Transcript Document

Prevention of
Transmission of the
Human Immuno Deficiency Virus
from
MOTHER
to her
FETUS & INFANT
Th.Nabachandra
7/16/2015
1
Global Estimates (Dec. 2004)
-
40 million HIV-I infected.
95% infections in developing countries
47% occur in women of child bearing age.
15000 new infections a day.
One HIV-I infected infant born every minute of
the day.
- Number of deaths to HIV/AIDS in 2004 – 3.1
million.
GLOBAL ESTIMATES
(Children below 15 yrs)
2.2 million children are infected
Number of deaths due to HIV/AIDS in
2004 – 5,10, 000 children.
INDIAN SCENARIO
- 5.1 million are Sero-Positive
- 10% of the global HIV/AIDS prevalence
- Prevalence in General Population
below 1 percent
- 30,000 children are born each year with
HIV.
MANIPUR
September - 2005
Age-Sex Proportion of HIV Positive Cases
(Sero-surveillance).
Age Group Male
Female
Total
0-10 Yrs
11-20 Yrs
356
238
806
1058
450
820
% of total positives
(n=20,980)
5.04
6.62
HIV-I PREVALENCE RATE IN
ANTENATAL MOTHER
- Sub Saharan Africa
- United States
- India
i) Mumbai
ii) Pune
iii) Chennai
iv) Manipur
6 % - 30%
0.17 %
2 % - 2.5 %
0.64 % - 3.34 %
FREQUENCY OF TRANSMISSION
UNITED STATES & WESTERN EUROPE
16 - 20 %
THAILAND
19 – 24%
AFRICA
25 - 40 %
FREQUENCY OF TRANSMISSION (Contd.)
INDIA :
• Rshid H. Merchant et al
• John TJ et al
• Kumar RM et al
• Manipur (Sero-Surveillance)
24 %.
35 %.
48 %.
33.05%
Estimated frequency of transmission 30%
ROUTES OF TRANSMISSION
Children
-
Vertical Transmission
87%.
Contaminated blood (7%) & blood products (4%)
Sexual abuse of children
Multiple injections with inadequately sterilised
equipments (IDU).
TIMING OF VERTICAL TRANSMISSION
- During gestation (in utero).
- During delivery (Intrapartum).
- Post partum through breast milk.
VERTICAL TRANSMISSION
DURING GESTATION
- 25 - 30% transmission through this route.
- Proportion of infants infected each trimester & routes or
mechanism – unknown.
- Potential Routes
- Admixture of maternal – Fetal blood.
- Infection across placenta.
EVIDENCES:
- HIV virus/ Provirus in aborted fetal tissue (8-12wks)
amniotic fluid/ blood of infected infants.
- P24 antigens 1 fetal blood (16.24 wks) (Cordocentasis).
- Positive PCR in first 24-48 hours of life.
Vertical Transmission : (During Delivery)
• 70 – 75% of transmission.
• Routes or mechanism – Unknown
• Potential mechanism
- Admixture of maternal & fetal blood
- Extensive mucocutaneous (Occular & GIT)
exposure of the newborn to maternal blood &
vaginal secretion.
Evidences :
- Higher in first born twin.
- Newborn with negative diagnostic studies in 1st and
2 days of life followed by detection of infection at 1
to 3 months of age (PCR).
HIV & BREAST FEEDING
- HIV-I detected in cellular & acellular components of breast
milk.
- Colostral Viral Load
High
- Proportion of transmission :
- Antibody positive before pregnancy
14%
- Mother infected during early post natal period
29%
- Maximum transmission takes place in the first few months
of life.
- Infection persists as long as breast feeding continues.
- Exclusive breast feeding carries a lower risk of transmission
than mixed feeding.
- Increased risk in case of breast abscesses, mastitis, nipple
cracks.
SUGGESTION:
 Breast feeding may be avoided in HIV infected mother
if it is economically feasible & safe
Other Options:
* Exclusive breast feeding for 3-4months followed by
early weaning
* Issue must be discussed with the family in the antenatal period & decision about feeding individualized.
FACTORS AFFECTING MOTHER TO
CHILD TRANSMISSION OF HIV.
MATERNAL FACTORS:
Higher Transmission
Immunological status:
- Low CD4 Count.
Clinical Status:
- Advanced HIV disease
- Seroconverting during pregnancy
- Presence of ulcerative STDs at delivery
Nutritional Status :
- Low Vit. A concentration ??
- Anaemia.
FACTORS AFFECTING MOTHER TO CHILD
TRANSMISSION OF HIV.
Maternal Factors (Contd.)
