Jennifer Knight-Madden | Responding to a call could save your baby’s life

BELIEVE IT or not, if your child is born with sickle cell disease (SCD), their greatest risk of preventable death is in the first four to five years of life. Needless death can be prevented by simple and inexpensive interventions.

This is the reason for newborn screening for SCD. The baby can be identified at birth and started on specific treatment as early as six weeks of life. However, they only get the treatment if their mother responded to the call to bring her baby in for confirmatory SCD testing and treatment.

Sickle cell disease is a genetic disease that affects the blood. One in every 150 babies born in Jamaica has the disease. Most often, both parents only have sickle cell trait (SCT). They carry one gene for sickle haemoglobin (HbS) and a normal adult haemoglobin gene (HbA). The gene for HbA is stronger (dominant). Persons with SCT are rarely affected by it. They only find out that they have SCT if they are tested. When both parents have SCT, there is a 25-per-cent chance that the baby inherits HbS from both parents, giving them SCD.

FOLLOW-UP CALLS

In Jamaica, pregnant women are tested for SCD and SCT, but research shows that most do not remember the result or understand their risk of having a child with SCD. Furthermore, the fathers are not usually tested. Parents are often shocked when they are called to say that their child might have SCD. Many go into denial as their baby looks well and they do not bring them in for the confirmatory test, sometimes refusing to answer follow-up calls.

The situation is further complicated by the type of tests done to check if adults have a trait. The least expensive test only identifies HbS. This is the test most often done in pregnant women. However, five per cent of Jamaicans carry other abnormal genes that affect the Hb. These include genes for thalassemia and HbC. A child who inherits HbS from one parent and one of the other genes, such as HbC or thalassemia, also has SCD, and is at risk of the serious complications. The screening test done in newborns in Jamaica identifies the different forms of SCD.

Once the newborn test result is in keeping with SCD or shows contamination of the sample by the mother’s blood, the mothers are contacted by either the Sickle Cell Unit (SCU) or Regional Health Authority to bring the baby in for retesting. This ensures that the diagnosis is correct before treatment begins. Initial treatment is all about preventing the dangerous early complications of SCD.

In many people living with SCD (PLWSCD), the spleen, a part of the body’s immune system, doesn’t work well from early life. This puts them at much higher risk of serious infection from germs such as the bacterium, streptococcus pneumoniae. This bacterial infection can spread from the blood (septicemia) to the lungs (acute chest syndrome which is like pneumonia, but worse), brain (meningitis, deafness or mental challenges) and bone (chronic bone infection). This bacterium is most likely to cause death in the first few years of life.

ROUTINE VACCINE SCHEDULE

Thankfully, there are inexpensive, effective ways to prevent this infection. These include vaccination and use of antibiotics. There are two vaccines used to prevent Strep. Pneumoniae infection – Prevnar13 and Pneumovax. These vaccines are not in the routine vaccine schedule that all children receive in Jamaica. Four shots of Prevnar are required (before age 18 months), each costing more than $20,000 in the private system, as well as Pneumovax at age four. All are free for babies with SCD at health centres and the SCU.

In addition, use of a simple antibiotic, penicillin, from age four months to four years can help prevent infection in babies with severe forms of SCD. If parents do not respond to the call, these babies do not get the free vaccines unless their parents pay more than $100,000 in the private system. When they are not known to have SCD, private doctors might not recommend them, given the cost. Answering that call gives access to these vaccines and penicillin treatment.

The other cause of early death in babies with SCD, also related to the spleen, is acute splenic sequestration (ASS). The spleen is an organ in the abdomen (belly) but it hides behind the ribs, and is not normally felt. It filters blood – removing old, damaged cells and germs. In PLWSCD, the abnormal sickle red cells can suddenly get stuck in the spleen, leaving insufficient blood for the rest of the body. They can literally go from running around one day to dead the next.

When parents answer that call, and the diagnosis of SCD is confirmed, they are trained to feel the baby’s belly daily. If the spleen gets big, they are advised to go to their baby’s clinic or the hospital immediately. Blood transfusion can save the life of a baby with ASS. If they have two episodes of ASS, removal of the spleen is recommended. If parents do not respond to the call to bring their baby in, they will be unable to feel the enlarged spleen and unaware of the possible danger their baby faces.

Newborn screening identifies babies at risk of severe illness and death due to SCD. When parents answer the call, they learn about the illness and partner with health care providers to give potentially lifesaving treatment and identify serious complications quickly.

They can start a disease modifying medicine, hydroxyurea, from nine months of age to delay or prevent many complication. Jamaica is one of few low- and middle-income countries that screen 99.9 per cent of babies born for SCD and provide comprehensive care, including free vaccines for affected babies. But it only works if parents responded to that call.

Professor Jennifer Knight-Madden, is professor of paediatric pulmonology and clinical research at the Sickle Cell Unit, Caribbean Institute for Health Research, UWI. Email: jennifer.knightmadden@uwimona.edu.jm. Send feedback to columns@gleanerjm.com