

1. Recognize that viruses cause major outbreaks of encephalitis and hemorrhagic fevers or other dangerous syndromes

Objectives

1. (cont)

and that some of these infections (e.g. yellow fever played an important role in the history of mankind)

Objectives

3. Recognize that many viral infections have animal reservoirs (e.g. Birds, mammals, rodents, etc)

Objectives

4. List the major arboviral infections that have been reported in Saudi Arabia

Objectives

5. Recognize the possibility of nosocomial transmission or direct transmission of some dangerous viral infections

Objectives

6. Recognize situations in which vaccination against some arboviral infections is indicated

Objectives

7. Describe means of control

of some arboviral or

non-arboviral exotic

infections

Objectives

2. List the names of at least five viral illnesses transmitted by arthropods

Viral Encephalitis

Viral Encephalitis

Natural cycle Human Infection

Wild Bird Man

Mosquito Mosquito Mosquito Mosquito

Wild Bird Man SLE

Domestic Birds, man deadend

Mammals horse WEE, EEE

Viral Encephalitis

Natural cycle Human Infection

Wild Bird Man

Mosquito Mosquito Mosquito Mosquito

Wild Bird Man SLE

Domestic Birds, man deadend

Mammals horse WEE, EEE

Arboviruses

Members of the Following Families :

• Togaviruses (genus Alphaviruses)

• Flaviviruses

• Bunyaviruses

• Reoviruses (genus Orbiviruses)

Flavivruses

• Includes 69 viruses:

67 are arthropod borne (mosquitoes, ticks)

• includes pestiviruses and hepatitis C virus

• includes the most important arboviral

diseases of man : Yellow fever,

Japanese Encephalitis,

Dengue

West Nile Virus Comes to New York

Ghazi A. Jamjoom

West Nile Virus

West Nile-New York, August 99

• 60 patients sick

• 7 died

• first appearance of virus in U.S.

• Extensive spraying with insecticide

West Nile – USA 2003

• 4007 hospitalized cases (estimated 100000

cases

• 263 deaths

• 40 States

Patients

• Mostly elderly

• Disease : Encephalitis

Definitive Studies :

Virus is the West Nile Virus, for the first

time coming to North America

West Nile Virus USA:

Genomic Relationships

• Whole genome is 99% identical to a West

Nile strain isolated in Israel in 1998, and a

strain found earlier in Egypt, suggesting

origin from Middle East

West Nile Virus : Zoonotic Infection

• Natural reservoir : Birds

• Vector : Mosquitoes (e.g. Culex, Aedes,

Anopheles, etc, ticks)

• Some birds may die from infection

(e.g. crows, other birds at N.Y.zoo ,e.g. one

bald eagle)

• May cause encephalitis in horses

How did it reach New York ?

• Travel by infected humans

• Illegal importation of birds or other pets

• By virus-infected ticks or mosquitoes

West Nile Virus

Comes to New York

West Nile Virus : Classification

• Family : Flaviviruses

• Antigenic Complex :

Japanese Encephalitis :

JE (Japanese encephalitis)

MVE (Murray valley encephalitis (Australia)

SLE (St. Louis encephalitis)

WN (West Nile)

Kun (Kunjin (Australia)

• Distant relatives : Yellow Fever, Dengue, Tick-borne encephalitis

complex

Flavivruses : antigenic relationships

• Dengue Virus Group DEN 3

DEN 1

DEN 2

DEN 4

• Japanese Encephalitis Group

WN

KUN

MVE

JE

SLE

• Yellow FeverYF

• Tick-Borne EncephalitisPow

LGT

LI

TBE

Flavivruses : Disease Patterns

• Flaviviruses associated primarily with the encephalitis

syndrome :

St. Louis Encephalitis (SLE) Japanese Encephalitis (JE)

Murray Valley Enceph. (MV) Tick-borne Encephalitis (TBE)

• Flaviviruses associated primarily with fever, arthralgia,

and rash:

