Intussusception among infants in Tanzania: findings from prospective hospital-based surveillance, 2013-2016.

INTRODUCTION: intussusception surveillance was initiated in Tanzania in 2013 after monovalent rotavirus vaccine was introduced, as part of the 7-country African evaluation to assess whether the vaccine was associated with an increased risk of intussusception. An increased risk from vaccine was not identified. Published data on intussusception in Tanzanian infants are limited. METHODS: prospective intussusception surveillance was conducted at 7 referral hospitals during 2013-2016 to identify all infants with intussusception meeting Brighton Level 1 criteria. Demographic, household and clinical data were collected by hospital clinicians and analyzed. RESULTS: a total of 207 intussusception cases were identified. The median age of cases was 5.8 months and nearly three-quarters were aged 4-7 months. Median number of days from symptom onset to admission at treatment hospital was 3 (IQR 2-5). Seventy-eight percent (152/195) of cases had been admitted at another hospital before transfer to the treating hospital. Enema reduction was not available; all infants were treated surgically and 55% (114/207) had intestinal resection. The overall case-fatality rate was 30% (62/206). Compared with infants who survived, those who died had longer duration of symptoms before admission to treatment hospital (median 4 vs 3 days; p < 0.01), higher rate of intestinal resection (81% [60/82] vs 44% [64/144], p < 0.001), and from families with lower incomes (i.e., less likely to own a television [p < 0.01] and refrigerator [p < 0.05). CONCLUSION: Tanzanian infants who develop intussusception have a high case-fatality rate. Raising the index of suspicion among healthcare providers, allocating resources to allow wider availability of abdominal ultrasound for earlier diagnosis, and training teams in ultrasound-guided enema reduction techniques used in other African countries could reduce the fatality rate.

Incidence of pediatric inflammatory bowel disease within the Vaccine Safety Datalink network and evaluation of association with rotavirus vaccination.

BACKGROUND: Recent studies have reported an increase in Inflammatory bowel disease (IBD) incidence in young children, highlighting the need to better understand risk factors for the development of IBD. Licensed for use in infants in 2006, the oral, live-attenuated rotavirus vaccine has biologic plausibility for instigating inflammation of the gut mucosa as a pathway to immune dysregulation. METHODS: Over a ten-year period, we evaluated incidence of IBD within a cohort of children under the age of ten, enrolled in seven integrated healthcare delivery systems. We conducted a nested case-control study to evaluate the association between rotavirus vaccination and IBD using conditional logistic regression. Cases were confirmed via medical record review and matched to non-IBD controls on date of birth, sex, and study site. RESULTS: Among 2.4 million children under the age of 10 years, 333 cases of IBD were identified with onset between 2007 and 2016. The crude incidence of IBD increased slightly over the study period (p-value for trend = 0.046). Of the 333 cases, 227 (68%) were born prior to 2007. Forty-two cases born in 2007 or later, with continuous enrollment since birth were included in the case-control study and matched to 210 controls. The adjusted odds ratio for any rotavirus vaccination in IBD cases, compared to matched controls, was 0.72 (95% confidence interval 0.19-2.65). CONCLUSIONS: Data from this large pediatric cohort demonstrate a small overall increase in IBD incidence in young children over a ten-year period. The data suggest that rotavirus vaccination is not associated with development of IBD.

[False beliefs about vaccines]. / Falsas creencias sobre las vacunas.

Vaccines are an essential tool for the prevention of infectious diseases. However, false ideas and rumours with no scientific foundation about their possible negative effects may dissuade people from being vaccinated, with the consequent risks for the health of the population. The objective of this article is to evaluate the origin and the arguments of some of the most frequent mistaken ideas and rumours about the possible adverse effects of vaccines. Some clearly established adverse effects are presented, as well as false beliefs about various vaccines and potential harm to health. Vaccines, like any drug, can cause adverse effects, but the possible adverse effects of vaccination programs are clearly lower than their individual (vaccinated) and collective benefits (those vaccinated and those who cannot be vaccinated for medical reasons). The possible adverse effects attributable to vaccines should be detected by powerful and well-structured pharmacovigilance systems.

Recurrent intussusception among infants less than 2 years of age in Vietnam.

In some settings, rotavirus vaccines have been associated with a low-level risk of intussusception, the most common cause of bowel obstruction in infants. As Vietnam prepares to introduce rotavirus vaccine into the national immunization program, we sought to better characterize the epidemiology of recurrent intussusception. We enrolled children <2 years of age who were hospitalized for intussusception retrospectively from January 2013 through December 2014 and prospectively from January 2015 through December 2016 at 2 hospitals in Vietnam. We enrolled 2477 children. Nearly all children were successfully treated by enema with low surgery rate (1%). We found 10% of children (n = 254) experienced at least once recurrence (range: 1-6) and 57% of first recurrences happened within the first 12 weeks after treatment of the first episode. The median age at first intussusception was 13 months for children without a recurrent episode and 10 months for children with a recurrence. The symptoms of the recurrent cases were milder with less vomiting (67%), bloody stool (7%) and fever (10%) compared to the initial cases (p < 0.01). We found the rate of recurrences following enema reduction of intussusception to be similar to that reported from other countries. Due to the high rate of intussusception and recurrent episodes in Vietnam, a better understanding of the cause of recurrent intussusception will be critical in assessing intussusception cases after rotavirus introduction.

Intussusception in southern India: comparison of retrospective analysis and active surveillance.

Surveillance for intussusception is a post marketing requirement for rotavirus vaccines following observation of a small increased risk of intussusception after rotavirus vaccination in some global settings. This study presents the clinical presentation and outcomes of children who presented with intussusception at a large tertiary care facility directly (non-surveillance) as retrospective analysis of a period where rotavirus vaccine was not in routine use, or as part of active surveillance in a phase III oral rotavirus vaccine trial. Hospital records of children under 2 years of age treated for intussusception between 1 January 2010 and 31 August 2013 at the Christian Medical College Hospital, Vellore, India, were reviewed. Sixty-one cases of intussusception in children under two years of age presented at the hospital. An additional 16 cases of ultrasound diagnosed intussusception were identified through the active surveillance of a cohort of 1500 children participating in a rotavirus phase III trial in the same period. In the nonsurveillance group, median age at presentation was 214 days (IQR 153-321) with 52 events (85.3%) occurring in the first year of life. Cases were seen year-round with no definitive evidence of seasonality. Thirty-one (50.8%) intussusceptions required surgical reduction, 26 (42.6%) had pneumatic reduction and 2 (3.3%) barium enema reduction. Two intussusceptions (3.3%) resolved spontaneously. There were no deaths, all children were discharged after recovery. Active surveillance identified 16 children with a median age at event of 375 days (IQR 248-574). Nine (56%) children had small bowel or transient intussusception that resolved spontaneously. Seven intussusceptions were reduced radiologically; none required surgery. In summary, there were significant differences between presentation and outcomes in cases of intussusception identified by passive and active surveillance, likely related to enhanced and early detection of intussusception through active monitoring in the trial. The WHO recommendation of sentinel hospital based surveillance for post-marketing surveillance after rotavirus vaccine introduction is likely to a better approach than active surveillance.

Risk of intussusception after monovalent rotavirus vaccination.

BACKGROUND: Although current rotavirus vaccines were not associated with an increased risk of intussusception in large trials before licensure, recent postlicensure data from international settings suggest the possibility of a small increase in risk of intussusception after monovalent rotavirus vaccination. We examined this risk in a population in the United States. METHODS: Participants were infants between the ages of 4 and 34 weeks who were enrolled in six integrated health care organizations in the Vaccine Safety Datalink (VSD) project. We reviewed medical records and visits for intussusception within 7 days after monovalent rotavirus vaccination from April 2008 through March 2013. Using sequential analyses, we then compared the risk of intussusception among children receiving monovalent rotavirus vaccine with historical background rates. We further compared the risk after monovalent rotavirus vaccination with the risk in a concurrent cohort of infants who received the pentavalent rotavirus vaccine. RESULTS: During the study period, 207,955 doses of monovalent rotavirus vaccine (including 115,908 first doses and 92,047 second doses) were administered in the VSD population. We identified 6 cases of intussusception within 7 days after the administration of either dose of vaccine. For the two doses combined, the expected number of intussusception cases was 0.72, resulting in a significant relative risk of 8.4. For the pentavalent rotavirus vaccine, 1,301,810 doses were administered during the study period, with 8 observed intussusception cases (7.11 expected), for a nonsignificant relative risk of 1.1. The relative risk of chart-confirmed intussusception within 7 days after monovalent rotavirus vaccination, as compared with the risk after pentavalent rotavirus vaccination, was 9.4 (95% confidence interval, 1.4 to 103.8). The attributable risk of intussusception after the administration of two doses of monovalent rotavirus vaccine was estimated to be 5.3 per 100,000 infants vaccinated. CONCLUSIONS: In this prospective postlicensure study of more than 200,000 doses of monovalent rotavirus vaccine, we observed a significant increase in the rate of intussusception after vaccination, a risk that must be weighed against the benefits of preventing rotavirus-associated illness. (Funded by the Centers for Disease Control and Prevention.).

