Epidemiology of AIDS

1. EPIDEMIOLOGY OF AIDS
Acquired Immune DeficiencyAcquired Immune Deficiency
SyndromeSyndrome
By
Dr. Anusha Divvi
Post graduate student
Department of Public Health
Dentistry

2. CONTENTS
• History
• Problem statement
• AIDS in world
• AIDS in India
• Epidemiological features
• Clinical manifestations

3. • Diagnosis of AIDS
• Control of AIDS
• Summary
• Conclusion
• References

4. What is HIV?
• H  Human
• I  Immunodeficiency
• V  Virus
• It affects only humans and lives only in
humans
• Immunodeficiency refers to lack(deficiency)
or breakdown of immune system

5. What is AIDS?
• AIDS Acquired Immunodeficiency
Syndrome
• To acquire -- to develop over a period of time
• Immune system gets deficient
• Syndrome - group of signs and symptoms
that collectively indicate a disease

6. Where it came from??
• In 1999 - SIV (Simian Immunodeficiency
virus) - chimpanzee - almost identical to HIV
• Chimpanzees were the source of HIV-1 -
virus - from chimps to humans
• More research - how SIV could have
developed in the chimps

7. • Chimps had hunted and eaten 2 smaller species of
monkeys and became infected with 2 different strains
of SIV.
Greater spot-
nosed monkey Red-capped
mangabeys Chimp hunting

8. HOW DID VIRUS CROSS FROM CHIMPS TO
HUMANS?
• Simple and plausible theory - “Hunter Theory”
or “Bush Meat Theory”
• Blood of chimps getting into cuts or wounds on
the human hunter

9. DID HIV START IN AFRICA?
• Researchers concluded that the first
transmission of SIV to HIV in humans took
place around 1920 in Kinshasa in the
Democratic Republic of Congo, Central Africa.

10. How the virus came out of Kinshasa???
SEX TRADE
MIGRANTS

11. TIME - TRAVEL
• First reported case (1981)
• 1982 CDC coined “acquired
immunodeficiency syndrome” (AIDS)
• First isolation of LAV (1983)
– Luc Montagnier and colleagues -
African patient – lymphadenopathy
– LAV

12. • First isolation of HTLV (1984)
– Robert Gallo and colleagues
• First cases of HIV - India - 1986 - sex workers -
Chennai
• May 1986 - HIV
• National AIDS committee - 1986
• First AIDS case - 1987 in Mumbai.
• March 19, 1987 - Zidovudine - Food and Drug
Administration (FDA)

13. • 1st December - World AIDS Day - 1988
• Red ribbon - International symbol of AIDS
awareness – 1991
• NACO and NACP - 1992
• Triple-drug therapy - 1996 - world AIDS
conference in Vancouver
• David Ho - 1997 - a new treatment strategy
“Hit early, hit hard”

14. PROBLEM STATEMENT
• Global statistics (2015)
– 36.7 million [34.0 million–39.8 million]
people globally were living with HIV
– 2.1 million [1.8 million–2.4 million] people
became newly infected with HIV
– 1.1 million people died from AIDS-related
illnesses
– (http://www.unaids.org)

15. • 17 million people were accessing
antiretroviral therapy
• 78 million people have become infected with
HIV since the start of the epidemic
• 35 million people have died from AIDS-
related illnesses since the start of the epidemic

16. Indian statistics 2015
Estimated No. of people with
HIV
21,16,581
Adults 19,78,125
Children (<15) 1,38,456
Male 12,60,094
Female 8,56,487
Estimated AIDS prevalence
Total 0.26
Male 0.30
Female 0.22

17. Estimated No. of annual new
HIV infections
Total 86,309
Adults 75,948
Children (<15) 10,361
Estimated No. of AIDS related
deaths
Total 67,612
Adults 60,086
Children (<15) 7,526

18. Estimated ART need
Adults 12,70,678
Children (<15) 74,220
Estimated No. of mothers
needing PPTCT
Mothers needing PPTCT 35,255

