Association between nutritional status and dengue severity in Thai children and adolescents.

Most cases of dengue virus infection are mild, but severe cases can be fatal. Therefore, identification of factors associated with dengue severity is essential to improve patient outcomes and reduce mortality. The objective of this study was to assess associations between nutritional status and dengue severity among Thai children and adolescents. This retrospective cross-sectional study was based on the medical records of 355 patients with dengue treated at the Hospital for Tropical Disease (Bangkok, Thailand) from 2017 to 2019. Subjects were Thai children aged less than 18 years with dengue virus infection confirmed by positive NS1 antigen or IgM. The 1997 and 2009 World Health Organization (WHO) dengue classifications were used to define disease severity and body mass index for age while the WHO growth chart was used to classify nutritional status. The proportions of patients with dengue fever who were underweight, normal weight, and overweight were 8.8%, 61.5%, and 29.7%, respectively. The proportions of patients with dengue haemorrhagic fever (DHF) who were underweight, normal weight, and overweight were 10.2%, 66.1%, and 23.7%, respectively. The proportions of patients with non-severe dengue who were underweight, normal weight, and overweight were 8.6%, 60.9%, and 30.5%, respectively; the same proportions of patients with severe dengue were 10.5%, 67.1%, and 22.4%, respectively. Higher proportions of patients with severe plasma leakage (DHF grade III and IV) were overweight compared with those with mild plasma leakage (DHF grade I and II) (45.5% vs. 18.8%). No difference in nutritional status was observed in patients with different dengue severity.

Introduction

Dengue is a common mosquito-borne disease and is distributed worldwide, especially in tropical and subtropical areas. The disease results from infection by dengue virus, a positive single-stranded RNA virus in the family Flaviviridae [1]. More than a hundred countries have recorded cases of dengue. In 2010, it was estimated that the numbers of detected and undetected dengue infections worldwide were 294 million and 96 million, respectively [2].

Most individuals with dengue will experience mild illness, but severe cases and deaths represent one third and two percent of those who are hospitalized, respectively [3]. Therefore, dengue infection remains a global health concern, and recognition of severe disease is necessary to decrease mortality and improve patient outcomes. However, identification of factors associated with severe dengue is challenging, and the roles of some factors and their impacts on dengue infection remain unclear. Moreover, nutritional status is also a global health issue including both under-nutrition and over-nutrition. According to a malnutrition report from the World Health Organization (WHO), more than 200 million children were stunted, wasting, or overweight; additionally, 45% of deaths among children under the age of 5 years were associated with nutritional factors [4]. Both under and over nutrition are health issue. In Thailand, overweight had been appeared an emerging disorder. The prevalence of obesity from 3 to 18 years old of children and adult were 9.1% and 6.5% respectively [5]. However, the rate could be changed from urban and rural population.

Significantly, nutrition was matter to immune functions which it could influence on genomics and metabolisms, and the role of adipose tissue in overweight could stimulate more inflammatory mediators which leading to increase capillary permeability and plasma leakage [6,7]. However, whether nutritional status is really the risk of severe dengue, there might need more further evidences. The potential association between nutritional status and dengue severity remains controversial. A systematic review conducted in 2016 was unable to show a significant association between nutritional status and dengue severity [8]. Therefore, the objective of this study was to identify associations between nutritional status and dengue severity in children and adolescents. These data will contribute to the evidence base regarding the role of nutritional status in dengue infection and may raise awareness among clinicians and researchers to improve patient’s outcome.

Materials and methods

Ethics statement

This study was approved by the director of the Hospital for Tropical Diseases and Ethics Committee of the Faculty of Tropical Medicine, Mahidol University (EC Approval MUTM 2020-020-01). The formal consent was not obtained due to the retrospective study design. However, all medical records were anonymous.

Study design and setting

This was a cross-sectional study conducted at the Hospital for Tropical Diseases, Bangkok, Thailand. All available medical records of paediatric patients who diagnosed dengue infection were retrieved from both outpatient and inpatient departments from 1 January 2017 to 31 December 2019. All Thai children aged less than 18 years with acute dengue infection confirmed by positive NS1 antigen or IgM were included. Patients were excluded if data were unavailable on nutritional status (e.g. age, weight and height) and/or dengue severity (e.g. haematocrit on defervescent date and its baseline, vital signs and bleeding information). Pre-set Case Record Form were used to check eligibilities and extracted specific information related to dengue severity and nutritional status from patient records.

