Measles-induced Vitamin A Deficiency" GREGORY D. HUSSEY AND MAX KLEIN Department of Paediatrics and Child Health University of Cape Town Rondehosch 7700, South Africa
INTRODUCTION In I875 an epidemic of measles occurred in the immunologically naive population of the island of Fiji, infecting virtually every person and killing 25% of the populace.' This historical example typifies the severity of the most infectious disease known to humans. It still remains a worldwide problem despite the availability of an effective vaccine for over three decades.* Measles is endemic in the poorer developing countries where it predominantly affects children under two years of age and is estimated to cause over I .5 million deaths annually, or about 10% of all early childhood deaths in the world.3 In the developed countries it tends to occur in sporadic outbreaks, mainly in unimmunized older children and adolescents, and carries a lower case fatality rate.4 Measles also has a major impact on childhood morbidity, crippling an untold number through blindness,' chronic lung disease,' and malnutrition.' Although there is no specific therapy for measles, recent studies show that high-dose vitamin A therapy can markedly reduce morbidity and mortality from the disease. The purpose of this paper is to review the effect of measles on serum vitamin A status,8-" the effects of therapy,'?-Is and to discuss the pathogenesis of measles-induced vitamin A deficiency.
HYPORETINEMIA IN MEASLES Case-controlled studies in children with acute measles from India,8 Thailand,9 Nigeria,'O and South Africa" have all shown retinol binding protein (RBP) levels to be depressed (FIG.1) and serum vitamin A (retinol) levels to be below levels that are biologically desirable (FIG.2). During the recovery phase these levels return to control values. In a longitudinal study of 32 children in India, the serum retinol levels declined by 27%, from 16.5 pg/dL before measles to 11.1 pg/dL during the acute phase, and subsequently, after 8 weeks, returned to pre-measles levels without supplementation.8 Hyporetinemia has an adverse effect on outcome in the course of measles. A study from Zaire found that children aged
INTRODUCTION In I875 an epidemic of measles occurred in the immunologically naive population of the island of Fiji, infecting virtually every person and killing 25% of the populace.' This historical example typifies the severity of the most infectious disease known to humans. It still remains a worldwide problem despite the availability of an effective vaccine for over three decades.* Measles is endemic in the poorer developing countries where it predominantly affects children under two years of age and is estimated to cause over I .5 million deaths annually, or about 10% of all early childhood deaths in the world.3 In the developed countries it tends to occur in sporadic outbreaks, mainly in unimmunized older children and adolescents, and carries a lower case fatality rate.4 Measles also has a major impact on childhood morbidity, crippling an untold number through blindness,' chronic lung disease,' and malnutrition.' Although there is no specific therapy for measles, recent studies show that high-dose vitamin A therapy can markedly reduce morbidity and mortality from the disease. The purpose of this paper is to review the effect of measles on serum vitamin A status,8-" the effects of therapy,'?-Is and to discuss the pathogenesis of measles-induced vitamin A deficiency.
HYPORETINEMIA IN MEASLES Case-controlled studies in children with acute measles from India,8 Thailand,9 Nigeria,'O and South Africa" have all shown retinol binding protein (RBP) levels to be depressed (FIG.1) and serum vitamin A (retinol) levels to be below levels that are biologically desirable (FIG.2). During the recovery phase these levels return to control values. In a longitudinal study of 32 children in India, the serum retinol levels declined by 27%, from 16.5 pg/dL before measles to 11.1 pg/dL during the acute phase, and subsequently, after 8 weeks, returned to pre-measles levels without supplementation.8 Hyporetinemia has an adverse effect on outcome in the course of measles. A study from Zaire found that children aged
