This document discusses several emerging and re-emerging infectious diseases including SARS, MERS, Nipah virus, Chikungunya, West Nile virus, Lyme disease, Kyasanur forest disease. It provides details on the causative agents, modes of transmission, symptoms, treatment and prevention measures for each disease. It also discusses definitions of emerging and re-emerging diseases and factors responsible for their emergence or re-emergence such as rapid population growth, international travel, antibiotic resistance.

1. Emerging & Re-emerging Infections-I
Dr. Mamta T.G.
Asst Prof Comm Med
MMC

2. Brushing up the basics-
1. Endemic
2. Epidemic (and Outbreak)
3. Pandemic

3. Terms we should know-
1. Disease Control
2. Disease Elimination
3. Disease Eradication

4. More terms-
1. Primary case
2. Secondary case
3. Index case

5.  Some diseases rare now -polio, guineaworm disease, chagas disease etc.
 We are on the verge of eradicating these diseases.
 In recent days new infectious diseases have emerged with high fatality.
 They are not only a health issue but also became a social problem.
 Theme of World Health day april7 1997.
 Emerging infectious disease --- global alert & global response is of great significance.

7. EMERGING DISEASES
Definition:-
the diseases whose incidence in humans has increased during
the last two decades or which threaten to increase in future.

8. Includes
newly appearing
infectious diseases
which are spreading to
new geographical areas

9. Reemerging diseases
Definition:-
The diseases which were previosly easily controlled by antibiotics,
but now developed antimicrobial resistance & apearing in epidemic
form.

10. Factors responsible
• Unplanned & underplanned urbanisation
• Overcrowding & rapid population growth
• Poor sanitation
• Inadequate public health infrastructure
• Resistance to antibiotics
• Increased exposure to vectors & reservoirs of infection
• Rapid & intense international travel

11. Mode of spread:-
by all modes of transmission
- person to person
- by insects & animals
- throuth contaminated
water & food

12. Coronaviruses
SARS in 2002 MERS in 2012

13. SARS
1. Severe acute respiratory syndrome (SARS)
2. first identified in 2002 in China.
3. high case fatality rate of about 10%.

14. SARS is transmitted through respiratory aerosols, released while an SARS patient coughs or
sneezes infecting the nearby people through mouth, nose or eyes. The virus also can spread by
touching infected surfaces, and then touching the mouth, nose, or eye.
Incubation period 2 to 10 days.
Signs and symptoms: high fever, migraine,
Discomfort in respiration
and body pains, slight
Respiratory problem,
Diarrhea (10–20%),
and cough (after 2–7 days)

16. SARS

18. MERS
1. Middle East Respiratory Syndrome (MERS), Bourbon virus, discovered in
Kansas
2. A zoonotic viral pneumonia
3. Camels are considered the source of infection to the humans.
4. Many people with MERS had close contact history with camels and
drinking camel milk.
5. Subsequently, human to human transmission of MERS-CoV occurs from
patients to health care workers through droplet infection, or through
touching contaminated surfaces.
6. Incubation period of MERS-Co V ranges from 2 to 14 days.

19. MERS TRANSMISSION

20. 1. General signs and symptoms
comprise: rigor, feeling cold with
shivering, migraine, cough, sore
throat, difficulty in breathing,
muscular rheumatism, chest
pain, kidney failure, pneumonia,
giddiness, nausea and vomiting,
dysentery, and stomach pain.
2. The PCR diagnosis method by
collecting sputum or any other
sample from the patient.
3. Till date, no proper treatment or
prophylaxis exists for MERS CoV.

23. Nipah virus disease is an emerging infectious disease spread by
secretions of infected bats. It can spread to humans through
contaminated fruit, infected animals, or through close contact with
infected humans
Nipah virus

25. Outbreak summary-
• In May 2018, three deaths due to Nipah virus infection were reported in Kozhikode District, Kerala
State, India in a family cluster and a fourth death in a health care worker involved in treatment.
• Laboratory testing of throat swabs, urine and blood samples by the National Institute of Virology in
Pune; confirmed positive for Nipah virus (NiV) by real-time polymerase chain reaction (RT-PCR) and
IgM ELISA for NiV.
• The field investigation team found bats living in the abandoned water well on the premises of a new
house of the family. One bat was sent to the National Institute of Virology, Pune for laboratory testing.
• With further investigations and contact tracing, 18 people tested positive for NiV in Kozhikode and
Malappuram districts, Kerala State; 17 of them died, including health care workers.
• The index case, could not be tested but was epidemiologically linked to a confirmed case.
• In the current outbreak, acute respiratory distress syndrome and encephalitis have been observed.
• This is the first NiV outbreak reported in Kerala State and third NiV outbreak known to have occurred
in India, with the most recent outbreak reported in 2007.