Behavioral Factors:
- Cigarette Smoking
- Hard drug use
- Unprotected sexual intercourse during pregnancy.
Obstetrical Factors:
- Prolonged rupture of membrane (>4hrs)
- Intrapartum haemorrhage
- Obstetrical procedures
- Mode of delivery
- Invasive fetal monitoring
HOST FACTORS:
• PREMATURITY
• MULTIPLE PREGNANCY
1st Twin (26%) : 2nd Twin (13%)
• GASTRO-INTESTINAL TRACT FACTORS:
- Low gastric acidity
- Thin mucosa and microvilli.
- Deficiency of IgA secreting cells.
HOST FACTORS (Contd).
• Ability of Neonatal cell to support viral replication.
• Reduced ability to generate virus specific immune
responses.
- Deficient cell mediated immune responses
- Inability for lymphocyte to proliferate & produce
‘’ interferon.
- Diminished capability of neonatal natural killer
cells to mediate ADCC of HIV 1 infected target
cells.
- Inability to generate virus specific CTL.
VIRAL FACTORS:
• Viral Genotype and Phenotype
M-Tropic > T - Tropic
High Maternal Viral Load
> 50,000 RNA copies/ml
> 10,000 RNA copies/ml
< 1000 RNA copies/ml
Frequency of Transmission
-
50 %
29 %
12 %
• Presence and amount of virus in genital tract.
Strategies To Prevent
The Vertical Transmission of HIV
Ultimate goal :
Effective retroviral Drugs or Vaccine.
Three complementary strategies :
1) The protection of girls and women from HIV
infection (Primary Prevention)
2) The provision of efficient, acceptable & accessible
family planning services.
3) Anti-retroviral drug strategy.
Others :
1) Maternal nutritional intervention
2) Bypassing the route of exposure.
PREVENTION OF MTCT
A. Protection of girls & women
(Primary prevention)
- Providing knowledge of HIV/ AIDS
- Safe & responsible sexual behavior in
couples.
- Ensuring necessary personal skills &
access to condoms.
- Providing good quality, user friendly
prevention & treatment program of STDs.
PREVENTION OF MTCT (contd).
B. Provision of efficient, acceptable & accessible
family planning services.
• Aim is to ensure informed reproductive choice.
• Abortion where this is legal.
- To enable women to avoid unwanted
pregnancies and births.
PREVENTION OF MTCT (contd).
C.Anti-retroviral drug strategy :
• VCT
• ARD for HIV+Ve pregnant women
(and sometimes for their babies)
• Counseling on infant feeding.
• Support for the feeding methods chosen by
the mother.
REDUCTION OF VIRAL LOAD IN
MATERNAL (BLOOD &VAGINAL SECRETIONS)
• AZT (ACTG 076) TRIAL 1993
- 402 Mother- Infant pair
- 14 – 34 wks of pregnancy
- CD4 count >200 cells/ml.
• 194 women:
- Oral AZT during pregnancy
- I/V AZT during labour.
- Infants on AZT for 6 wks.
No breast feeding:
- HIV transmission rate =7.6%
• 204 women on placebo.
- HIV transmission rate =22.6%.
THAILAND AZT DOUBLE BLIND
PLACEBO TRIAL 1996
• 414 Pregnant women
• AZT on the last three wks of pregnancy (300
mg BD). 300 mg 3 hourly during labour.
• No AZT to infant.
• No breast feeding
• Study group : 7% transmission rate
• Placebo group : 25% transmission rate.
HIV INFECTED WOMEN IN LABOUR NO
PRIOR THERAPY
REGIMEN:
• MOTHER
- Nevirapine 200 mg single dose at onset of labour.
• NEONATE
- 2 mg/kg. NVP oral dose at 48 - 72 hrs.
- Breast feeding allowed.
• 47% reduction in transmission rate.
ADVANTAGES:
- Inexpensive
- Oral regimen
- Simple, easy to administer.
- Can give directly observed treatment.
VARIABLE RISK OF MTCT OF HIV
1. No ARD and baby breastfed
30.35%
2. No ARD and baby not breastfed
20%
3. AZT for 1 month & Baby not breastfed 10%
4. AZT for 1 month and baby not breastfed
upto 6 months
18%.
VARIABLE RISK OF MTCT OF HIV (Contd.)
5. 2 ARD (AZT & 3TC) at labour with breast
feeding at 6 weeks
11%.
6. 2 ARD for 1 month & 1wks after delivery
and breast feeding
9%
7. Nevirapine in labour & to baby within 3 days
of birth and breast feeding at 3 months of life.
13%.