Michiko Izumida

Risk factors of renal involvement and significant proteinuria in Henoch-Schönlein purpura

Abstract. Risk factors of renal involvement and significant proteinuria in patients with Henoch-Schönlein purpura (HSP) were retrospectively evaluated by univariate and multivariate analyses. The analysis was performed in 134 patients with HSP. Renal involvement was found in 65 patients (49%) and 97% of the renal involvement was found within 3 months of disease onset. Moderate or severe proteinuria was recognised in 25 patients. A univariate analysis revealed that an age of more than 4 years at the onset, severe abdominal pain with gastrointestinal bleeding, persistent purpura over a month, coagulation factor XIII activity <80%, and treatment with factor XIII concentrate were associated with developing renal involvement. A multivariate analysis showed that severe abdominal symptoms, an age of more than 4 years, and persistent purpura increased the risk of renal involvement. Risk factors of moderate or severe proteinuria were also examined. The risk factors in a univariate analysis were severe abdominal symptoms, persistent purpura, decreased factor XIII activity, treatment with steroids, and treatment with factor XIII concentrate. Of those, persistent purpura, treatment with factor XIII concentrate, and factor XIII activity <80% were associated with significant proteinuria in a multivariate analysis. Among the patients with severe abdominal symptoms, factor XIII activity was significantly decreased in patients with significant proteinuria compared to other patients without significant proteinuria. Conclusion: Long-term prognosis of Henoch-Schönlein purpura is dependent on the severity of renal involvement. In those patients who have the risk factors of renal involvement, especially significant proteinuria, close attention should be paid to a urinalysis for at least 3 months from the onset of the disease.

Epidemics of Vector-borne Diseases Observed in Infectious Disease Surveillance in Japan, 2000-2005

BACKGROUND Observing the epidemics of vector-borne diseases is important. One or more cases of 6 vector-borne diseases were reported to the National Epidemiological Surveillance of Infectious Diseases in Japan in 2000-2005. METHODS The reports of those cases were available. The incidence was observed by region of acquired infection, prefecture reporting, and week and year of diagnosis. RESULTS The incidence rate per year per 1,000,000 population was 0.36 for dengue fever, 0.04 for Japanese encephalitis, 0.38 for Japanese spotted fever, 0.08 for Lyme disease, 0.74 for malaria, and 3.50 for scrub typhus. There were no cases of dengue fever or malaria derived from domestic infections. The yearly incidence rate increased for dengue fever and Japanese spotted fever, and declined for malaria and scrub typhus. The proportion of cases reported in Tokyo was 44% for dengue fever and 37% for malaria. The number of prefectures reporting one or more cases of Japanese spotted fever increased in western Japan. The cases of scrub typhus increased in autumn-winter in prefectures of eastern Japan, and increased both in autumn-winter and spring in western prefectures. CONCLUSIONS The study reveals the epidemiologic features of both temporal and geographic distributions of cases of 6 vector-borne diseases in Japan, 2000-2005.

Epidemics of Drug-Resistant Bacterial Infections Observed in Infectious Disease Surveillance in Japan, 2001-2005

BACKGROUND Drug-resistant bacteria have been increasing together with advancement of antimicrobial chemotherapy in recent years. In Japan, the target diseases in the National Epidemiological Surveillance of Infectious Diseases (NESID) include some drug-resistant bacterial infections. METHODS We used the data in the NESID in Japan, 2001-2005. Target diseases were methicillin-resistant Staphylococcus aureus (MRSA), penicillin-resistant Streptococcus pneumoniae (PRSP) and multi-drug-resistant Pseudomonas aeruginosa (MDRPA) infections. The numbers of patients reported by sentinel hospitals (about 500) on a monthly basis were observed. RESULTS The numbers of patients per month per sentinel hospital of 2001-2005 were 3.37-3.98 in MRSA, 0.96-1.19 in PRSP, and 0.11-0.13 in MDRPA infections. The sex ratios (male / female) of patients were 1.69-1.82, 1.34-1.43, and 1.71-2.52, respectively. More than 50% of all patients were adults aged 70 years or older in MRSA and MDRPA infections, but more than 60% were children under 10 years in PRSP infections. The number of patients per sentinel hospital in MRSA infections showed little variation between months, but evidenced a large variation in PRSP and MDRPA infections. The annual trend in the number of patients per sentinel hospital was increasing significantly for the 5-year period in MRSA and PRSP infections, but not in MDRPA infections. CONCLUSIONS We revealed sex-age distributions of the patients reported to NESID in Japan, 2001-2005. An increasing incidence of MRSA and PRSP infections and monthly variation in PRSP and MDRPA infections were observed for the 5-year period. Extended observation would be necessary to confirm these trends and variations.

