2. MODULE OUTCOMES
• This module is designed to enable the learner develop
self awareness in prevention and risk assessment of
HIV/AIDS to effectively contribute to the national HIV
3. Module Units
• Fundamentals of HIV and AIDS
• Prevention of HIV infection and post exposure prophylaxis
• Behavior change communication and attitude training
• Opportunistic infections
• HIV treatment and monitoring
• Nutrition in the context of HIV & AIDS
• HIV testing and counseling (HTC)
By the end of the module, the learner should;
Apply the knowledge of epidemiology of HIV in preventing
Identify risks associated with exposure to HIV & AIDS
Demonstrate a positive attitude towards HIV & AIDS
Provide health education to PLWHA on prevention of
Monitor patients for ARV drug interactions
Provide nutritional education to clients/ patients suffering
from HIV & AIDS
Provide HIV& AIDS counseling to clients and patients
5. FUNDAMENTALS OF HIV &AIDS
By the end of the lesson, the learner should be able to;
Define common terms
Explain the historical background of HIV/AIDS
describe the global, regional, national and local epidemiology
and distribution of HIV
State the modes of transmission and the key risk factors
Explain the impact of HIV/AIDS on
individual,community,nationally and globally
Describe the HIV/AIDS infection and disease progression
State the WHO classification system of HIV/AIDS
6. Acronyms and Abbreviations
ADR Adverse drug reaction
AIDS Acquired immunodeficiency syndrome
ANC Antenatal care A&E
ART Antiretroviral therapy ARV Antiretroviral drug(s)
BMI Body Mass Index
BP Blood Pressure
CCC Comprehensive Care Centre
CHV Community Health Volunteer
7. Acronyms and Abbreviations
DNA Deoxyribonucleic acid
DRT Drug Resistance Testing
ECP Emergency contraceptive pill
EID Early Infant Diagnosis
eMTCT Elimination of Mother to Child Transmission
EPTB Extra-pulmonary Tuberculosis
FBC Full Blood Count
FBS Fasting Blood Sugar
FP Family Planning
GIT Gastro-intestinal tract
GOK Government of Kenya
GBV Gender-Based Violence
8. Acronyms and Abbreviations
HCW Health Care Worker
HEI HIV Exposed Infant
HIV Human immunodeficiency virus
HIVST HIV self-testing
HTS HIV Testing Services
INH Isoniazid INSTI
IPT Isoniazid Preventive Therapy
KS Kaposi’s sarcoma
MOH Ministry of Health
MSM Men who have sex with men
MUAC Mid-upper arm circumference
NASCOP National AIDS and STI Control Program
9. Acronyms and Abbreviations
OI Opportunistic infection
PCP Pneumocystis jirovecii pneumonia
PCR Polymerase chain reaction
PEP Post-exposure prophylaxis
PITC Provider initiated HIV testing and counselling
PLHIV People living with HIV
PMTCT Prevention of mother-to-child transmission
PrEP Pre-exposure prophylaxis
PTB Pulmonary tuberculosis
PWID People who inject drugs
STI Sexually transmitted infection
VL Viral Load
• HIV stands for Human Immunodeficiency Virus, the virus
that causes AIDS.
AIDS stands for acquired immunodeficiency syndrome
and refers to the most advanced stage of HIV infection.
A: Acquired — (not inherited) to differentiate from a
genetic or inherited condition
I: Immuno — refers to the immune system
D: Deficiency — inability to protect against illness
S: Syndrome — a group of symptoms or illnesses that
occur as a result of the HIV infection
12. HIV & AIDS :HISTORICAL BAGROUND
• Doctors in US recognized Pneumocytstis carinii
Pneumonia(PCP in homosexual males, a condition previously
unreported in healthy adults
• Later recognized that all these patients were
• Scientist described the cause of this acquired
immunodeficiency syndrome (AIDS) as a retrovirus
• Lymphadenopathy Associated Virus (LAV)
• AIDs Associated Retrovirus (ARV)
• Human T- lymphotrophic Virus (HTLV)
• First case described In Kenya
• Human Immunodeficiency Virus (HIV) accepted as
international designation for the retrovirus in a WHO
• 1996……ARVs available in the world
• 1997……ARVs available in Kenya private sector
• 2003…..ARVs available in Kenya public sector
• 2005…..54,000 patients on ART
• 2010……Approx.426,870 patients on ART
15. EPIDEMIOLOGY OF HIV
HIV infection/AIDS is a global pandemic, especially in
developing countries. The current estimate of the number of
cases of HIV infection worldwide is ~33.2 million, two-thirds
of whom are in sub-Saharan Africa; ~50% of cases are in
women. HIV has continued to be a public health threat
In Kenya, over 1.5 million people are estimated to be living
with HIV, of whom 1,136,000 were on antiretroviral therapy by
A pandemic is a global disease outbreak. HIV/AIDS is an
example of one of the most destructive global pandemics in
• HIV/AIDS is caused by infection by the human retroviruses
HIV-1 or -2.
