Association between nutritional status and dengue infection: a systematic review and meta-analysis.
BACKGROUND
Dengue infection has various clinical manifestations, often with unpredictable clinical evolutions and outcomes. Several factors including nutritional status have been studied to find the relationship with dengue severity. However, the nutritional status had conflicting effects on the complication of dengue in some previous studies. Therefore, we conducted a systematic review and performed a meta-analysis to analyze the association between nutritional status and the outcome of dengue infection.


METHODS
Eleven electronic databases and manual searching of reference lists were used to identify the relevant studies published before August 2013. At least two authors worked independently in every step to select eligible studies and extract data. Dengue severity in the included studies must be classified into three categories: dengue fever (DF), dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS).


RESULTS
Thirteen articles that met the inclusion criteria came to final analysis. A meta-analysis using fixed- or random-effects models was conducted to calculate pooled odds ratios (OR) with corresponding 95 % confidence intervals. It has shown that there was no statistically significant association between DHF group and DSS group in malnutritional and overweight/obesity patients with OR: 1.17 (95 % CI: 0.99-1.39), 1.31 (0.91-1.88), respectively. A significantly inverse relation between DF and DHF groups of malnutritional patients was revealed (OR = 0.71, 95 % CI: 0.56-0.90). Our meta-analysis also indicated a statistically significant negative correlation between malnourished children with dengue virus infection and healthy children (OR = 0.46, 95 % CI: 0.3-0.70). When analyzing patients with normal nutrition status, we found out that there was a significantly negative relationship between DHF and DSS groups (0.87; 95 % CI: 0.77-0.99). Other comparisons of DSS with DF/DHF groups, DSS/DHF with DF groups, and DHF with DF groups in normal nutritional patients showed no significant correlation. However, the findings should be interpreted cautiously because all significant associations were lost after removing of the largest study.


CONCLUSIONS
Results from previous studies failed to show any solid consistency regarding the association between the nutritional status and dengue infection. Consequently, the effects of nutritional status on dengue disease outcome has been controversial. Further studies are recommended to clarify the impact of nutritional status on dengue infection.
Hue University of Medicine and Pharmacy, Hue City, Vietnam.|Online Research Club, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.
Nguyen Thi Huyen
NTH
Trang
Online Research Club, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.|University of Medicine and Pharmacy, Ho Chi Minh City, Vietnam.
Nguyen Phuoc
NP
Long
Online Research Club, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.|Hanoi Medical University, Ha Noi, Vietnam.
Tran Thi Minh
TTM
Hue
Online Research Club, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.|University of Medicine and Pharmacy, Ho Chi Minh City, Vietnam.
Le Phi
LP
Hung
Online Research Club, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.|Da Nang University of Medical Technology and Pharmacy, Da Nang city, Vietnam.
Tran Dinh
TD
Trung
Online Research Club, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.|Health Strategy and Policy Institute (HSPI), Ha Noi, Vietnam.
Doan Ngoc
DN
Dinh
Online Research Club, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.|University of Medicine and Pharmacy, Ho Chi Minh City, Vietnam.
Nguyen Thien
NT
Luan
Online Research Club, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan. tienhuy@nagasaki-u.ac.jp.|Department of Clinical Product Development, Institute of Tropical Medicine (NEKKEN), Leading Graduate School Program, and Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan. tienhuy@nagasaki-u.ac.jp.
Nguyen Tien
NT
Huy
Department of Immunogenetics, Institute of Tropical Medicine (NEKKEN), Leading Graduate School Program, and Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan. hiraken@nagasaki-u.ac.jp.
Kenji
K
Hirayama
D016208:Databases, Factual; D003715:Dengue / Q000175:diagnosis* / Q000473:pathology / Q000821:virology; D003716:Dengue Virus / Q000302:isolation & purification; D006801:Humans; D044342:Malnutrition; D009752:Nutritional Status; D009765:Obesity / Q000473:pathology; D016017:Odds Ratio; D012720:Severity of Illness Index
Dengue; Meta-analysis; Nutritional status; Systematic review