|
Roger Shrimpton and Andrew Tomkins
Roger Shrimpton and Andrew Tomkins,
respectively of the Centre for International Child Health and
Institute of Child Health, at the University College London, examine
breastfeeding and dietary management for infants and mothers suffering
from the devastating disease.
The number of infants born with HIV infections
is growing every day, such that they assume an increasingly large
area of concern for programmes aimed at preventing HIV/AIDS and
mitigating its effects. In Africa this is reversing the improvements
in child mortality achieved in the last two decades. The first
global policy statement on HIV and infant feeding (UNAIDS, UNICEF,
WHO 1997) has been complemented by policy recommendations from
a technical consultation on the prevention of mother-to-child
transmission of HIV in the light of new findings (WHO 2000). As
the epidemic unfolds, nutrition is increasingly understood to
be a critical element in both the prevention and treatment of
HIV/AIDS. The aim of this article is to review the evidence available
showing the importance of nutrition in both prevention and treatment
of HIV/AIDS. In particular the role of nutrition in relation to
mother to child transmission (MTCT) will be reviewed together
with the latest policy recommendations.
HIV/AIDS and breastfeeding
Children represent an increasingly larger proportion of those
getting infected and dying from HIV/AIDS than of those living
with the disease. At the end of 2001, three million children were
living with HIV/AIDS, 0.8 million got infected and 0.6 million
died of the disease. The vast majority of these children were
in Sub-Saharan Africa, and were infected through mother-to-child-transmission
(MTCT).
MTCT can occur during pregnancy, at the time
of delivery, and after birth through breastfeeding. Based on a
compilation of studies, it is estimated that MTCT rates, in the
absence of any preventive intervention, range from 15-30 per cent
in the absence of breastfeeding, to 25-35 per cent if there is
breastfeeding through 6 months and to 30-45 per cent if there
is breastfeeding through 18 to 24 months (De Cock, Fowler, Mercier
et al 2000).
With the use of short-course antiretroviral
therapy such as nevirapine, transmission rates can be cut by 51
per cent in non-breastfeeding populations and by almost 40 per
cent in breastfeeding populations (Semba & Gray, 2001).
The risk factors for MTCT through breastfeeding are various and
relate to the timing of infection, the viral load, the pattern
of infant feeding and co-existing pathologies in both mother and
infant. Severe HIV infections during pregnancy or after delivery
have been associated with an increased rate of MTCT through breastfeeding
(John, Nduati, MboriNgacha, et al 2001; Semba, Kumwenda, Hoover,
et al 1999.)
The risk of HIV transmission through breastfeeding
is greatest in early infancy (before 6 months of age), and persists
as long as breastfeeding continues, with some studies showing
that longer duration of breastfeeding is associated with increased
risk of MTCT (Leroy V, Newell ML, Dabis F, et al 1998)
There is increasing evidence that the danger for MTCT through
breast milk may not be breast milk per se, but be more the non-exclusive
nature of breastfeeding that is so commonly practised in Africa
(Coutsoudis 2001).
Various studies have found that inflammatory
conditions such as mastitis, fissures and breast abscesses all
increase the risk of MTCT through breastfeeding. Poor breastfeeding
technique (poor attachment) is a frequent cause of such conditions.
It seems that if the breast is not completely emptied, as is often
the case in mixed feeding, there is increased risk of inflammation
and/or of sub-clinical infection (mastitis) of the breast tissues.
This inflammation/infection leads to an increased permeability
of the linings of the milk ducts in the mammary glands, with increased
leakage of serum contents into breastmilk (Willumsen, Filteau,
Coutsoudis, et al 2000).