• HIV-1 is the most common cause worldwide; HIV-2 has about
40% sequence homology
18. HIV VIRUS
virus is a small infectious agent that replicates only inside
the living cells of other organisms.
HIV belongs to a group known as retroviruses which carry
their genetic material in the form of ribonucleic acid(RNA).
A retrovirus from the Lentivirus family.
Viral particle is spherical in shape with a diameter of 80-
100 nanometers (nm).
19. HIV Structure
Has an outer double lipid membrane, (derived from the
The lipid membrane is lined by a matrix protein.
The lipid membrane is studded with the surface
glycoprotein (gp) 120 and the transmembrane gp 41
These glycoprotein spikes surround the cone-shaped
• The gp120 and gp41 mediate the entry of virus into the
The core (capsid) is made up of several proteins:-
P24 the main protein
Within the capsid are
two identical single strands of RNA (the viral genetic material).
• Most important: Reverse Transcriptase (RT), Protease
• RT converts viral single-stranded RNA into a double
stranded deoxyribonucleic acid (DNA).
• DNA is incorporated into host nucleus as the proviral
• Integrase facilitates integration of the DNA into the host’s
• Protease enzyme splits generated macro-proteins into
smaller viral proteins (core, envelope & regulatory
proteins and enzymes) which go into forming new viral
23. TYPES OF HIV
There are two types of HIV.
• HIV – 1
• Is found worldwide
• Is the main cause of the worldwide pandemic
• HIV – 2
• Is mainly found in West Africa, Mozambique and
• Causes a similar illness to HIV – 1
• Less efficiently transmissible rarely causing vertical
• Less aggressive with slower disease progression
24. HIV subtypes
• HIV-1 has many subtypes: A-K
• A-E are the predominant subtypes
• A: W. Africa, E. Africa, Central Africa East Europe
& Middle East
• B: N. America, Europe, Middle East, E. Asia, Latin
• C: S. Africa, S. Asia, Ethiopia
• D: E. Africa
• E: S. E. Asia
26. Modes of HIV transmission
• HIV can be transmitted in the body through these fluids
which contains free virions and infected CD4 T cells:
• Vaginal fluids
• Breast milk
• Amniotic fluids.
• Inflammation and breaks in the skin or mucosa results in
the increased probability that the HIV exposure will lead to
• Unprotected sexual intercourse with infected person.
• Direct contact with body fluids of infected person. (blood,
semen, vaginal secretions)
• Note: Sexual transmission accounts for 87% of HIV
Mother to Child transmission
• During pregnancy
• During labour and delivery(most mother to child transmission
occurs at this stage).
• During breast feeding.
Blood transfusion of infected blood or blood
Exposure to infected blood or body fluids- IDU
through needle-sharing or needle stick
29. % infection by transmission route
route transmission %
Sexual intercourse 70-80
Blood transfusion 3-5
Injecting drug use 5-10
Health care – eg needle stick injury <0.01
30. Risk factors
Unprotected sex – vaginal and anal sex.
Multiple sex partners.
STI infected people especially STIs that cause ulcerations like
herpes, chancroid and syphillis.
Use of intravenous drugs, Sharing needles.
Children born to HIV positive mothers.
Alcohol and drug addiction.
Occupational exposure; where precautions are neglected or fail
eg. Not using gloves or accidental needle prick injuries.
Blood transfusions especially where blood is not adequately
31. NOT Transmitted through:
• Sharing food or a drinking cup.
• Shaking hands
• Coughing or sneezing
• Being near a PLWHA
• Sharing latrines
• Mosquitoes or insect bites even if they carry human blood. HIV
cannot live outside humans.
32. MostAt Risk Populations for HIV infection.
• Injection drug users
• Sex workers and their clients.
• Men who have sex with men
• Female sex workers
These groups are more vulnerable to HIV infection due a variety of
factors such as:
- More frequent exposures to the virus.
- Involvement in risky behavior.
- Potentially weak family and social support systems,
- Lack of resources
- Inadequate access to health care services,
- Stigma and Criminalization.