28. Chikungunya
1. Chikungunya virus is a mosquito-borne alphavirus
2. Name comes from a Makonde word describing the bent posture of persons
with the severe arthralgia that is a hallmark of chikungunya fever
3. Chikungunya virus was first isolated after a 1952–1953 epidemic in present-
day Tanzania.

35. West Nile virus
• Detected in Uganda in 1937.
• West Nile virus has produced the 3 largest arboviral neuroinvasive
disease outbreaks ever recorded in the United States.

37. • Highest in mid-July to early September.
• West Nile fever develops in approximately 25% of those infected, varies greatly
in clinical severity, and symptoms may be prolonged.
• Neuroinvasive disease (meningitis, encephalitis, acute flaccid paralysis) develops
in less than 1% but carries a fatality rate of approximately 10%.
• Encephalitis has a highly variable clinical course but often is associated with
considerable long-term morbidity. Approximately two-thirds of those with
paralysis remain with significant weakness in affected limbs.
• Diagnosis usually rests on detection of IgM antibody in serum or cerebrospinal
fluid.
• Treatment is supportive; no licensed human vaccine exists.
• Prevention uses an integrated vector management approach

38. Lyme disease
1. Lyme disease, a tick-borne illness transmitted to humans.
2. Spread by bites of Ixodes species ticks infected with the spirochete
Borrelia burgdorferi.
3. Named so because first time in 1970s, high prevalence found in Lyme
(Connecticut).
4. most common among age 5–9 years and 55–59 years. More in Men.
5. 3,00,000 individuals are diagnosed each year.

42. KFD
1. Kyasanur forest disease (KFD) was first recognised as a febrile illness in the
Shimoga district of Karnataka, India in 1957
2. KFD virus (KFDV), is a highly pathogenic member in the family Flaviviridae,
producing a haemorrhagic disease in infected human beings.
3. KFD is a zoonotic disease and has so far been localised in a southern part of
India.
4. A variant of KFDV, Alkhurma haemorrhagic fever virus (AHFV), has been
recently identified in Saudi Arabia.
5. KFDV may be persisting silently in several regions of INDIA.
6. An increasing number of KFD cases have been detected in Karnataka state.

46. 1. The incubation period before sudden manifestation
of the disease varies between 3–8 days.
2. After this initial stage a biphasic course with mild
meningoencephalitis and fever developing after an
afebrile period of 1–2 weeks is common.
3. Relative bradycardia is frequently
seen along with inflammation of the conjunctiva.
4. A small proportion of patients develop coma or
bronchopneumonia prior to death.
5. The acute phase of illness lasts for 2 weeks .
6. The case fatality in KFD is 2–10% , significantly
lower than in Alkhurma virus infection where case
fatality has been reported to be 25%.

47. Treatment
There is no specific treatment for KFD, but early hospitalization and
supportive therapy is important. Supportive therapy includes the
maintenance of hydration and the usual precautions for patients
with bleeding disorders.

48. 1. Formalin inactivated KFDV vaccine produced in chick embryo fibroblasts
is currently in use in the endemic areas in Karnataka state of India.
2. The places for vaccination were selected on the basis of prevalence of
KFDV activity in the previous years, including the villages from which
mortality in monkeys was reported and those adjacent to the KFDV
affected areas.
3. The efficacy and Coverage of vaccine are good. Almost all the individuals
including children are being routinely vaccinated by the local
government authorities.
4. However, the occurrence of KFD cases, despite vaccination, has
suggested some changes in virus antigenic determinants in due course.
KFD vaccine

49. Investigation of epidemic
1. Verification of diagnosis
2. Confirmation of epidemic existence
3. Defining population at risk
4. Rapid search for all cases
5. Data analysis- epidemic curve,spot map
6. Formulation of hypothesis
7. Testing of hypothesis
8. Evaluation of ecological factors
9. Furthur investigation of population at risk
10. Writing the report