Passive surveillance for Kawasaki disease in San Diego County

Cardiovascular outcomes in children with Kawasaki disease: a population-based cohort study

BACKGROUND

The risk of cardiovascular events after Kawasaki disease (KD) remains uncertain. Our objective was to determine the risk of cardiovascular events and mortality after KD.

METHODS

Population-based retrospective cohort study using Ontario health administrative databases (0-18 years; 1995-2018).

EXPOSURE

pediatric KD hospitalizations. Each case was matched to 100 non-exposed controls.

PRIMARY OUTCOME

major adverse cardiac events (MACE; cardiovascular death, myocardial infarction, or stroke composite).

SECONDARY OUTCOMES

composite cardiovascular events and mortality. We determined incidence rates and adjusted hazard ratios (aHR) using multivariable Cox models.

RESULTS

Among 4597 KD survivors, 79 (1.7%) experienced MACE, 632 (13.8%) composite cardiovascular events, and 9 (0.2%) died during 11-year median follow-up. The most frequent cardiovascular events among KD survivors were ischemic heart disease (4.6 events/1000 person-years) and arrhythmias (4.5/1000 person-years). KD survivors were at increased risk of MACE between 0-1 and 5-10 years, and composite cardiovascular events at all time periods post-discharge. KD survivors had a lower mortality risk throughout follow-up (aHR 0.36, 95% CI 0.19-0.70).

CONCLUSION

KD survivors are at increased risk of post-discharge cardiovascular events but have a lower risk of death, which justifies enhanced cardiovascular disease surveillance in these patients.

IMPACT

Among 4597 Kawasaki disease (KD) survivors, 79 (1.7%) experienced major adverse cardiac events (MACE) and 632 (13.8%) had composite cardiovascular events during 11-year median follow-up. KD survivors had significantly higher risks of post-discharge MACE and cardiovascular events versus non-exposed children. Only nine KD survivors (0.2%) died during follow-up, and the risk of mortality was significantly lower among KD survivors versus non-exposed children. Childhood KD survivors should receive preventative counseling and cardiovascular surveillance, aiming to mitigate adult cardiovascular disease.

Health care utilization and costs following Kawasaki disease

Objectives

Kawasaki disease (KD) is a common childhood vasculitis with increasing incidence in Canada. Acute KD hospitalizations are associated with high health care costs. However, there is minimal health care utilization data following initial hospitalization. Our objective was to determine rates of health care utilization and costs following KD diagnosis.

Methods

We used population-based health administrative databases to identify all children (0 to 18 years) hospitalized for KD in Ontario between 1995 and 2018. Each case was matched to 100 nonexposed comparators by age, sex, and index year. Follow-up continued until death or March 2019. Our primary outcomes were rates of hospitalization, emergency department (ED), and outpatient physician visits. Our secondary outcomes were sector-specific and total health care costs.

Results

We compared 4,597 KD cases to 459,700 matched comparators. KD cases had higher rates of hospitalization (adjusted rate ratio 2.07, 95%CI 2.00 to 2.15), outpatient visits (1.30, 95%CI 1.28 to 1.33), and ED visits (1.22, 95%CI 1.18 to 1.26) throughout follow-up. Within 1 year post-discharge, 717 (15.6%) KD cases were re-hospitalized, 4,587 (99.8%) had ≥1 outpatient physician visit and 1,695 (45.5%) had ≥1 ED visit. KD cases had higher composite health care costs post-discharge (e.g., median cost within 1 year: $2466 CAD [KD cases] versus $234 [comparators]). Total health care costs for KD cases, respectively, were $13.9 million within 1 year post-discharge and $54.8 million throughout follow-up (versus $2.2 million and $23.9 million for an equivalent number of comparators).

Conclusions

Following diagnosis, KD cases had higher rates of health care utilization and costs versus nonexposed children. The rising incidence and costs associated with KD could place a significant burden on health care systems.

Incidence and short-term outcomes of Kawasaki disease

OBJECTIVE

Kawasaki disease (KD) is a childhood vasculitis with conflicting reported North American trends in incidence and patient characteristics.

OBJECTIVES

(1) determine KD incidence between 1995 and 2017; (2) compare patient characteristics by era and age group; (3) determine complication and cardiovascular follow-up rates.