34. Impact on Morbidity and mortality of other
People with HIV/AIDS are susceptible to other
Due to lowered immunity
High HIV prevalence increases the pool of people
with suppressed immunity
Any other infectious condition within such
population (e.g.TB) therefore finds a highly
susceptible group of people.
35. Impact on food security
Food consumption decrease after the death of an adult in
the poorest households
Reduction in agricultural work or even abandonment of
farms is likely.
With fewer people, households farm smaller plots of land
or resort to less labor-intensive subsistence crops, which
often have lower nutritional or market value.
36. Impact on the health sector
Stretched health budgets and systems.
demand for out-patient services/ hospitalization
Increased patient load and the staff shortages/staff
More time and money spent on diagnosing and
Demand for specialized services such as counselling also
37. Impact on the education sector
Decline in school enrolment
Removal of children from school to care for parents and
Inability to afford school fees and other expenses
AIDS-related infertility and a decline in birth rate
Infection of more children who do not survive through the
years of schooling
38. HIV infection and disease progression
HIV is an infectious disease therefore, its important to
understand how it integrates itself into persons immune system
and how the immune response plays a role .
The immune system functions as the body’s defense
mechanism against invasion.
Immunity: refers to the body’s speciﬁc protective response to
an invading foreign agent or organism.
Immune function is affected by age and by a variety of other
factors, such as central nervous system function, emotional
status, medications, the stress of illness, trauma, and surgery.
Normal immune system Consists of two arms;
• Innate (ancient) immune system
• Adaptive (acquired) immune system
• Innate immunity –
• It is non-specific and includes natural killer cell
lymphocytes that kill the target cells directly or indirectly
by antibody-dependent cellular cytotoxicity (ADCC), and
dendritic cells that localize and present antigens to
responsive T and B cells.
• Other participating cells are, monocytes, macrophages,
neutrophils, basophils, eosinophils, tissue mast cells and
• Adaptive immune system – Is characterized by antigen-
specific responses to a foreign antigen.
• It consists of cellular and humoral immunity.
• T cells are the main mediators of cellular immunity.
• The CD8 cytotoxic T cells target the virus-infected cells or
foreign cells while the CD4 T cells are the primary
regulatory cells of both cellular and humoral specific
• The CD4 T cells activity can be either by direct cell
contact or indirectly by release of regulatory chemical
messengers called cytokines.
• The latter then activates the CD8 T cells, antibody-
producing B cells or monocytes and macrophages.
• The B cells are the principal effectors of humoral immunity
and leads to specific antibody production once activated.
Together, the innate and the adaptive immunity protect the
host from infections by multiple organisms.
HIV attaches to cells of the immune systems with
specials surface markers called CD4 receptors
The following immune cells have CD4 receptors
T-Lymphocytes – CD4 Cells
• Many are genetically based, others are acquired.
Disorders of the immune system may stem from excesses
or deﬁciencies of immunocompetent cells, alterations in
the function of these cells, immunologic attack on self-
antigens, or inappropriate or exaggerated responses to
When an infectious agents enters the body by tackling the
skin and the mucous membrane barries, then its tackled
by cellular elements and tissue macrophages which
activates specific immune response (antibodies,sensitised
T cells, memory cells )
• When the virus enters the body and gets into the blood
stream, it binds itself to specific defence cells known as
CD4 lymphocytes. When the retrovirus enters the CD4
cell, an enzyme from the virus called reverse
transcriptase takes over the cells genetic equipment to
produce more retroviruses which are released outside
the infected cell and go on to infect and destroy other
• This process goes on over a period of years during which
the number of CD4 lymphocytes gradually decreases.
• although the body of an infected person struggles to
form antibodies against the HIV, these antibodies
cannot destroy all the viruses because they keep on
multiplying and the body's defense system is being
depleted and is, therefore, unable to produce enough
antibodies to match the viruses.
47. CD4 CELLS
CD4 cells are the immune cells that protect the body from
They prevent infections and keeps the body healthy
CD4 cells are measured through a blood test, called CD4
count. For adults a normal CD4 count is above 500
How are CD4 cells affected by HIV –
HIV attacks and destroys CD4 cells - After years of
constant attack from HIV, the CD4 count falls (usually
below 200), diseases called “opportunistic infections” are
able to infect the body because the body cannot defend
• Common opportunistic infections include: tuberculosis,
pneumonia, skin problems, and chronic diarrhea
• Once treatment for HIV started, VL test to monitor
response to anti-retroviral treatment done.
49. HIV life cycle
• All virus target specific cells.
• HIV targets cells with CD4+ receptors which are
expressed on the surface of T lymphocytes ,monocytes,
dendrites cells and brain microglia.
