Disease Reporting

Communicable Disease Surveillance Data are derived from reports filed with the New York City Department of Health and Mental Hygiene as required by Article 11 of the New York City Health Code. The Bureau of Communicable Disease manages the data derived from these reports. Data are cleaned, analyzed, and reported for public health surveillance. The data presented in EpiQuery include all confirmed and probable cases of selected reportable communicable diseases diagnosed since 2000 among patients known to reside in one of the five New York City boroughs.

Diseases reportable to the Bureau of Communicable Disease include:

The NYC HIV Epidemiology and Field Services Program (HEFSP) manages the HIV surveillance registry, a population-based registry of all people diagnosed with AIDS (since 1981) or HIV infection (since 2000) and reported to the Health Department according to standard Centers for Disease Control and Prevention (CDC) case definitions. The Registry contains demographic, HIV transmission risk, and clinical information on HIV-diagnosed people, as well as all diagnostic tests, viral load tests, CD4 counts, and HIV genotypes reportable under New York State law. For a list of surveillance definitions and technical notes, see https://www1.nyc.gov/site/doh/data/data-sets/hiv-aids-annual-surveillance-statistics.page.

Article 11 of the New York City Health Code mandates that health care providers diagnosing sexually transmitted diseases (STDs) and clinical laboratories licensed to perform laboratory testing for New York City (NYC) residents are required to report seven STDs, designated as 'notifiable' or reportable, to the NYC Department of Health and Mental Hygiene's Bureau of STD Control. These diseases include chlamydia, lymphogranuloma venereum, gonorrhea, syphilis (all stages), chancroid, granuloma inguinale and neonatal herpes. The Bureau of STD Control manages the data derived from these reports. Data are cleaned, analyzed and reported as part of public health surveillance.

For some STDs, there are a large number of infections that are not diagnosed because they frequently lack symptoms, such as chlamydia. Asymptomatic persons may not be screened, and thus diseases may exist at higher levels in the population than notifiable disease data indicate. In some instances, considerable differences in numbers and rates of infection between subgroups may be largely attributable to screening and testing practices, rather than real differences in disease burden. For example, there are national recommendations that young women be screened for chlamydia annually, while there are no similar recommendations for young men. Consequently, the number of reported cases of female chlamydia in NYC is substantially higher among women than men, although the gender difference in actual disease rates is likely to be much smaller.

The Syndromic Surveillance Unit in the Bureau of Communicable Disease collects data from all 53 emergency departments (ED) in New York City, as required by Section 11.03(d) of the New York City Health Code. All ED patient encounters are sent to the Health Department on a daily basis.

ED patient encounters are categorized into broad syndromes based on chief complaint, or the patient’s reason of visit, and International Classification of Diseases (ICD-10) discharge diagnosis code. Text processing algorithms are used to identify words or character strings in the chief complaint and diagnosis code which subsequently identifies whether the patient falls into one of the following syndrome categories:

• Asthma: includes mention of asthma, wheezing, or reactive airway, or diagnosis codes of J45 or R06.2
• Diarrhea: includes mention of diarrhea, enteritis, gastroenteritis, loose stools, and stomach flu, or diagnosis codes of R19.7 or A09
• Influenza-like-illness (ILI): includes mention of flu, fever, and cough or sore throat
• Respiratory: includes mention of bronchitis, chest cold, chest congestion, chest pain, cough, difficulty breathing, pneumonia, shortness of breath, and upper respiratory infection, or diagnosis codes of J24.0, R05, J12-J18, R06.02, J04.2, and J06
• Vomiting: includes mention of throwing up and vomit, or a diagnosis code of R11

Data are provided at the citywide, borough, and ZIP code levels. There are 140 ZIP code areas, with some small-population ZIPs merged to larger contiguous ZIPs. Each ZIP area has 30,000 residents or more. Borough is based on the ZIP code of the patient’s residence. In the case of missing ZIP code data, the patients are allocated to a probable ZIP code of residence based on the address of ED and demographic characteristics.

Patients are included in the all age group data but excluded from the age-specific categories in the case of missing age data.

Ratios are calculated using the proportion of daily syndrome visits (numerator) among total daily visits (denominator).

Syndromic data typically show a day-of-week pattern, with the highest volume of ED visits on Monday and the lowest volume on weekends. Major holidays also tend to have a lower volume of ED visits. In addition, there may be occasional under-reporting from some hospitals. Data for the most recent two weeks may change daily due to reporting delays from some hospitals.

Syndrome data are inherently non-specific and not based on diagnostic testing.

While the New York City syndromic surveillance system captures 100% of all ED visits in the city (as of 5/1/16, 99% prior to that), the data are not comprehensive as only a proportion of residents seek care in EDs. Therefore the data are not exact measures of morbidity.

In New York City, reporting of confirmed cases of tuberculosis (TB), persons suspected of having TB, and children under 5 with a positive test for latent TB infection to the Health Department is mandated by the New York City Health Code and New York State Public Health Laws. Reports are received from health care providers and clinical laboratories throughout the city. The data received are tracked and analyzed for public health and programmatic purposes.

The vaccine-preventable disease surveillance data are derived from reports filed with the NYC Department of Health and Mental Hygiene, as required by Section 11.03 of the NYC Health Code. The Bureau of Immunization manages the data cleaning, analysis and reporting for public health surveillance. Minor variations in data presented here and elsewhere (including other DOHMH publications) may be due to several factors, including:

• Reporting delays
• Census data availability
• Corrections
• Data-processing refinements (for example, the removal of duplicate reports)

The data presented in EpiQuery include all confirmed and probable cases of disease diagnosed since 2000 among patients known to reside in the city. Reported cases and crude rates are available by selected demographic (age group, sex) and geographic (borough) characteristics.

Rates for congenital rubella were calculated per 1,000 live births, using data from the DOHMH Office of Vital Statistics. All other rates were calculated per 100,000 population using DOHMH population estimates, modified from US Census Bureau interpolated intercensal estimates.

Diseases reportable to the Bureau of Immunization include: