There are nearly 100 viruses of the herpes group that infect many different animal species.
Official name of herpesviruses that commonly infect human is Humans herpesvirus (HHV)
herpes simplex virus types 1 (HHV 1)
Herpes simplex virus type 2 (HHV 2)
Varicella-zoster virus (HHV 3)
Epstein-Barr virus, (HHV 4)
Cytomegalovirus (HHV 5)
Human herpesvirus 6 (HHV 6)
Human herpesvirus 7 (HHV 7)
Human herpesvirus 8 (HHV 8) (Kaposi's sarcoma-associated herpesvirus).
Herpes B virus of monkeys can also infect humans
hELMINTHS#corona virus#Aspergillosis#BUGANDO#CUHAS#CUHAS#CUHAS
3. INTRODUCTION
AIDS means Acquired Immunodeficiency
Syndrome
HIV means Human immunodeffiency virus
HIV is the virus that causes immune
deficiency
AIDS is the progression of HIV infection due to
destruction of immune system leading to
occurrence of diseases.
4. HIV
HIV:Human Immunodeficiency Virus
HIV is the virus that can ultimately lead to
AIDS
HIV like other viruses needs to enter other
cells in order to replicate.
6. VIROLOGY & IMMUNOLOGY:
HIV is a single stranded RNA retrovirus from the
Lentivirus family.
It consists of a cylindrical center surrounded by a
sphere shaped lipid envelope. The center consists
of 1 single strand with two molecules of RNA.
The virus can use RNA & host’s DNA to make viral
DNA.
7.
8. VIRAL GENES:
NAME OF GENE FUNCTIONS
LTR The Long Terminal Repeats are used for integration of the
virus into the host genome and also contain promoter and
enhancer sequences.
gag The Group-specific Antigen corresponds to the core and
capsid proteins.
pol: This gene encodes the reverse transcriptase, which actually
has several functions
env: This Envelope gene encodes the gp120 glycoprotein.
tat/rev This region encodes factors involved in transactivation and
other regulatory functions.
9. RETROVIRAL STRUCTURAL GENES
gag = group specific antigen (internal structural proteins)
matrix (MA), binds envelope, organization
capsid (CA), protects genome and enzymes
nucleocapsid (NC) chaperones RNA, buds
pol = polymerase enzymes
reverse transcriptase + RNA to DNA
RNAase H (RT) degrades template RNA
protease (PR) maturation of precursors
integrase (IN) provirus integration
env = envelope proteins
surface glycoprotein (SU) receptor binding
transmembrane protein (TM) virus-cell fusion
10.
11. CLASSIFICATION:
Types
HIV-1
HIV-2
HIV-1
Groups Subtypes Recombinants
Major (M) A,B,C,D,E,F,G,H,I,J AG,AE,AB,CRFs
Outlier (O)
Novel (N)
HIV-2: 6 subtypes, A,B,C,D,E,F
Jawetz Melnick and Adelberg. Medical Microbiology AIDS and Lentiviruses Mc Graw-
Education chpt 44 fourth ed 2007
12. MAJOR STEPS IN HIV LIFECYCLE
1. The virus attaches itself
to CD4+ T lymphocytes
2. Fusion and release of
RNA into the cytoplasm
3. Reverse transcription to
produce pro-viral DNA
4. Integration of pro-viral
DNA within host DNA
and synthesis of viral
proteins
5. Viral assembly and
release of mature
particles
13. LIFE CYCLE AND DRUGS
Warren Levinston review of medical microbiology and immunology, pathogenesis
and immunology Mc Graw-Education ed 13 pg 825 2014
14. IMMUNE SYSTEM/BODY DEFENCE
Host defenses against viruses fall into two major
categories;
1.Nonspecific defenses;- interferons, natural killer
cells
2.Specifc defence ;-humoral, cell-mediated immunity
NONSPECIFIC DEFENSES
Alpha and beta interferons are a proteins produced
by human cells after viral infection (or after
exposure to other inducers
They block the synthesis of viral proteins.
15. MECHANISM OF ON HOW THEY ACT
One is a ribonuclease that degrades mRNA
The other is a protein kinase that inhibits protein
synthesis.
Interferons are divided into three groups based on the cell
of origin, namely, leukocyte, fibroblast, and lymphocyte,
They are also known as alpha, beta, and
gamma interferons, respectively
Alpha and beta interferons are induced by viruses
16. PATHOGENESIS OF HIV INFECTION
HIV infection leads to profound
pathology, either directly, through
destruction of CD4+ T cells, other
immune cells, and neuroglial cells, or
indirectly, through the secondary
effects of CD4+ T-cell dysfunction and
resultant immunosuppression.
Once HIV has killed so many CD4+ T
cells that there are fewer than 200 of
these cells per microliter (µL) of blood,
17. 1.HUMAN IMMUNODEFICIENCY
VIRUS -MEDIATED INHIBITION OF
HEMATOPOIESIS.-
-failure of normal hematopoiesis is
an obvious candidate mechanism to
account for depletion of CD4+T cells
during HIV infection
19. 3.INNOCENT BYSTANDERS.
Uninfected cells may die in an
innocent bystander scenario:
HIV particles may bind to the cell
surface, giving them the
appearance of an infected cell
and marking them for destruction
by killer T cells (cellular immune
response).
20. 4.SYNCYTIA FORMATION. Infected
cells also may fuse with nearby
uninfected cells through CD4-mediated
fusion, forming balloon
(multinucleared)-like giant cells called
syncytia.
This mechanism of cell-to-cell spread
of HIV has been associated with the
death of uninfected cells. The
presence of syncytia-inducing
variants of HIV has been correlated
with rapid disease progression in
HIV-infected individuals.
21. PATHOGENESIS CONT…..
5.APOPTOSIS and Pyoptosis. Infected
CD4+ T cells may be killed when cellular
regulation is distorted by HIV proteins,
probably leading to their suicide by a
process known as programmed cell
death or apoptosis mediated by
caspase3.
-Uninfected cells also may undergo
apoptosis.
-Investigators have shown in cell
cultures that the HIV envelope alone or
bound to antibodies sends an
inappropriate signal to CD8+ T cells
causing them to undergo apoptosis
even though not infected by HIV.
22. PYROPTOSIS
It has been known for some time now that apoptosis is a major
factor contributing to T-cell depletion, mediated by caspase-3, in
T-cells that are permissive to infection by HIV. However, there are
subsets of T-cells (abortive T-cells) that are non-permissive and
do not support HIV replication. In this subset of cells, cell death
occurs through a process called pyroptosis, driven by caspase-1
Pyroptosis is a highly inflammatory form of programmed cell
death in which the dying cell releases all its cytoplasmic contents,
including inflammatory cytokines; these cytokines in turn trigger
pyroptosis in other T-cells as part of a vicious cycle of abortive T-
cell depletion
23. 6.DIRECT CELL KILLING. Infected
CD4+ T cells may be killed directly
when large amounts of virus are
produced and bud off from the cell
surface, disrupting the cell
membrane, or
when viral proteins(gp120) and
nucleic acids collect inside the
cell, interfering with cellular
machinery → cell death.
24. Regulatory T-Cells (Treg)
Chronic immune Activation
immune Activation and inflammation
-Cytikine storm,il 2 inhibited hence no maturation of
t cells
25. RISK FACTORS FOR HIV IN THE
GENERAL POPULATION
TRANSMISSION
1.MEN WHO HAVE SEX WITH MEN Study
done in Dar es Salaam, Tanzania by Nyoni and Ross in 2013
found that condom usage was very low among the MSM,
another study in Zanzibar 85% of the respondents reported
inconsistent condom use(M. Dahoma, L. et al 2011.Prevalence
(22-42%) (Leshabari et al. A Prevalence of the Human Immunodeficiency
Virus, other sexually transmitted infections, and health-related perceptions,
reflections, experiences and practices among men having sex with men in Dar
2013)
2.FEMALE SEX WORKERS mobile populations and sex
workers Prevalence 14-35%)(National AIDS Control Programme; A study
of Female Sex Workers in seven Regions: Dar es Salaam, Iringa, Mbeya, Mwanza,
Shinyanga, Tabora and Mara. A Report published in 2014 (ISBN 978-9987-650-83-5)
26. RISK FACTORS FOR HIV IN THE
GENERAL POPULATION CONT…..