Operating definitions

For assessing nutritional status, patient weight and height were measured on the first day of hospitalization and used to calculate body mass index (BMI). The 2006 WHO growth chart for children aged 0 to 5 years [9] and the 2007 WHO growth chart for children aged 5 to 19 years were used to classify nutritional status [10]. In accordance with the 2006 WHO growth chart, underweight was defined as < -2 standard deviations (SD), normal weight was defined as -2 SD to + 2 SD, overweight was defined as > +2 SD, and obesity was defined as > +3 SD. In accordance with the 2007 WHO growth chart, underweight was defined as < -2 SD, normal weight was defined as -2 SD to +1 SD, overweight was defined as > +1 SD, and obesity was defined as > +2 SD.

The 1997 and 2009 WHO guidelines on dengue infection were used to classify dengue severity. Diagnoses of dengue fever (DF) and dengue haemorrhage fever (DHF) were made after the critical phase in accordance with the 1997 WHO classification, and diagnoses of severe dengue were made in accordance with the 2009 WHO classification [11,12]. The day of defervescence was defined as when fever had resolved for at least 24 hours. For in case of dengue classification disagreement between final diagnosis in medical record and investigator’s judgment, it would be re-justified by the group of independent paediatricians.

Statistical analysis

SPSS version 18.0 (SPSS Inc., Chicago, IL, USA) was used for statistical analysis. Data were summarized using descriptive statistical methods including frequencies, percentages, proportions, median, and interquartile ranges (IQR). The Chi-square test as well as odd ratios (ORs) and 95% confidence intervals (CIs) were used to assess associations between categorical variables. Non-parametric tests were used to determine the difference between continuous variables. Two-tailed values of P<0.05 were considered statistically significant.

Results

Demographic data

A total of 574 medical records were screened against the inclusion and exclusion criteria. After review, 355 cases were included and 219 cases were excluded as age were greater than 17 years (112 cases), non-Thai (37 cases), unavailable result of laboratory confirmed dengue infection (44 cases), and unavailable clinical data (26 cases). Among these 355 patients, 243 (68.4%) were inpatients and 179 (50.4%) visited the hospital in 2018. Most patients (79.4%) were between the ages of 11 and 17 years with a median age of 15 years. The male to female ratio was 1.6:1. Fifty-two (14.6%) patients had underlying diseases, most commonly allergic rhinitis (7.9%), G6PD deficiency (2.3%), and thalassemia minor (1.7%). Seventeen (4.8%) patients had co-infections. Most patients (99.7%) fully recovered. The one patient who died was an obese 8-year-old boy who presented with profound shock, severe plasma leakage, and bleeding with fluid overload (Table 1).

Table 1

Demographic data, nutritional status and dengue clinical classifications.

