Vitamin A for treating measles in children

 

Abstract

Background

Measles is a major cause of childhood morbidity and mortality. Vitamin A deficiency is a recognized risk factor for severe measles infections. The World Health Organization (WHO) recommends a daily oral dose of vitamin A for two days to children with measles living in areas where vitamin A deficiency may be present.

Objectives

To determine whether vitamin A, commenced after measles has been diagnosed, prevents mortality, pneumonia or other complications in children.

Search methods

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 1), which contains the Cochrane Acute Respiratory Infections Group's Specialized Register, MEDLINE (1966 to February week 3, 2011) and EMBASE (1980 to February 2011).

Selection criteria

Randomized controlled trials (RCTs) in children with measles given vitamin A or placebo, along with standard treatment.

Data collection and analysis

Two review authors independently assessed the results. We analyzed dichotomous outcomes and expressed results as risk ratios (RRs) with 95% confidence intervals (CIs). We carried out subgroup analyses for dose, formulation, age, hospitalization and pneumonia-specific mortality. We calculated mean differences (MDs) with 95% CIs for continuous outcomes.

Main results

Eight trials met the inclusion criteria (2574 participants). There was no significant reduction in the risk of mortality in the vitamin A group when all the studies were pooled (RR 0.70; 95% CI 0.42 to 1.15). The evidence suggests that vitamin A in a single dose was not associated with a reduced risk of mortality. However, two doses of vitamin A (200,000 international units (IUs) on consecutive days) reduced the mortality in children aged less than two years (RR 0.21; 95% CI 0.07 to 0.66) and pneumonia-specific mortality (RR 0.57; 95% CI 0.24 to 1.37). Two doses of vitamin A reduced the incidence of croup (RR 0.53; 95% CI 0.29 to 0.89) but not pneumonia morbidity (RR 0.92; 95% CI 0.69 to 1.22), nor diarrhea morbidity (RR 0.80; 95% CI 0.27 to 2.34). None of the studies included in this review reported any adverse effects.

Authors' conclusions

No overall significant reduction in mortality with vitamin A therapy for children with measles was found. However two doses reduced overall and pneumonia-specific mortality in children aged less than two years. No trials directly compared a single dose with two doses.

 

Plain language summary

Vitamin A for measles in children

Measles is caused by a virus and possible complications include pneumonia. Measles is a major cause of death in children in low-income countries and is particularly dangerous in children with vitamin A deficiency. Eight studies involving 2574 participants were included in this review and we found that there was no significant reduction in mortality in children receiving vitamin A. However, vitamin A megadoses (200,000 international units (IUs) on each day for two days) lowered the number of deaths from measles in hospitalized children under the age of two years. Two doses of vitamin A are not considered to be too expensive, and are not likely to produce adverse effects.

The authors conclude that vitamin A megadoses appear effective in reducing mortality from measles in children under two years old and have few associated adverse events. There is insufficient evidence to draw conclusions regarding effectiveness in preventing pneumonia or other complications in children. However, the quality of the evidence was generally moderate. Better quality randomized trials are needed to evaluate the efficacy of Vitamin A for treating measles in children.

 

摘要

背景

維生素A(vitamin A)治療兒童麻疹(measles)

麻疹是兒童致病與致死的主要原因。維生素A缺乏症是一種已知會造成嚴重麻疹感染的危險因素。世界衛生組織(World Health Organization；WHO)建議在可能有維生素A缺乏症的地區，給予罹患麻疹的兒童每日口服200,000國際單位(international units；IU)；或嬰兒100,000國際單位共2天。

目標

確定在兒童麻疹確診後，給予維生素A治療是否有利於防止死亡、肺炎及其他次要併發症。

搜尋策略

我們搜尋了Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2005)資料庫。同時也搜尋了MEDLINE(1966年至2005年3月)、EMBASE(1980年至2004年12月)等資料庫及其他未發表的研究結果。

選擇標準

我們只收納針對感染麻疹的兒童，在標準治療之外，加上維生素A或者安慰劑的隨機對照試驗 。

資料收集與分析

這些研究是由兩位作者獨立評估。二分結果(dichotomous outcomes)的分析是用StatXact軟體；其結果以相對危險度(relative risk；RR)和95％信賴區間(confidence interval；CI)表示；並對劑量、劑型、年齡、住院和肺炎的死亡率進行次群體分析(subgroup analyses)。針對連續性結果(continuous outcomes)則計算加權平均差異(Weighted mean differences；WMD)及95％信賴區間。

主要結論

集合所有研究並使用隨機作用模型(randomeffects model)後發現，維生素A組並無法顯著降低死亡率(RR 0.70; 95% CI 0.42 to 1.15)。連續給予2個劑量的維生素A(200,000國際單位)可在2歲以下兒童減少死亡率(RR 0.18; 95% CI 0.03 to 0.61)並減少肺炎死亡率(RR 0.33; 95% CI 0.08 to 0.92)。並沒有證據顯示單一劑量的維生素A可降低兒童麻疹的死亡率。給予2個劑量的維生素A可減少哮吼的發生率(RR 0.53; 95% CI 0.29 to 0.89)；但只有非顯著性地降低肺炎(RR 0.92; 95% CI 0.69 to 1.22)與腹瀉(RR 0.80; 95% CI 0.27 to 2.34)的發生率。

作者結論

雖然給予維生素A治療兒童麻疹無法顯著降低死亡率；但有證據表明，使用2個劑量的維生素A可在2歲以下兒童減少死亡率與肺炎的死亡率。目前並無任何文獻直接比較單一劑量與2個劑量。

翻譯人

本摘要由臺灣大學附設醫院耿立達翻譯。

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

給予2個大劑量維生素A可降低在2歲以下感染麻疹的住院兒童的死亡風險；但並非所有兒童麻疹患者皆然。 麻疹是由病毒引起的；會導致發高燒與皮疹。可能的併發症包括肺炎。麻疹是發展中國家的兒童死亡的主要原因；特別是有維生素A缺乏症的兒童。這篇文獻顯示當集合所有研究後，給予維生素並無法顯著降低兒童的死亡率。然而， 大劑量維生素A(每日200,000國際單位共2天)可降低在2歲以下感染麻疹的住院兒童的死亡。單一劑量並不會降低死亡率。