19. OVERVIEW OF HIV IN INDIA
Prevalence of HIV in different states
• Manipur – 1.15%
• Mizoram – 0.80%
• Nagaland – 0.78%
• Andhra Pradesh – 0.66%
• Karnataka – 0.53%
• Tamilnadu – 0.28%

20. HIV EPIDEMICS
Who and UNAIDS defined 3 types of HIV
epidemics
• Low level HIV epidemics
• Concentrated HIV epidemics
• Generalized HIV epidemics

21. • Low level – prevalence has not consistently
exceeded 5% in any defined sub-population
• Concentrated – prevalence is consistently over
5% in at least one defined sub-population but is
below 1% in pregnant women
• Generalized – prevalence consistently over 1%
in pregnant women

22. EPIDEMIOLOGICAL FEATURES
1. AGENT
• Group: Lentivirus
• Subgroup: Retrovirus
• CD4+ T lymphocytes
• Macrophages and monocytes
• Slow infection with prolonged incubation
period.

23. Structure of the virus
• 120nm in diameter
• Envelope gp160; gp120 & gp41
• Icosahedral symmetry
• Nucelocapsid
• Outer matrix protein (p17)
• Major capsid protein (p24)
• Nuclear protein (p7)
• RNA with reverse transcriptase

24. RETRO VIRAL GENES
• gag (group-specific antigen): makes the
cone shape viral capsid
• pol (polymerase): codes for viral enzymes
reverse transcriptase, integrase, and viral
protease
• env (envelope): makes surface protein
gp120 and trans membrane gp41, enabling
HIV to fuse to CD4 cells.

25. RETRO VIRAL GENES
• Tat
The Trans
activator gene influences the function of
genes some distance away.
• Rav
The differential regulator of expression of

26. RETRO VIRAL GENES
• vif
• The virus infectivity factor gene required
for infectivity
• nef
• The negative regulator factor retards HIV
replication
• vpr
virus protein R - undetermined function

27. GENES IN HIV 1 AND HIV 2
• vpu
• Virus protein U gene is required for efficient
viral replication
• Found only in HIV-1
• vpx
• The virus protein X gene has an
undetermined function.
• It is found only in HIV-2

28. HIV REPLICATION
– Attachment
– Penetration
– Uncoating
– Reverse Transcription
– Integration
– Replication
– Assembly
– Release

30. Reservoir of infection
• Cases and carriers.
• Once infected, the virus remains
in life-long
• Risk of developing AIDS
increases with time
• Symptomless carrier can infect
other people for years

31. SOURCE OF INFECTION
High concentration
• Blood
• Semen/Vaginal fluids
(as high as blood)
• Pus from sores
• CSF
Low concentration
• Sweat
• Tears
• Urine
• Saliva
• Breast milk

32. 2. HOST FACTORS
• Age: 20-49 years
• High risk groups: Male homosexuals, bisexuals,
intravenous drug abusers, transfusion
recipients of blood and blood products,
hemophiliacs

33. IMMUNOLOGY
• HIV selectively infects T-helper cells
• Healthy individual - twice as many helper
cells as suppressor cells
• It is reversed in AIDS
• striking feature - total lymphocyte count -
below 500 cu.mm.
• More prone for opportunistic infection,
neoplasm

34. MODE OF TRANSMISSION
• Sexual transmission
• Blood contact
• Maternal – foetal transmission

35. • Unprotected sex with multiple partners
• Sharing needles
• Pregnancy
• Breast feeding
• Blood transfusion
• Wound contacts
• Occupational exposure

36. INCUBATION PERIOD
• Current data suggest that the incubation period
is uncertain
• From a few months to 10 years or more
• Virus can lie silent in the body for many years
• Among the people infected with HIV- possibly
10-30 % - develop AIDS

37. • Another 25-30 % - AIDS-related complex.
• 75 per cent of those infected with HIV will
develop AIDS by the end of ten years

38. CLINICAL MANIFESTATIONS
1. Initial infection with the virus and
development of antibodies
2. Asymptomatic carrier state
3. AIDS – related complex
4. AIDS

39. INITIAL INFECTION
• Most HIV - infected people have no symptoms
for the first five years
• Look healthy and feel well
• Can transmit the virus to others.
• Once infected, people are infected for life
• HIV antibodies – 2 to 12 weeks – blood
stream

