Viral zoonotic disease

1. VIRAL ZOONOTIC
DISEASES
Dr. Dinesh Kr Jain, MD.,
Assistantprofessor,
Department of Microbiology,
SMS Medical college, Jaipur

2. ZOONOSES
• The word 'Zoonosis' (Pleural: Zoonoses) was introduced by
Rudolf Virchow in 1880.
• Zoonoses are "those diseases and infections which are
naturally transmitted between vertebrate animals and
man“
• A public health problem
• Most of the infections of man that have been discovered in
the last twenty years are shared with lower animals.
• Number of other diseases previously thought to be limited
to man have now been found to be zoonotic. E.g. Marburg,
Ebola, etc.
• Prevent the efficient production of food of animal origin
• Create obstacles to international trade in animal products.
• No longer solely a national problem. For effective control of
zoonoses global surveillance is necessary.

3. FACTORS INFLUENCING PREVALENCE OF
ZOONOSES
 Ecological changes in man's environment- constructing roads,
deforestation
 Handling animal by-products and wastes (occupational hazards)
 Increased movements of man- pilgrimages,tourism
 Increased trade in animal products
 Increased density of animal population
 Transportation of virus infected mosquitoes
 Cultural anthropological norms- In Kenya, people allow the dogs
and hyenas to eat human dead bodies infected with hydatidosis.
This helps to perpetuate the transmission cycle of the disease.

4. CLASSIFICATION
According to the etiological agents:
I. Bacterial zoonoses - anthrax, brucellosis, plague, leptospirosis,
bovine T.B, tuleremia, campylobacter,
psittacosis salmonellosis,
lyme disease
II. Viral zoonoses - rabies, arbovirus infections, KFD, yellow
fever, influenza,
CCHF
III. Rickettsial zoonoses - murine typhus, tick typhus, scrub typhus,
Q-fever
IV. Protozoal zoonoses - toxoplasmosis, trypanosomiasis,
leishmaniasis
V. Helminthic zoonoses - echinococcosis , taeniasis, dracunculiasis,
cysticercosis,
giardiasis, schistosomiasis
VI. Fungal zoonoses - deep mycosis - histoplasmosis,
cryptococcosis,
superficial dermatophytes.
VII. Ectoparasites - scabies, myiasis

5. According to mode of transmission:
• Direct zoonoses- infected vertebrate host to a susceptible host (man) by direct
contact, by fomite or by a mechanical vector. e.g. rabies, anthrax, brucellosis,
leptospirosis, toxoplasmosis
• Cyclozoonoses- require more than one vertebrate host species, but no invertebrate
host for the completion of the life cycle of the agent, e.g. echinococcosis, taeniasis.
• Metazoonoses- transmitted biologically by invertebrate vectors, in which the agent
multiplies or develops and there is always an extrinsic incubation (prepatent) period
before transmission to another vertebrate host e.g., plague, arbovirus infections,
schistosomiasis, leishmaniasis.
• Saprozoonoses- require a vertebrate host and a non-animal developmental site like
soil, plant material, pigeon dropping etc. for the development of the infectious agent
e.g. aspergillosis, coccidioidomycosis, cryptococosis, histoplasmosis, zygomycosis.

6. According to the reservoir host:
Anthropozoonoses-Infections transmitted to man from
lower vertebrate animals e.g. rabies, leptospirosis, plague,
arboviral infections, brucellosis and Q-fever.
Zooanthroponoses- Infections transmitted from man to
lower vertebrate animals e.g. streptococci, staphylococci,
diphtheria, enterobacteriaceae, human tuberculosis in
cattle and parrots.
Amphixenoses- Infections maintained in both man and
lower vertebrate animals and transmitted in either
direction e.g. salmonellosis, staphylococcosis

7. RABIES VIRUS
• Causes progressive infection of CNS
• Family- Rhabdoviridae
• Genus- Lyssa virus
• RNA virus ; bullet shaped, round at one end
and flat at the other.
• The virus is covered with a lipid envelope
having spike like projections.

8. EPIDEMIOLOGY
• Worldwide the number of human rabies deaths is estimated to be between
35,000 and 50,000 annually.
• Rabies occurs in all continents with the exception of Australia and Antarctica.
• In Africa and Asia (with few important exceptions such as Japan and Singapore)
rabies is prevalent in almost whole of the territory with a stable pattern.
• Most of the countries of Americas and Europe report occurrence of disease in
limited or border areas.
• Age: although all ages are affected, children aged 5-15 years are at greater risk
• Rabies is responsible for extensive morbidity and mortality in India.
• The estimated number of deaths per year is, however, around 20,000.
• Almost 18 lakhs people annually receive post exposure prophylaxis against
rabies following bite or exposure to rabid or suspected rabid animal.
• With the exception of Andaman & Nicobar islands and Lakshadweep islands,
human cases of rabies are reported from all over the country.
• 96% of the mortality and morbidity is associated with dog bites. Cats, wolf,
jackal, mongoose and monkeys are other important reservoirs of rabies in
India.
• Bat rabies has not been conclusively reported from India.

10. CLINICAL DIAGNOSIS
• First symptom in human - pain and tingling in the affected limb,
especially around the site of bite.
• Hydrophobia- pathognomic feature
• It is due to a violent jerky contraction of the diaphragm and accessory
muscles of inspiration that is triggered by the patient’s attempts to
swallow liquid, strong current of air, loud noise and bright light.
• In dog - change in behavior ,bark tone, feeding habits. They may
develop fever, vomiting, excessive salivation, paralysis of lower jaw,
anxiety, restlessness, convulsions, paralysis leading to death with in 5-7
days of onset of disease.
• In cats - extreme aggressiveness, great sensitivity to touch/voice,
profuse salivation and may attempt to attack dog or man.
• In cattle- abnormal movements of posterior extremity, foamy yellow
froth from mouth and decrease in yield of milk.
• No hydrophobia in animals.

11. LABORATORY DIAGNOSIS
• Sample collection from
human
 Saliva/sputum
 Corneal smears
 Skin biopsy
 Hair follicle
 CSF
 Blood
 Urine
 Brain
• Sample collection from
animal
 Brain
 Salivary gland
NOTE-Collected in wide
mouth leakproof
container
• Preservation- on ice
 10% formol saline/Zenker's fluid for half of
the brain
 50% glycerol saline for other half of the
brain and salivary glands.
 Tissue culture medium 2% NHS saline for
saliva, CSF, urine etc.
• Labelling with proper information
• Packaging- container-paraffin sealing-
plastic bag- thermocol box with
sufficient ice

12. LABORATORY TESTS
• Negri body detection in
histopathological staining of
brain biopsies
(hippocampus)-for
postmortem diagnosis of
rabies.
• Antibody detection-
 Indirect fluorescent antibody
test (FAT)
 Serum virus neutralization
test
 Counter
immunoelectrophoresis (CIE)
 Rapid Fluorescent Focus
Inhibition Test (RFFIT).
• Electron microscopy
• Antigen detection-
 from hair follicles at nape of
the neck
 corneal smear- by direct IF
test.
• Viral Isolation by:
 Mouse inoculation
 Cell lines inoculation- Mouse
neuroblastoma and BHK cell
lines
• Viral RNA detection- by RT-
PCR
• Enzyme Linked
Immunosobent Assay (ELISA)

13. • Table:-WHO Guide for post-exposure treatment against rabies
Category Type of contact with a
suspect or confirmed
rabid diagnostic or wild
animal, or animal
unavailable for
observation
Recommended
treatment
I Touching or feeding of
animals Licks on intact skin
None, if reliable case history
is available
II Nibbling of uncovered skin
Minor scratches of abrasions
without bleeding
Licks on broken skin
Administer vaccine
immediately Stop treatment
if animal remains healthy
throughout an observation
period of 10 days or if animal
is killed humanely and found
to be negative for rabies by
appropriate laboratory
techniques
III Single or multiple
transdermal bites or
scratches
Contamination of mucous
Administer rabies
immunoglobulin and vaccine
immediately. Stop treatment
if animal remains healthy

14. PREVENTION OF HUMAN
RABIES• The post-exposure treatment is a three pronged approach.
All three carry equal importance and should be done
simultaneously.
 Management of wound
 Passive immunization
 Active immunization
A. Management of wound
o Wound toileting- immediately flushing the wound with running
water with soap and detergent for 10 min.
o Suturing of wound should be avoided
o Cauterization of wound is no longer recommended
o Inj. tetanus toxoid should be given to the unimmunized
individual. To prevent sepsis in the wound, a suitable course of
an antibiotic may be recommended.
o Savlon and Dettol after thorough washing of wound

15. B) Passive Immunization (Rabies
lmmunoglobulin)
Two types of RIGs are available:
i. Equine rabies immunoglobulin
(ERIG): given at dose of 40 IU/kg.
It is associated with serum
sickness.
ii. Human rabies immunoglobulin
(HRIG): given in a dose of
20IU/kg. It is devoid of side
effects.
• Maximum volume of RIGs should be
infiltrated into and around the bite
wound(s); remaining volume if any
should be administered by deep
intramuscular injection at a site distant
from the vaccine injection site.
C) Active Immunization (Rabies Vaccine)
i. Neural vaccine – not in use since
2004 as associated with neurological
complications.
ii. Cell Culture vaccines
o Human Diploid Cell Vaccine (HDCV)
o Purified Chick Embryo Cell Vaccine
o (PCEC) Purified Vero Cell Rabies
Vaccine (PVRV)
iii. Purified Duck Embryo Vaccine
Control of rabies
 Epidemiolgocial surveillance
 Mass vaccination
 Dog population management
 Community participation

16. Regimen for post exposure prophylaxis
o IM regimen or Essen regimen (1-1-1-1): Five doses of intramuscular(IM)
injections; one dose (0.5 or 1 mL) each given on days O, 3, 7, 14 and 28.
o ID regimen (or Thai Red Cross Schedule) (2-2-2-0-2): Intradermal (ID)
injection of 0.1 mL of reconstituted vaccine on two sites per visit on
days 0, 3, 7 and 28.
o Site of injection: Deltoid region is ideal site. Gluteal region is not
recommended because fat retards the absorption of antigen. Infants
and young children-Antero lateral part of the thigh is the preferred site.
o Risk category:
• Vaccine is indicated for category II and III bites.
• Rabies immunoglobulin may be considered if the exposure is of
category III type.

17. Regimen for Pre-exposure Prophylaxis
• Recommended for high risk groups like laboratory staff handling the virus and
infected material, clinicians or any person attending to human rabies cases,
veterinarians, animal handlers and travellers from rabies free areas to rabies
endemic areas.
• Three doses are given on day-0, 7, and 21 or 28 days either by IM (0.5 mL) or ID
(0.1 mL)schedule.
• Antibody titre should be checked every 6 months for 2 years and thereafter
every 2 yearly. Booster dose is given if the titre falls below 0.5 IU/mL.
Regimen for Post-exposure Prophylaxis In Previously Vaccinated Individuals
• Severe bite or titre unknown: 3 doses are given on-0,3 and 7 days.
• Less severe bite or titre >0.5 lU/mL: 2 doses given on 0 and 3 days.
• Immunoglobulins are usually not needed.

18. LASSA FEVER VIRUS
EPIDEMIOLOGY
• Lassa fever is an acute viral haemorrhagic illness of 2-21 days duration
that occurs in West Africa.
• Single-stranded RNA virus belonging to the virus family Arenaviridae.
• Virus is transmitted to humans via contact with food or household items
contaminated with rodent urine or faeces. Animal reservoir is
multimammate or Mastomys rat.
• Endemic in Benin, Ghana, Guinea, Liberia, Mali, Sierra Leone, and
Nigeria and in other West African countries as well.
• The illness was discovered in 1969 and is named after the town in
Nigeria where the first case occurred.
• An estimated 100,000 to 300,000 infections of Lassa fever occur
annually, with approximately 5,000 deaths.
• In some areas of Sierra Leone and Liberia, 10-16% of people admitted
to hospitals annually have Lassa fever, demonstrating the serious
impact of disease on the region.