3.PEOPLE WHO INJECT DRUGS (PWID).
PWID and their partners represent another population that can
serveas a “bridging population” for HIV transmission.
prevalence 16-51%(Dar es salaam. Integrated Bio-Behavioural Survey
Among People Who Inject Drugs in Dar es Salaam. April 16, 2014)
4.MOBILE POPULATION like,fishermen, prisoners and truck
drivers (Anthony Kapesa1 et al 2018) bridging population.
27. RISK FACTORS FOR HIV IN THE GENERAL
POPULATION CONT…..
The prevalence of HIV among young people aged 15-
19 years was 1% (1.3% among girls, and 0.8%
among boys). Furthermore, the percentage of
women aged 20-24 infected with HIV is higher (4.4%)
than that of men (1.7%) in the same age
group.(National Bureau of Statistics, ICF International. Tanzania HIV AND AIDS
and Malaria Indicator Survey 2011-12. Dar es Salaam, March 2013).
Women are disproportionally more affected, with an
HIV prevalence of 6.3 % versus 3.9% among men.
(THMIS 2011-12).
28. PREVENTION OF HIV INFECTION
1.MOTHER-TO-CHILD
TRANSMISSION OF
HIV( PMTCT) during,
labour, delivery or
breastfeeding ranges from
15% to 45%. PMTCT)
interventions can reduce this
risk to below 5%
(World Health Organization
(WHO) 'Mother-to-child
transmission of
HIV' [accessed November
2018])
29. 2.PRE EXPOSURE PROPHYLAXIS (PREP)
POST EXPOSURE PROPHYLAXIS (PEP)
PrEP. Prevent by 70%(Virginia A Fonner et al 2016 Jul.)
Populations targeted for PrEP include Sex workers, Men who
have sex with men, People who inject drugs, Vulnerable
adolescent girls (15-19) and Young women (20-24) and Sero-
discordant couples. The
recommended PrEP regimen in Tanzania is:
Emtricitabine (FTC) 200 mg/Tenofovir Disoproxil Fumarate
(TDF) 300 mg (Truvada) PO Daily.
PEP.The guidelines recommend the use of TLD
(TDF+3TC/FTC+DTG) for adults and adolescents
30. 3.VOLUNTARY MEDICAL MALE CIRCUMCISION
(VMMC) reduces female-to-male sexual
transmission of HIV by 60%.(Auvert, B et al.
(2005)
In Tanzania, the national prevalence of
male circumcision 77.6% among male
aged 15 years and older (THIS 16/17)
33. LABORATORY DIAGNOSTICS IN HIV
INFECTION
Antibody detection using rapid
tests/ELISA
Virological tests
Assays to detect p24 antigen
Assays to detect HIV DNA or RNA
(PCR)
Viral culture
34. LABORATORY DIAGNOSTICS IN HIV
INFECTION CONT........................
Antibody methods for diagnosing HIV
include:
Rapid tests
Enzyme Linked Immunosorbent Assay
(ELISA)
Western Blot (confirmatory test if available)
Effective 12 weeks after infection, as
antibodies appear 6 to 12 weeks following
HIV infection in a majority of patients
Not suitable for use in infants under 18
months (use PCR)
35. LABORATORY DIAGNOSTICS IN HIV
INFECTION CONT.....
p24 tests
Detect the p24 antigen.
Based on the detection of antibodies
against HIV-1 antigens in serum.
Can be effective 2 to 3 weeks after
HIV infection.
Detect HIV antigen before antibody
can be detected.
36. LABORATORY DIAGNOSTICS IN HIV
INFECTION CONT........
DNA PCR tests
Useful in early diagnosis and infant
diagnosis (<18 months)
37. TB/HIV CO-INFECTION
Tuberculosis (TB) is a disease caused by
a bacterium called Mycobacterium
tuberculosis.
TB is spread by airborne route: droplet
nuclei
When a person with TB disease of the
lungs coughs or speaks, droplets of TB
bacteria spread through the air.
Once in the body, TB can be inactive or
38. THE IMAGE BELOW SHOWS THE DIFFERENCE
BETWEEN LATENT TB INFECTION AND TB DISEASE
39. TB/HIV CO-INFECTION CONT......
When the TB bacterium is inactive,
this is called Latent TB infection.