40. • Window period
• Period before the antibodies are produced
• Although the person is infectious he will test
negative on standard antibody blood test

41. ASYMPTOMATIC CARRIER STATE
• Infected people have antibodies
• No overt signs of disease
• Persistent generalized lymphadenopathy

42. AIDS RELATED COMPLEX
• Unexplained diarrhoea
• Fatigue
• Malaise
• Loss of more than 10% body weight
• Fever
• Night sweats and generalized
lymphadenopathy
• No opportunistic infections or cancers

43. AIDS
• End stage of HIV infection
• Tuberculosis and Kaposi sarcoma – seen early
• When T helper cells dropped to 100:
– Candida oesophagitis, Cryptococcus meningitis and
penicillosis
– Parasitic infections such as Pneumocystis carini
pneumonia or Toxoplasma gondii encephalitis
• AIDS encephalopathy dementia

45. ORAL MANIFESTATIONS OF AIDS
Hairy leukoplakia Kaposi sarcoma
Herpes
simplex

47. QUESTIONS
• Target cells of HIV _________
• World’s AIDS day __________
• 3rd
clinical stage of HIV infection ______
• The genetic material of HIV _________
• GP 41 is ___________

48. THANKYOU

49. EPIDEMIOLOGY OF AIDS
Acquired Immune DeficiencyAcquired Immune Deficiency
SyndromeSyndrome
By
Dr. Anusha Divvi
Post graduate student
Department of Public Health
Dentistry

50. • Diagnosis of AIDS
• Control of AIDS
• Summary
• Conclusion
• References

51. DIAGNOSIS
A. Clinical diagnosis
B. Laboratory diagnosis

52. CLINICAL
1. WHO case definition for AIDS surveillance
• At least 2 major signs in combination with at
least 1 of the minor signs
• Not due to a condition unrelated to HIV
infection

53. • Major signs
– Weight loss > 10% of body weight
– Chronic diarrhoea
– Prolonged fever
• Minor signs
• Persistent cough
• Oropharyngeal candidiasis
• Generalized lymphadenopathy

54. • History of herpes zoster
• Generalized pruritic dermatitis
• Chronic progressive herpes simplex infection
HSV 1

55. CHILDREN
• At least 2 major signs and 2 minor signs are
present

57. Expanded WHO case definition for AIDS
surveillance
• For the purposes of AIDS surveillance
• If a test for HIV antibody gives a positive
result, and one or more of the following
conditions are present :

58. • > 10% body weight loss with diarrhoea or
fever or both
• Cryptococcal meningitis
• Pulmonary or extra-pulmonary tuberculosis
• Kaposi sarcoma
• Neurological impairment
• Candidiasis of oesphagus
• Invasive cervical cancer

59. CLINICAL STAGING
• WHO has developed a clinical staging system,
based on clinical criteria
• Clinical stage is important as a criterion for
starting antiretroviral therapy

60. • Clinical stage 1
– Asymptomatic
– Persistent generalized lymphadenopathy

61. • CLINICAL STAGE 2
• Moderate unexplained weight loss
• Recurrent respiratory tract infections
• Herpes zoster
• Angular cheilitis
• Recurrent oral ulcerations
• Papular pruritic eruptions
• Seborrhoeic dermatitis
• Fungal nail infections

62. • Clinical stage 3
• Unexplained severe weight loss
• Unexplained chronic diarrhoea for longer
than one month
• Unexplained persistent fever
• Persistent oral candidiasis
• Oral hairy leukoplakia
• Pulmonary tuberculosis
• Severe bacterial infections

63. Clinical stage 4
• HIV wasting syndrome
• Severe bacterial pneumonia
• Chronic herpes simplex infection
• Extra pulmonary tuberculosis
• Kaposi sarcoma
• HIV encephalopathy
• Invasive cervical carcinoma

64. Laboratory diagnosis of AIDS
• Immunological tests
• Specific tests
– Antigen detection
– Virus isolation
– Polymerase chain reaction
– Antibody detection