METHODS

We used population-based health administrative data to identify children (0-18 yr) hospitalized with KD in Ontario, Canada between 1995 and 2017. We excluded children with prior KD diagnosis or incomplete records. We determined the annualized incidence and follow-up trends.

RESULTS

KD was diagnosed in 4,346 children between 1995 and 2017. Annual KD incidence was 22.0 (<5 yr), 6.1 (5-9 yr), and 0.6 (10-18 yr) per 100,000 children. KD incidence increased significantly for all age groups, including from 18.4 to 25.0 cases per 100,000 children <5 yr. Ninety-day mortality occurred in ≤5 children (≤0.1%). Coronary artery aneurysm (CAA) occurred in 106 children (2.4%, 95% confidence interval 2.0-2.9) during admission and 151 (3.5%, 95% confidence interval 3.0-4.1) during 11-year median follow-up. Children 10-18 yr had longer hospitalizations (4.3 vs. 3.5 days, p = 0.003) and more CAA (7.4% vs. 3.4%, p = 0.007). By 1-year post-diagnosis, 3970 (91.3%) and 2576 (59.3%) children had echocardiography and cardiology follow-up, respectively.

CONCLUSIONS

KD incidence is increasing in Ontario, with greater healthcare utilization from hospitalizations and subsequent follow-up.

IMPACT

4346 children were hospitalized for Kawasaki disease over 22 years in Ontario, and Kawasaki disease incidence increased significantly for all age groups, males and females. Older children (10-18 years) had longer hospital length of stay, more PICU admissions and more frequent coronary artery aneurysms. Nearly all children with Kawasaki disease had follow-up echocardiography within 1 year.

Long-term hearing and neurodevelopmental outcomes following Kawasaki disease: A population-based cohort study

BACKGROUND

Kawasaki disease (KD) incidence is increasing in Ontario. Cardiovascular sequelae following KD are well-described. However, there are limited data on non-cardiovascular outcomes.

OBJECTIVES

To determine the risk of hearing loss, anxiety, developmental disorders, intellectual disabilities and attention-deficit/hyperactivity disorder (ADHD) among KD survivors vs. non-exposed children.

METHODS

We included all Ontario children (≤18 yr) surviving hospitalization with a KD diagnosis between 1995 and 2018, using population-based health administrative databases. We excluded children with prior KD diagnoses and non-residents. KD cases were matched with 100 non-exposed children by age, sex and year. Follow-up continued until death or March 2019. We calculated the prevalence, incidence and adjusted hazard ratios (aHR [95%CI]) of outcomes between 0-1 yr, 1-5 yr, 5-10 yr and >10 yr follow-up.

RESULTS

Among 4597 KD survivors, 364 (7.9%) were diagnosed with hearing loss, 1213 (26.4%) anxiety disorders, 398 (8.7%) developmental disorders, 51 (1.1%) intellectual disability and 21 (0.5%) ADHD, during median 11 year follow-up. Compared to 459,700 non-exposed children, KD survivors were not at increased risk of hearing loss after adjustment for potential confounders. KD survivors were at increased risk of anxiety disorders between 0-1 yr (aHR 1.75 [1.46-2.10]), 1-5 yr (aHR 1.13 [1.01-1.28]), 5-10 yr (aHR 1.14 [1.03-1.28]) and >10 yr (aHR 1.11 [1.02-1.22]); developmental disorders between 0-1 yr (aHR 1.49 [1.28-1.74]) and 1-5 yr (aHR 1.19 [1.02-1.40]); intellectual disabilities >10 yr (aHR 2.36 [1.36-4.10]); and ADHD >10 yr (aHR 2.01 [1.14-3.57]).

CONCLUSIONS

KD survivors are at increased risk of being diagnosed with anxiety disorders sooner, being diagnosed with developmental disorders between 0 and 5 yr and being diagnosed with intellectual disabilities or ADHD >10 yr after KD diagnosis. This may justify enhanced developmental and audiological surveillance of KD survivors.

Clinically Apparent Arterial Thrombosis in Persons with Systemic Vasculitis

Objective

To estimate the incidence rate of clinically apparent arterial thrombotic events and associated comorbidities in patients with primary systemic vasculitis.

