Perinatal HIV-1 Transmission
and
Pediatric HIV/AIDS in Manipur

By Dr. Laishram Ranbir Singh *

Perinatal HIV-1 transmission is the leading cause of pediatric AIDS and it accounts for over 90% of prepubertal AIDS cases and almost all new pediatric HIV in fection. Every minute of the day, an infant is born infected with HIV-1 [1].

In USA, approximately 7,000 infants are born to HIV infected mothers each year and approximately 2000 infants become infected [2]. The rate of perinatal transmission ranges from 14% to 33% in developed countries whereas rates as high as 43% have been reported from developing countries.

Perinatal transmission of HIV-1 can occur during pregnancy (in utero), intrapartum (during labour and delivery) and post-partum (through breast feeding).

Indirect evidence suggests that nearly two-thirds of the perinatal transmission occur during labour and delivery; however, the timing of transmission remains an area of active investigation. Possible mechanisms of neonatal acquisition of HIV-1 during labour and delivery include direct exposure to maternal blood and genital tract secretions and transplacental micro-transfusions [1]

Penilatal HIV-1 transmission is multifactorial and major factors that have been associated with increased transmission include a high maternal viral load, decreased CD4+ count, lack of HIV neutralising antibody, advanced clinical disease, primary infection, first born twins and obstetric factors including chorioamnionitis, mode of delivery and more than 4 h. of ruptured membranes [3].

One of the major advances in preven tion of perinatal transmission is the AIDS Clinical Trial Group ACTG 076 trial which showed that antiretroviral therapy with Zidovudine (ZVD) given to the HIV-1 positive mother from 14 weeks gestation through labour and delivery and for 6 weeks in neonates reduced transmission to 8%.

The extent to which the prenatal and intrapartum therapy of the mother and neonatal therapy contributes to the overall reduction in trans mission is not known. However, shorter and less intensive antiretroviral combination regimen has also shown to decrease the transmission.

In Thailand, the Bangkok Perinatal AZT Study, a collaboration between the Thai Ministry of Public Health and the US Centre for Disease Control and Prevention evaluated the safety and efficacy of a short course of oral ZVD administered during late preg nancy and labour to reduce the risk for perinatal HIV-1 transmission.

The ZVD regimen consisted of 300mg orally twice daily from 36 weeks gestation until the onset of labour and 300 mg every 3 hour from the onset of labour until delivery. All the women were recommended not to breast feed and were provided with infant formula. The above regimen resulted in reduction of transmission to 9.2%.

In Manipur, as the HIV/AIDS epidemic progresses an ever increasing number of women of childbearing age are infected through heterosexual route resulting in the corresponding increase in the number of in fants acquiring HIV infection from their mothers.

Although the real magnitude of pediatric HIV infection remains to be documented with any precision, as of Oct. '98 a total of 91 children (47 males and 44 fe males) below 10 year and 763 individuals (704 males and 59 females) below 20 year have been reported to the Manipur State AIDS Control Society [5].

So far, all the in fected children have acquired their infection through perinatal transmission. Based on the projected 21, 96901 population of Manipur for the year 1998 as on 1 Oct. 1986 and the recorded birth rate of 19.4 in Manipur [7] the annual estimated number of pregnant women [8] who would be delivering live ba bies is 42620 .

The seroprevalence rate of HIV infection among antenatal mothers in Manipur is 1.69% as per the sentinel surveillence report of Aug.-Sept. 1985. If we calculate at the above rate, annually an estimated 720 HIV infected mothers are ex pected to deliver their live babies.

Again at an estimated rate of 40% perinatal transmission for the developing countries, at least 288 infants are infected perinatally with HIV annually. As there is no effective cure and vaccine all these infected children will die of AIDS resulting in the increase in infant mortality and also in under-5 mortality rates in Manipur.

Besides, there will be a growing population of orphans (non-HIV infected children whose both HIV infected parents have died of AIDS) which will be a great burden to the society.

At present, IDUs account for 72.20% of the total HIV seropositive cases in Manipur [5]. As more and more of these young IDUs are getting married an increasing number of young women are infected heterosexually with HIV. Most of the young infected women are well and they have no suspicion of HIV infection as they are ignorant of their husbands' high risk behaviour (past or present).

And as clinical disease occurs within months in infected infants, pediatric AIDS is often the first evidence of heterosexually transmitted HIV infection at the family level leading to serious social consequences. If young women are self motivated, they can be a great force for change of the course of HIV/AIDS epidemic in Manipur by voluntary disclosure of their husbands IDU status and resorting to voluntary HIV testing during pregnancy.

When found to be positive they can be given ZVD (short course) after proper counselling to reduce perinatal transmission. This may decrease the number of perinatally acquired pediatric AIDS cases in Manipur.

The cost of short course ZVD regimen though prohibitive is affordable. The cost of one tablet ZVD (lOOmg) is twenty rupees as of now. For the short course Thai regimen a particular pregnant woman has to spend around four thousand rupees which is affordable by the average Manipuri family. This area needs to be studied and it may be of great importance in the coming years to save hundreds and thousands of children from being infected perinatally.

To conclude, with the increasing number of infants born to HIV-1 infected women in Manipur, perinatally acquired pediatric HIV/AIDS is becoming a major public health problem. With the availability of potentially preventive therapy, there is need to recommend offering of routine HIV testing with informed consent to all those pregnant women in Manipur who are at risk.

Women found to be infected should be coun selled regarding HIV related pregnancy care issues including the risk and benefit of ZVD) therapy.

References:

1. Luzuriaga K. Sullivan JL. Prevention and Treatment of Pediatric HIV infection, JAMA 1998,280:1:17-18.
2. Wade Parks, "Human Immunodeficiency Virus Infection" ; In Nelson's Text book of Pediatrics, 15th Edn. Eds. Behrman RE, Kliegman RM. Philadel phia, W.B. Saunders Co. 1996 pp 916-919.
3. AIDS Research and Control Centre (ARCON) "Perinatal HIV Transmission " AIDS update. 1997, 3:1:1
4. AIDS Research and Control Centre (ARCON) "Short Course perinatal ZVD Trial in Bangkok" AIDS update, 1988 3:3:5
5. Epidemiological Analysis of HIV/AIDS in Manipur, Monthly update, Oct.'98, Manipur State AIDS Control Society, Manipur 1998:1-4
6. Projected population of Manipur 1992-2011, Directorate of Economics and Sta tistics, Government of Manipur.
7. Sample Registration Bulletin, Registrar General of India, New Delhi, 1998:32:1:7.
8. National Child survival and safe Motherhood Programme, Training module. Plan and Implement. MCH Division, Ministry of Health and Family Welfare, Government of India, New Delhi, Janu ary 1994 p6.