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Biomedical subjects

H G Chang

Publications and source records attributed to H G Chang.

At least 19 recordsLinked to original sources
PubMed2005

Estimating the mortality rate of hepatitis C using multiple data sources.

The New York State hospital discharge database and the multiple cause-of-death file were used to estimate the mortality rate of hepatitis C in New York State excluding New York City in 1997. The mortality rate with hepatitis C was severely underestimated when each data source was used alone. Applying the capture recapture method using the hospital discharge database and the multiple cause-of-death file appears to be an efficient method to estimate the mortality rate with hepatitis C.

Adult↗
PubMed2001

Rotavirus and central nervous system symptoms: cause or contaminant? Case reports and review.

Rotavirus is a common cause of severe gastroenteritis in children. In 2 patients with rotavirus gastroenteritis who developed encephalopathy, rotavirus RNA was detected in the cerebrospinal fluid (CSF) by reverse transcription-polymerase chain reaction; in 1 patient, rotavirus RNA was detected on 2 occasions 3 weeks apart. There are increasing reports of cases in which patients who have seizures after an episode of rotavirus diarrhea have evidence of rotavirus in their CSF. A search of 2 large hospital discharge databases suggested that seizures are noted as part of the discharge diagnosis in the records of, at most, <4% of patients with rotavirus diarrhea versus 7% of patients with bacterial diarrhea. Although evidence suggesting that rotavirus is a cause of central nervous system sequelae remains inconclusive, the 2 case reports presented in this study further illustrate a possible association. Further study is required to determine whether detection of rotavirus in CSF represents a true pathogen, CSF contamination that occurs at the time of lumbar puncture or in the laboratory, or carriage of rotavirus RNA in trafficking lymphocytes.

Central Nervous System Diseases↗
PubMed2001

West Nile virus: a case study in how NY State Health Information infrastructure facilitates preparation and response to disease outbreaks.

New York's (NY) Health Information Network (HIN) provided timely access to West Nile Virus (WNV) data during the initial outbreak in the late Summer 1999. In December 1999, NY developed a plan to deal with WNV in 2000 that required an integrated surveillance system for humans, birds, mammals, and mosquitoes. The HIN infrastructure allowed NY to deploy this system statewide in three months. Local health departments throughout NY used the system to report, track, and retrieve surveillance data as WNV spread throughout NY in 2000. The HIN infrastructure includes partnerships, training/support, technical capacity and architecture similar to NEDSS as proposed by the US CDC.

Animals↗
PubMed2001

Intussusception, rotavirus diarrhea, and rotavirus vaccine use among children in New York state.

OBJECTIVE: To describe epidemiologic features of intussusception and rotavirus diarrhea in New York, to examine the baseline incidence and trends over time, and to ascertain whether an excess of cases occurred in the 9 months of vaccination with the newly licensed rotavirus vaccine. METHODS: Hospital discharge data from 1989 through 1998 were reviewed for children (<1 year old) whose primary or secondary diagnosis was coded as intussusception or rotavirus diarrhea. Characteristics of patients admitted for intussusception and rotavirus diarrhea were compared, and trends over time were examined. For a subset of patients, medical records and vaccine histories for intussusception hospitalizations from October 1998 through June 1999 were analyzed. The number of intussusception cases attributable to rotavirus vaccine was calculated based on the penetration of the vaccine (21%) and a range of excess risks of intussusception among vaccinated children as estimated by the National Immunization Program (NIP). RESULTS: From 1989 through 1998, 1450 intussusception-associated hospitalizations were reported in children <1 year old (average annual incidence 5.4/10 000). Among these children, 47% were treated medically and 53% had surgery, with 9% needing surgical resection. The incidence of intussusception declined over time from 6.1 per 10 000 in 1989 to 3.9 per 10 000 in 1998. Intussusception hospitalizations occurred throughout the year, whereas rotavirus-associated hospitalizations peaked from February to April. Of 20 patients with intussusception whose hospitalization charts were reviewed, 5 had received rotavirus vaccine. All 5 were hospitalized after their first dose of vaccine, were admitted before 7 months of age, were white, and had private insurance. A total of 81 cases of intussusception occurred during the 9-month period of rotavirus vaccination, compared with 78 during the same period in the prevaccination year. The number of excess intussusception cases observed (n = 3) was lower than expected using the NIP estimate of excess risk (1.8) among rotavirus vaccinated children (n = 12) but not significantly different from the risks identified in the NIP cohort studies (1 in 12 000). CONCLUSION: Our data suggest that in New York the rate of intussusception has declined, and approximately 1 child in 2600 develops intussusception before 1 year of age. The different seasonality between intussusception and rotavirus-related hospitalizations suggests that if any causal association exists, it must be small. Unlike other studies, analysis of New York hospitalized discharge data failed to show an appreciable increase in the incidence of intussusception after introduction of the rotavirus vaccine.