65. Immunological tests
• Lymphocyte count falls below 2000/cu mm
• T helper cell count will be less than 200/cu mm
• T4 : T8 cell ratio is reversed
• Thrombocytopenia
• Raised IgG levels

66. SPECIFIC TESTS
• Antigen detection
• Antibody detection
• Virus isolation

67. • P24 detection – ELISA
• Virus isolation – cultivation of patients
lymphocytes on uninfected lymphocytes
• Polymerase chain reaction:
– Gold standard for diagnosis
– Amplification of DNA segments for the detection of
pathogenic virus
• Antibody detection
– ELISA – screening
– Western blot - confirmatory

68. • To ensure accuracy two different tests
• First a sensitive test is used to detect the HIV-
antibodies
• second confirmatory test - any false positive
results.

69. • The screening test is normally the ELISA
•

70. • The confirmatory test is Western Blot -
detecting specific antibody to viral core protein
(p24) and envelop glycoprotein (gp41)

71. CONTROL OF HIV/AIDS
• There are four basic approaches to the control
of AIDS :
1. Prevention
2. Antiretroviral treatment
3. Specific prophylaxis
4. Primary health care

72. PREVENTION :
a)Education
b) Prevention of blood-borne HIV transmission

73. II. ANTIRETROVIRAL TREATMENT:
 Advent of potent antiretroviral therapy -
1996 - revolution in the care of patients.
 Treatments are not for cure
 Meant for reduction of morbidity and
mortality

74. DRUGS USED FOR ART
• Nucleoside reverse transcriptase
inhibitors
–Lamivudine
–Stavudine
–Zidovudine
• Fusion inhibitors
–Enfuvirtide

75. • Nucleotide reverse transcriptase inhibitors
• Tenofovir
• Non nucleoside reverse transcriptase inhibitors
• Efavirenz
• Etravirine
• Nevirapine

76. • Protease inhibitors
• Saquinavir
• Ritonavir
• Indinavir
• Integrase strand transfer inhibitors
• Raltegravir

78. HAART(Highly active antiretroviral therapy)
• Synergistic combinations of NRTIs and
Protease inhibitors
• Popular HAART combinations
• NRTIs(2)+PI(1)
• NRTI(1)+NNRTI(1)+PI(1)
• NRTI(1)+NNRTI(1)+PI(2)

79. III. SPECIFIC PROPHYLAXIS:
• Prophylaxis against M. tuberculosis is 300
mg Isoniazid daily for 9 months to 1 year
• Kaposi's sarcoma might be treated with
interferon or chemotherapy
•Antifungal drugs for candidiasis

80. IV. PRIMARY HEALTH CARE
Focus on five strategic directions:
1. Increasing knowledge of HIV serostatus
2. Accelerating HIV prevention
3. Accelerating the scale-up of HIV treatment
and care
4. Health systems strengthening

81. National AIDS control program
• It was launched in India in the year 1987.
• To implement and closely monitor the various
components of the programme
• Aim - to prevent further transmission of HIV to
decrease morbidity and mortality

82. • The Govt. of India initiated programmes of
prevention and raising awareness under:
»NACP-I (1992-99)
»NACP-II (1999-2006)
»NACP- III( 2006-2011)

83. • India has now developed the fourth National
Programme Implementation Plan (NACP-IV,
2012-2017).
• To halt and reverse - over the next 5 years by
integrating programmes for prevention, care,
support and treatment.

84. The services are :
1. Prevention services
2. Care support and treatment services

85. Preventive services
• Needle syringe exchange program
• Prevention and control of sexually transmitted
diseases
• Blood safety
• HIV counselling and testing services
• Prevention of parent to child transmission
• Condom promotion

86. Care support and treatment services
• Laboratory services for CD4 testing and other
investigations
• Free antiretroviral therapy
• Early infant diagnosis for HIV exposed infants
and children below 18 months
• HIV- TB coordination
• Treatment of opportunistic infections

87. Guidelines on HIV and infant feeding
• Till 2009, WHO advised HIV – positive
mothers to avoid breast feeding if they were
able to afford and store formula milk safely
• On 30th
November 2009, WHO released new
recommendations on infant feeding by HIV
positive mothers