Whether this is inflammation or sub-clinical
infection is still debated (Featherstone 2001). However, independent
of this, in HIV infected mothers viral loads in breastmilk are
higher when there is mastitis and increased leakage as shown by
higher sodium content of breastmilk (Semba, Kumwenda, Hoover et
al. 1999). At the level of the child's intestine, during the first
six months of life, the gut membrane is more open to the absorption
of whole proteins than later in life and the gastric lymph system
less well equipped to stop whole proteins reaching the enteric
blood system. The introduction of foreign proteins during this
period leads to increased likelihood of an allergic response,
with inflammation and reduced integrity of the mucosal membrane
of the intestine, all of which will increase the facility of penetration
across the gut wall by the virus.
The benefits of exclusive breastfeeding in
the first six months of life still outweigh the risks for MTCT
in most resource-constrained environments. Policy guidelines emphasise
the importance of 'informed choice' by parents who have to decide
how best to feed their child if the mother tests positive for
HIV.
The potential risks of not breastfeeding obviously vary by country
and individual conditions. In most industrialised societies the
recommendation is not to breastfeed the infant but to use breastmilk
substitutes. In most countries where HIV/AIDS is rampant however,
the use of breastmilk substitutes will likely result in an even
greater number of child deaths than that likely to occur through
HIV/AIDS (Fowler and Newell 2000).
A recent study has shown that in Latin America,
if exclusive breastfeeding for the first four months of life were
practiced, it would save 52,000 lives a year, which is 15 per
cent of all infant deaths in that region (Betran, de Onis, Lauer
and Villar 2001). The potential benefits of exclusive breastfeeding
for six months in Africa are likely to be greater than in Latin
America, since the potential risks of not exclusive breastfeeding
are greatest in the first six months of life and exclusive breastfeeding
rates are poor in most African countries (WHO 2000).
The biggest barrier to the implementation
of programmes to prevent MTCT is the lack of voluntary counselling
and testing. The prevention of MTCT is predicated on the availability
of voluntary and confidential HIV testing and counselling. The
enormous problem is that in Africa where the majority of the cases
are, few people know their HIV status.
In Sub-Saharan Africa, less than one percent
of women in antenatal care in urban areas have access to HIV testing,
and in rural areas the number is even smaller (Piot 2001). Even
where services are available the stigma attached to being positive
is still a great deterrent. The challenge is not only to provide
such services but also to increase their usage.
Nutrition and HIV/AIDS
The need and the potential for including nutrition services in
the treatment and care of HIV/AIDS patients are great. Where voluntary
counselling and testing services are made freely available and
HIV/AIDS patients are increasingly discovered, the provision of
nutritional services should become a considerable part of the
treatment and care regimes that need to be implemented.
The well known synergistic relationship between nutrition and
infection is of even more relevance in the case of infection with
HIV. Malnutrition increases both the progression of HIV infection
and the risk of transmission of the disease from mother to baby.
In turn, HIV infection exacerbates malnutrition through its damaging
effects on the immune system and with the consequent increase
in infections and debilitation capacity to work and/or to produce
food is reduced.
HIV/AIDS both causes and/or exacerbates malnutrition.
The weight loss and wasting commonly associated with HIV/AIDS
is associated with three overlapping processes: reductions in
food intake; nutrient malabsorption; and metabolic alterations.
Mouth sores, anorexia, depression and loss of appetite cause reductions
in food intake. Nutrient malabsorption is caused by frequent diarrhoea
and changes in the structure of the intestine, which lead to decreased
fat absorption.
HIV/AIDS also has an in-direct effect on
malnutrition through the suppression of immunity. Infections lead
to metabolic alterations causing increased requirements for nutrients
and increased losses of micronutrients. Special diets are part
of the treatment of HIV/AIDS patients (Kotler 2000). HIV/AIDS
in turn has a profound effect on food security. In Zimbabwe for
example, there has been a 61 per cent reduction in maize production,
a 49 per cent reduction in vegetable production and a 37 per cent
reduction in groundnuts, due to HIV/AIDS deaths amongst the productive
adult population. The total number of orphaned children left in
the wake of the AIDS epidemic is estimated at 14 million (UNAIDS
2002).
Poor nutrition has long been thought to have
an influence on the outcome of HIV/AIDS. Micronutrient deficiencies
are more common in people with human immunodeficiency virus infection
(Friis & Michaelsen 1998).
People with HIV/AIDS are more likely to have insufficient dietary
intake, malabsorption, diarrhoea, and impaired storage and altered
metabolism of micronutrients, all of which contribute to the development
of micronutrient deficiencies. Low plasma or serum levels of vitamins
A, E, B6, B12 and C, carotenoids, Se, and Zn are common in HIV-infected
populations.
Micronutrient deficiencies may contribute
to the pathogenesis of HIV infection through increased oxidative
stress and compromised immunity. Low levels or intakes of micronutrients
such as vitamins A, E, B6 and B12, Zn and Se have been associated
with adverse clinical outcomes during HIV infection, and new studies
are emerging which suggest that micronutrient supplementation
may help reduce morbidity and mortality during HIV infection.
There is evidence that the oxidative stress caused by the HIV/AIDS,
in the face of an inadequate diet, infection may indirectly hasten
HIV replication (Semba & Tang 1999). Whilst evidence that
the provision of micronutrient supplements reduces the progression
of the disease is still lacking, there is evidence that micronutrient
supplements can help prevent low birth weight babies amongst mothers
that are infected with HIV (Fawzi, Msamanga, Spiegleman, et al
1998).
There is also evidence that the compromised
anti-oxidant status, common in HIV infected mothers, increases
the likelihood of breast inflammation and hence of vertical transmission.
In Tanzania when mothers were given either sunflower oil or refined
palm oil as energy supplements during lactation, there was increased
transmission amongst mothers receiving the refined palm oil.
This is hypothesised to be due to the higher levels of vitamin
E in sunflower oil (Filteau, Lietz, Mulokozi, et al 1999). There
is also evidence that vitamin A supplementation of HIV-infected
pregnant women may prevent the deterioration in gut integrity
in the subgroup of their infants who themselves become infected.
Improving vitamin A status of HIV-infected infants may decrease
their gastrointestinal morbidity. (Filteau, Rollins, Coutsoudis
et al 2001)
HIV/AIDS and dietary management
The dietary management of HIV/AIDS includes both the nutritional
care of the mother found to have HIV/AIDS and of the infant, in
order to reduce the risks of MTCT. The relative risks of MTCT
are different depending on the resource constraints that the infected
mother and her family find themselves.
The voluntary and confidential counselling and testing for HIV
package of health care provided to pregnant mothers should include
a strong nutrition component. The demands of both pregnancy and
lactation on maternal body reserves will compound the negative
impact HIV infection has on maternal nutritional status.
Large numbers of babies are being born to mothers without becoming
infected. However, they have low birth weight. Unless efforts
are made to improve maternal nutritional status in HIV-positive
pregnant mothers, the progression of the disease is likely to
accelerate and the risks that the baby is born both infected and
low birth weight will be increased.
The nutrition component of the counselling
package should include dietary advice for the mother in order
to help her improve her diet, and a micronutrient supplement containing
not only iron and folate, but also other anti-oxidant micronutrients.
Every effort should be made to protect and
promote exclusive breastfeeding for six months amongst the majority
of mothers who either does not know their HIV status, or who are
found negative. The strategies for protecting and promoting exclusive
breastfeeding are well known and include the full implementation
of the code of marketing of breastmilk substitutes, and the implementation
of the Baby Friendly Hospital Initiative in all health facilities.
(WHO 1981, WHO 1998).
Strengthening the capacity of health facilities
to provide lactation counselling services can have dramatically
positive effects on exclusive breastfeeding rates over the short
term that are beneficial for both infected and non-infected mothers
(Haider et al 2000).
Infant feeding mothers should be helped to make choices, including
the following options: replacement feeding from birth, exclusive
breastfeeding for six months followed by rapid cessation at around
six months and introduction of replacement feeding.
For all of these options the task is then
to ensure adequate complementary feeding from six months onwards.
When replacement feeding is acceptable, feasible, affordable sustainable
and safe avoidance of all breastfeeding by HIV-infected mothers
is recommended. Otherwise, exclusive breastfeeding is recommended
during the first months of life. To minimise HIV transmission
risk, breastfeeding should be discontinued as soon as feasible,
taking into account local circumstances, the individual woman's
situation and the risks of replacement feeding.
In most countries in Latin America HIV-positive
women are encouraged to avoid breastfeeding and in some cases
even provided with breastmilk substitutes. In the resource-constrained
situations encountered in most Sub-Saharan African countries replacement
feeding from birth is not an option. The rapid cessation of exclusive
breastfeeding at around six months and a rapid transition to exclusive
replacement feeding requires considerable advice and counselling
support for the mother and her family in order to be successful
(Piwoz, Huffman, Lusk et al 2001).
The capacity to carry out such counselling
is remarkably weak in most country settings where HIV/AID prevalence
rates are rising rapidly.
The problem of ensuring adequate complementary feeding is compounded
in the infants of HIV/AIDS infected mothers since the nutritional
benefits of continued breastfeeding are missing after six months
of age. The provision of 'transitional foods' more commonly known
as weaning foods, are recommended for the period between 6 and
12 months of age (WHO 1998). In the absence of breastmilk some
form of replacement milk should be used, such as goat's milk or
cow's milk if they are available. Ensuring the nutritional adequacy
of transitional foods with regard to both nutrient and energy
density and food safety is a demanding task that requires considerable
supportive counselling and advice. In the second year of life
the problem is less acute since the child has acquired teeth and
can be fed from the family pot using chopped or minced preparations.
During the period of complementary feeding
the provision of a micronutrient supplements is recommended since
ensuring their provision through transitional foods is often not
easy and the infant is likely to already have been born with inadequate
stores of iron and vitamin A for example, that need to be replenished.
Conclusions and recommendations
Dealing with the risks of MTCT is assuming increasing importance
in HIV/AIDS programmes. Whilst in industrialised countries mothers
are advised not to breastfeed their babies, such advice is not
appropriate in most non-industrialised countries. The benefits
of exclusive breastfeeding in the first six months of life are
likely to outweigh the risks of MTCT in most resource-constrained
environments where HIV/AIDS prevalence rates are increasing. In
such situations the rapid cessation of breastfeeding and the switch
from exclusive breastfeeding to exclusive replacement feeding
at about six months of life seems the most pragmatic approach,
but implementation may meet many cultural barriers.
The adoption of MTCT reduction strategies based on changes in
infant feeding practices requires a heavy investment in the capacity
to carry out voluntary counselling and testing for HIV/AIDS. The
nutrition component of such counselling is considerable, and should
include improved capacity for lactation counselling and management,
nutrition education, and micronutrient supplementation for both
the mother and child.
References
Betran, A.P., de Onis, M., Lauer, J.A., Villar, J. 2001. Ecological
study of the effect of breastfeeding on infant mortality in Latin
America. BMJ. 323:303
Coutsoudis A 2001. Breastfeeding and HIV
transmission. Nutrition Research Reviews. 14: 191-206.
De Cock KM, Fowler MG, Mercier E, et al.
2000. Prevention of mother-to-child HIV transmission in resource-poor
countries - Translating research into policy and practice. JAMA.
283(9): 1175-1182
Fawzi WW, Msamanga GI, Spiegelman D, et al,
1998. Randomized trials of effects of vitamin supplements on pregnancy
outcomes and t cell counts in HIV-1-infected women in Tanzania.
The Lancet 351: 1477-1482.
Filteau SM, Lietz G, Mulokozi G, Billota
S, Henry CJK, Tomkins AM. 1999. Milk Cytokines, and sub-clinical
breast inflammation in Tanzanian women: effects of dietary red
palm or sunflower oil supplementation. Immunology 97: 595-600.
