Sickle cell anemia (SCA) is recognized as a global health problem by the World Health Organization, with two resolutions in 2006 and 2010, committing the organization to promote awareness of the condition together with improved access to health care and support for research. However, there are still no accurate data on the numbers of patients with SCA in the world; published studies often suggest a figure of 20 to 25 million, with 10 to 15 million living in Africa,1 though this is more of a commonly quoted figure rather than an evidence-based estimate. Given the number of people affected, it is disappointing but maybe not surprising, that we still know so little about the condition, particularly how patients in Africa are affected. Even the most basic questions are difficult to answer, not only for African patients but also for patients in the Northern Hemisphere. For example, there is very little evidence on managing common complications such as acute chest syndrome, acute pain, and anemia, and it is unclear when to use such fundamental treatments as intravenous fluids, oxygen, antibiotics, and blood transfusion. To answer these questions and improve care, we must first identify all patients who have SCA. In some countries, including the United States and the United Kingdom, established neonatal screening programs identify nearly all children with SCA at birth, allowing access to clinical follow-up and the emerging improvements in care. In most of the world, neonatal screening is at best sporadic and most children present acutely with serious complications. Even then it is difficult to know who has SCA as opposed to malaria, bacterial infections, or other causes of anemia in the acute setting, even if some sort of hemoglobinopathy testing is available locally.
In this paper, Dr. Peter Olupot-Olupot and colleagues develop a simple algorithm to identify which children with anaemia are more likely to have SCA. They observed approximately 4,000 children presenting to hospitals in Uganda with hemoglobin less than 6.0 g/dL. The main study looked at the use of blood transfusion.2 However, researchers then used simple clinical parameters and data collected from this trial to predict who had SCA. They were then able to compare their estimates to the results of genotyping performed at the end of the study. They found that they could identify 73 percent of children with SCA by considering routinely available factors including age, sibling with known SCA, presence of malaria, white cell count, mean cellular volume, and platelet count. Interestingly, they also found that SCA was not associated with worse outcomes in these very anemic children, and the 28-day mortality was significantly less in those with SCA (hazard ratio, 0.41; 95% CI, 0.19-0.88; p=0.02).
In Brief
This paper moves us toward being able to identify more children with SCA in African countries, which is the first step toward better treatment and outcomes. In time, the hope is that national neonatal screening programs, well equipped diagnostic laboratories, and point-of-care testing will be established in all countries with a high prevalence of SCA, but in the meantime this sort of pragmatic approach will allow significant numbers of patients to be diagnosed and to access treatment. This article forms one small part of an increasing body of work on SCA emerging from Africa, shedding important new light on the condition. This includes studies characterizing childhood mortality in SCA,3 the establishment of pan-African disease registries,4 the development of international genetic consortia,5 and clinical trials on treatment in Africa.6 The latter study in particular showed the benefits of using higher doses of hydroxyurea in SCA, which has important implications for the treatment of SCA, not just in Africa, but also Europe, North America, and Asia. It seems likely that this trend of trials performed in Africa informing clinical practice in high-income countries will continue.
Competing Interests
Dr. Rees indicated no relevant conflicts of interest.