Diarrhea↗
PubMed2000

Consented testing of newborns and childbearing women for human immunodeficiency virus through a newborn metabolic screening program.

OBJECTIVE: In this program a postpartum woman could consent to receive her newborn's human immunodeficiency virus test result from the New York State Newborn Screening Program. STUDY DESIGN: By state regulation each postpartum woman was counseled and offered her newborn's human immunodeficiency virus test result. With the mother's consent, newborn human immunodeficiency virus antibody test results from the Newborn Screening Program were sent to the baby's pediatrician; otherwise, test results were blinded. Data were analyzed for births from August 1, 1996, to January 31, 1997. RESULTS: Overall, 92.5% of women offered newborn human immunodeficiency virus testing consented to receive the result. Among 444 human immunodeficiency virus-positive women offered newborn testing, consented testing resulted in a 21.4% increase in knowledge of human immunodeficiency virus status from 72.3% (n = 321) at delivery to 93.7% (n = 416) after newborn testing; 6.3% (n = 28) of human immunodeficiency virus-positive women delivered of infants who did not consent apparently remained unaware of their human immunodeficiency virus status. CONCLUSION: Combined prenatal and consented newborn testing identified 94% of human immunodeficiency virus-positive mothers and exposed newborns, allowing early entry into care. Such testing may provide an opportunity for women not previously tested for the human immunodeficiency virus to learn their status but is not a substitute for universal prenatal human immunodeficiency virus counseling and consented human immunodeficiency virus testing.

Adult↗
PubMed1998

Human babesiosis in New York State: Review of 139 hospitalized cases and analysis of prognostic factors.

BACKGROUND: Babesiosis infections are infrequent, occur in limited geographic locations, and range from asymptomatic infection to severe illness and death. METHODS: Descriptive clinical and epidemiological information on human babesiosis cases was collated from state communicable disease reports and medical records of patients hospitalized from 1982 to 1993. Univariate and multivariate analyses were performed to determine prognostic factors associated with severe disease outcome (hospitalization ending in death, duration of hospitalization > 14 days, or intensive care unit stay > 2 days). RESULTS: Between 1982 and 1993, 139 patients were hospitalized with babesiosis in New York State. Nine patients (6.5%) died, 35 (25.2%) were admitted to the intensive care unit, and 35 (25.2%) required hospitalization for more than 14 days. Mean age at first hospitalization was 62.5 years. Sixty-two percent were male, and 91% resided in Suffolk County, Long Island. The most common symptoms were fatigue/malaise/weakness (91%), fever (91%), shaking chills (77%), and diaphoresis (69%). Past medical records showed that 52% of patients had a history of chronic disease; 12% had a history of Lyme disease; 12% had undergone a splenectomy; and 2% had undergone a blood transfusion. There was a 12- to 14-day delay between onset of symptoms and initiation of appropriate antibiotic treatment. Univariate analyses showed alkaline phosphatase levels greater than 125 U/L, white blood cell counts greater than 5 x 10(9)/L, history of cardiac abnormality, history of splenectomy, presence of heart murmur, and parasitemia values of 0.04 or higher to be significantly associated with disease severity. Multiple logistic regression analyses indicated that male sex, alkaline phosphatase values greater than 125 U/L, and white blood cell counts greater than 5 x 10(9)/L remained strong predictors of severe outcome. CONCLUSIONS: Human babesiosis is a rare but debilitating and potentially fatal illness, especially in the elderly. Prompt disease diagnosis and treatment are essential but are often delayed, as seen in our series. This delay reinforces the need for enhanced public and physician education targeted toward residents and visitors to the few high-risk geographic areas where disease and Ixodes scapularis ticks are endemic. Patients presenting with certain prognostic indicators (male sex, alkaline phosphatase values > 125 U/L, and white blood cell counts >5 x 10(9)/L) require comprehensive and aggressive medical care to prevent further deterioration. Since babesiosis is only 1 of 3 currently recognized diseases transmitted by I scapularis ticks, primary prevention recommendations will also reduce human exposure to Lyme disease and human granulocytic ehrlichiosis.