When the TB bacterium is active, this
is called TB disease.
Most exposed people do not become
infected.
Persons co-infected with HIV and TB
have highest risk for developing TB
disease
40. TB/HIV CO-INFECTION
CONT......
The lifetime risk of developing activeTB among people
living with HIV (PLHIV) maybe 20 times higher than in
people without HIV [Organization WH. Global report TB 2015].
Tanzania is among the 30 countries with high TB burden
and TB and HIV co-infection in the world.
[Organization WH. Global tuberculosis report 2018]
Despite the increased access to antiretroviral therapy
(ART), mortality in PLHIV is still high, and TB is the leading
cause of mortality[Lawn SD,et al 2008]’
Some studies found that TBpreventive therapy by isoniazid
reduces the incidence of TB in HIV-infected
Patients.(Mwinga A et all 1999)
41. TB/HIV CO-INFECTION CONT......
Impact of HIV on TB:
HIV is a high risk factor for the development of TB
HIV increases risk of recurrent TB
HIV promotes progression to active TB in people with
both recently acquired and latent M. tuberculosis
Impact of TB on HIV:
TB is the leading cause of death among PLHIV
TB increases the risk of progression from HIV to AIDS
TB is the most common OI in HIV infected people
42. TB/HIV CO-INFECTION CONT......
Clinical presentation
Atypical presentation of pulmonary
disease
Extra-pulmonary manifestations
Diagnosis of TB
More smear negative (low bacterial
load)
HIV positive persons are more likely
to have a negative TB skin test due
to skin test anergy (especially if CD4
is low)
43. Characteristics 2011 2012 2013 2014 Total
Overall 8765 (2.1) 9798 (2.3) 11,212 (2.5) 9857
(1.9)
39,632 (2.2)
Age group
< 15 years 687 (2.1) 784 (2.3) 1066 (3.2) 854
(2.4)
3391
(2.5)
≥ 15 years 8078
(2.1)
9014 (2.3) 10,146 (2.4) 9003
(1.9)
36,241 (2.2)
Sex
Male 3858 (2.9) 4474 (3.2) 5066 (3.5) 4681
(2.8)
18,079 (3.1)
Female 4907 (1.8) 5324 (1.8) 6146 (2.0) 5176
(1.5)
21,553 (1.7)
ART status
ART 1145 (1.5) 883 (1.4) 630 (1.2) 699
(1.2)
3357 (1.3)
Non-ART 7620 (2.3) 8915 (2.4) 10,582 (2.6) 9158 36,275 (2.3)
Table 2 Prevalence of TB among individuals enrolled in HIV care,
treatment, and support program in Tanzania from 2011 to 2014. . Majigo et
al. 2020
45. TYPICAL TB PRESENTATION IN HIV-POSITIVE
PATIENTS
TB related Condition % of PLHIV who
Develop Condition
Pulmonary disease 75%
Hilar/ mediastinal adenopathy 20 - 59 %
Pleural effusions 12 - 28 %
Miliary pattern 7 - 18 %
Normal CXR, positive sputum
culture
12 %
46. TUBERCULOSIS-HUMAN IMMUNODEFICIENCY
VIRUS (HIV) CO-INFECTION IN ETHIOPIA: A
SYSTEMATIC REVIEW AND META-ANALYSIS
TEWELDEMEDHIN ET AL. BMC INFECTIOUS DISEASES (2018) 18:676
Our searches returned a total of (n = 26,746) records from 30
articles of which 21 were cross-sectional,
7 were retrospectives and 2 were prospective studies. The
range of prevalence of TB-HIV co-infection was found to
be from 6 to 52.1% with random effects pooled prevalence of
22% (95% CI 19–24%) and with substantial
heterogeneity chi-square (X2) = 746.0, p < 0.001, (I2 =
95.84%).
47. EFFECT OF TUBERCULOSIS INFECTION ON MORTALITY OF
HIV-INFECTED PATIENTS IN NORTHERN TANZANIA. MOLLEL
ET AL. TROPICAL MEDICINE AND HEALTH (2020) 48:26
The overall mortality rate of 28.4 (95% CI 27.6–29.2)
per 1000 person years.