Characteristics	Total(n = 355)	OPD cases(n = 112)	IPD cases(n = 243)	P-value
Age, years [median (IQR)]	15 (12–16)	13 (9–16)	15 (13–16)	0.001
Age groups, n (%)
• 0–2 years	2 (0.6)	1 (0.9)	1 (0.4)	0.57
• 3–5 years	15 (4.2)	8 (7.1)	7 (2.9)	0.64
• 6–10 years	56 (15.8)	28 (25.0)	28 (11.5)	0.01
• 11–14 years	103 (29.0)	32 (28.6)	71 (29.2)	0.9
• 15–17 years	179 (50.4)	43 (38.4)	136 (56.0)	0.02
Male: female, n (ratio)	221: 134(1.6: 1)	63: 49(1.2: 1)	158: 85(1.8: 1)	0.11
Year, n (%)
• Year 2017	77 (21.7)	24 (21.4)	53 (21.8)	0.57
• Year 2018	179 (50.4)	52 (46.4)	127 (52.3)	0.30
• Year 2019	99 (27.9)	36 (32.1)	63 (25.9)	0.22
Length of hospitalization, days [median (IQR)]	4 (3–5)	n/a	4 (3–5)	n/a
Prior medical consultation, n (%)	204 (57.5)	34 (30.4)	170 (70.0)	< 0.01
Duration of fever at first visit, n (%)
• 1–3 days	241 (67.9)	86 (76.8)	155 (63.8)	0.01
• ≥ 4 days	114 (32.1)	26 (23.2)	88 (36.2)
Underlying diseases, n (%)
• Allergy rhinitis	28 (7.9)	12 (10.7)	16 (6.6)	0.18
• G6PD deficiency	8 (2.3)	0	8 (3.3)	0.05
• Thalassemia minor	6 (1.7)	0	6 (2.4)	0.09
• Others	10 (2.8)	0	10 (4.1)	0.02
Co-infection, n (%)
• Bacterial infection	6 (1.7)	0	6 (2.4)	0.09
• Viral infection	4 (1.1)	3 (2.6)	1 (0.4)	0.06
• Sepsis (unknown cause)	7 (2.0)	0	7 (2.9)	0.07
Outcome, n (%)
• Recovery	354 (99.7)	112 (100)	242 (99.6)	0.49
• Death	1 (0.3)	0	1 (0.4)
Nutritional status, n (%)
• Underweight	32 (9.0)	10 (8.9)	22 (9.1)	0.97
• Normal	221 (62.3)	70 (62.5)	151 (62.1)	0.94
• Overweight*	102 (28.7)	32 (28.6)	70 (28.8)	0.96
(Obesity)	57 (16.0)	17 (15.2)	40 (16.5)	0.76
Diagnosis according to WHO 1997 classification, n (%)
• DF	296 (83.4)	109 (97.3)	187 (77.0)	<0.01
• DHF grade I	36 (10.1)	3 (2.7)	33 (13.6)	0.02
• DHF grade II	12 (3.4)	0	12 (4.9)	0.01
• DHF grade III	10 (2.8)	0	10 (4.1)	0.02
• DHF grade IV	1 (0.3)	0	1 (0.4)	0.49
Diagnosis according to WHO 2009 classification, n (%)
• Non-severe dengue	279 (78.6)	109 (97.3)	170 (70.0)	<0.01
• Severe dengue	76 (21.4)	3 (2.7)	73 (30.0)

Abbreviations: IQR, interquartile range; OPD, out-patient department; IPD, In-patient department; WHO, World Health Organization; DF, dengue fever; DHF, dengue haemorrhagic fever; G6PD, glucose-6-phosphate dehydrogenase n/a: Not applicable

*Overweight: > +2 SD BMI for ages 0 to <5 years; > +1 SD BMI for ages 5 to 17 years.

Association between nutritional status and dengue severity

Tables 2 and 3 show the distribution of dengue severity according to the 1997 and 2009 WHO classifications and nutritional status. Twenty-six (8.8%), 182 (61.5%), and 88 (29.7%) patients with DF (n = 296) were underweight, normal weight, and overweight, respectively. Six (10.2%), 39 (66.1%), and 14 (23.7%) patients with DHF (n = 59) were underweight, normal weight, and overweight, respectively. According to the WHO 2009 classification, 24 (8.6%), 170 (60.9%), and 85 (30.5%) patients with non-severe dengue (n = 279) were underweight, normal weight, and overweight, respectively while 8 (10.5%), 51 (67.1%), and 17 (22.4%) patients with severe dengue (n = 76) were underweight, normal weight, and overweight, respectively.

Table 2

Patient’s characteristics by 1997 WHO classification.