• During acute/recent infection, the virus use chemokine
receptors for entry to T cells.
Gp 120 and Gp 41(glycoproteins of HIV) bind with the
hosts uninfected CD4+ receptors and chemokine
coreceptors which results in fusion.
50. Life cycle Cont.…..
• The content of viral core(2 single strands of viral RNA and
3 viral enzymes, reverse transcriptase,integrase and
protease) are emptied into the CD4+ T cell.
HIV changes its genetic material from RNA to DNA through
action of reverse transcriptase resulting to double stranded
DNA that carries instruction for viral replication.
51. Life Cycle cont…..
• New viral DNA enters the nucleus of the CD4+ T cells and
through the action of intergrase is blended with the DNA
of the CD4+ T cell, resulting in permanent lifelong
• Prior to this, the uninfected person has only been
exposed to and not infected.
• When the CD4+ T cells is activated, the double stranded
DNA forms a single stranded messenger RNA(mRNA)
which binds new viruses
• The mRNA creates chains of new proteins and
enzymes(polyproteins) that contain the components
needed in the construction of new viruses.
• The HIV enzyme protease cuts the polyprotein chain into
the individual proteins that make up the new virus
• New protein and viral RNA migrate to the membrane of
the infected CD4+ T cell exit from the cell and start the
process all over.
• The CD4 cells are often destroyed by HIV virus infection
and replication resulting in profound immunodeficiency.
55. Host immune response during HIV
Primary HIV Infection
The period from infection with HIV to the development of
antibodies . During this period, there is intense viral
replication and widespread dissemination of HIV
throughout the body. Symptoms associated with the
viremia range from none to severe ﬂu-like symptoms.
During the primary infection period, the window period
occurs because a person is infected with HIV but tests
negative on the HIV antibody blood test.
56. Asymptomatic Phase
Can last from 2 to 15 years – range mainly due to genetic
differences in patient
Virus replicates in lymphoid tissue, CD4 cells at high rates
CD4 levels gradually decline
Immunity gradually weakens
Patients remain asymptomatic
Patients are infectious
57. Symptomatic Phase (progression to
Approximately 10 to 12 years after infection
Increased demands on immune system
Production of CD4 cells cannot match destruction,
immune system fails
Viral load reaches extremely high levels
Increased risk of opportunistic infections and tumours
Progression to AIDS
58. Classification system of HIV
For Adults and Adolescents
Persistent Generalized Lymphadenopathy (PGL)
59. Stage 2
Moderate unexplained weight loss (< 10% of presumed
or measured body weight)
Minor mucocutaneous manifestations (seborrheic
dermatitis, papular pruritic eruptions, fungal nail
infections, recurrent oral ulcerations, angular cheilitis) •
Recurrent upper respiratory tract infections (sinusitis,
tonsillitis, bronchitis, otitis media, pharyngitis)
60. Stage 3
Unexplained severe weight loss (over 10% of presumed
or measured body weight)
Unexplained chronic diarrhoea for longer than one month
Unexplained persistent fever (intermittent or constant for
longer than one month)
Persistent oral candidiasis
Oral hairy leukoplakia
Severe bacterial infections (e.g. pneumonia, empyema,
pyomyositis, bone or joint infection, meningitis,
Acute necrotizing ulcerative stomatitis, gingivitis or
Unexplained anaemia (below 8 g/dl ), neutropenia (below
0.5 x 109/l) and/or chronic thrombocytopenia (below 50 x
62. Stage 4
HIV wasting syndrome
Pneumocystis jirovecipneumonia (PCP)
Recurrent severe bacterial pneumonia (≥ 2 episodes
within 1 year) Cryptococcal meningitis
Toxoplasmosis of the brain
genital or ano-rectal herpes simplex infection for > 1
Kaposi’s sarcoma (KS)
Extra pulmonary tuberculosis (EPTB) Conditions where
confirmatory diagnostic testing is necessary
Cryptosporidiosis, with diarrhoea > 1 month
Cryptococcosis (extra pulmonary)
Disseminated non-tuberculous mycobacterial infection
Cytomegalovirus (CMV) retinitis or infection of the organs
(other than liver, spleen, or lymph nodes)
Progressive multifocal leucoencephalopathy (PML)
Any disseminated mycosis (e.g. histoplasmosis,
Candidiasis of the oesophagus or airways
Non-typhoid salmonella (NTS)
• Lymphoma cerebral or B cell Non-Hodgkin’s Lymphoma
• Invasive cervical cancer
• Visceral leishmaniasis
• Symptomatic HIV-associated nephropathy or HIV