19. MODE OF TRANSMISSION
• From rodents to human
o Ingestion- contaminated food
o Inhalation- tiny particles in the air contaminated with infected rodent
excretions, during cleaning activities like sweeping.
o Direct contact- with urine and droppings of virus, through touching
soiled objects, exposure to open cuts or sores.
• From human to human
o exposure to virus in the blood, tissue, secretions, of a Lassa virus-
infected individual.
o common in health care settings (called nosocomial transmission) where
proper personal protective equipment (PPE) is not available or not
used.
o contaminated medical equipment, such as reused needles.
o sexual transmission of Lassa virus has been reported.

20. SIGNS AND SYMPTOMS
• Incubation period ranges from 6–21 days
• Fever, general weakness, and malaise.
• After a few days, headache, sore throat, muscle pain, chest pain, nausea,
vomiting, diarrhoea, cough, and abdominal pain.
• In severe cases facial swelling, fluid in the lung cavity, bleeding from the
mouth, nose, vagina or gastrointestinal tract and low blood pressure.
• Proteinurea
• Shock, seizures, tremor, disorientation, and coma in the later stages.
• Deafness in 25% of patients who survive the disease.
• Transient hair loss and gait disturbance may occur during recovery.
• Death usually occurs within 14 days of onset in fatal cases.
• Especially severe in late pregnancy, with maternal death and/or fetal loss
occurring in more than 80% of cases during the third trimester.

21. DIAGNOSIS
• Reverse transcriptase polymerase chain reaction (RT-PCR) assay
• Antibody enzyme-linked immunosorbent assay (ELISA)
• Antigen detection tests
• Virus isolation by cell culture.
• Immunohistochemistry, performed on formalin-fixed tissue specimens, can be
used to make a post-mortem diagnosis.
PREVENTION AND CONTROL
• avoiding contact with Mastomys rodents
• food kept in rodent-proof containers and keeping the home clean.
• Trapping in and around homes can help reduce rodent populations
• Using these rodents as a food source is not recommended.
• Using PPE such as masks, gloves, gowns, and goggles
• Complete equipment sterilization
• Isolation
• Educating people in high-risk areas about ways to decrease rodent
populations in their homes

22. WEST NILE VIRUS
EPIDEMIOLOGY
• West Nile Virus (WNV) belongs to flavivirus genus and
family Flaviviridae
• Cause a fatal neurological disease in humans.However, approximately
80% of people who are infected will not show any symptoms.
• Transmitted through the bites of infected mosquitoes. Humans, horses
and other mammals can be infected
• Birds are the natural hosts of West Nile virus.
• WNV is commonly found in Africa, Europe, the Middle East, North
America and West Asia.
• WNV was first isolated in a woman in the West Nile district of
Uganda in 1937.
• During 1997 it became more virulent in Israel and caused encaphelitis
and paralysis in birds.
• In 1999- outbreak in NEW YORK and thereby whole of USA.
• The largest outbreaks occurred in Greece, Israel, Romania,
Russia and USA.
• Now widely established from Canada to Venezuela.

23. MODE OF TRANSMISSION
In a very small number of cases, West Nile
virus has been spread through:
o Exposure in a laboratory setting
o Blood transfusion and organ donation
o Mother to baby, during pregnancy,
delivery, or breast feeding.
West Nile virus does not spread:
o Through coughing, sneezing, or touching
o By touching live animals
o From handling live or dead infected birds.
o Through eating infected birds or animals.

24. Signs and symptoms
• Incubation period is usually 3 to 14 days.
• Asymptomatic in around 80% of infected people,
or can lead to severe West Nile disease.
• Symptoms- fever, headache, tiredness, and body
aches, nausea, vomiting, occasionally with a skin
rash (on the trunk of the body) and swollen lymph
glands.
• Severe disease ( West Nile encephalitis or
meningitis or West Nile poliomyelitis) - headache,
high fever, neck stiffness, stupor, disorientation,
coma, tremors, convulsions, muscle weakness,
and paralysis.
• People over the age of 50 and some
immunocompromised persons are at the highest
risk for getting severely ill when infected with
WNV.
Diagnosis
• IgG antibody sero-conversion (or
significant increase in antibody titres) in
two serial specimen collected at a one
week interval by ELISA.
• IgM antibody capture ELISA
• Neutralisation assays;
• Viral detection by RT-PCR assay, and
• Virus isolation by cell culture.
 IgM can be detected in nearly all CSF and
serum specimens received from WNV
infected patients at the time of their
clinical presentation.
 Serum IgM antibody may persist for
more than a year.

25. PREVENTION AND CONTROL
• Preventing transmission in horses- establishment of an
active animal health surveillance system to detect new
cases in birds and horses.
• Vaccines have been developed for horses
• Reducing the risk of mosquito transmission- mosquito
nets, repellents etc
• Reducing the risk of animal-to-human transmission- PPE
during slaughtering
• Reducing the risk of transmission through blood
transfusion and organ transplant
• Vector Control- source reduction (with community
participation), water management, chemicals, and
biological control methods.
• Preventing infection in health-care settings- implementing
standard infection control precautions.

27. EPIDEMIOLOGY
Geographical distribution
 The disease is endemic in more than 100 countries in South-
east Asia, Western Pacific, Eastern Mediterranean, Africa,
the America. South-east Asia and Western Pacific are most
seriously affected. Before 1970 only nine countries had
experienced DHF epidemic, and the number had increased
more than four-fold by 1995.
 WHO currently estimates there may be 500 lakhs cases of
dengue infection worldwide every year with around 24,000
deaths.
Situation in India
 India is also endemic for Dengue Fever (DF) and Dengue
Haemorrhagic Fever (DHF).