Patient’s characteristics[n(%)]	DF	DHF (n = 59)				P-value	P-value
	(n = 296)	gr. I(n = 36)	gr. II(n = 12)	gr. III (n = 10)	gr. IV(n = 1)	DF vs DHF	DHF gr. I, II vsDHF gr. III, IV
Age 15–17 years	141 (47.6)	24 (66.7)	6 (50.0)	8 (80.0)	0	0.01	0.52
Male	180 (60.8)	24 (66.7)	9 (75.0)	7 (70.0)	1 (100)	0.20	0.79
IPD	187 (63.2)	33 (91.7)	12 (100)	10 (100)	1 (100)	<0.01	0.39
Underlying diseases	44 (14.9)	6 (16.7)	2 (16.7)	1 (10.0)	0	0.79	0.63
Clinical presentation
Clinical bleeding	50 (18.9)	0	12 (100)	0	1 (100)	0.34	0.25
Major organ involvement
• Transaminitis    (ALT >100U/L)	40/196 (20.4)	10/33 (30.3)	3 (25.0)	3 (30.0)	1 (100)	0.11	0.62
• Creatinine > 1.5 mg/dL	0	0	0	0	1 (100)	0.09	0.11
• Respiratory distress	2 (0.67)	0	0	2 (20.0)	1 (100)	<0.01	<0.01
Treatments
• Colloidal solution	0	1 (2.7)	1 (8.3)	3 (30.0)	1 (100)	<0.01	0.01
• Blood transfusion	0	0	2 (16.7)	2 (20.0)	1 (100)	<0.01	0.01
Nutritional status
• Underweight	26 (8.8)	4 (11.2)	2 (16.7)	0	0	0.73	0.58
• Normal	152 (61.5)	25 (69.4)	8 (66.7)	6 (60.0)	0	0.50	0.37
• Overweight	88 (29.7)	7 (19.4)	2 (16.7)	4 (40.0)	1 (100)	0.35	0.06
(Obesity)	50 (16.9)	3 (8.3)	2 (16.7	1 (10.0)	1 (100)	0.33	0.60

Abbreviations: WHO, World Health Organization; DF, dengue fever; DHF, dengue haemorrhage fever; gr.,grade; n, number; IPD, in-patient department; ALT, alanine transaminase; U/L, units per litre; mg/dL, milligrams per litre

Table 3

Patient’s characteristics by 2009 WHO classification.

Patient’s characteristics[n(%)]	Non-severe dengue(n = 279)	Severe dengue (n = 76)				P-value
		Total(n = 76)	Severe bleeding(n = 29)	Plasma leakage / shock(n = 59)	Major organ involvement(n = 24)	non-severe vs severe
Age 15–17 years	133 (37.7)	46 (60.5)	13 (44.8)	38 (64.4)	18 (75.0)	0.04
Male	179 (64.2)	42 (55.3)	10 (34.5)	41 (69.5)	18 (75.0)	0.15
IPD	170 (60.9)	73 (96.1)	29 (100)	56 (94.9)	24 (100)	<0.01
Underlying diseases	43 (15.4)	9 (11.8)	2 (6.9)	8 (13.6)	3 (12.5)	0.43
Major organ involvement
• Transaminitis    (ALT >100U/L)	35/182 (19.2)	22/70 (31.4)	8/26 (30.8)	17/56 (30.4)	22 (91.7)	0.03
• Creatinine > 1.5 mg/dL	0	1/38 (2.6)	1/12 (8.3)	1/34 (2.9)	1/15 (6.7)	0.12
• Respiratory distress	2 (0.7)	3 (3.9)	1 (3.4)	3 (5.1)	3 (12.5)	0.03
Treatment
• Colloidal solution	0	5 (6.6)	1 (3.4)	5 (8.5)	2 (8.3)	<0.01
• Blood transfusion	0	5 (6.6)	3 (10.3)	5 (8.5)	3 (12.5)	<0.01
Nutritional status
• Underweight	24 (8.6)	8 (10.5)	4 (13.8)	6 (10.2)	1 (4.2)	0.60
• Normal	170 (60.9)	51 (67.1)	19 (65.5)	39 (66.1)	18 (75)	0.32
• Overweight	85 (30.5)	17 (22.4)	6 (20.7)	14 (23.7)	5 (20.8)	0.16
(Obesity)	49 (17.6)	8 (10.5)	4 (13.8)	7 (11.9)	3 (12.5)	0.13

Abbreviations: WHO, World Health Organization; n, number; IPD, in-patient department; ALT, alanine transaminase; U/L, units per litre; mg/dL, milligrams per litre