The mortality rate was 26.2 (95% CI 25.4–27.0)
per 1000 person-years among PLHIV who had no TB,
and 57.8 (95% CI 53.6–62.3) per 1000 person-years
among those with HIV/TB co-infection .
48. ISONIAZID PREVENTIVE THERAPY PLUS ANTIRETROVIRAL
THERAPY FOR THE PREVENTION OF TUBERCULOSIS: A
SYSTEMATIC REVIEW AND META-ANALYSIS OF INDIVIDUAL
PARTICIPANT DATA
JENNIPHER M ROSS ET AL 2021
Risk for tuberculosis was lower in participants given
isoniazid preventive therapy and ART than participants given
ART alone (hazard ratio [HR] 0·68, 95% CI 0·49-0·95,
p=0·02). Risk of all-cause mortality was lower in participants
given isoniazid preventive therapy and ART than participants
given ART alone, but this difference was non-significant (HR
0·69, 95% CI 0·43-1·10, p=0·12).
49. IMPACT OF ISONIAZID PREVENTIVE THERAPY ON TUBERCULOSIS
INCIDENCE AMONG PEOPLE LIVING WITH HIV: A SECONDARY DATA
ANALYSIS USING INVERSE PROBABILITY WEIGHTING OF INDIVIDUALS
ATTENDING HIV CARE AND TREATMENT CLINICS IN TANZANIA
Werner M. Maokola et all 2021
PLHIV enrolled in 315 HIV care and treatment clinic 2012-2016
Results
Of 171,743 PLHIV enrolled in the clinics over the five years, 10,326
(6.01%) were excluded leaving 161,417 available for the analysis. Of
the 24,800 who received IPT, 1.00% developed TB disease
whereas of the 136,617 who never received IPT 6,085 (4.98%)
developed TB disease. In 278,545.90 person-years of follow up, a
total 7,052 new TB cases were diagnosed. Using the weighted
sample, the overall TB incidence was 11.57 (95% CI: 11.09–12.07)
per 1,000 person-years. The TB incidence among PLHIV who
received IPT was 10.49 (95% CI: 9.11–12.15) per 1,000 person-
years and 12.00 (95% CI: 11.69–12.33) per 1,000 person-years in
those who never received IPT. After adjusting for other covariates
there was 52% lower risk of developing TB disease among those
who received IPT compared to those who never received IPT: aHR =
0.48 (95% CI: 0.40–0.58, P<0.001)
51. TREATMENT WITH ARTS
Types of Antiretroviral Drugs
1.The recommended antiretroviral drugs to be used in Tanzania
guidelines fall into the following five main categories:
1.Nucleotide reverse transcriptase inhibitors (NtRTIs)
2. Nucleoside reverse transcriptase inhibitors (NRTIs)
3.Non-nucleoside reverse transcriptase inhibitors (NNRTIs)
4. Protease inhibitors (Pls)
5. Integrase strand transfer inhibitors (INSTI)/ Integrase
inhibitors
Other antiretroviral drugs used elsewhere include:
5.Fusion inhibitors e.g. Enfuvirtide (ENF)
6.Chemokine receptor inhibitors/ CCR5 inhibitors e.g. Maraviroc
53. TREATMENT WITH ARTS CONT………
Protease Inhibitors (PIs)
1st generation currently available Protease Inhibitors (PIs)
1.Atazanavir (ATV).
2.Lopinavir (LPV),
3.Ritonavir (usually used as a booster with other PIs)
2nd generation currently available Protease Inhibitors (PIs)
Darunavir (DRV)
Integrase Strand Transfer Inhibitors (INSTI)/ Integrase
inhibitors
1.Dolutegravir (DTG) 2.Raltegravir
(RAL)
55. FIRST LINE REGIMEN USED IN TANZANIA
ART Initiation: within 7 days of a positive HIV test, unless
there is a medical or psychosocial contraindication
a) DTG based regimens:
TDF + 3TC + DTG (Default first Line regimen)
o ABC + 3TC+ DTG
AZT+ 3TC+ DTG
b) EFV based regimens:
TDF + 3TC + EFV600 or EFV400 TDF+FTC+EFV600
or EFV400
c) NVP based regimens:
AZT+3TC+NVP
56. 2ND LINE
Adults, adolescents (>15 years) and Pregnant women /
breastfeeding mothers
AZT/3TC+ATV/r: if TDF was used in first-line
TDF/FTC+ATV/r: if AZT was used in first line
Who Inject Drugs (PWID) AZT/3TC + DTG
57. 3RD LINE
Adults, adolescents (>15 years)
DTG+DRV/r+AZT/3TC
People Who Inject Drugs (PWID)
DTG+DRV/r+AZT/3TC
HIV and TB co-infection
DTG (BD) + LPV/r+ (AZT/3TC or
TDF/FTC)
58.