28.  Again in the year 2003 an outbreak of DF and DHF was reported
from various parts of the country especially Delhi, Kerala,
Karnataka, Punjab, Tamil Nadu, Uttar Pradesh & Maharashtra.
 Between 2010-17,>6 lakhs cases with >1560 deaths have been
reported .Maximum cases were reported from West Bengal ,
Tamil Nadu, Punjab, Kerela,Delhi, Karnataka and Maharashtra.
 In 2017 ,nearly 1,57,220 cases were reported ;maximum from
Tamil Nadu followed by West Bengal.
 In 1996, there was a large outbreak of DF and DHF. Cases and
deaths were reported from various parts of the country viz.
Delhi 10,252 cases and 423 deaths, Haryana 1631 cases and
54 deaths and Maharashtra 3068 cases and 5 deaths. In total,
16517 cases and 545 deaths were reported from all over the
country.

29. CLINICAL APPROACH
I.P. : 5-6 days
Dengue fever : Abrupt onset of fever(breakbone or saddle
back fever), maculopapular rashes, muscle and joint pains,
retro orbital pain, loss of appetite ,nausea and vomiting
Dengue hamorrhagic fever :high grade fever,
hepatomegaly, thrombocytopenia, raised haematocrit,
spontaneous bleeding from nose, skin,mouth and gums
Dengue shock syndrome: DHF and features of shock

30. LABORATORY DIAGNOSIS
• Sample: serum, plasma, whole blood
• Transport specimen to the laboratory at 2-8⁰C as soon as
possible
• Virus isolation from blood: -1 to +5 days of onset of
symptoms; by inoculation into mosquito cell line or in
mouse
• NS1 Antigen detection: ELISA and ICT(day1 of fever upto 18
days
• Antibody detection: ELISA,HAI(Hemagglutination inhibition
test),CFT(complement fixation test),neutralization test etc
• Molecular: detection of specific genes of viral RNA by real
time RT-PCR

31. VACCINATION
• Licensed for human use since 2015
• Chimeric yellow fever-dengue,live
attenuated,tetravalent dengue vaccine(CYD-
TDV);commercially available as dengvaxia
• Uses live attenuated yellow fever 17D virus as
vaccine vector containing target genes for all
four dengue serotypes
• Indicated for 9-45yrs; 3 inj. Of 0.5ml s.c. at 6
months interval
• Currently approved in Mexico, Philippins,
Brazil, Indonasia,Thailand and Singapore
• Not available in India yet.

32. PREVENTION
ENVIORMENTAL CONTROL:
• Proper solid waste disposal
• Covering water storage containers ,prevent access
by egg-laying female mosquitoes.
CHEMICAL METHODS:
• Application of appropriate insecticides to larval
habitats i.e. water storage vessels
BIOLOGICAL CONTROL:
• Larvivorous mosquito–eating fish, dragon fly
larvae, copepods (mesocyclops), peppermint oil
and a fungus lagenidium gigantum

33. JAPANESE B ENCEPHALITIS
Vector:
C.tritaeniorhynchus
C.vishnui
Amplifying host:Pigs
Natural host: Ardeid
birds
e.g.herons,ducks
Dead end:Humans

34. EPIDEMIOLOGY
Geographical distribution
 occurring in a large number of countries of Asia, including
Cambodia, China, Indonesia, Japan, Laos, Malaysia, Myanmar,
Philippines, Korea, Thailand, Vietnam, South-eastern Russian
Federation and the Indian subcontinent.
Occurrence of JE in India
 In India, it was first recorded in Vellore and Pudducherry in mid
1950s.
 The first major outbreak occurred in 1973 in Bankura & Burdwan
districts of West Bengal.
 In 1976, wide spread outbreaks were reported from Andhra
Pradesh, Assam, Karnataka, Tamil Nadu, Uttar Pradesh and West
Bengal.
 In 1978 cases were reported from 21 states and Union
Territories.

35.  The worst ever recorded outbreak in India was reported from
Uttar Pradesh during 1988 when 4485 cases with 1413 deaths
were recorded from eight districts with case fatality rate of 31.5%.
The highly affected states include Andhra Pradesh, Assam, Bihar,
Goa, Karnataka, Manipur, Tamil Nadu, Uttar Pradesh and West
Bengal.
 Between 2010-2017;total 10,710 cases(Av.1,340 cases/yr) and
1,782 deaths(Av. 222 deaths/yr) have been reported.
 In 2017,nearly 2,040 cases were reported from India with 230
deaths. Maximum cases from UP followed by Assam, Manipur,
West Bengal, Tamil Nadu, Tripura, Bihar and Odisha.
 Outbreaks usually coincide with monsoons and postmonsoon
period when the vector density is high. However, in endemic
areas, sporadic cases may occur throughout the year. Case fatality
rate in newly affected areas ranged from 10 – 70%.

36. CLINICAL APPROACH
 I.P. : 5-15 days
 Shows iceberg phenomena
 Prodromal stage: febrile illness, abrupt(1-6hrs);
acute(6-24hrs); subacute(2-5 days)
 Acute encephalitis stage : acute onset of fever,
neck stiffness mental confusion,
disorientation,delirium or coma
 Late stage :may recovered fully or retain some
neurological deficits permanently; mental
impairment, personality changes etc.
 Case fatality rate:20-50%

37. LABORATORY DIAGNOSIS
Specimen: serum, CSF, brain tissue
Transport: VTM or glycerol saline(brain tissue)
Storage: if delay, place at 4⁰C
Isolation of virus
Detection of antigen
Fluorescent antibody test
Detection of antibody
Haemagglutination Inhibition Test (HI) test, IgM Capture
ELISA test.
Molecular:RT-PCR(viral specific envelope E gene)

38. VACCINATION
 Live attenuated SA 14-14-2 vaccine
• Cell derived; primary hamster kidney cell lines
• Under NIP, given to children(1-15yrs)in endemic states
• 2 doses;9-12months;16-24 months;0.5ml/dose;s.c. at left
upper arm
 Inactivated vaccine(Nakayama strain and Beijing strain)
• Both mouse brain derived; formalin inactivated
 Combined vaccine
• Includes SA-14-14-2 strain and yellow fever vaccine strain
17D(YF 17D) virus
PREVENTION
• residual insecticidal spraying in all animal dwellings with
appropriate insecticide before the onset of transmission season