Tables 4 and 5 show associations between nutritional status and dengue severity. The odds ratio (OR) of underweight in patients with DHF was 1.17 (95% CI 0.46–2.99, P = 0.73) while that of overweight was 0.73 (95% CI 0.38–1.40, P = 0.35). The OR of underweight in patients with severe dengue was 1.25 (95% CI 0.53–2.90, P = 0.60) while that of overweight was 0.65 (95% CI 0.36–1.19, P = 0.16). Thus, there were no statistically significant associations between nutritional status and DHF or severe dengue. However, the proportion of patients with dengue shock syndrome (DHF grade III and IV) who were overweight (5/11; 45.5%) was higher than the same proportion among patients with mild plasma leakage (DHF grade I and II) (9/48; 18.8%) (OR 3.61, 95% CI 0.90–14.5, P = 0.06) as shown in Table 2.

Table 4

Association between nutritional status and dengue severity according to the 1997 WHO classification.

Nutritional status[n(%)]	DHF(n = 59)	DF(n = 296)	odds ratio(95% CI)	P-value
Underweight (n = 32)	6 (10.2)	26 (8.8)	1.17 (0.46.-2.99)	0.73
Overweight (n = 102)	14 (23.7)	88 (29.7)	0.73 (0.38–1.40)	0.35
Obese (n = 57)	7 (11.9)	50 (16.9)	0.66 (0.28–1.54)	0.33

Abbreviations: DHF, dengue haemorrhagic fever; DF, dengue fever; CI, confidential interval

Table 5

Association between nutritional status and dengue severity according to the 2009 WHO classification.

Nutritional status [n(%)]	Severe dengue (n = 76)	Non-severe dengue(n = 279)	odds ratio(95% CI)	P-value
Underweight (n = 32)	8 (10.5)	24 (8.6)	1.25 (0.53–2.90)	0.60
Overweight (n = 102)	17 (22.4)	85 (30.5)	0.65 (0.36–1.19)	0.16
Obese (n = 57)	8 (10.5)	49 (17.6)	0.55 (0.24–1.22)	0.13

Abbreviation: CI, confidential interval

Discussion

The overall distribution of nutritional status among children with dengue in this study was as follows: underweight (9.0%), normal weight (62.3%), and overweight/obese (28.7%). This finding suggested that a relatively high proportion of children with dengue are overweight in Thailand. However, our results were derived from a single study centre located in the capital city. The study site was also a tertiary care hospital and therefore the characteristics of patients tended to be more serious. In this study, the proportions of patients with DHF (16.6%) and severe dengue (21.4%) may not reflect the general distribution of dengue severity in the Thai population. The result of study also demonstrated higher proportion of severe dengue and DHF in the older children which may relate to more severity in the secondary dengue infection. In this study, 52 (14.6%) patients who had underlying diseases were included in analysis because they were mild conditions and had no difference in distribution among dengue severity.

The major goal of this study was to assess associations between nutritional status and dengue severity. as human immunity was lined with nutrition. Weight for height was used to classify nutritional status, weight on the first day of visit may not reflect the ideal underlying weight due to loss of appetite, however it was the practical underlying weight. In addition, BMI for age of WHO growth charts were used as they could be accepted widely and internationally by others. Similar patterns of distribution of nutritional status were observed in patients with DF vs. DHF and patients with non-severe vs. severe dengue: most patients had normal weights, followed by overweight and underweight. This finding may vary depending on the criteria used to classify nutritional status and dengue severity. We did not identify any statistically significant associations between dengue severity and nutritional status, although higher proportions of patients with dengue shock syndrome (DHF grade III/IV) (5/11; 45.5%) were overweight/obese compared with those with DHF grades I and II (9/48; 18.8%). However, this result may have arisen from the small number of patients with severe dengue studied.

Using another type of statistical analysis, Z-scores for the BMI in each patient which may provide a fine details of nutrition status, were also calculated using the WHO growth charts as references. Independent t-tests comparing Z-scores in patients with different dengue severity did not reveal any associations between dengue severity and nutritional status (S1 and S2 Tables).

