Characteristics of intussusception among children <24 months old before rotavirus vaccine introduction in Lao PDR

To the editor:

Intussusception, the invagination of the bowel into a distal segment, is the most common cause of acute bowel obstruction in infants [1]. Nearly all intussusception cases require either enema or surgical reduction and untreated intussusception can result in death. Typically, the cause of naturally occurring intussusception is unknown but rotavirus vaccines are associated with a small elevated risk of intussusception in some settings [2]. In preparation for rotavirus vaccine introduction, we describe intussusception epidemiology and management in Lao PDR.

From December 2018 through September 2020, we prospectively enrolled children <24 months old admitted to any of the three sentinel surveillance hospitals in Lao PDR for intussusception meeting the Brighton level 1 criteria [3]. Children were identified by surveillance staff who gathered standardized information from the children’s families and medical records. We compared children by enema and surgical management. We also compared the period before (December 1, 2018 through February 29, 2020) and during (March 1, 2020 through September 30, 2020) the COVID-19 pandemic. We assessed differences by the Mantel-Haenszel chi square and rank sum tests; p-values <0.05 were considered statistically significant. This activity was considered routine public health surveillance and non-research by the institutional review board at the US Centers for Disease Control and Prevention. This study received ethic approval (ID 2018.119.MC; 117/NECHR (31 Dec 2018)) from the National Ethic Committee for Health Research (NECHR), Lao PDR.

Twenty-eight (48%) of the 58 children included in this analysis were managed with enema reduction and 30 (52%) were managed surgically, of whom 3 (10%) had bowel resection (Table 1). No seasonality was observed in case enrollment. Overall, 32 (55%) of cases were male. The median age was 14.5 months (IQR: 8.5–19 months) among children managed by enema and 8 months (IQR: 6–19 months) among children managed surgically. Children managed surgically were transferred more frequently (surgery: n=13, 43%; enema: n=5, 18%; p=0.038) and had a longer median transfer interval (surgery: 1.5 days, IQR: 0.5–2 days; enema: 0 days, IQR: 0–0 days; p=0.112), and hospitalization (surgery: 6 days, IQR: 4–8 days; enema: 1 day, IQR: 0–1 days; p<0.001). There was no difference in the proportion requiring surgery before or during the COVID-19 pandemic (before: n=17 of 35, 49%; during: n=13 of 23, 57%; p=0.557). None of the children died or had received rotavirus vaccine.

Table 1.

Characteristics of intussusception cases <24 months old and comparison by treatment modality, Lao PDR 2018–2020

		Total		Enema		Surgery		p-value1
		N=58	%	N=28	%	N=30	%
Sex	Male	32	55	14	50	18	60	0.448
	Female	26	45	14	50	12	40
Age (months)	Median, IQR2	12	7–19	14.5	8.5–19	8	6–18	0.132
Ever breastfed3		51	89	23	85	28	93	0.408
Chronic medical condition		0	0	0	0	0	0	-
Had been transferred to the surveillance hospital		18	31	5	18	13	43	0.038
Days from symptom onset to transfer	Median, IQR2	1	0–2	0	0–0	1.5	0.5–2	0.112
Outcome	Discharged	58	100	28	100	30	100	-
	Died	0	0	0	0	0	0
Duration of hospitalization at surveillance hospital (days)	Median, IQR2	2.5	1–6	1	0–1	6	4–8	<0.001
Surveillance hospital	Mahosot Hospital	43	74	24	86	19	63	0.024
	Children’s Hospital	11	19	4	14	7	23
	Champasak Hospital	4	7	0	0	4	13
Admission before or during COVID-19 pandemic	Before (Dec 2018-Feb 2020)	35	60	18	64	17	57	0.557
	During (Mar 2020-Sep 2020)	23	40	10	36	13	43
Symptoms at time of admission	Any of the list below	54	93	24	86	30	100	0.033
	Fever	17	29	4	14	13	43	0.016
	Diarrhea3	33	57	14	50	19	63	0.358
	Vomiting	45	78	18	64	27	90	0.020
	Constipation4	10	17	3	11	7	23	0.177
	Bloody stool	31	53	10	36	21	70	0.010
Days from symptom onset to admission to surveillance hospital	Median, IQR2	0	0–1	0	0–1	1	0–2	0.044
Complications	Any	3	5	1	4	2	7	0.498
	Wound infection	0	0	NA	0	0	0
	Would dehiscence	0	0	NA	0	0	0
	Peritonitis	1	2	1	4	0	0
	Secondary Obstruction	2	3	0	0	2	7
	Other	0	0	0	0	0	0

¹p-value calculated from chi-squared for categorical variables or rank sum test for continuous variables

²Interquartile range

³1 missing

⁴2 missing

To our knowledge, this is the first intussusception surveillance report from Lao PDR and one of the first globally during the COVID-19 pandemic. These findings point to important differences between enema and surgical management of intussusception. While no child died, the invasiveness of surgery and the burden of extended hospitalizations are important considerations. As intussusception sensitization is expected to be part of rotavirus vaccine introduction, this is an opportunity to increase awareness of intussusception. It is noteworthy that the COVID-19 pandemic did not interrupt surveillance. It has been hypothesized that SARS-COV-2 can cause intussusception [4], however we were unable to assess this. Understanding the local intussusception epidemiology and treatment patterns will be useful for rotavirus vaccine preparation.