39. YELLOW FEVER
• Vector: A.aegypti or
tiger mosquito
• Transmission cycle:
• Jungle cycle
• Urban cycle

40. EPIDEMIOLOGY
 The disease occurs only in South America, Central
America and Africa however, historically, major
outbreaks have also been reported from Europe and
North America too.
 Not found in rest of the world including India
 Hypothetical reasons for absence in India:
 Measures taken in airport:unvaccinated travelers
coming from endemic zone will be kept in quarantine
for the longest I.P.(6days)
 Breteau index should be <1, surrounding 400 meter of
an airport
 Being endemic for dengue, many people possess
dengue antibodies(cross reactive);provide protection

41. CLINICAL APPROACH
I.P. : 3-6 days
 Acute phase : fever, headache, backache,
muscle pain,nausea vomiting and red eyes.
 Toxic phase/Severe phase: jaundice, dark
urine, reduced amounts of urine production,
bleeding from the gums, nose or in the stool,
vomiting blood, hiccups, diarrhea
LABORATORY DIAGNOSIS
 Serology:IgM ELISA, neutralization test
 Molecular: RT-PCR
 Isolation of virus using cell culture

42. VACCINATION
Yellow fever 17D vaccine:
 Live attenuated;prepared in allantoic cavity of
chick embryo
 In India, prepared in Central Research
Institute,Kasauli
 Single dose, given s.c.
 Effective within 7 days of administration
 Contraindications:
children<9months,pregnancy,HIV infected, people
allergic to egg
PREVENTION : Includes vaccination and avoidance
of mosquito bites in areas where yellow fever is
endemic.

43. ZIKA VIRUS

44. EPIDEMIOLOGY
 It was first identified in a rhesus monkey in the tropical Zika Forest in
Uganda in April 1947 by the scientists of the Yellow Fever Research
Institute. The first human Zika Fever infection was identified in
Nigeria in 1954.
 Until 1981, evidence of human infection with Zika virus was
reported from other African countries, such as the Central African
Republic, Egypt, Gabon, Sierra Leone, Tanzania, and Uganda, as well
as in parts of Asia including India, Indonesia, Malaysia, the
Philippines,Thailand, and Vietnam.
Global Situation
Outbreak in Yap in 2007:Remote island of Yap reported 49 confirmed
and 59 probable cases of ZVD. No hospitalization,haemorrhagic
manifestations, or deaths were reported. Aedes hensilli was identified
as the predominant vector species. This outbreak represents
transmission of Zika virus outside Africa and Asia.

45. • Recent outbreak(2015-2016):
• During this period,about 5,28,157 confirmed cases
and 18 deaths have been reported worldwide;out of
which Brazil alone witnessed nearly 2,00,465
confirmed cases
• Other countries reported maximum cases were Puerto
Rico,Colombia and Mexico
• In february 2016,WHO declared the Zika virus
outbreak a public health emergency of international
concern
• Situation in India: three confirmed cases have been
reported from Gujrat in 2017

46. CLINICAL APPROACH
 80% of persons are asymptomatic. In the majority of cases,
it is a self-limiting disease.
 Symptoms are usually mild - fever, skin rashes,
conjunctivitis, muscle and joint pain, malaise, headache,
dizziness, edema of the extremities, retro-orbital pain,
anorexia, photophobia, gastro-intestinal disorders, sore
throat, cough,back pain, sweating and lymphadenopathies.
Complications: Birth defects like microcephaly, neurologic
complications like Guillain-Barré syndrome are temporarily
associated with this outbreak.

47. LABORATORY DIAGNOSIS
• Detection of RNA in blood and urine by RT-PCR
• Antibody detection: ELISA and Plaque reduction neutralization test
VACCINE: under trial
• ZIKA DNA vaccine: conducted by Vaccine Research Center,USA;
entered phase-2 trial in 2017
• Killed ZIKA vaccine: under phase 1 trial
PREVENTION :
 Personal protection: mosquito coils, pyrethrum space spray and
aerosols,Insecticide treated bed nets
 Biological control:Larvivorous fish ,Endotoxin-producing bacteria,
Bacillus thuringiensis serotype H-14
 Chemical control
• Larvicide: Temephos, an organophosphate compound
• Adulticide:Pyrethrum spray at a concentration of 0.1% - 0.2% @ 30-
60 ml/1000 cu. ft.

48. KYASANUR FOREST DISEASE(KFD)

49. EPIDEMIOLOGY
 Virus was restricted to three areas of Shimoga district till 1971
and subsequently reported from other districts of the state viz.,
Chikamagalore, North Kannada,South Kannada and Udupi and
later in 2012 from Chamaraja Nagar and more recently in 2016
from Belagavi district of Karnataka state.
 Largest outbreak occurred in 1983-1984,with 2,167 cases and 69
deaths
 From 2003-2012 there were 3,263 suspected cases,823
confirmed and 28 deaths
 In 2013, it was detected in autopsy of dead monkeys in Nilgiris
district of Tamil Nadu. Monkey deaths as well as human cases
were reported in Wayanad and Malappuram districts of Kerala
during 2014 – 2015.
 KFD outbreak has been reported from North goa district of Goa
state bordering Karnataka in 2015. Another outbreak was
reported from Sindhu Durg district of Maharashtra in 2016.

