1. Emerging and Re-emerging
diseases
Dr. Mhaske M.S.
Associate professor
Community Medicine

2. Competency CM 8.1
●Epidemiological characteristics and control
measures including the use of essential
laboratory tests at the primary care level for
Emerging and reemerging diseases eg Ebola
virus disease, Nipah.

3. SLO
●At the end of session 4 th semester students should be
able to
○Define and enlist emerging and reemerging diseases .
○Know Epidemiological characteristics of recently
emerged diseases ie. Covid 19, Zika virus, Ebola virus
diseases and Nipah virus
○Discuss control measures including the use of essential
laboratory tests at the primary care level for Emerging
and reemerging diseases eg Ebola virus disease, Nipah
and Covid 19.

4. Introduction
●The theme of the World Health Day on 7th April 1997
was “Emerging infectious diseases-Global response ,global
alert”.
● The eradication of smallpox and effective control of many
communicable diseases, has led to a false sense of security
and complacency in many countries. Resources for public
health were curtailed as more immediate priority areas
were identified for financial support.

5. ●The outbreaks of plague in 1994, cholera in
1995 and dengue hemorrhagic fever in 1996,
among many others, have highlighted the
urgency for strengthening the disease
surveillance system so that early warning
signals are recognized and appropriate
control measures are initiated in a timely
manner.

6. Definition
● Emerging infectious diseases have been defined by
● WHO as “those infections the incidence of which in humans has either increased
during the last two decades or threatens to increase in near future.”
● The term includes newly-appearing infectious diseases or those spreading to
new geographical areas.
● It also refers to those diseases which were previously easily controlled by
antimicrobials but have now developed resistance to these drugs.

7. Causes of Emergence of pathogens
●Environmental degradation
• Uncontrolled urbanization
• Unhygienic living conditions
• Migration of population
• Natural disasters
• Growing international trade, tourism and rapid travel
• Alterations in microorganisms
• Resistance to antimicrobials
• Insecticide resistance
• Weak public health system

8. Overcrowded,
ever growing
urban areas

9. Environmental
changes,
pollution,
Climate
change

10. Uncontrolled urbanisation

11. Emerging diseases
• Acquired immunodeficiency syndrome (AIDS)
• Cholera due to Vibrio cholerae O 139
• Tuberculosis, especially due to multidrug resistant organisms
• Malaria
• Kala-Azar
• Dengue, DHF and DSS
• Hepatitis B, C and E
• Japanese encephalitis
• Rabies
• Antimicrobial resistance

12. Since 1973
39 newly identified pathogens,
examples
1973 Rotavirus
1977 Ebola virus, Hantaan virus
1980 HTLV-1
1983 HIV virus H pylori
1988 Hepatitis E
1992 Vibrio cholerae O139
1996 Avian influenza A (H5N1)
1999 Nipah virus
2003 SARS
2009 Pandemic Influenza A
(H1N1)
The microbial world is dynamic
….Emergence of pathogens continues ….
Dengue/DHF
Cholera
Malaria
Chikungunya
J. Encephalitis
Leptospirosis
N.meningitidis
Others re-
emerged

13. Recent list
year agent disease
2014 Ebola Virus EBV, Renal failure
2015 Zika virus Microcephaly
2018 Nipah Encephalitis
2019 SARS – CoV-2 Covid 19

14. Reemerging infections
●Reemerging infectious diseases are those that have
reappeared after a significant decline in their incidence
may be because of antibacterial resistance.
●Appearance of plague in an explosive form in 1994
after a period of quinscence of almost 27 years is an
important example of reemerging infections.

15. Causes for drug resistance and
reemergence
●Increasing use of antibiotics in sub therapeutic doses
●Change in behavior of the patients.
●Travel including tourism.
● Practice of modern medicine, transplantation ,
dialysis , blood transfusions
●Relaxation about immunization

16. Potentially emerging diseases
●Infection Reported in
●Hanta virus Myanmar, Sri Lanka, USA
●Yellow fever Kenya, many African and Latin
American countries
●Ebola virus Zaire, South Africa
●E. coli O 157:H7 Australia, South Africa,
Japan, USA

17. Examples of antimicrobial resistance
●M. tuberculosis:MDR TB(INH, Rifampicin)
○ especially in HIV and immunocomprimised
pt
○ lead to longer duration for recovery, death,
increases cost
●Malaria:resistance to chloroquine ,vectors
resistant to insecticides LIke-DDT, BHC
●Enterococci: resistant to B laectamase,
aminoglycoslides.
○ can cause sepsis ,abcess, endocarditis

18. cont...
I. Streptococci: Resistance to Penicillin,
A. pneumonia, skin infections, gangrene
I. H influenzae:Resistance to Ampicillin, Co-Trimaxazole
I. Shigella dysentriae: resistance to routine antibiotics
A. cause of epidemics in camps, causing more deaths
because of resistance
I. Salmonella typhimurium:outbreaks in India, Pakistan,
Thailand and UK

