To the uninitiated, if perchance you happen to be in the midst of those involved in policy formulation, treatment, care and support of HIV clients and you hear them pronounce the acronym PMTCT, you’d almost think that it is one word without a vowel. It is not. It stands for HIV Prevention of Mother To Child Transmission. It is quite a phenomenal venture in the management of HV infections generally. A pregnant woman afflicted with the virus can transmit it to the newborn child during pregnancy, labour, delivery and breast feeding. The importance of PMTCT become evident on the realization that Nigeria is home to over30% of the global of HIV infected children. And with the current economic meltdown and conflicts, this is bound to spiral.
Ironically there are many factors that predispose to increased risk of HIV transmission from mother to child. These would include high viral load which could be as a result of new infection or an advanced disease. Infection of the placenta by the virus, poor nutritional status of the mother and ante partum haemorrhage are known factors associated with increased risk of mother to child transmission. Delivery related occurrences like early rupture of membrane or water bag lasting for more than four hours before commencement of uterine contraction, an infection of the placenta and amniotic fluid known as chorioamnionitis, prolonged labour, and instrumental traumatic delivery procedures with vaginal cut known as episiotomy are factors known to increase the risk of HIV transmission during confinement.
Other factors that may increase the risk of mother to child transmission include premature babies, the first infant in multiple birth and preterm deliveries. In terms of breastfeeding, high maternal viral load is a known factor. This does not in any way preclude transmission under relatively reduced viral load. Extended duration of breastfeeding as its all commonplace in our environment can be a contributory factor. Early introduction to mixed feeding, infection or inflammation of the breast with abscess formation, cracks in the nipple, poor maternal nutritional status and oral disease of the infant are all associated factors. It must always be remembered that HIV easily gains access into the human body through infected tissues and skin interruptions.
The examination of a pregnant woman with a high index of suspicion of being HIV positive is very important. It is necessary to look out for things like ANAEMIA or shortage of blood, persistent loose stool or diarrhoea, respiratory tract infection especially TUBERCULOSIS, oral and vaginal thrush or Candidiasis. Weight loss or gain is another important parameter especially when we realize that in our environment a pregnant woman gains between 10 to 12.5kg in body weight during the period of her antenatal. Other sexually transmitted infections must be looked out for; the simple reason being that the virus in terms of transmission thrives in an infected or inflamed environment.
Barring the current economic challenges, a full complement of laboratory investigations should be the norm in the execution of PMTCT. A full blood count with blood film for malaria parasite should be done. Liver and kidney function tests must be carried out because of the additional burden of metabolism and clearance these organs would be subjected to in the course of PMTCT. Their status must be known. Lipid profile must also be known. Not uncommonly some anti-retroviral drugs can lead to fat mobilization and redistribution in the body.
Hepatitis B and C viral screening is an essential part of this laboratory work up.
Finally the CD4+ cell count and the viral load must be determined. The common failure among caregivers in the investigation of this type of patients is just doing the CD4 count and the viral load and ignoring other ancillary tests while waiting for something to crop up. Sometimes it may just be due to financial constraints.
Pregnancy is an absolute indication for initiation into anti retroviral therapy. This must be done for all pregnant women and breast feeding mothers regardless of the clinical stage of the disease and CD4 count and continued for life. Secondly treatment must be commenced immediately in all pregnant and breastfeeding mothers even if the detection was made late in pregnancy or after delivery. The simple reason is that the most effective way to prevent mother to child transmission is to reduce the viral load.
Since the pioneering advent of Zidovudine , the arsenal of anti retro viral drugs is loaded. The discussion is beyond the scope of this outing. Suffice it to say that in practice at least two generics are combined in this treatment. The popular combination in this environment is Tenofovir, Lamivudine and Efevrenz. It is always good to allow the care giver to juggle the drugs based on his local challenges especially the logistics of drug delivery and sometime drug resistance due to poor adherence and adverse drug reaction. So far antiretroviral drugs are free in this country and hopefully will continue to be.
In a lot of instance it is expedient to continue antiretroviral drugs for exposed infants up to the age of six weeks. Usually the more common ARVs used are ZIDOVUDINE and NEVIRAPIN. This is usually applicable to infants of mothers with HIV considered to be of high risk. Ironically this procedure is referred to prophylaxis. On the other hand, infants delivered to HIV mothers considered to have been stabilized on drugs, are recommended to be on Nevirapine for at least six weeks. Here again this is better left in the hands of paeditricians who are very familiar with the HIV/ART terrain.
It must always be remembered that the sole purpose of PMTCT is to spare the next generation of infected parents. Thus extension of the period of prophylaxis is the norm in our environment taking into cognizance of breast fed infants who are born to women with HIV who have only been on treatment for less than four months. These are very likely those picked up during routine antenatal screening. Another category would be already diagnosed mothers who have received less than four weeks of antiretroviral therapy at the time of delivery. If the viral load of an infected mother is more than1000 copies four weeks and less before delivery, it calls for extension of the period of prophylaxis for the infant .And finally breast fed infants born to women identified as being positive in the immediate post partum period irrespective of their status during the antenatal period are candidates. As rule the period of extended prophylaxis is usually a minimum of twelve weeks or more depending on the discretion of the care giver.