Filteau SM, Rollins NC, Coutsoudis A, Sullivan
KR, Willumsen JF, Tomkins AM. 2001. The effect of antenatal vitamin
A and beta-carotene supplementation on gut integrity of infants
of HIV-infected South African women. J Pediatr Gastroenterol Nutr
32(4):464-70b
Featherstone C. 2001. Mastitis in lactating
women: physiology or pathology? Breastfeeding Reviews. 9(1): 5-12.
Friis H & Michaelsen KF 1998. Micronutrients
and HIV infection: a review. European Journal of Clinical Nutrition.
52(1): 157-163
Fowler MG and Newell ML 2000. Breastfeeding,
HIV transmission and options in resource poor settings. WHO: Geneva
(www.who.int/reproductive -health/rtis/MTCT/mtct_consultation_october_2000/c)
Haider R, Ashworth A, Kabir I, Huttly SRA.
2000. Effect of community-based peer counsellors on exclusive
breastfeeding practices in Dhaka, Bangladesh: a randomised controlled
trial. Lancet 356: 1643-7
John GC, Nduati RW, MboriNgacha DA, et al.
2001.Correlates of mother-to-child human immunodeficiency virus
type 1 (HIV-1) transmission: Association with maternal plasma
HIV-1 RNA load, genital HIV-1 DNA shedding, and breast infections.
J Infec Dis. 183(2): 206-212
Kotler DP. 2000 Nutritional alterations associated
with HIV infection. J Acquir Immune Defic Syndr 25 Suppl 1:S81-7
Leroy V, Newell ML, Dabis F, et al. 1998.
International multicentre pooled analysis of late postnatal mother-to-
child transmission of HIV-1 infection. Ghent International Working
Group on Mother-to-Child Transmission of HIV. Lancet. 352(9128):
597-600
Piot P. 2001. Keynote Address. Nutrition
and HIV/AIDS. Nutrition Policy Paper No. 20. Geneva: ACC/SCN.
Piwoz E, Huffman SL, Lusk D, Zehner ER, O'Gara
C 2001. Issues, risks and challenges of early breastfeeding cessation
to reduce potential transmission of HIV in Africa. Washington:
Academy for educational development.
Semba RD & Tang AM. 1999. Micronutrients
and the pathogenesis of human immunodeficiency virus infection.
Br J Nutr 81(3):181-9.
Semba RD, Kumwenda N, Hoover DR, et al. 1999.
Human immunodeficiency virus load in breastmilk, mastitis, and
mother-to-child transmission of human immunodeficiency virus infected
women. J Hum Lact. 15(4): 301-6.
Semba RD & Gray GE, 2001. Human Immunodeficiency
virus infection. In: Nutrition and Health in Developing Countries.
Semba RD & Bloem MW (Eds). Totowa, NJ: Human Press Inc
UNICEF, UNAIDS, & WHO 1998. HIV and Infant
feeding: a guide for decision makers. Geneva: WHO/FRH/NUT/CHD/98.1
WHO. 1981. International Code of Marketing
of Breast-milk Substitutes. Geneva: WHO. (http://www.who.int/nut/documents/code_english.PDF)
WHO 1998. Nutrition - The Innocenti Declaration.
Progress and achievements Part 1. Weekly Epidemiological Record.
73: 25-30
WHO 2000. Collaborative Study Team on the
role of breastmilk on the prevention of infant mortality: Effect
of breastfeeding on infant and child mortality due to infectious
diseases in less developed countries: a pooled analysis. Lancet.
355:451-455.
Willumsen JF, Filteau SM, Coutsoudis A, Uebel
KE, Newell ML, Tomkins AM. 2000. Subclinical mastitis as a risk
factor for mother-infant HIV transmission. Adv Exp Med Biol 478:211-23
|