Aged↗
PubMed1998

Biomechanical testing of the lumbosacral spine.

OBJECTIVE: To assess various forms of anterior and posterior sacral fixation and to study the influence of anterior lumbosacral fixation and posterior pedicle fixation at L5 in conjunction with lumbosacral fixation. SUMMARY OF BACKGROUND DATA: Moments at the lumbosacral junction are high in the long constructs requiring lumbosacral fixation. The purpose of this study was to assess bending moments in flexion-extension and lateral bending and rotational forces at the lumbosacral junction involving a variety of long constructs to the lumbosacral junction. The incidence of pseudarthrosis in such constructs in the adult spine literature ranges from 7% to 40%. METHODS: An alignment jig was designed to display three-dimensional motion in the three orthogonal planes. Nine constructs of five specimens each were tested. These consisted of fixation at T12-L5-S1 (construct 1), T12-L5-S1 with anterior L5-S1 fixation and grafting (construct 2), T12-L5-S1, S2 with and without L5-S1 fixation and grafting anterior (constructs 3 and 4, respectfully), T12-S1, S2 with and without L5-S1 anterior grafting and fixation (constructs 5 and 6, respectfully), T12 Jackson intrasacral fixation with or without L5-S1 grafting anteriorly at the anterior fixation (constructs 7 and 8, respectfully), and T12-L5-S1, S2 fixation with anterior grafting only (construct 9). RESULTS: The use of anterior fixation statistically increased stiffness in extension. There was a trend toward increasing stiffness in constructs with anterior fixation (two anterior anterior-oblique L5-S1 screws) and in other loading modes as well. Failure to use L5 screw fixation significantly decreased torsional rigidity in long constructs without anterior fixation. CONCLUSIONS: In long constructs, particularly in scoliosis surgery requiring lumbosacral fixation, the addition of anterior fixation at L5-S1 is recommended. The addition of L5 fixation in addition to sacral fixation significantly decreases rotational stresses and is recommended as well.

Animals↗
PubMed1995

Knowledge and attitudes of healthcare workers about influenza: why are they not getting vaccinated?

In a survey of employees at a chronic care psychiatric facility following an influenza outbreak, previous influenza vaccination (relative risk [RR], 69.7; 95% confidence interval [CI95], 25.2 to 192.4), age > or = 50 years (RR, 2.4; CI95, 1.3 to 4.5), and knowledge that vaccine does not cause influenza (RR, 2.3; CI95, 1.3 to 3.7) were the factors most predictive of current influenza vaccination. Medical personnel were less likely than nonmedical employees to be vaccinated (RR, 0.5; CI95, 0.3 to 0.9). Educational efforts to address misconceptions about vaccination plus more vigorous administrative measures to vaccinate employees should be considered.

Adolescent↗
PubMed1993

Survival and mortality patterns of an acquired immunodeficiency syndrome (AIDS) cohort in New York State.

The survival experience and causes of death of acquired immunodeficiency syndrome (AIDS) patients were studied using a cohort of 3,699 AIDS patients in New York State, excluding New York City, whose illness was diagnosed before January 1990 at age 13 years or older. The median length of survival for all cases was 11.5 months, and survival increased over time from 5.3 months pre-1984 to 9.3 months in 1984-1986 and to 13.2 months in 1987-1989. In a Cox proportional hazards model, risk of dying was higher for persons aged 35 years or more at diagnosis and for persons with a diagnosis other than Pneumocystis carinii pneumonia or Kaposi's sarcoma whose illness was diagnosed before 1986. In this AIDS cohort, 2,834 (77 percent) persons died before 1991; 87 percent of the death certificates listed human immunodeficiency virus (HIV)/AIDS or an AIDS indicator disease as one of the multiple causes of death. The finding that 13 percent of the death certificates did not mention AIDS/HIV suggests that use of death certificates alone to count HIV-related deaths would result in an undercount. The recent expansion of the federal AIDS case definition is expected to add HIV-infected persons who die from conditions, such as recurrent pneumonia, that were not included in the earlier definition.

Acquired Immunodeficiency Syndrome↗
PubMed1993

High prevalence of syphilis detected through a jail screening program. A potential public health measure to address the syphilis epidemic.