50. CLINICAL APPROACH
I. P. : 3-8 days
Acute stage: sudden onset with fever, headache, severe
myalgia, signs of dehydration,bleeding from nasal
cavity,throat and gums,gastro-intestinal disturbances
and haemorrhages occur in severe cases.
Second phase : meningo-encephalitis may occur 7-21
days after the first stage . It is manifested by a return of
fever, severe headache followed by neck stiffness,
mental disturbance, coarse tremors, giddiness and
abnormal reflexes.
LABORATORY DIAGNOSIS
 Virus isolation from blood
 IgM antibody detection by ELISA
 Viral RNA detection by nested RT-PCR and real time RT-PCR

51. PREVENTION:
Prevention of tick bites: Application of repelling agents
(such as Dimethylphthalate (DMP), NN-Diethyl-m-Tolumaide
(DEET) and other proprietory preparations e.g. Mylol (Boots)
on the exposed parts is effective from one to a few hours.
Source reduction : Benzene hexachloride(BHC) “Lindane”
as wettable powder, effective for six weeks; sprayed at the
rate of approximately 1 kg. per hectare.
VACCINE:
 Formalin-inactivated chick embryo vaccine,developed in
Haffkine institute, Mumbai
 Recommended in endemic areas of karnataka

52. Marburg virus
• Marburg virus disease (MVD), formerly known as Marburg
haemorrhagic fever, is a severe, often fatal illness in humans.
• CDC lists it as a Category A Bioterrorism Agent
• First recognized in 1967.
• First man infected had been exposed to African green monkeys.
• Case fatality rate: around 50%.
• Agent: genus Marburgvirus, family Filoviridae ,linear nonsegmented,
single-stranded RNA genomes.
• Natural reservoir: Rousettus aegyptiacus, fruit bats of the
Pteropodidae family.
• Transmission : from fruit bats and spreads among humans through
human-to-human transmission( blood, secretions, organs or other
bodily fluids of infected people, and with contaminated surfaces and
materials).

53. Marburg hemorrhagic fever
pathogenesis

54. Diagnosis
• Difficult to clinically distinguish MVD from other infectious diseases
such as malaria, typhoid fever, shigellosis, meningitis and other viral
haemorrhagic fevers.
• Incubation period: 2-21 days
• Begins abruptly, with high fever, severe headache and severe malaise,
• Severe watery diarrhoea(a week), abdominal pain and cramping,
nausea and vomiting, internal bleeding can begin on the third day.
• Appearance of patients at this phase has been described as “ghost-
like” drawn features, deep-set eyes, expressionless faces, and
extreme lethargy.
• Laboratory diagnostics consist of virological, serological and
molecular methods.
• Sample: blood (whole blood and serum), saliva (oral swab),urine (less
reliable),breast milk, semen.

55. • Laboratory testing on non-inactivated samples should be conducted
under maximum biological containment conditions.
• All biological specimens should be packaged using the triple
packaging system when transported nationally and internationally.
• First–line diagnostics:
– antibody-capture enzyme-linked immunosorbent assay (ELISA)-
viral antigen,
– reverse transcriptase polymerase chain reaction (RT-PCR) assay-
viral genome,
• Main alternative assay for acute MHF is antigen-capture detection,
• Confirmatory test -electron microscopy(unique filamentous
shapes)
-virus isolation by cell culture(grivet kidney
epithelial Vero E6 or MA-104).
-serum neutralization test

56. Prevention and control
• No licensed vaccines or post-exposure therapies are currently
available,
• Supportive care includes balancing fluids, maintaining oxygen status,
blood pressure, replacing lost blood and treatment for complicating
infections,
• Good outbreak control relies on- case management, surveillance and
contact tracing, a good laboratory service,
– Reducing the risk of bat-to-human transmission, human-to-
human transmission in the community,
– ensure that the population is well informed about the nature of
the disease, prompt and safe burial of the dead,
– Reducing the risk of possible sexual transmission,
– Healthcare workers should always take standard precautions .

57. Ebola virus
• One of the largest and deadliest outbreaks in recent times,
• Named after the Ebola River in the Democratic Republic of Congo,
(one of the two places documented outbreaks first occurred in
1976).
• India is among the top five financial contributors to the United
Nations’ ebola response.
• Agent: genus Ebolavirus, family Filoviridae, order Mononegavirales,
non-infectious RNA genomes.
• Natural hosts- fruit bats (Hypsignathus monstrosus), porcupines and
non-human primates.
• Average case fatality rate is around 50%.
• Transmission : Blood or body fluids , objects contaminated with body
fluids from a person sick with EVD or the body of a person who died
from EVD, Infected fruit bats or nonhuman primates.
• On dry surfaces, virus can survive for several hours and in body fluids,

59. Diagnosis
• Difficult to clinically distinguish EVD from other infectious diseases,
• Incubation period :2-21 days,
• Clinically patient shows Fever, Severe headache, Muscle pain,
Weakness, Fatigue, Diarrhea, Vomiting, Abdominal pain, Unexplained
hemorrhage (bleeding or bruising).
• Laboratory findings include low white blood cell and platelets and
elevated liver enzymes.
• Preferred specimen: Whole blood and serum, Oral fluid specimen
stored in universal transport medium.
• Ebola virus is a group 4 agent and requires high containment facility.
• Viral inactivation methods include chemical inactivation, gamma
irradiation, and heat treatment under BSL 2.

60. • WHO recommends-Automated or semi-automated nucleic acid tests
(NAT) for routine diagnostic management,
-Rapid antigen detection tests(screening
purposes as part of surveillance
• Confirmation of symptoms are made using the following diagnostic
methods:
– Antibody-capture enzyme-linked immunosorbent assay (ELISA)
– Antigen-capture detection tests
– Serum neutralization test
– Reverse transcriptase polymerase chain reaction (RT-PCR) assay
– Electron microscopy
– Virus isolation by cell culture.

61. PREVENTION AND CONTROL
• Focused on outbreak containment and control,
• Blocking nosocomial transmission by employing good barrier
protection ,
• Patient isolation to prevent spread from infected patients to health
care personnel and/or other non-infected patients in a hospital or
health care setting,
• An experimental vaccine called rVSV-ZEBOV was found to be highly
protective against the virus in a trial conducted by the WHO in
2015.
• FDA licensure for the vaccine is expected in 2019,
• The rVSV-ZEBOV vaccine is being used in the ongoing 2018-2019
Ebola outbreak in DRC.