In a previous study applying the 1997 WHO criteria, the distribution of nutritional status among a large group of Thai children with DF and DHF was similar to that observed in our study: the majority of children were normal weight, followed by overweight and then underweight [13]. However, the study used weight for age and a Thai growth chart to classify nutritional status. Another study applied the 2009 WHO criteria and found a slightly different distribution of nutritional status compared with our study: the proportions of underweight and overweight in patients with non-severe dengue or severe dengue without shock were 14% and 23%, respectively, while in patients with dengue shock syndrome these proportions were 11.6% and 27%, respectively [14]. In agreement with our findings, a systematic review found that the ORs (95% CIs) of dengue shock syndrome compared with DHF grade I/II in overweight and underweight children were 1.31 (0.91–1.88) and 1.17 (0.99–1.39), respectively [8]. The systematic review also showed that 25% of obese children developed severe dengue compared with 22.7% of non-obese children (OR 1.38; 95% CI 1.10–1.73) [15]. However, these results were derived from pooled data from 15 studies that used various classifications of nutritional status.

Conclusions

The distributions of nutritional status by dengue severity using the 1997 and 2009 WHO classifications were similar. However, there was a trend toward higher prevalence of overweight in patients with dengue shock syndrome compared with those with mild plasma leakage (45.5% vs. 18.8%). Larger prospective studies may be necessary to more accurately assess associations between nutritional status and dengue severity.

Z score of BMI and dengue severity according to the 1997 WHO classification.

(DOCX)

Click here for additional data file.

Z score of BMI and dengue severity according to the 2009 WHO classification.

(DOCX)

Click here for additional data file.

22 Nov 2021

Dear Dr. Limkittikul,

Thank you very much for submitting your manuscript "Association between nutritional status and dengue severity in Thai children" for consideration at PLOS Neglected Tropical Diseases. As with all papers reviewed by the journal, your manuscript was reviewed by members of the editorial board and by several independent reviewers. In light of the reviews (below this email), we would like to invite the resubmission of a significantly-revised version that takes into account the reviewers' comments.

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Reviewer's Responses to Questions

Key Review Criteria Required for Acceptance?

As you describe the new analyses required for acceptance, please consider the following:

Methods

-Are the objectives of the study clearly articulated with a clear testable hypothesis stated?

-Is the study design appropriate to address the stated objectives?

-Is the population clearly described and appropriate for the hypothesis being tested?

-Is the sample size sufficient to ensure adequate power to address the hypothesis being tested?

-Were correct statistical analysis used to support conclusions?

-Are there concerns about ethical or regulatory requirements being met?

Reviewer #1: The study design is not fully appropriate for the stated objectives.

• Suggest to compare OPD and IPD group to see any different in their nutritional status or not and analyze each group separately?

• Suggest to add more detail of clinical and hospital management, eg. complications (hepatitis, AKI, bleeding,…), Dextran, blood transfusion, Length of stay in the hospital

Reviewer #2: The authors did not describe a designed retrospective chart review with the classification of dengue severity based on both the 1997 and 2009 Dengue WHO guidelines.

- They did not show how they sample, record, and review the dengue cases as well as confirm the classifications.

- Furthermore, they should clarify why they included the dengue cases with underlying diseases in the study.

Reviewer #3: o 0-17 years is a *huge* age range. I would strongly suggest to do some sort of adjustment or stratification across age groups. It is possible that if an association exists, it is different in the very young vs. adolescents.

o I would also suggest adjusting for sex of the child in addition.

o Is there a reason why 11-17y are together in one group? This is almost 80% of the sample, could split this group.

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Results

-Does the analysis presented match the analysis plan?

-Are the results clearly and completely presented?

-Are the figures (Tables, Images) of sufficient quality for clarity?

Reviewer #1: The results are not clearly and completely presented.

Figure 1 – prefer to present as tables with p-values

Table 1

• Suggest to add 2 more columns of OPD (n = 113), IPD (n = 242) group in Table 1.

• Underlying diseases may be excluded because this contributes to more severe disease and complication? If underlying disease remained in the manuscript, please specify in each category of the nutritional status.

• Parasite infection, please specify. If only minor parasitic infection without fever or systemic signs and symptoms, they may be omitted in underlying diseases?

