Communicable Disease & Epidemiology

The Communicable Disease and Epidemiology program at District Health Department #10 monitors the occurrence of specific diseases on a ten-county wide basis.

An explanation of the communicable disease and epidemiology functions at the health department would be incomplete without first providing a definition for that which serves as the foundation of this practice, epidemiology and surveillance.


Epidemiology is defined as “the study of the distribution and determinants of health-related states or events in specified populations and the application of this study to the control of health problems.” To put it more simply, epidemiology is the task of using data to answer questions of:

  • Who is getting sick?
  • What is making people sick? And,
  • How can we use this information to reduce the risk of others getting sick?

Without quality health data, it is very difficult to answer these questions. A surveillance system that serves to collect health data in a complete and timely manner is thus essential to the practice of epidemiology.


Surveillance is defined as “the ongoing systematic collection, analysis, and interpretation of outcome-specific data for use in planning, implementation, and evaluation of public health practice.

Data collected in a surveillance system can be used for many purposes, including:

  • To estimate the magnitude of a health problem in a population
  • To understand the natural history of a disease
  • To detect outbreaks or epidemics
  • To document the distribution of a health event
  • To test hypotheses about causes of disease
  • To monitor changes in infectious organisms

Communicable Disease Surveillance

Communicable diseases are those that can be transmitted from person to person (or animal to human) via direct contact with body fluids, ingesting contaminated food or water, inhalation of contaminated air, or the bite of an infected insect. Bacteria, viruses, and parasites are some of the organisms that can cause communicable diseases. Examples of communicable diseases are Hepatitis B, Salmonellosis, Measles, and West Nile Virus.

Preventing and controlling communicable disease is a necessary and critical aspect of assuring community health, and is an affirmative duty of local public health departments. Protecting the public’s health from communicable disease threats requires a proactive public health disease surveillance system, timely epidemiological assessment, and ongoing disease prevention education.

Because community disease surveillance and control is a critical component of disease prevention, District Health Dept. #10 monitors the occurrence of specific diseases on a community-wide basis. Physicians, laboratories, and schools all report cases of disease to the Health Department. With this information, we can monitor both the incidence (number of new cases) and prevalence (number of existing cases) of disease in the District Health Department #10 jurisdiction.

The “Big Picture”

In Michigan, the state Public Health Code requires that healthcare providers (physicians, physician assistants, pharmacists, dentists, nurses, veterinarians, etc.) report any of 77 specific diseases and that laboratories report any of 42 specific organisms identified to the local health department. While health care providers are typically concerned with the health of an individual patient, the focus of public health nurses and epidemiologists is on the “big picture” of health in a community.

A single case of a disease may not cause alarm in a physician’s office. However, timely and accurate reporting of communicable disease data allows health department personnel to determine whether this single case may be part of a larger problem in the community. With complete information, health department personnel can check if the disease is related to other cases as part of a cluster or is part of an outbreak (where the number of cases is greater than the number expected during a defined period).

Disease Detectives

Public health nurses and epidemiologists act as detectives who try to connect pieces of a puzzle in solving disease mysteries. These public health professionals monitor disease information to determine if there are more cases of a particular disease than expected. In addition, they investigate cases of disease to discover clues that may link the infected individuals and uncover the source of their infection. Once the culprit is discovered, these public health professionals provide education to those who are ill and those at risk of becoming ill to help prevent the spread of infection.


Timely and accurate reporting of communicable disease information thus allows health department personnel to:

  • Quickly identify single or multiple cases of disease occurring within a similar location or time
  • Identify persons at risk of acquiring or transmitting disease
  • Identify care needs and recommend appropriate prevention measures for those affected
  • Provide education for future prevention
  • Assess the effectiveness of public health disease prevention programs

Quick Links

MDHHS List of Reportable Diseases

Tuberculosis (TB)

TB bacteria are spread through the air from one person to another. People nearby may breathe in these bacteria and become infected. People with TB disease are most likely to spread it to people they spend time with every day. This includes family members, friends, and coworkers or schoolmates.
DHD#10 provides Mantoux Tuberculosis Skin Test (TBST) for those who believe they may have been exposed, those who require a TB test for new employment, or as requested by healthcare providers. The TBST requires two visits 48-72 hours apart. During the first visit the TBST is planted and during the second test it is read following Center for Disease Control Guidelines. Should the test show any induration the public health nurse will ask questions as indicated and determine if it is negative or positive.

Once the TBST is assessed negative clients are issued a card indicating the date it was applied, the date it was read, the amount of induration and that the test was interpreted as negative.

Positive TBSTs are questioned about symptoms and risk factors and assessed for the presents of active TB. A chest X-Ray is ordered at the hospital and the clients insurance pays for it. In the event that a client has no insurance the county communicable disease fund is billed for the cost of the X-Ray and its interpretation. All positive clients are offered prophylactic treatment and actual cases are followed per agency protocol.

Occasionally, there is need for Two Step TBST which is the same procedure as above with the addition of a second TBST done in the opposite arm 1-3 weeks after the first if it was negative and two negative cards are issued.

DHD#10 will bill most insurances. Payment is due at the time of first appointment. Cost with no insurance is $24.00.

Basic TB Facts
Tuberculin Skin Testing
We Are TB Peer Support

Animal Bites/Rabies

All human who experience an animal bite or other types of exposures to potentially rabid animals or bats must be reported to your local DHD#10 office within 24 hours of seeking medical care. An interview will be conducted by a public health nurse at DHD#10 to understand what happened at the time of the bite.
Bats and some other animals who have bitten a person may need to be shipped to Michigan Department of Health and Human Services. For that reason, do not dispose of the bat. Watch the video below for instructions on how to contain the bat/animal.