Workshop on intussusception in African countries--meeting report.

Rotavirus causes approximately 450,000 deaths annually among children less than 5 years of age worldwide, almost half of which occur in Africa. After the recent completion of successful trials of 2 new rotavirus vaccines, the World Health Organization has recommended these vaccines for all children worldwide. Because a previous rotavirus vaccine, Rotashield(®), was associated with intussusception, a form of intestinal obstruction among infants, the current rotavirus vaccines were tested in large clinical trials and found to be safe. However, due to the past Rotashield(®) experience, post licensure monitoring of intussusception is considered to be crucial after the introduction of future oral rotavirus vaccines. Thus, in planning for future introductions of rotavirus vaccine in Africa, a workshop of experts working on intussusception was convened by the World Health Organization in May 2004 in association with the Pan-African Association of Paediatric Surgeons (PAPSA) in Malawi. In brief, delegates from ten countries presented data from retrospective record reviews of intussusception events from 1993 to 2003 at selected hospitals in their respective countries. This review showed that age of intussusception onset during infancy varies markedly with peak prevalence between 4 and 6 months of life. Diagnostic modality (e.g., contrast enema, ultrasound) was employed in <20% of the events; nearly 70% of the intussusception events were diagnosed at the time of surgery. Overall, case-fatality was high, ~13%, in these African countries. The findings of this meeting highlight the challenges in implementing surveillance for intussusception after rotavirus vaccine introduction in Africa. The deliberations identified some concrete steps necessary to establish active surveillance at sentinel sites in African countries. This is becoming more urgent now that many countries are expressing interest in introducing rotavirus vaccines.

Intussusception: incidence and treatment-insights from the nationwide German surveillance.

OBJECTIVE: Intussusception (IS) is one of the most common paediatric emergencies, and the best mode of conservative reduction and its exact incidence remains unclear. For different reasons, availability of reliable incidence data are useful and additionally may be fundamental to monitor potential effects of recently introduced rotavirus (RV) vaccines. METHODS: We performed a prospective German nationwide surveillance between January 1, 2006 and December 31, 2007, followed by separate collection of all IS cases in a random sample of 31 clinics for an unbiased estimation of underreporting. For case definition, the Brighton Collaboration (BC) criteria were applied. RESULTS: A total of 1200 children with at least 1 episode of IS were included. For children younger than 1 year the incidence was calculated to be 60.4/100,000 child-years. The risk for surgery increased 2-fold if the interval between onset of symptoms and first attempt of conservative reduction exceeded 5 hours (95% confidence interval [CI] 1.2-3.1). We also observed a 2.8-fold increased risk for surgery for hydrostatic (CI 1.2-6.4) and a 3.7-fold for barium enema reduction (CI 1.6-8.8) compared to pneumatic reduction. The level of specialisation of the hospital did not influence the success of conservative management. CONCLUSIONS: For children with IS a fast attempt of pneumatic reduction seems to be the optimal management. Considering the current practice we estimated that approximately 104 (CI 46-161) surgical interventions would be preventable in Germany every year. Also, conduction of reliable postmarketing monitoring of the new RV vaccines is now possible based on the provided incidence data.

Childhood intussusception in Uzbekistan: analysis of retrospective surveillance data.