19. Causes of drug resistance
●Uncontrolled and inappropriate use of drugs
●Used in wrong dosage and wrong duration
●Over use of drug
●Ready availability of over the counter ,self treatment
●Sub standard drugs

20. Responding to Epidemics
● Reducing human exposure- strategies to reduce human-animal contact
(coordination-veterinary and public health)
● prrotecting humans,vaccination of animals etc.
● Strengthening surveillance and early warning system:IDSP in India
● so that warning symptoms can be identified
● Laboratory capacity for confirmation More lab network , increase level
of labs .providing kits, developing easier ways of diagnosis for early
detection
s

21. intensifying rapid response system:making task force,Mobile team
IEC/BCC- community participation in vector control
Coordinating scientific research and development:making the record
of new symptoms, vaccines, treatments identified , complications
Guiding Principle, Protocols, epidemiology findings so that it can be
dessiminated to others and referred in future

22. ●Surveillance at national, regional, global level
○Epidemiological,
○laboratory
○ecological
○anthropological
●Investigation and early control measures.
●Implement prevention measures
○behavioural, political, environmental
●Monitoring, evaluation

23. Ebola Virus disease
● WHO has declared EVD outbreak in west Africa as a public health
emergency on international concern on 8.8. 2014
● Ebola virus named after a river Congo where it was first detected in
1976
● Worlds most virulent disease
● Case fatality rate is up to 90%

24. ●Transmission : blood and body secretions of infected
animals ,ex.chimpanzees , Monkey, gorilla, fruit bats
●Human to human –
○direct through blood and body secretions of
infected person .
○Indiect – contact with environment of patient
○Incubation period-2-21 days

26. ▪ Distribution :1711 cases and 932 deaths reported from Liberia, Nigeria, Siera
▪ Symptoms :fever, bodyache, headache, sorethroat, Vommitting, Impaired kidney and
liver function.
▪ DD: Malaria, Typhoid, leptospirosis, Plague, hepatitis .
▪ Diagnosis: ELISA , RTPCR
▪ Management: No specific treatment , isolation and qurantine of the patient and suspect

28. Zika
●Agent – Zika virus
●Transmitted by Aedes mosquito
●In May 2015 – Brazil reported first case of zika.
● Spread to 84 countries
●Complications: microcephaly in newborn born to
Prgnant women with Zika.
●Symptoms: fever, skin rash, Muscle
pain,conjectivities for 2-7 days

30. ● Treatment : No specific treatment and vaccine available.
Symptomatic treatment is given.
●Prevention by vector control , prevention of breeding , and bites.

31. NIPAH Virus
●First reported in 1998 in Nipah village of Malaysia.
●2001- Bangladesh
●2007- West Bengal , India
●2018- kerala , India
●Outbreak of Nipah reported on May 2018 ,at kozhikode
and Malapuram district of Kerala.
●Highly virulent Paramyxovirus virus with CFR is 88%.

32. ●Incubation period -4 days to 2 weeks
●Transmission : direct contact with bats, animals, person.
○Patients secretions are main source ,drinking of raw
date palm sap
●Symptoms: fever, headache ,dizziness, vommitting ,
encephalitis.
●Diagnosis – ELISA and RTPCR
●Mortality – 40-75%
●Treatment; no specific treatment /vaccine .

33. ●Prevention :
○Avoid using raw date palms,
○Hand washing with soap and water
○Avoid eating half consumed fruit and wash fruits
before eating
○Contact tracing
○Monitoring and Quarantine .
○Containment of source of infection.

34. COVID -19 Pandemic
● Agent: SARS- CoV –2, newly emergent virus –
● Single stranded RNA with spikes on it
● 60-140nm in diameter
● Sensitive to UV rays , alcohol
● Based sanitizers

35. ● First case was detected in Dec 2019 in Wuhan , China
● First case in India reported on 30 Jan 20 ,in Kerala .
● WHO declared it as Public health emergency on 14th feb. 2020
● Lockdown was done from 23 march 2020 to june 2
● Pandemic is still on – first wave in india declinrd in dec
● Second wave started from feb 2021

36. Problem statement
● Globally, as of, 5 April 2021, there have been 131,020,967 confirmed cases of
COVID-19, including 2,850,521 deaths, reported to WHO.
● Cases in South-East Asia- 15,330,286 Confirmed cases
In India -COVID-19 INDIA as on : 12 April 2021,
(↑↓ Status change since yesterday)
Active (8.88%) 1201009 (92922)
Discharged (89.86%) 12156529 (75086)
Deaths (1.26%) 170179 (904)

38. Prevention

39. Thank You