Methods

Using large cohort administrative data from Quebec, Canada, we identified patients with vasculitis, including polyarteritis nodosa (PAN) and granulomatosis with polyangiitis (GPA). Incident acute myocardial infarctions (AMIs) and cerebrovascular accidents (CVAs) after the diagnosis of vasculitis were ascertained in the PAN and GPA group via billing and hospitalization data. These were compared to rates of a general population comparator group. The incidences of comorbidities (type 2 diabetes mellitus, dyslipidemia, and hypertension) were also collected.

Results

Among the 626 patients identified with vasculitis, 19.7% had PAN, 2.9% had Kawasaki disease, 23.8% had GPA, 52.4% had GCA, and 1.3% had Takayasu arteritis. The AMI rate was substantially higher in males aged 18–44 with PAN, with rates up to 268.1 events per 10,000 patient years [95% CI 67.1–1070.2], approximately 30 times that in the age- and sex-matched control group. The CVA rate was also substantially higher, particularly in adults aged 45–65. Patients with vasculitis had elevated incidences of diabetes, dyslipidemia, and hypertension versus the general population.

Conclusion

Atherothrombotic rates were elevated in patients identified as having primary systemic vasculitis. While incident rates of cardiovascular comorbidities were also increased, the substantial elevation in AMIs seen in young adults suggests a disease-specific component which requires further investigation.

Infectious shock and toxic shock syndrome diagnoses in hospitals, Colorado, USA

In Colorado, USA, diagnoses coded as toxic shock syndrome (TSS) constituted 27.3% of infectious shock cases during 1993–2006. The incidence of staphylococcal TSS did not change significantly overall or in female patients 10–49 years of age but increased for streptococcal TSS. TSS may be underrecognized among all ages and both sexes.

Repeated systematic surveillance of Kawasaki disease in Ontario from 1995 to 2006

BACKGROUND

Rising incidences of Kawasaki disease (KD) have been reported worldwide. Reported herein are the results of 4 triennial KD surveillances conducted in Ontario.

METHODS

Between 1995 and 2006 all hospitals in Ontario were asked on 4 occasions to identify all patients with discharge diagnoses of KD and report incident cases.

RESULTS

The latest surveillance identified 697 new KD patients (100% response rate) for a total of 2378 KD patients through all 4 surveillances. Yearly incidence was 26.2/100,000 for <5 years old, 6.7/100,000 for 5-9 years old and 0.9/100,000 for 10-14 years old. KD incidence significantly increased from 1995 to 2006, although the increase seemed to plateau between the 3rd and 4th surveillance. There was an increase in the proportion of patients diagnosed with incomplete KD and a significant reduction in the rate of coronary artery abnormalities, possibly due to better disease recognition and treatment. Hospitals reporting <20 cases per surveillance were found to be more likely to report cases with incomplete KD. These patients were also less likely to be treated with i.v. immunoglobulin and aspirin but were more likely to be treated with antibiotics, suggesting uncertainties regarding diagnosis and management of KD patients in those centers.

CONCLUSIONS

The incidence of KD in Ontario is possibly one of the highest outside of Asia and has been rising since 1995. Although the most recent surveillance demonstrated improved cardiac outcomes, treatment delays or absence thereof continue to be a problem. Effective diagnosis and prompt treatment remain critical aspects of KD management.

The incidence of Kawasaki syndrome in West Coast health maintenance organizations

BACKGROUND

Kawasaki syndrome (KS) causes an acute vasculitis of unknown etiology. It is a leading cause of acquired heart disease of children in Japan and the United States.

METHODS

We examined the incidence of KS in a well-defined population group of children < or =6 years of age, using data collected through the Vaccine Safety Datalink (VSD) project. The VSD database contains information on >1 million children enrolled in four West Coast health maintenance organizations (HMOs).

RESULTS

During 1993 through 1996 a total of 234 physician-diagnosed KS patients were reported in the 4 HMOs; 152 (65.0%) were boys and 195 (83.3%) were <5 years of age. The incidence of KS among children <5 years of age in the HMOs ranged from 9.0 to 19.1 per 100,000 person years. KS incidence was higher among boys in 3 of the sites. In the 2 sites with the highest number of KS patients, a seasonal occurrence of KS in winter and early spring was observed. Overall 226 (96.6%) of the KS patients were reported to have been hospitalized; hospitalization rates for children <5 years of age ranged from 9.0 to 16.8 per 100,000 person years.