Annual and weekly incidence rates of influenza and pediatric diseases estimated from infectious disease surveillance data in Japan, 2002-2005.

BACKGROUND The method for estimating incidence of infectious diseases from sentinel surveillance data has been proposed. In Japan, although the annual incidence rates of influenza and pediatric diseases estimated using the method were reported, their weekly incidence rates have not. METHODS The weekly sex- and age-specific numbers of cases in the sentinel medical institutions in the National Epidemiological Surveillance of Infectious Diseases in Japan in 2002-2005 were used. Annual and weekly incidence rates of influenza and 12 pediatric diseases were estimated by the above-mentioned method, under the assumption that sentinels are randomly selected from all medical institutions. RESULTS The annual incidence rate of influenza in 2002-2005 was 57.7-142.6 per 1,000 population. The highest weekly incidence rate was 7.4 at week 8 in 2002, 14.9 at week 4 in 2003, 14.1 at week 5 in 2004, and 21.2 at week 9 in 2005. The annual incidence rate per 1,000 population of 0-14 years old in 2002-2005 was less than 5.0 for pertussis, rubella and measles, 293.2-320.8 for infectious gastroenteritis, and 5.3-89.6 for 8 other diseases. The highest weekly incidence rate was less than 1.0 for exanthem subitum, and was more than 5.0 for infectious gastroenteritis, hand-foot-mouth disease and herpangina. CONCLUSION We estimated annual and weekly incidence rates of influenza and pediatric diseases in Japan in 2002-2005, and described their temporal variation.

Epidemics of Influenza and Pediatric Diseases Observed in Infectious Disease Surveillance in Japan, 1999-2005

BACKGROUND A method for determining epidemics in small areas from the sentinel surveillance data has been proposed and applied in the National Epidemiological Surveillance of Infectious Diseases (NESID) in Japan. We observed epidemics of influenza and 11 pediatric diseases by the method in the NESID in Japan during 1999-2005. METHODS We assumed that an epidemic in a public health center area began in a week when the number of cases reported to the NESID per sentinel clinic and hospital in the area in the week exceeded a given value, and that the epidemic ended when the number was lower than another given value. The proportion of public health center areas with epidemics (epidemic area proportion) by week in fiscal 1999-2005 was calculated. Total public health center area-weeks observed were about 30,000 each year. RESULTS The mean epidemic area proportion in the 7 years was 6.0% for influenza and 0.2-7.4% for pediatric diseases. The proportion increased in pharyngoconjunctival fever and group A streptococcal pharyngitis, decreased in measles and was less than 1.0% in pertussis and rubella. In influenza, the height of the peak in the weekly epidemic area proportion varied between 6 and 90% in the 7 years and the week of the peak varied widely. In some pediatric diseases, the height of the peak varied, while the week of the peak was relatively constant. CONCLUSION The frequency and temporal change were described in the epidemics of influenza and pediatric diseases in public health center areas from the NESID data in Japan, 1999-2005.

Wide-area epidemics of influenza and pediatric diseases from infectious disease surveillance in Japan, 1999-2005.

BACKGROUND Epidemics of infectious diseases usually start in small areas and subsequently become widespread widely. Although a method for detecting epidemics in public health center (PHC) areas has been proposed and used in the National Epidemiological Surveillance of Infectious Diseases in Japan, wide-area epidemics have not been fully investigated. METHODS Using the abovementioned method, we defined an epidemic as that occurring for a week in at least one PHC area in a prefecture and a wide-area epidemic as that when the number of people living in epidemic PHC areas exceeds 30% of the prefectural population. The number of weeks of an epidemic or wide-area epidemic for influenza and 11 pediatric diseases was observed in 47 prefectures in Japan from 1999 through 2005. RESULTS Epidemics and wide-area epidemics of influenza occurred for an average of 7.0 and 4.3 weeks in a year in a prefecture, respectively. The proportion of wide-area epidemics in epidemic weeks was 62%. The average number of wide-area epidemic weeks for pediatric diseases varied among diseases; it was more than 4 weeks for infectious gastroenteritis and herpangina and less than 1 week for pertussis, rubella, and measles. The proportion of wide-area epidemics in epidemic weeks was 28-41% for infectious gastroenteritis, hand-foot-mouth disease, and herpangina and less than 20% for other diseases. CONCLUSIONS The frequency of wide-area epidemics of influenza and pediatric diseases in various prefectures was observed. Epidemics of infectious diseases such as influenza and herpangina occurring in small areas were likely to spread to wide areas.