BACKGROUND: In June 1990, a syphilis initiative was undertaken to help control New York's most extensive syphilis epidemic since the 1940s. METHODS: To evaluate the usefulness of syphilis screening in local jails, were reviewed demographic and syphilis screening data from a county jail in an area with a high prevalence of syphilis that has routinely tested incoming inmates. RESULTS: Of 12,685 inmates, 9797 (77%) were screened for syphilis, and 321 (3.3%) had a positive test result; 258 (80%) of the positive results were confirmed. Data were available for 244 of the inmates with a confirmed positive result: 162 (67%) had newly diagnosed syphilis (overall rate, 1.6%), 112 of whom had early syphilis; 50 (20%) had been previously treated for syphilis; and 32 (13%) were unavailable for follow-up. Of 162 inmates with newly diagnosed syphilis, 122 (75%) were treated in jail, and 40 were treated after their release from jail. The median time from screening to treatment was 17 days. The median jail stay was 45 days for inmates who were evaluated for treatment vs 5 days for those who were unavailable for follow-up. CONCLUSIONS: Screening inmates for syphilis was a productive public health measure, as inmates accounted for 20% of the county's syphilis morbidity. Given the high prevalence of syphilis among inmates and the inability to reach them for treatment after release, strategies are needed to rapidly screen and treat inmates before their release from jail.

Adult↗
PubMed1993

Typhoid fever at a resort hotel in New York: a large outbreak with an unusual vehicle.

The largest outbreak of typhoid fever in the United States since 1981 occurred in 1989 among guests and staff at a New York hotel. There were 43 culture-confirmed and 24 probable cases among guests, 1 culture-confirmed case and 1 asymptomatic culture-positive case among hotel employees, and 1 culture-confirmed secondary case. Twenty-one persons were hospitalized and 2 had bowel perforation. Breakfast on 13 June was the only meal consumed by all ill persons (relative risk, infinite; P = .004). In a case-control study, case-patients were more likely than controls to have consumed orange juice (odds ratio, 5.6; 95% confidence interval, 1.1-54.7), which had been prepared in a 208-L container with ample opportunity for hand contact. No other food was associated with illness. S. typhi was isolated from the stool of an asymptomatic food worker who handled orange juice but who was not known to be a typhoid carrier. S. typhi is a foodborne pathogen with continuing potential to cause large outbreaks in the United States.

Beverages↗
PubMed1992

A multistate outbreak of sporotrichosis associated with sphagnum moss.

In the spring of 1988, the largest documented US outbreak of cutaneous sporotrichosis to date occurred, with 84 cases among persons from 15 states who were exposed to Wisconsin-grown sphagnum moss used in packing evergreen tree seedlings. In New York State, 13 cases occurred among 109 forestry workers. All 13 cases occurred among 76 workers who had handled evergreen seedlings and moss (attack rate = 17%). For those exposed to evergreens and moss, the risk of infection increased as worktime exposure to moss increased (attack rates: less than 10 hours, 8%; 10-19 hours, 12%; greater than 19 hours, 33%). While environmental samples of moss from the Wisconsin supplier were negative, Sporothrix schenckii was cultured from multiple samples of the sphagnum moss obtained from one of six Pennsylvania tree nurseries, representing the nursery that was identified as the source for 79 (94%) of the moss-associated cases. Differences in tree-handling procedures at this nursery--including the use of 1- to 3-year-old moss to pack seedlings, use of a pond water source to wet the moss, use of an organic polymer gel on the seedling root system, and underground storage and longer storage of moss-packed seedlings before shipping--suggested possible explanations for the association. Efforts to prevent sporotrichosis among persons handling evergreen seedlings should include the use of alternate types of packing material (e.g., cedar wood chips or shredded paper) and protective clothing such as gloves and long-sleeved shirts.

Adolescent↗
PubMed1991

The geographic spread and temporal increase of the Lyme disease epidemic.

OBJECTIVE: To describe the temporal and geographic progression of the Lyme disease epidemic in New York State from 1977 through 1989. DESIGN: Communicable disease surveillance system. SETTING: Statewide. MAIN OUTCOME MEASURES: The progression of the epidemic was examined by analyzing trends in Lyme disease cases reported to the state surveillance system, town and county Lyme disease incidence rates, Lyme disease hospital discharge rates, and the distribution of Ixodes dammini ticks obtained from surveillance efforts and submitted for identification. MAIN RESULTS: The number of confirmed Lyme disease cases in New York has increased with concurrent increases in the number of hospital discharges. The number of counties endemic for Lyme disease increased from four to eight between 1985 and 1989. The number of counties with documented I dammini ticks increased from four in 1985 to 22 in 1989. Incidence of the disease also increased within known endemic counties. CONCLUSIONS: Tick surveillance indicated that the range of I dammini has expanded annually into areas up to 384 km from the original known endemic areas of Long Island, NY, and Connecticut. Cumulative data from human surveillance resources document both temporal increases and geographic expansion of the Lyme disease epidemic in New York.