CONCLUSIONS

The incidence of KS in the HMOs was similar to that reported in other population-based studies in the United States and higher than estimates for Australia and several European countries.

Kawasaki disease: A brief history

Tomisaku Kawasaki published the first English-language report of 50 patients with Kawasaki disease (KD) in 1974. Since that time, KD has become the leading cause of acquired heart disease among children in North America and Japan. Although an infectious agent is suspected, the cause remains unknown. However, significant progress has been made toward understanding the natural history of the disease and therapeutic interventions have been developed that halt the immune-mediated destruction of the arterial wall. We present a brief history of KD, review progress in research on the disease, and suggest avenues for future study. Kawasaki saw his first case of KD in January 1961 and published his first report in Japanese in 1967. Whether cases existed in Japan before that time is currently under study. The most significant controversy in the 1960s in Japan was whether the rash and fever sign/symptom complex described by Kawasaki was connected to subsequent cardiac complications in a number of cases. Pathologist Noboru Tanaka and pediatrician Takajiro Yamamoto disputed the early assertion of Kawasaki that KD was a self-limited illness with no sequelae. This controversy was resolved in 1970 when the first Japanese nationwide survey of KD documented 10 autopsy cases of sudden cardiac death after KD. By the time of the first English-language publication by Kawasaki in 1974, the link between KD and coronary artery vasculitis was well-established. KD was independently recognized as a new and distinct condition in the early 1970s by pediatricians Marian Melish and Raquel Hicks at the University of Hawaii. In 1973, at the same Hawaiian hospital, pathologist Eunice Larson, in consultation with Benjamin Landing at Los Angeles Children's Hospital, retrospectively diagnosed a 1971 autopsy case as KD. The similarity between KD and infantile periarteritis nodosa (IPN) was apparent to these pathologists, as it had been to Tanaka earlier. What remains unknown is the reason for the simultaneous recognition of this disease around the world in the 1960s and 1970s. There are several possible explanations. KD may have been a new disease that emerged in Japan and emanated to the Western World through Hawaii, where the disease is prevalent among Asian children. Alternatively, KD and IPN may be part of the spectrum of the same disease and clinically mild KD masqueraded as other diseases, such as scarlet fever in the preantibiotic era. Case reports of IPN from Western Europe extend back to at least the 19th century, but, thus far, cases of IPN have not been discovered in Japan before World War II. Perhaps the factors responsible for KD were introduced into Japan after the World War II and then reemerged in a more virulent form that subsequently spread through the industrialized Western world. It is also possible that improvements in health care and, in particular, the use of antibiotics to treat infections caused by organisms including toxin-producing bacteria reduced the burden of rash/fever illness and allowed KD to be recognized as a distinct clinical entity. Itsuzo Shigematsu, Hiroshi Yanagawa, and colleagues have conducted 14 nationwide surveys in Japan. These have indicated that: 1) KD occurred initially in nationwide epidemics but now occurs in regional outbreaks; 2) there are approximately 5,000 to 6,000 new cases each year; 3) current estimates of incidence rates are 120 to 150 cases per 100,000 children <5 years old; 4) KD is 1.5 times more common in males and 85% of cases occur in children <5 years old; and 5) the recurrence rate is low (4%). In 1978, David Morens at the Centers for Disease Control and Prevention published a case definition based on Kawasaki's original criteria. The Centers for Disease Control and Prevention developed a computerized database in 1984, and a passive reporting system currently exists in 22 states. Regional investigations and national surveys suggest an annual incidence of 4 to 15 cases per 100 000 children <5 years o

Kawasaki syndrome in Jamaica

OBJECTIVE

To determine the epidemiology, management and outcome of Kawasaki syndrome in patients presenting to the major referral centers in Jamaica (population, 2.5 million) from May, 1986, through June, 1998.