Table 2 & 3

• Suggest to add another 2 tables of % of DSS, DHF, DF and Severe, non-severe dengue in and please clarify category of severe dengue, whether shock, respiratory distress, bleeding or organ (s) failure.

• Separate OPD and IPD group will be presented as in Table 2 &3.

Results

• Page 5 – explanation of Figure 1, please add % of obese patients in both WHO 1997 and 2009 classifications. In WHO 1997, please add 5 of DSS and DHF separately. In WHO 2009, please add detail category of severe dengue, i.e. shock, respiratory distress, bleeding or organ (s) involvement.

• Page 7, first paragraph: please re-calculate % of normal weight (62.3%) and overweight/obese (28.7%). The number for normal weight = 164, overweight = 102 and overweight = 57 and the total number = 355 patients.

Reviewer #2: - For Figure 1, instead of the bar chart, the data should be represented in Table to more clarify and reduce repeated picture.

- The clinical characteristics of pediatric patients should be represented and shown the differences among groups.

Reviewer #3: Results

o Add an explanation of why cases were excluded (574 records were screened and 355 met inclusion/exclusion criteria) – could add information that XX were over 18y, xx did not have nutritional status, etc.

• Table 2 and Table 3

o Incorrect labelling, the first column is not “n(%)” – that is rather for the 2nd and 3rd columns (and an accurate heading should be put for the first column information)

o Add what the reference group is (tables should be self-contained)

o Define all acronyms used in the table (tables should be self-contained)

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Conclusions

-Are the conclusions supported by the data presented?

-Are the limitations of analysis clearly described?

-Do the authors discuss how these data can be helpful to advance our understanding of the topic under study?

-Is public health relevance addressed?

Reviewer #1: The conclusion will depend on the suggested study design.

Reviewer #2: The authors may discuss why to choose the BMI-for-age Z-score as an indicator based on WHO nutritional classification, instead of WHZ based on Thai Growth chart.

Reviewer #3: Discussion

o It seems like the authors looked for something and did not find it.. but it is difficult as the reader to piece together why they were looking for it in the first place. From this paper, I was not convinced that this was worth looking for or what they really added to the literature on this topic. I would have expected an explanation of the biological plausibility, rationale, and implications for clinical work / policy that makes this topic worth examining.

o A systematic review was cited so it seems this is worth examining but there was little to no justification of why this is helpful to look into for the reader of this paper. Add this so that the reader understands the biological plausibility and relevance, in particular, of an association between overweight/obesity and mild plasma leakage.

o Weight was taken on the first day of hospitalization. Add a point to the discussion of the potential bias that this may have (if weight loss already occurred during the disease progression prior to hospital admittance)? Or why this should *not* be an issue.

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Editorial and Data Presentation Modifications?

Use this section for editorial suggestions as well as relatively minor modifications of existing data that would enhance clarity. If the only modifications needed are minor and/or editorial, you may wish to recommend “Minor Revision” or “Accept”.

Reviewer #1: As in the above suggestion

Reviewer #2: (No Response)

Reviewer #3: (No Response)

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Summary and General Comments

Use this section to provide overall comments, discuss strengths/weaknesses of the study, novelty, significance, general execution and scholarship. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. If requesting major revision, please articulate the new experiments that are needed.

Reviewer #1: To identify the association between nutritional status and dengue severity need the same population, i.e. only the admitted patients. OPD patients, about 1/3 of the study population in this study tend to have milder illness that may interfere with the results of the study.

Reviewer #2: Please specify how the data was extracted and by whom as well as reviewed and confirmed in the classifications.

Please clearly state inclusion/exclusion criteria with a brief rationale.

Please reveal the clinical characteristics of patients.