88. • HIV positive mothers or their infants take
antiretroviral drugs throughout the period of
breast feeding and until the infant is 12 months
old
• Child can benefit from breast feeding with very
little risk of becoming infected with HIV

89. Nutrition requirements for people living with
HIV/AIDS
• Energy requirements – increase by 10% -
asymptomatic HIV infected adults and children
• 20 -30 % - symptomatic HIV and AIDS
• HIV infected 6-59 month old children –
Vitamin A supplements – 1 lakh IU – every 4-6
months

90. HIV SURVEILLANCE :
• To detect the spread of the disease
• To make appropriate strategy for prevention
and control
• Types of surveillance :
• HIV sero surveillance
• HIV sentinel surveillance
• AIDS case surveillance
• STD surveillance

91. Counselling and HIV testing services
1. Integrated counselling and testing
centres(ICTC)
2.Prevention of parents to child transmission
of HIV ( PPTCT)
3. HIV/ tuberculosis collaborative activities.

92. I. Integrated counselling and testing
centres(ICTC):
A) Fixed facility ICTCs:
i.Standalone ICTC( SA-ICTC)
ii.Facility integrated counselling and
testing centres( F-ICTC)
B) Mobile ICTC:

93. 2. Prevention of parents to child transmission of
HIV ( PPTCT)
 Started in 2002
Now 15000 ICTCs offer PPTCT services to
pregnant women
Single dose of Nevirapine to multi-drug ARV
prophylaxis from 2012

94. • Andhra Pradesh, Karnataka and Tamil Nadu.
• From May 2013 national wide implementation
has done

95. 3. HIV/ tuberculosis collaborative activities
The risk of TB infection in HIV positive persons
increases manifolds.
NACO - with RNTCP - promoting cross referrals
for early diagnosis and treatment of
tuberculosis

96. NATIONAL AIDS TELEPHONE HELPLINE :
• A toll free national AIDS telephone helpline has
been set up to provide access to information
and counselling, on HIV/AIDS related issues.
• This is a computerized 4 digit number 1097,
with a voice response system linked with a
telephone helpline

97. HIV VACCINE
• Developing a safe, effective and affordable
vaccine to prevent HIV infection is the best
hope for controlling HIV epidemic
• In 2015 NIAID and collaborators launched
HVTN 100, an early stage clinical trial in South
Africa
• Designed to determine whether the regimen is
safe, tolerable and effective

98. • Further information about HIV vaccine will be
announced in November 2016

99. CONCLUSION
• AIDS has rapidly established itself throughout
the world.
• Still a major health problem and lot needs to be
done to ensure the sustainability of these
programs
• Evolve mechanisms to ensure that HIV care is
provided along with general health care.

100. REFERENCES
1. Park.K. A textbook of Preventive and Social
Medicine.23rd
edition. Jabalpur. M/s
Banarsidas Bhanot Publishers:2014
2. Current Medical Diagnosis and Treatment
edited by Lawrence M. Tierncy, Jr Siephen J.
McPhee and Maxine A. Papadakis,
43rdEd.2004

101. 3. WHO 2004: Scaling up antiretroviral therapy
in resource-limited settings: treatment
guidelines for a public health approach; 27-47
4. WHO. 2008. Operations Manual for Delivery of
HIV Prevention, Care and Treatment at
Primary Health Centres in High-Prevalence
5. WHO Technical Consultation on Nutrient
Requirements for People Living with
HIV/AIDS (2003 : Geneva, Switzerland)

102. 6. Nutrient requirements for people living with
HIV/AIDS: report of a technical consultation,
World Health Organization, Geneva, 13-15
May 2003.
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energy balance in stable human
immunodeficiency virus- infected patients: a
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Laboratory and Clinical Medicine, 2001,
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103. 8.Govt. of India (2011), Strategy and
Implementation Plan. National AIDS
Control Programme Phase IV (2012-2017),
NACO. Ministry of Health and Family
Welfare, New Delhi.
9. http://www.unaids.org
10. http://www.naco.gov.in
11. http://www.who.int