59. THE IMPACT OF ANTIRETROVIRAL THERAPY ON ADULT
MORTALITY IN RURAL TANZANIA MILLY MARSTON1, DENNA MICHAEL2, WRINGE1, RAPHAEL
ISINGO2, BENJAMIN D. CLARK1,2, ASWILE JONAS2,JULIUS MNGARA2, SAMWELI KALONGOJI2, JOYCE MBAGA3, JOHN CHANGALUCHA2, JIM TODD1,
BASIA ZABA1 AND MARK URASSA AUGUST 2012
Results
Overall, the crude adult mortality rate among 15–59-year
olds declined by 17% (hazard rate ratio (HRR) = 0.83;
95%CI: 0.72–0.95) between the pre-ART and the post-ART
periods. This change in mortality over the two time periods was
predominantly because of a fall in female mortality from 8.8
deaths per 1000 person-years to 6.5 deaths per 1000
person-years (HRR = 0.73; 95%CI: 0.60–0.89). The crude
male mortality rate remained similar over the two time periods
at 9.1 in the pre-ART period and 8.5 in the post-ART period.
Over the whole time period, the crude mortality rate in those
who are HIV positive is very high compared with those who are
HIV negative, with a hazard rate ratio of 11.4 (95% CI: 8.9–4.7)
for men and 9.4 (95% CI: 7.4–12.12) for women.
60. IMMUNE RECONSTITUTION
INFLAMMATORYSYNDROME(IRIS)
A spectrum of clinical signs and symptoms
resulting from the body’s restored ability to
mount an inflammatory response associated
with immune recovery
Worsening of symptoms of OI’s that were
already under effective treatment (TB,)
shortly after starting ART
May be confused with new infection.
Difficult to distinguish with: side effects,
relapse, treatment resistance
61. PATHOGENESIS OF IRIS:
The likelihood and severity of IRIS correlates with
two interrelated factors:
The extent of CD4 T-cell immune suppression prior
to initiation of ART
The degree of viral suppression and immune
recovery following initiation of ART
63. MANAGEMENT PRINCIPLES:
Consider other possible etiologies
Continue ART if possible (interrupt if life
threatening)
Attempt to diagnose infection or condition
responsible for IRIS
Initiate disease specific therapy if not in place
Provide anti-inflammatory therapy
64. HIV RESISTANCE
The mainstay of resistance of HIV is Mutations.
1. High replication rate: they produce billions of
virions per day account for rapid emergence of viral
variants
2. Lack of proofreading activity of reverse
transcriptase and recombination
65. PREVALENCE OF REVERSE TRANSCRIPTASE AND PROTEASE
MUTATIONS ASSOCIATED WITHANTIRETROVIRAL DRUG RESISTANCE
AMONG DRUG-NAÏVEHIV-1 INFECTED PREGNANT WOMEN IN KAGERA
AND KILIMANJARO REGIONS,
TANZANIA
BALTHAZAR M NYOMBI ET AL 21 JUNE 2008
Methods: 100 HIV-1 pregnant women of 246.
Results:HIV-1 subtypes A, C, D, CRF10_CD and Unique
Recombinant Forms (URF) were detected. Primary mutations
associated with NRTI and NNRTI resistance were detected
among 3% and 4% of treatment-naïve strains, Primary
mutations associated with NRTI and NNRTI resistance were
detected in 1.6% and 11.5% of women who had received sd
NVP, respectively. None of the primary mutations associated
with PI resistance was found.
66. CONTROL OF DRUG RESISTANCE
Adherence
Use of multidrug therapy
Determine HIV status before administering PEP
Genotypic resistance surveillance