Dengue Fever, West Nile Fever, Other Viruses

• Flaviviruses associated primarily with hemorrhagic

fever:

Yellow Fever, Dengue Hemorrhagic Fever, Others

Arboviruses

Members of the Following Families :

• Togaviruses (genus Alphaviruses)

• Flaviviruses

• Bunyaviruses

• Reoviruses (genus Orbiviruses)

Bunyaviruses

California Encephalitis:

• most serious Bunyavirus disease

in USA

• Vector : Aedes

• Amplifying hosts: chipmunks,

squirrels

Viral Hemorrhagic Fever

Hepatitis Arthralgia hemorrhageYF CHIK Dengue

CCHF O’nyong YF

Dengue CCHF

RVF

Fever

Shock EncephalitisDengue EEE

YF WEE

CCHF JE

RVF SLE

Renal FailureHantaan

Arboviruses

Members of the Following Families :

• Togaviruses (genus Alphaviruses)

• Flaviviruses

• Bunyaviruses

• Reoviruses (genus Orbiviruses)

Flavivruses : antigenic relationships

• Dengue Virus Group DEN 3

DEN 1

DEN 2

DEN 4

• Japanese Encephalitis Group

WN

KUN

MVE

JE

SLE

• Yellow FeverYF

• Tick-Borne EncephalitisPow

LGT

LI

TBE

Distribution of Dengue

Arboviruses

Members of the Following Families :

• Togaviruses (genus Alphaviruses)

• Flaviviruses

• Bunyaviruses

• Reoviruses (genus Orbiviruses)

Bunyaviruses

• Crimean-Congo virus

• Rift Valley Fever virus

• Hantavirus

• Rift Valley Fever

(املتصدع)محى وادي الصدع م 2000 -العربية السعودية واليمن يف اململكة

Rift Valley Fever

In Saudi Arabia and Yemen –2000

غبس عجذ اللطف جوجىم. د

ملخ الطت والعلىم الطجخ

جبهعخ الولل عجذ العشش ثجذح

(م2000-10)هـ 7-1421

تبرخ المرض ف إفرقب

1930مب •

1950جىة افزقب •

هعظن االوثئخ ف شزق وجىة افزقب حت عبم •1977

1977الىثبء صل هصز عبم •

1987الىثبء صل السغبل وهىرتبب عبم •

1993وثبء آخز ف هصز عبم •

مب، الصىهبل ، )الىثبء تفش ف شزق افزقب•1998-3إل 1997-10تبشاب ، واثىثب هي

المرض ف إفرقب تواجدمىاطه

القربة والت كبيرة أمبكه األوبئة الاستمر فهب تىطه المرض ف إفرقب

وببء شرق افرقب 19998-1997ف

شخص ف مب ، عذح هئبد ف الصىهبل، 300وفبح •وآالف الحىابد ف الجلذي

هي FAOتحذز هظوخ األغذخ والشراعخ •

أى الىثبء قذ عجز الجحز األحوز إل الجشزح العزثخ لهذد الوبشخ والبص هبك

الوظوخ تزفع حظزهب عي دول القزى األفزق عبم •وتشاذ ( ظهىر الجفبف)لتغز األحىال الجىخ 1999

الوبعخ لذي الوبشخ

محى وادي الصدع العربية السعودية يف اململكة

م 2000 - Rift Valley Fever

In Saudi Arabia –2000

كف جبء المرض

•

•

•

مه أه جبء المرض ؟

•

RNA Sequence

لمبرا ف مىطقة جسان ؟

•

•

•

•

لمبرا أغلب الحبالت ف جسان(ثم عسر )

•

•

Theالفروش

Virus

• Family : Bunyaviruses

• Group : Phlebovirus

• Negative –stranded RNA

trisegmented genome

(3 circular segments)

Bunyaviridae(over 300 virueses)

Genera :

• Bunyavirus (Bunyamwera, Calif. Enceph, LaCross

• Hantavirus (Hantaan)

• Nairovirus (Crimean Congo)