Adolescent↗
PubMed1990

Application of the Cox model as a predictor of relative risk of coronary heart disease in the Albany Study.

Patients in long term studies of coronary heart disease may have different levels of risk during the course of study. Smoking habits, blood pressure, and obesity may change drastically during this period. The multiple logistic model, the most commonly used model for the analysis of coronary heart disease studies, does not consider survival time in assessment of the dependent covariates and does not account for the censoring which usually occurs in such studies. We propose a Cox model with time-dependent covariates to model the risk of coronary heart disease in the Albany study. The Cox model we fitted evaluates the patients' risk on the basis of the data at the last visit. With this methodology, we can evaluate whether it is advantageous for individuals to modify their risk of disease by their effecting changes in their covariates, that is to stop smoking, lose weight, change diet and so on. The important covariates that explain the risk of coronary heart disease were the same in our model as in the models used in the earlier reports. The estimated relative risks were slightly higher in most cases and lend more support to the need to encourage patients to achieve a better covariate state.

Adult↗
PubMed1990

Assessment of AIDS knowledge in selected New York State sexually transmitted disease clinics.

A 1988 survey regarding the level of knowledge about acquired immunodeficiency syndrome (AIDS) among 505 clients of sexually transmitted disease (STD) clinics demonstrated 80% correct responses. However, 13% thought AIDS could be transmitted via sharing utensils, and 51% were unaware that acquiring another STD could increase one's risk of human immunodeficiency virus (HIV) infection. In addition, only 10% always used condoms. An average 69% of patients obtained their AIDS information from newspapers, magazines, television, or radio; and 30% acquired information from medical or clinic staffs. In response to this survey, a videotape on AIDS was developed to show to patients of STD clinics while they are waiting to see a physician.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Health effects of low-level exposure to polychlorinated biphenyls.

A polychlorinated biphenyl (PCB) spill resulting from a transformer explosion in Syracuse, New York, with no subsequent fire, provided an opportunity for the examination of the effects of low-level PCB exposure without the confounding presence of furans and dioxins. The incident provided 52 individuals exposed to PCB among building personnel, police, firemen, and public utility employees. Sixty-eight nonexposed were matched to the exposed group by sex, age, employer, and job description. Data were collected on the exposed relative to their activities at the spill site, their location, possible routes of exposure, duration of exposure, and subsequent health effects. Exposed and nonexposed were interviewed for past medical history and relevant symptoms. Blood chemistries were studied inclusive of SGOT, SGPT, total protein, CBC, cholesterol, and triglyceride levels, as well as a fasting blood PCB level measurement. Six weeks after the spill, exposed and nonexposed were reinterviewed and had their blood work repeated except for the CBC and PCB levels. Exposed and nonexposed laboratory results were unremarkable. Some transient skin irritation believed to be associated with PCBs was noted. There were significant PCBs in blood level trends for occupation, age, duration of exposure, and level of alcohol consumption. Triglyceride level was highly correlated with PCB level. This relationship held when age and alcohol consumption were controlled for.

Adolescent↗
PubMed1980

Characteristics that predict risk of breast cancer before and after the menopause.

In a case-control study of 1868 breast cancer patients and 3391 control patients we searched for characteristics that predicted risk of breast cancer diagnosed before and after menopause. Common to increased risk of this disease in both periods of womanhood were: early menarche and late menopause; delayed marriage and first childbirth; more nulliparity or reduced gravidity and parity; reduced frequency of abortions; shorter overall child-bearing interval; more advanced education, higher socioeconomic status, and more contraceptive usage; and familial tendencies toward the disease. Breast cancer patients diagnosed before menopause were leaner than controls at age 20 and at time of diagnosis, but breast cancer risk in the postmenopausal period was related to increased weight-for-height at diagnosis and greater weight-for-height at diagnosis and greater weight gain since age 20. Postmenopausal breast cancer patients had a longer interval between first and second childbirths. Frequency and duration of the gravid state, inversely related to breast cancer risk, were largely dependent on contraceptive practices rather than unexplained infertility per se. Whether the breast cancer reaches diagnosis before or after menopause, the bulk of evidence examined here supports the view that it has a common cause and is subject to modifying influences over the long period of cancer latency.

Abortion, Spontaneous↗