BACKGROUND: Estimates of baseline incidence of childhood intussusception could help safety monitoring after the introduction of rotavirus vaccines. We studied the incidence of intussusception in Uzbekistan, a GAVI-fund eligible state in Central Asia. METHODS: We retrospectively reviewed intussusception cases in children <2 years of age treated during 2004-2008 at 15 hospitals in the Bukhara region of Uzbekistan. Demographic and clinical data as well as information on diagnostic and treatment practices were obtained from hospital records. We categorized cases using the Brighton collaboration clinical case definition and calculated the national incidence rate. RESULTS: Over a 5-year study period, 67 confirmed cases were identified, of which 67% were boys. The median age was 12 months, and no seasonal trend in the distribution of cases was observed. The diagnostic methods used included abdominal radiography (87%) and ultrasonography (57%). Intussusception reduction by air enema was successful in 33 (49%) patients and 34 (50%) cases underwent surgery. A total of 4 deaths occurred, including 3 deaths in infants aged 0-6 months. The median length of hospital stay was 7.3 (range 0-37) days. The incidence of intussusception is estimated at 23 (95% CI 13.6-32.4) cases per 100,000 child-years, corresponding to approximately 237 cases annually. CONCLUSIONS: This is the first study to estimate the incidence of childhood intussusception prior to the introduction of the rotavirus vaccination in Uzbekistan. A prospective surveillance system using a standardized case definition is needed in order to better examine the occurrence of intussusception in developing countries.

Intussusception: trends in clinical presentation and management.

BACKGROUND: The association of a rotavirus vaccine and intussusception has renewed interest in understanding the incidence, clinical presentation and outcome of intussusception. METHODS: A retrospective chart review of all patients diagnosed with intussusception at Royal Children's Hospital, Melbourne over a 6.5-year period (1 January 1995-30 June 2001) was conducted using patients identified by a medical record database (ICD-9-CM code 560.0 1993-1997; ICD-10-CM code 56.1 1998-2001). Patient profile, clinical presentation, diagnosis methods, treatment and outcome were analyzed and compared to data previously reported on children with intussusception at the same hospital during 1962-1968. RESULTS: The hospitalization rate for primary idiopathic intussusception increased marginally from 0.19 to 0.27 per 1000 live births during the period 1962-1968 to 1995-2001. Most patients (80%) were <12 months of age (median age 7 months, range 2-72 months). The combination of abdominal pain, lethargy and vomiting was reported in 78% of infants. Air enema confirmed the diagnosis of intussusception in 186 of 191 cases (97%) and air reduction was successful in most cases (82%). Factors associated with increased risk of intestinal resection included abdominal distension (32%), bowel obstruction on abdominal X-ray (27%) and hypovolemic shock (40%). No mortality was observed in the present study. CONCLUSIONS: Over the past 40 years at Royal Children's Hospital, Melbourne the hospitalization rate due to primary idiopathic intussusception has marginally increased from 0.19 to 0.27 per 1000 live births. Diagnosis and treatment using air enema has been highly successful, resulting in a reduction in patients requiring surgery and reduced hospital stays.

Intussusception among young children in Europe.

Intussusception, a potentially lethal condition with poorly understood etiology, is the most common cause of acute intestinal obstruction in children younger than 5 years old. In some cases, the condition has been associated with administration of the first licensed rotavirus vaccine, the reassortant rhesus-human tetravalent rotavirus vaccine (RRV-TV; RotaShield). No such association has to date been reported from large phase III safety trials with new rotavirus vaccines. As 2 new, live-attenuated oral rotavirus vaccines are currently under review for approval by the European Union regulatory authorities, a review of the clinical, etiologic and epidemiologic aspects of intussusception in Europe is urgently needed. We conducted a review of Medline literature, published from 1995 onwards on intussusception in the World Health Organization's European Region. The results are compared with data from previous reviews and other regions. The classic triad of intussusception symptoms (abdominal pain, abdominal mass, bloody stools) was present in 29-33% of patients according to the medical literature reviewed. Conservative treatment (barium, air or saline enema) was the rule (81% of cases), and few complications were observed during treatment. Treatment outcome was generally favorable, with recurrence occurring in approximately 1 in 10 patients, and only 1 death reported. Structural lead points were seen in 3% of patients; no other reliable data on the etiology of intussusception were found. The incidence of acute intussusception in young children in Europe, according to 6 heterogeneous hospital-based studies, ranged from 0.66 to 2.24 per 1000 children in inpatient departments and from 0.75 to 1.00 per 1000 children in emergency departments. Peak incidences were found in children 3-9 months of age. There are still gaps in our knowledge of intussusception with respect to its etiology and especially by which mechanisms RRV-TV might have caused it to occur. Data from regions outside Europe showed that rotavirus infection and disease are not associated with intussusception. As new rotavirus vaccines become available for use in Europe, postlicensure surveillance for intussusception is indicated and may be instrumental in further understanding the epidemiology of this condition and in further assessing the safety of future vaccines.