Academic journal article Bulletin of the World Health Organization

Prevention and Control of Haemoglobinopathies

Academic journal article Bulletin of the World Health Organization

Prevention and Control of Haemoglobinopathies

Article excerpt

Introduction

Haemoglobinopathies - i.e., the thalassaemias and sickle-cell disorder (SCD) - are recessive inherited diseases which are globally widespread. At present, about 250 million people (4.5% of the world population) carry a potentially pathological haemoglobinopathy gene. Each year about 300 000 infants are born with a major haemoglobinopathy (Table 1, Fig. 1). These hereditary anaemias were originally confined to the subtropics and tropics, with a high incidence because healthy carriers were protected against the lethal effects of malaria. Owing to increasing global migration, however the haemoglobinopathies have appeared in many areas where they were not endemic. In the USA, 10% of the population is at risk for SCD, and in north-west Europe between 2% and 9% of most populations now belong to ethnic minorities who are at risk for the haemoglobinopathies. In some south-east Asian countries, population movements could increase the rate of infants born with thalassaemia. Globally, there are more carriers of thalassaemia than of SCD, but the high frequency of the sickle-cell gene in certain areas leads to a high birth rate of homozygotes. As a result, SCD accounts for about 70% of haemoglobin disorders worldwide. Nearly 70% of affected births occur in sub-Saharan Africa where up to 2% of all children are born with SCD[1].(a,b)

[TABULAR DATA OMITTED]

Haemoglobinopathy control programmes based on WHO recommendations, which have been established in countries in all six WHO Regions, have shown success in the management of the problem. In many developing countries, the appearance of a haemoglobinopathy is the first indicator of the need to develop genetic approaches for the control of chronic childhood diseases.(c,d,e)

This article summarizes the presentations and discussions at the first joint WHO/Thalassaemia International Federation (TIF) meeting, which was convened in Cyprus to review the progress in ongoing programmes in the different WHO Regions.

Situation in the African region

Some 60-70% of all births of children with a major haemoglobin disorder occur in Africa,(b) the region with the least resources for coping with the problem; the numbers are rising since developments in primary health care have increased the survival of patients with sickle-cell disorder. Several motivated clinicians are making efforts to provide some services, and to sensitize the governments and the WHO Regional Office for Africa (AFRO) to the importance of this problem. Because of the global economic downturn some of the gains are being lost, e.g., malnutrition is increasing, and many trained people have left the region for political or economic reasons. In 1987 WHO proposed a plan to develop services for sickle-cell disorder throughout the African continent which required US$ 3 million to carry out, but so far there has been no donor. In 1991 WHO/AFRO brought together eight African experts (4 francophone, 4 anglophone) to plan a meeting to include representatives from all countries and initiate a regional working group on sickle-cell disorder. Unfortunately, this meeting could not take place in 1992, as planned, owing to lack of funds.

Future proposals for action by AFRO could involve: - making efforts to find a donor, perhaps through the United Nations Children's Fund (UNICEF) or the Food and Agriculture Organization of the United Nations (FAO);

- establishing a position with respect to sickle-cell disorder in each country within AFR;

- identifying key workers;

- convening the AFRO meeting, as planned, to initiate an AFRO Working Group on Sickle-Cell Disorder.

Nigerian experience

An extended survey of 16 000 randomly selected individuals over the age of 15 from the 30 states showed that 25.3% had the AS, AC, SS or SC Hb genotypes (Table 2). Beta-thalassaemia trait could not be evaluated in these surveys: its prevalence is thought to be about 1%. These figures are considered to be generally representative for sub-Saharan Africa. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.