DESIGN AND METHODS

Retrospective review of all cases of Kawasaki syndrome in major referral centers island wide. American Heart Association diagnostic criteria were used in case definition. Demographic, clinical diagnostic and laboratory data, management and outcome findings were analyzed.

RESULTS

Of 98 probable cases 57 were diagnosed with definite Kawasaki syndrome. The average annual incidence was 2.7 per 100,000 children in the 0- to 5-year age group, in a predominantly black population. Eighty-one percent of cases were from the Kingston Metropolitan area (population, 800,000). Children in the first 3 years of life were represented by 67% of cases, with a mean age of presentation of 32 months (range, 5 to 120 months). There was a male preponderance (M:F ratio, 1.71:1). The mean time between onset of illness and diagnosis was 9.1 days (SD 3.9 days). The most common presenting clinical features included fever, anorexia, vomiting, conjunctivitis, exanthema and oropharyngeal and peripheral extremity changes (>45% of patients). Only 7 children received treatment with intravenous gamma-globulin. Overall 38.8% of patients had cardiovascular changes and 28% had coronary artery abnormalities. Girls (8 of 21, 38.1%) were significantly more likely to have coronary changes than boys (8 of 36, 28.5%) [P < 0.05]. Two (3.5%) patients experienced a recurrence.

CONCLUSION

There is a tendency for late recognition and, hence, failure of treatment of Kawasaki syndrome in Jamaica. Greater awareness of the condition needs to be implemented. The finding of female children with an increased occurrence of coronary abnormalities warrants further investigation.

Lack of association between Kawasaki syndrome and Chlamydia pneumoniae infection: an investigation of a Kawasaki syndrome cluster in San Diego County

BACKGROUND

The etiology of Kawasaki syndrome (KS), the leading cause of acquired coronary artery disease in children, is unknown. Recent studies have suggested that Chlamydia pneumoniae, a common respiratory pathogen associated with an increased risk of heart disease, might lead to KS.

OBJECTIVE

To assess whether KS was associated with an elevated risk of having a current or antecedent infection with C. pneumoniae.

METHODS

Blood, urine and pharyngeal specimens from KS patients in San Diego County, CA, during a period of high KS incidence were analyzed for evidence of recent C. pneumoniae infection by culture, PCR and serology. Specimens collected from two control groups, family members of KS patients and age-matched children attending outpatient clinics for well child visits, were similarly analyzed.

RESULTS

Thirteen cases were identified. Forty-five outpatient controls and an average of three family members per patient were enrolled in the study. All specimens tested negative for the presence of C. pneumoniae by PCR and culture except for one blood specimen from the mother of a case-patient. Serologic analysis of patients and a subset of outpatient and family controls revealed no evidence of current C. pneumoniae infection; 4 of 13 adult family controls had IgG titers consistent with past exposure to C. pneumoniae. Case patients were no more likely than outpatient controls to have had a respiratory illness in the preceding 2 months (11 of 13 patients vs. 35 of 45 controls; odds ratio, 1.57; 95% confidence interval, 0.3 to 11.9).

CONCLUSIONS

We found no evidence that C. pneumoniae infection was associated with KS.

Kawasaki disease

Kawasaki disease is a leading cause of acquired heart disease in children in the USA. An acute vasculitis of unknown etiology, it occurs predominantly in infancy and early childhood, and more rarely in teenagers. Coronary artery aneurysms or ectasia develop in approximately 15-25% of children with the disease. Treatment with intravenous gamma globulin, 2 g per kg, in the acute phase reduces this risk three- to fivefold. Angiographic resolution occurs in approximately one-half of aneurysmal arterial segments, but these show persistent histologic and functional abnormalities. The remainder continue to be aneurysmal, often with development of progressive stenosis or occlusion. The worst prognosis occurs in children with so-called 'giant aneurysms', i.e. those with a maximum diameter greater than 8 mm, because thrombosis is promoted both by sluggish blood flow within the massively dilated vascular space and by the frequent development of stenotic lesions. Serial stress tests with myocardial imaging are mandatory in the management of patients with Kawasaki disease and significant coronary artery disease to determine the need for coronary angiography and transcatheter interventions or coronary bypass surgery. Continued long-term surveillance in patients with and without detected coronary abnormalities is necessary to determine the natural history of Kawasaki disease.