• Phlebovirus (Sandfly fever Naples, Toscana, Rift

Valley, Sandfly fever Sicilian)

• Tospovirus (Tomato Spotted Wilt (Plants)

Mosquitos

• Culex tritaeniorrhynchus

• Aedes caspius

Mosquitos

• Culex tritaeniorrhynchus : vector

• Aedes caspius : vector

reservoir

(between epidemics)

Sheep and Goats

• More than 90% had antibody to RVF

( Al – Ardah district )

Control Measures -1

• Intensive mosquito-control program;

• Restriction of movement of domestic animals;

• Comprehensive educational campaign to eliminate contact with sick animals and mosquitoes (including provision of free permethrin-impregnated bednets);

Insecticide-Impregnated Bednets

for Protection fromMosquitoes

طرق اوتقبل العذوي

•

•

•

•

Aerosol Trasmission

البعىض الىبقل للعذوي

•

Aedes, Culex, Anopheles

•Aedes

Transovarial Transmission

•

•Ticks

Mosquitoes control

• Bed nets:

Animal control

Control of animal movement.

Vaccination.

Live attenuated.

Killed vaccine.

Elimination.

Vaccinesاللقبح

• Formalin-Inactivated vaccines

- Animals

- Veterenarians, Lab Workers

• Live-Attenuated Vaccine (MP-12)

( experimental)

Human Infection Control

• Treatment

Ribavirin – under evaluation

• Vaccination (for veterinarians, lab workers,

other exposed people)

• Protection ( Window screens, bednets,

repellants )

هل تىتقل العذوي مه شخص خر ؟

•

Hospital Cross Infection

•

إل مت ستمر وجىد المرض ؟

•

•

•

Human Infection

• Asymptomatic

• Self-limited febrile illness

• Complications :

Retinitis 15%

Hemorrhagic fever 1%

Encephalitis 1%

التشخص المخبر

Laboratory Diagnosis

• Detection of viral antigen (ELISA)

• Detection of patient Ab (ELISA –IgM)

• Detection of viral RNA with PCR

• Virus Isolation in cell culture (e.g

vero) and confirmation by IF stain

• Immunoperoxidase staining of viral antigens in sections of the liver

العالج

•

Ribavirin

احتبطبت السالمة الالزمة للتعبمل مع العىبت المصببة

وعسل الفروش

•

•( Biosafety level 3 Laboratory )

Hantaviruses

• Forms a separate genus in the

Bunyavirus family.

• Unlike under bunyaviridae, its

transmission does not involve an

arthropod vector.

• Enveloped ssRNA virus.

• Virions 98nm in diameter with a

characteristic square grid-like

structure.

• Genome consists of three RNA

segments: L, M, and S.

Rodent Carriers of Hantaviruses

Stripped field mouse (Apodemus agrarius)

Bank vole (Clethrionomys glareolus)

Deer Mouse (Peromyscus maniculatus) Rat (Rattus)

Hantavirus Pulmonary Syndrome (HPS)

• More than 250 cases of HPS have been reported throughout North

and South America with a mortality rate of 50%

• In common with classical HVD, HPS has a similar febrile phase.

• However, the damage to the capillaries occur predominantly in the

lungs rather than the kidney.

• Shock and cardiac complications may lead to death.

• The majority of HPS cases are caused by the Sin Nombre virus.

The other cases are associated with a variety of other hantaviruses

e.g. New York and Black Creek Canal viruses.

Additional Hemorrhagic Fever

Viruses :

• Arenaviruses

• Filoviruses

Zoonotic Viral Infections Not Transmitted

by Arthropods (Direct Contact with

Animals, person-to-person, nosocomial,

etc.)

Lassa Fever

Found predominantly in West Africa, in

particular Nigeria, Sierra Leone and

Liberia.

The natural reservoir is multimammate rat

(Mastomys)

Man may get infected through contact with

infected urine and faeces.

Man to man transmission can occur

through infected bodily fluids and Lassa

fever had caused well-documented

nosocomial outbreaks.

Mastomys