Wednesday, June 27, 2007

Haiti, Sickle Cell Anemia, and Vaccination

Haiti is plagued by sickle cell anemia. The majority of Haitians are black. Sickle cell anemia is a disease that, for the most part, afflicts blacks.

I had never seen a child with a sickle cell crisis until I did my pediatric clerkship at Cook County Hospital in Chicago. I developed a new respect for this terrible disease.

Haiti's poor children, which is the vast majority of it's pediatric population, do well to receive the "first generation vaccinations". Very few obtain pneumococcal vaccine or Hemophilus influenza (Hib) vaccine. Both of these vaccines, when given to children in resource rich countries, dramatically decrease the incidence of invasive disease due to these organisms.

Children with sickle cell anemia succumb to invasive pneumococcal disease at a far greater rate than do children without sickle cell anemia.

Vaccine reduced bacterial illnesses in children who have sickle cell disease
by Kirsten H. Ellis
Infectious Diseases in Children Staff Writer

June 2007

Rates of invasive pneumococcal disease in children aged younger than 5 years with sickle cell disease decreased 93.4% after the pneumococcal conjugate vaccine was introduced in 2000, according to a new study published in Clinical Infectious Diseases.

Invasive pneumococcal disease is the leading cause of mortality among children with sickle cell disease. Compared with the general population, patients with sickle cell disease are between 30 and 600 times more likely to develop pneumococcal meningitis, bloodstream infection or other serious infections.

The researchers were not surprised by the decrease in invasive pneumococcal disease among vaccinated children with sickle cell disease, but were surprised by the magnitude of the reduction.

“That number says that the vaccine is doing well in a high risk population and is efficacious in preventing serotypes that are contained within the vaccine,” Natasha Halasa, MD, MPH, assistant professor of pediatric disease at Vanderbilt University School of Medicine and one of the study’s researchers, told Infectious Diseases in Children. “I was surprised that it was over 90% effective because there are other serotypes out there that are not covered by the seven-valent vaccine.”

The pneumococcal conjugate vaccine (PCV7, Prevnar, Wyeth) is recommended for all children aged younger than 2 years and for selected children aged 2 to 4 years with high risk conditions, including sickle cell disease.

Prior to the pneumococcal conjugate vaccine, children with sickle cell disease were given penicillin prophylaxis to thwart infections, which showed an 84% decrease of invasive pneumococcal disease, according to the findings of a prior study.

This vaccine is administered at routine checkup ages.

“Since all kids are supposed to get this vaccine at 2 months, 4 months, 6 months of age and then again at 12 months, children with sickle cell are now receiving this benefit at such an early age when the rates of pneumococcal disease are so high."

Sorry most Haitian children with sickle cell are not receiving this benefit.

1 comment:

Our Voice said...

I wonder what the situation is with sickle cell care after the earthquake. Do you have any idea?
I blog about sickle cell in America at, I would like to explore this issue in Haiti.