Childhood intussusception in Uzbekistan: Analysis of retrospective surveillance data
Reported, January 10, 2012
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 (IS) is the most common cause of bowel obstruction in young children, which involves an invagination of a proximal segment of the intestine into a distal segment. Intussusception is characterized by a sudden onset of abdominal pain, vomiting, rectal bleeding, and the presence of a palpable abdominal mass. The condition is diagnosed by ultrasonography, radiology or surgery, and is usually treated by using air or hydrostatic reduction enema under radiologic or ultrasound guidance. However, surgery may be required in some cases, and approximately 10% of patients with IS undergo an intestinal resection due to a vascular injury to the intestine . Intussusception primarily affects children, with the peak incidence reported at between 4 to 10 months of age , although adults cases are reported as well . The background incidence of IS varies from 0-17.8 cases per 100,000 children to 302 cases per 100,000 children across various regions, with a recently decreasing trend in IS incidence reported in the industrialized countries . Case-fatality rates also vary widely by region, and deaths from IS are more common in developing settings than in industrialized countries.
It is estimated that at least 30% of all hospitalizations for acute gastroenteritis in Uzbek children <5 years of age are attributable to rotavirus, and 1,174-1,857 rotavirus deaths in children <5 years old occur annually. In case of rotavirus vaccine introduction in Uzbekistan, monitoring IS as a part of the surveillance of vaccine-associated adverse events would be challenging since no IS surveillance is currently conducted.
During 5 years, 67 confirmed cases of IS in children <24 months of age were identified, corresponding to an incidence of 23 cases [95% CI 13.6-32.4] per 100,000 child-years or approximately 237 cases per year. A slightly higher incidence among children 0-6 months of age that will be targeted by rotavirus vaccination was observed . Among confirmed cases, boys (67%) were significantly (p < 0.05) younger than girls (10.4 vs. 15.4 months), and the median age was 12.1 months. We found a biphasic age distribution with the fist peak in children aged 3-6 months and the second peak among those 18 months and older.
The most frequent symptoms were abdominal pain (97%), palpable intestinal mass (97%), and bile-stained vomiting (80.6%). The lethargy (83.6%) and pallor (64.2%) were also observed frequently. Detection of blood on rectal examination (82.1%) and presence of IS (79.1%) or fluid level and dilated loops on plain abdominal radiography (20.9%) were the main symptoms for diagnosis. A rectal mass was detected in 3 cases (4.5%), and the presence of “red currant jelly” stool was only reported in a single case. The classic triad of vomiting, passage of blood through the rectum and abdominal pain was documented in 8 (11.9%) of 67 children. The clinical presentation at admission also included symptoms of concurrent gastroenteritis in 36% of children and concurrent respiratory symptoms in 49% of cases. We did not detect any significant differences in the distribution of symptoms by age or sex. No statistically significant changes in the monthly occurrence of IS were found despite a potential increase in the number of cases during April and May. Importantly, no increase was observed during autumn when most rotavirus disease occurs in Uzbekistan.
In conclusion,this study provides useful information on the incidence and epidemiology of childhood IS in Uzbekistan. Because we did not conduct prospective surveillance in the current study, additional research using an active surveillance approach is needed to better determine incidence rates. Such surveillance with a standard case definition will not only provide better information for future post-marketing assessments on the safety of rotavirus vaccines, but will also raise awareness on IS among pediatricians and surgeons. More education on diagnosis and management of IS in pediatric population is needed in developing countries to help improve rates of successful outcomes.
Credits:Renat Latipov,Rajabboy Khudoyorov,and Elmira Flem and Reference Laboratory, Tashkent, Uzbekistan & Scientific Center for Emergency Medicine, Bukhara, Uzbekistan
More Information:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3078088/?tool=pubmed