Introduction

Measles also known as rubeola is a viral infection. Measles is a preventable, but highly contagious, acute febrile viral illness. It remains an important cause of global mortality and morbidity, mainly in the regions of Africa and Southeast Asia. Measles is a reportable disease in most nations, including the United States.¹

 Vitamin A plays a crucial role in many important body functions, including helping us see (vision), grow, reproduce, make blood cells (deficiency leading to anaemia), and fight off illnesses (immunity). Even though we know a lot about the importance of vitamin A, not having enough of it is still a big health issue for many people. In kids, not having enough vitamin A makes them more likely to get very sick or even die from measles and diarrhoea. It can also lead to blindness and anaemia. In pregnant women, not having enough vitamin A could mean a higher chance of dying from pregnancy-related issues. A lot of these problems are connected to how vitamin A helps our immune system work. 

Association between measles and vitamin A deficiency

Vitamin A deficiency has been associated with weakened immune function, exacerbating infections, including measles. Malnourished children, particularly in developing countries, often have been observed with lower levels of vitamin A, which increases their risk of infecting with measles and experiencing severe other immune-related and overall health complications.

Causes and symptoms

Measles is caused by a virus which is an enveloped, single-stranded, nonsegmented, negative-sense RNA virus.

Transmission of measles

The causative organism of measles is the measles virus, which comes under the Paramyxoviridae family and Morbillivirus genus. Unlike many viruses, measles has no reservoir in animals and is restricted to humans. Measles is highly contagious, and each case is capable of leading to 14 to 18 secondary infections within susceptible populations. Measles spreads through person-to-person contact via respiratory droplets, small aerosols, and close contact. The incubation period for measles typically ranges from 10 to 14 days, though longer periods have been observed. Individuals at a higher risk of contracting measles include unvaccinated young children and pregnant women. Measles primarily affects young children, but there has been a recent shift towards older children and adolescents due to increased immunisation rates. Infants born to mothers with acquired immunity are initially protected from measles through passive antibody transfer, but their susceptibility increases as these antibodies diminish. Measles transmission is facilitated by close contact and airborne respiratory droplets, contributing to its high contagion rate. The incubation period of measles, averaging 10 to 14 days allows for potential spread before symptoms appear. Vulnerable populations, such as unvaccinated individuals and those with compromised immunity, are at heightened risk of measles transmission. Measles outbreaks often occur in communities with low vaccination rates, underscoring the importance of immunisation efforts in preventing disease spread.

Clinical symptoms and complications of measles

The most contagious period spans four days before and four days after the rash emerges and the presence of symptoms such as coughing, conjunctivitis, and coryza.¹ Complications of measles encompass a spectrum of conditions, including pneumonia, diarrhoea, encephalitis, and blindness, all of which pose significant health risks.

Vitamin A deficiency: causes and effects

Vitamin A, also known as retinol, is a micronutrient which plays a critical role in supporting the immune system, vision, reproduction, and cellular communication.

Factors contributing to vitamin A deficiency

• vitamin deficiency is most often related to the diet. Vitamins are complex molecules present in a wide range of food options including fruits, vegetables, grains, meat, poultry, and seafood. Various food choices offer a variety of vitamins. Not including all types of foods with vitamins in the diet can lead to vitamin deficiency
• Medical Illness such as malabsorption syndrome, liver diseases, kidney disease, inflammatory bowel disease, and chronic diarrhoea also leads to poor absorption of vitamins leading to vitamin deficiency

Impact of vitamin A deficiency on immune function

Vitamin A, also referred to as retinol, acts as an anti-infective agent by supporting immune function, specifically by increasing the expression of immunoglobulins and enhancing cellular immune response.

Evidence and research findings

1. A Study conducted by Melenotte C et.al; describes 6 adults from the Roma community in Marseille, France, who had measles and low levels of vitamin A; in which 2 persons had severe measles. Based on the study's author concludes, Vitamin A deficiency is implicated in worsening the severity of measles illness and increasing mortality rates, while also prolonging recovery and heightening the risk of ocular complications such as xerophthalmia, corneal ulceration, and blindness in children. While it remains premature to directly link vitamin A deficiency with severe measles in adult patients, there is a potential association worth considering. Adults with depleted vitamin A levels, who have not contracted measles, may face an elevated risk of experiencing a more severe form of the disease upon infection with the virus²
2. A study conducted by Villamor et al. has explored the impact of vitamin A on the antibody response to measles infection, drawing on insights from several clinical trials. Research conducted in South Africa (28) and Zambia (116) investigated the antibody response among children hospitalised with severe measles. In the study conducted in South Africa, children administered with vitamin A displayed notably higher IgG titers to the measles virus by day 8 in comparison to those given a placebo, although by day 42, there was no observable distinction. Whereas, in the Zambian study, it was observed that vitamin A did not influence measles virus antibodies at day 14. The discrepancy in results between the Zambian and South African trials could potentially be attributed to the higher dosage administered in South Africa, which was twice that of the Zambian trial before antibody assessment³

Public health interventions

Vitamin A Supplementation Programs in Integration with Measles Vaccination Campaigns: Vitamin A supplementation as part of measles vaccination campaigns in high-risk areas aims to not only reduce the incidence of measles but also to mitigate its severity and associated complications, ultimately saving lives, particularly in resource-limited settings where vitamin A deficiency is common.

Summary

The link between measles and vitamin A deficiency shows how important nutrition is in combating infectious diseases and advancing public health. Measles, being highly contagious, poses substantial threats to susceptible populations, particularly young children and those with compromised immune systems. Vitamin A deficiency further intensifies the severity and consequences of measles by heightening susceptibility to infection, worsening symptoms, and increasing the likelihood of complications and mortality.

Addressing the correlation between measles and vitamin A deficiency necessitates a comprehensive approach that integrates vaccination, nutritional interventions, and public health strategies. This multifaceted approach is essential for safeguarding vulnerable populations, reducing the burden of illness and death, and promoting global initiatives aimed at eliminating measles and enhancing child health outcomes.