62. NIPAH VIRUS
• First recognized in 1999 during an outbreak among pig farmers in,
Malaysia
• In India, limited to two districts in Kerala (Kozhikode & Malappuram).
• Agent: non-segmented SS-RNA virus family Paramyxoviridae,
genus Henipavirus.
• Natural Reservoir: Large fruit bats of Pteropus genus, pigs may
become infected after consumption of partially bat eaten fruits that
are dropped in pigsties.
• Seasonality: winter to spring (December-May).
• Transmission: direct contact with infected bats, infected pigs, or from
other Nipah virus infected people(bodily fluids), drinking of raw date
palm sap contaminated with NiV.
• Case–fatality rate : 40–75%

64. Diagnosis
• Laboratory diagnosis of a patient with a clinical history of NiV can be
made during the acute and convalescent phases of the disease by
using a combination of tests.
• Incubation period: 4 days to 2 months,
• Patients presents with fever, headache, dizziness, and vomiting,
severe encephalitis, reduced level of consciousness and prominent
signs of brainstem dysfunction, including abnormal doll's eye reflex,
pupillary reflexes, vasomotor changes, seizures, and myoclonic jerks,
• Nipah virus is classified internationally as a biosecurity level (BSL) 4
agent.
• Preferred samples: Throat swab (viral transport medium), Urine(10
ml)Blood in plain vial (5ml), CSF (at least 1 ml).

65. • Samples should be safely packed in triple container packing and
should be transported under cold chain to the testing laboratory.
• Sample must be stored at – 70°C if storage is required for longer
periods.
• Procedures for the laboratory diagnosis of Nipah virus infections
include
– ELISA
– Serum neutralization tests
– Polymerase chain reaction (PCR)
– Virus isolation(vero cells)
– Electron microscopy

66. PREVENTION AND CONTROL
• Includes interventions to prevent farm animals from acquiring NiV by
eating fruit contaminated by bats,
• Consumption of contaminated sap should be avoided,
• Focused on surveillance and awareness will help prevent future
outbreaks,
• Reliable laboratory assays for early detection of disease in
communities and livestock, and raising awareness of transmission
and symptoms,
• Standard precautions to avoid nosocomial infection,
• Multiple vaccines have been developed for NiV, though none are
commercially available:
– HeV soluble recombinant G subunit vaccine ,
– ALVAC-G/F vaccine ,
– Recombinant Newcastle disease virus vectored NiV vaccine,
– Recombinant Vesicular stomatitis virus (rVSV) vectored NiV vaccine

67. SWINE FLU
• First case: 18th March, 2009; Mexico
• Case fatality rate in Rajasthan: 5.3%
• Agent factors: Enveloped RNA virus, Orthomyxoviridae family, 80-
200 nm diameter
– 2 Surface antigen:
• Hemaglutinin (HA): Initiates infection following attachment of
virus to susceptible cell
• Neuraminidase (NA): Release of virus from infected cell.
• Reservoir of Infection:
– Humans primary reservoir for human infections,
– Major reservoir – animals & birds (swine, horses, dogs, cats,
domestic poultry, water birds, wild birds etc).
• Seasonality: monsoon to winters.
• Transmission:

68. Diagnosis
– Clinically difficult to diagnose since patient complaints of
Fever/chills, Cough, Headache, myalgia, Sore throat, Prostration,
Vomiting & diarrhea which are often confused with seasonal flu.
– Incubation period: 1-7 days.
• Viral diagnostic and research laboratory testing should be
conducted in a biosafety level-2 (BSL-2).
• Specimen : nasopharyngeal swab, nasal aspirate or a combined
nasopharyngeal swab with oropharyngeal swab, endotracheal
aspirate. Bronchoalveolar lavage (BAL) and sputum.
• Specimens should be placed into sterile viral transport media and
immediately placed on ice or cold packs or at 4°C (refrigerator) for
transportion.
• Diagnostic tests: Real-time RT-PCR, Rapid influenza antigen test,
Immunofluorescence (DFA or IFA), Viral culture

69. PREVENTION AND CONTROL
• Prevention of swine to human viral transmission, human to human
transmission,
• Early detection, investigation and containment of cases of influenza A
H1N1,
• Training and equipping manpower to investigate and contain number
of cases, Strengthening of health care infrastructure,
• Stockpiling of antiviral drugs, PPE, N-95 and triple layer mask &
Oseltamivir,
• Preparation of guidelines and standard operating procedures (SOPs)
and IEC material,
• Management of cases, Increasing Awareness, Contact Tracing ,
Enhanced Surveillance,
• Best-known prevention method:H1N1 swine flu vaccine, single dose
was enough to create sufficient antibodies to protect against the
virus within 10 days.

70. CRIMEAN-CONGO HAEMORRHAGIC
FEVER (CCHF)
• first characterized in the Crimea in 1944 , later recognized in 1969 in
the Congo,
• In India, first laboratory confirmed outbreak: January, 2011 Gujarat.
• Three outbreaks have been reported from Rajasthan (Chittorgarh,
Jodhpur, Sirohi) in 2014 and 2015.
• Case fatality rate of up to 40%.
• Causative Agent: CCHF virus, family Bunyaviridae, genus Nairovirus,
SS-RNA, enveloped, with tripartite genome,
• Vector: Adult hard tick, Dermacentor andersoni, (member of
Hyalomma genus, the family Ixodidae)
• Natural reservoir: hard ticks and wild animals and domestic ruminant
animals such as hares, rats, camel, cattle, sheeps and goats,
• Transmission: Animal to Human Transmission and Human to Human
Transmission.

