FACTORS INFLUENCING
HETEROSEXUAL &MOTHER
TO CHILD TRANSMISSION
OF HIV
% infection by transmission route
Transmission route
%
Sexual intercourse
70-80
Mother-to-child-transmission
5-10
Blood transfusion
3-5
Injecting drug use
5-10
Health care – e.g. needle stick injury
<0.01
 Main method of transmission in:
1. Anal sex
 Receptive anal sex-highest risk Why ?

Anal mucosa has less lubrication

Soft and has a rich blood supply
 Fragile , wounds and bleeds easily
2. Vaginal sex
 HIV is found in large quantities in semen
 Present in vaginal secretions but less than in
semen
 Risk of transmission is less compared to anal
sex
 Vagina is well lubricated and is elastic
 Receptive vaginal high risk to lady
 Lady on top high risk to the man
3. Oral sex
 Becoming common even in marriage
 Contact between genitals & the mouth
 Low risk compared to other methods
 Risk increased by ulcers in the mouth
 Poor hygiene lead to transmission of Herpes
labialis, typhoid fever, roundworms , oral
candidiasis
FACTORS IN HETEROSEXUAL TRANSMISSION
 Multiple sexual partners
 Unprotected sexual intercourse
 Presence of untreated STI’S
 Lack of Male circumcision
 Social vulnerability ;women &young girls
 Economic & political instability
 Lack of knowledge of serostatus
MOTHER TO CHILD
TRANSMISSION OF HIV
INTRODUCTION
 Majority of PLWA aged 15-49 years
 Approx 60 %of all PLWA are women
 The no. Of HIV infection in children less than 15 yrs 2.1
million (UNAIDS,2004)
 90 % of all children living with HIV/AIDS are in SSA
 104,000 Children LWHIV in Kenya(KAIS,2012)
 Infants who acquire HIV from their mothers
 MTCT can occur
 During Pregnancy
 During labor and delivery
 After birth through breast feeding
 35-40 % of children born of HIV positive mothers will acquire
HIV
 Globally 260,000 children got infected with HIV
(UNAIDS,2013)
 Intervention during pregnancy and childbirth crucial
 HIV prevention efforts can slow this trend,but only 45 % of
women in Kenya deliver in health facilities
Risk of MTCT
During pregnancy 5-10 %
 Labor and delivery 15-20 %
 Breastfeeding 10-15 %
Factors facilitating MTCT
1. VIRUS RELATED
 No virus /ml blood is called viral load
 High viral load increases risk of MTCT
 HIV-1 transmitted easily through the placenta compared to HIV-2
 Reinfection increases the risk of MTCT
3. DELIVERY RELATED CHARACTERISTICS
i.

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ii.
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Gestational age
premature birth increases risk
Body tissue very soft,easily bruised
Mode of delivery
C/S reduces risk by 50%
Vaginal delivery-contact with vaginal secretions and maternal
blood
Prolonged labor and premature rupture of membranes-contact
with genital secretions
Delivery x-tics ctd
iii. Instruments used in Delivery



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Baby too big or mothers pelvis contracted
Foetus cannot pass through the pelvis during labor
This is called obstructed labor
Instruments are used to pull the baby out
Include vacuum cap and Forceps for delivery
Traumatise baby,breaking skin-entry point for the virus
iv.



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Exposure to maternal blood
Events that cause maternal bleeding increase risk of MTCT
This includes Episiotomies, tares and laceration.
Episiotomies to be done only when absolutely necessary
To avoid tares and lacerations women encouraged to be
delivered by skilled health workers
BREAST MILK TRANSMISSION
 This is a well known phenomena
 Common in HIV-1 infection but rare in HIV-2 infections
 transmission is possible-HIV is detectable in B/milk
 Factors affecting B/Milk Transmission
 Maternal malnutrition Vit A &C deficiency
 High viral load in Acute and advanced phases
 Breast injuries and conditions e.g. Mastitis, Breast abscess,Cracked nipples
 Oral disease in the baby e.g. OPC