Reviewer #3: What was the distribution of nutritional status of the general population that you were looking at (children in urban Thailand/Bangkok)?

o To do this you could look at distribution of all at the clinic / or a comparison group (with another, clearly unrelated condition – or those children coming for wellness checks and therefore presumably healthy?)

o Published survey data from a large survey done in Bangkok recently (or at least in urban areas of Thailand?)

o For example, this national survey has much lower %s of overweight and obesity:

�  National survey of overweight/obesity: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5824639/

o This more recent article, however, mentions a survey with numbers more even higher than what was found in this study (36% obesity in high school students and 19.6% in primary-school-age children). But they don’t cite the specific survey.. (https://www.bumrungrad.com/en/health-blog/october-2019/child-obesity-becoming-a-growing-problem)

o Overall, my point is that these numbers need some context. How is this population of children different from this age group living in Bangkok? Even without collecting/calculating anything further you can add this information. In particular, among those 11-17y as that makes up the vast majority of the sample.

Introduction

o The rationale why you are looking at this association in the first place remains unclear. Justify why it is thought that underweight and, in particular, overweight may be associated with more severe dengue outcomes.

o Be more explicit about what this will mean for clinicians and researchers – if you find there is an association.

o I would call them children and adolescents. It seems a bit misleading to say just children when almost 80% are 11-17 years.

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Reviewer #1: Yes: Professor Siripen Kalayanarooj

Reviewer #2: No

Reviewer #3: No

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28 Feb 2022

Submitted filename: Responding to Reviewers-10-2-22.docx

Click here for additional data file.

6 Apr 2022

Dear Dr. Limkittikul,

We are pleased to inform you that your manuscript 'Association between nutritional status and dengue severity in Thai children and adolescents' has been provisionally accepted for publication in PLOS Neglected Tropical Diseases.

Before your manuscript can be formally accepted you will need to complete some formatting changes, which you will receive in a follow up email. A member of our team will be in touch with a set of requests.

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Thank you again for supporting Open Access publishing; we are looking forward to publishing your work in PLOS Neglected Tropical Diseases.

Best regards,

Olaf Horstick, FFPH(UK)

Associate Editor

PLOS Neglected Tropical Diseases

Sergio Recuenco

Deputy Editor

PLOS Neglected Tropical Diseases

***********************************************************

Reviewer's Responses to Questions

Key Review Criteria Required for Acceptance?

As you describe the new analyses required for acceptance, please consider the following:

Methods

-Are the objectives of the study clearly articulated with a clear testable hypothesis stated?

-Is the study design appropriate to address the stated objectives?

-Is the population clearly described and appropriate for the hypothesis being tested?

-Is the sample size sufficient to ensure adequate power to address the hypothesis being tested?

-Were correct statistical analysis used to support conclusions?

-Are there concerns about ethical or regulatory requirements being met?

Reviewer #1: OK

**********

Results

-Does the analysis presented match the analysis plan?

-Are the results clearly and completely presented?

-Are the figures (Tables, Images) of sufficient quality for clarity?

Reviewer #1: Yes.

**********

Conclusions

-Are the conclusions supported by the data presented?

-Are the limitations of analysis clearly described?

-Do the authors discuss how these data can be helpful to advance our understanding of the topic under study?

-Is public health relevance addressed?

Reviewer #1: OK.

**********

Editorial and Data Presentation Modifications?

Use this section for editorial suggestions as well as relatively minor modifications of existing data that would enhance clarity. If the only modifications needed are minor and/or editorial, you may wish to recommend “Minor Revision” or “Accept”.

Reviewer #1: In Author summary: second line: please modify the sentence ...that may kill infants and children.

Please add a sentence about comparing OPD and IPD cases in discussion.

**********

Summary and General Comments

Use this section to provide overall comments, discuss strengths/weaknesses of the study, novelty, significance, general execution and scholarship. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. If requesting major revision, please articulate the new experiments that are needed.

Reviewer #1: OK.

**********

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Reviewer #1: Yes: Professor Siripen Kalayanarooj

13 May 2022

Dear Dr. Limkittikul,

We are delighted to inform you that your manuscript, "Association between nutritional status and dengue severity in Thai children and adolescents," has been formally accepted for publication in PLOS Neglected Tropical Diseases.

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Thank you again for supporting open-access publishing; we are looking forward to publishing your work in PLOS Neglected Tropical Diseases.

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Shaden Kamhawi

co-Editor-in-Chief

PLOS Neglected Tropical Diseases

Paul Brindley

co-Editor-in-Chief

PLOS Neglected Tropical Diseases