72. Diagnosis
• Incubation period: 1-13 days.
• Clinically: patients presents with fever, sore throat, dizziness, neck
pain, stiffness, backache, headache, sore eyes and photophobia,
nausea, vomiting and diarrhoea ,
• Patient may also experience sharp mood swings, and may become
confused and aggressive,
• After 2-4 days, the agitation replaced by sleepiness, depression and
lassitude, abdominal pain localized to the right upper quadrant, with
detectable hepatomegaly, lymphadenopathy and a petechial rash,
other haemorrhagic phenomena.
• Mortality rate from CCHF is approximately 9-50% with in the second
week of illness.
• Differential diagnosis of CCHF: Malaria, Leptospirosis, Rickettesial
diseases, Meningococcemia, Dengue Haemorrhagic Fever,
Haemolytic Uremic Syndrome, and Thrombocytopenic Purpura.

73. • LABORATORY DIAGNOSIS: group 4 virus, hence clinical samples
should be handled in high biosafety level laboratories (BSL 3 plus or
4).
• Sample Collection:
– Ante-mortem: Blood sample: Serum/Plasma, urine.
– Postmortem: Tissue sample (liver, spleen, bone marrow, kidney,
Lung and brain).
• Transportation: safely packed in Triple container packing and
transported under cold chain.
• Before dispatching the container, Bleach can be used for disinfection.
A 1:100 dilution of bleach or 5% Lysol solution should be used to
clean the outer surfaces of the container.
• Diagnostic tests:- Molecular Technique RT-PCR,
- Virus Isolation(first 5 days of illness),
- Serology: IgG and IgM antibodies- ELISA , fourfold
or greater increase in antibody titre in paired serum
samples or IgM capture ELISA (MAC ELISA).

74. PREVENTION AND CONTROL
• Intensive monitoring to guide volume and blood component
replacement is required.
• Educate public about the mode of transmission, Tick control,
• Minimize exposure by wearing light clothing covering legs and arms,
• Apply tick repellent such as DEET (N,N-diethyl toluamide) to the skin
or permethrin to the clothings,
• Persons working with livestock or other animals should take practical
measures to protect themselves,
• Safe handling of dead bodies,
• Avoid spills, needle pricks, injury and accidents during case
management,
• Hospital waste management practices should be as per guidelines,
• All contacts should be advised to self-monitor twice daily for any
clinical symptoms for 14 days,
• NO VACCINE available for either people or animals.

75. Chikungunya
• Self-limiting and is rarely fatal disease,
• First described during an outbreak in southern Tanzania in 1952,
• Case fatality rate:
• Agent: chikungunya virus (CHIKV)RNA virus, family Togaviridae and
genus Alphavirus.
• Aetiological agent: Aedes albopictus and Aedes aegyptis.
• Reservoirs: monkeys, birds and other vertebrates ,
• Transmission : by the bites of infected female mosquitoes to
human.

77. Diagnosis
• Suspected when epidemic disease occurs with the characteristic triad
of fever, rash, and rheumatic symptoms.
• Other headache, nausea, fatigue, often misdiagnosed with to those
of Dengue and Zika.
• Incubation period- 2-12 days.
• Laboratory diagnosis is accomplished by testing serum or plasma.
• Chikungunya virus should be handled under biosafety level (BSL) 3
conditions.
• Detects virus, viral nucleic acid, or virus-specific immunoglobulin (Ig)
M and neutralizing antibodies.
• Viral culture may detect virus in the first 3 days of illness.
• During the first 8 days of illness, Chikungunya viral RNA can often be
identified in serum(rapid indicator of active infection) by 1-step PCR
assay.
• Antibodies develop toward the end of the first week of illness using
IgM-capture ELISA.

78. PREVENTION AND CONTROL
• No vaccine available,
• Preventive efforts are focused on vector control ,
• Elimination of breeding sites or source reduction is important,
• Larvivorous fish (eg: gambusia, guppy), which eat mosquito larvae,
may be introduced into local endemic areas,
• Protection from mosquito bites by insect repellent DEET (N, N-
diethyl-3-methylbenzamide), IR3535 (3-[N-acetyl-N-butyl]-
aminopropionic acid ethyl ester) or icaridin (1-piperidinecarboxylic
acid, 2-(2-hydroxyethyl)-1-methylpropylester)and use of insecticide-
treated mosquito nets,
• Well-planned fogging operations in high-risk villages,
• Active epidemiological surveillance for CHIKV for promoting effective
community education and transmission control.

79. Rift valley
• First identified in 1931 during an epidemic among sheep on a farm in
the Rift Valley of Kenya.
• Case fatality rate : less than 1 %.
• Agent: RVF virus, Phlebovirus type, Bunyavirales order, SS-RNA,
11.5 kb tripartite genome,
• Vectors: Culex tritaeniorhynchus and Aedes vexans.
• Reservoirs: Peter's epauletted fruit bat and the aba roundleaf bat,
infected livestock,
• Transmission: contact with blood, body fluids, or tissues of RVFV-
infected animals, mainly livestock, bites of infected mosquitoes ,
person to person has not been documented.
• Seasonality: Monsoon.

81. Diagnosis
• Symptoms of Rift Valley fever are varied and non-specific like fever,
generalized weakness, back pain, and dizziness at the onset of the
illness, hence clinical diagnosis is often difficult,
• Severe form of RVF in humans: Ocular form( blurred or decreased
vision followed by [permanent loss), Meningoencephalitis form,
Haemorrhagic fever form.
• Definitive diagnosis: malaria, shigellosis, typhoid fever, and yellow
fever.
• Incubation period: 2 to 6 days.
• Laboratory testing :
– reverse transcriptase polymerase chain reaction (RT-PCR) assay,
– IgG and IgM antibody enzyme-linked immunosorbent assay
(ELISA),
– virus isolation by cell culture.

82. PREVENTION AND CONTROL
• An inactivated vaccine has been developed but not licensed and is
not commercially available(under animal experiment),
• Restricting or banning the movement of infected livestock,
• Public health education, risk reduction and surveillance,
• Reducing the risk of animal-to-human transmission as a result of
unsafe animal husbandry and slaughtering practice, unsafe
consumption of fresh blood, raw milk or animal tissue,
• Personal and community protection against mosquito bites ,
• Standard Precautions when handling specimens from patients in
health care.