Contact your local DHD#10 office if you have questions about unusual situations especially if exposed to a wild animal bite, macque monkey bite, public show animal bite, and or a petting zoo/fair animal bite.

When should I seek medical attention?
What are the signs and symptoms of rabies?
Rabies Prevention


Animal Bite Exposure Form

Lyme’s Disease

Lyme disease is caused by a bacteria transmitted to humans through the bite of infected blacklegged ticks. People who suspect to be exposed to Lyme’s Disease should contact their healthcare provider or local DHD#10 office as soon as possible. An interview will be conducted by a public health nurse at DHD#10 to understand what happened at the time of the bite.

MDHHS – Lyme Disease
Michigan Trends in Tickborne Diseases
Got a Tick? Submit a Pic –
What you Need to Know about Lyme’s Disease
Tick Removal and Testing
Signs and Symptoms of Untreated Lyme Disease

Avian Influenza

Avian Influenza (Bird Flu) is a highly contagious, viral disease that infects wild birds such as geese, ducks, swans and shorebirds, as well as domestic poultry, including turkey, ducks, chickens, and geese. Avian influenza has been documented at lower levels in the US; however, highly pathogenic strains can cause severe illness and catastrophic losses in poultry. Signs of sickness include unusual deaths, a drop in egg production, significant decreases in water consumption.

If avian influenza is suspected for:

Domestic flocks: Contact MDARD IMMEDIATELY at 800-292-3939 (daytime) or 517-373-0440 (after hours).
Wild birds: Contact the DNR at 517-336-5030 if losses/deaths of three or more free-range birds occur.

What to know about Bird Flu
MSU Extension – Avian Influenza

Hepatitis A

Hepatitis A is a vaccine-preventable, communicable disease of the liver caused by the hepatitis A virus (HAV). It is usually transmitted person-to-person through the fecal-oral route or consumption of contaminated food or water. Hepatitis A is a self-limited disease that does not result in chronic infection. Most adults with hepatitis A have symptoms, including fatigue, low appetite, stomach pain, nausea, and jaundice, that usually resolve within 2 months of infection; most children less than 6 years of age do not have symptoms or have an unrecognized infection. Antibodies produced in response to hepatitis A infection last for life and protect against reinfection. The best way to prevent hepatitis A infection is to get vaccinated.


How is Hepatitis A spread?

Hepatitis A is usually spread when the Hepatitis A virus from an infected person’s feces (or stool, poop) gets into someone else’s mouth. This often happens when the infected person’s feces comes into contact with objects, food, or drinks. Most frequently, Hepatitis A is passed between people that spend a lot of time together, such as those that live together, share drugs, have sex, or someone that provides care to someone at risk. In the current outbreak in Southeast Michigan and other areas of Michigan, at least half of the cases appear to be linked to illicit drug use.

Risks for Hepatitis A during this outbreak include:

  • Injecting drugs or using street drugs (including pain killers)
  • Going to jail
  • Paying for sex or trading sex for money or drugs
  • Being homeless or having an unstable living situation
  • Men that have sex with men

​Anyone with these risk factors, or living with someone with one of these risk factors, should get vaccinated for hepatitis A.

​How do you prevent Hepatitis A?

Handwashing is one of the best ways to reduce your risk of getting hepatitis A. Hepatitis A is spread by the fecal-oral route, which means you can get ill if you eat, drink, or touch your mouth with any food, drink, object, or your hands that may have been in contact with stool (feces) from someone infected with hepatitis A. Washing your hands thoroughly after using the bathroom and before handling or eating food can help prevent this.

Getting vaccinated for hepatitis A is also extremely effective. Anyone with the risk factors listed above or those that have regular, close contact to people with those risk factors, should get vaccinated. It is also being recommended that food handlers with one or more of the above risk factors and food handlers in outbreak areas as well as healthcare workers caring for patients in the outbreak areas get vaccinated.

If you may have been exposed to someone infected with hepatitis A, you may be able to prevent illness by getting the hepatitis A vaccine or a dose of immunoglobulin (IG) within 2 weeks after you were exposed. This is referred to post-exposure prophylaxis (PEP).

​What should be given for PEP?

​If you have not been vaccinated for hepatitis A before or had a confirmed case of hepatitis A in the past, you should be given a hepatitis A vaccine* or IG (0.1 mL/kg) as soon as possible, again, within 2 weeks after exposure. Which one you get varies by age and health status:

  • For healthy people age 12 months to 40 years, Hepatitis A vaccine is preferred
  • For people age 41 years and older, IG is preferred because this age group wasn’t initially included in the studies done to determine if vaccination was effective to prevent infections after exposure. Also IG is recommended for older individuals because hepatitis A infection is usually more serious in older adults
    • However, vaccine should be given to individuals over 40 in addition to IG and can be used alone if IG is not available. Additional studies suggest vaccination alone is likely effective for PEP in healthy adults over 50 or 60 years old.
  • IG should be used:
    • For children aged less than12 months, immunocompromised persons, persons with chronic liver disease, and persons who are allergic to the vaccine or a vaccine component
    • Pregnant women that have been exposed should receive both the vaccine and IG (per recent unpublished recommendations from the CDC)

*NOTE: for complete and life-long protection against Hepatitis A, a second dose of Hepatitis A vaccine is needed at least 6 months later

​How else can I prevent Hepatitis A?

Hepatitis A vaccination is recommended for all children at age 1 year, for anyone at increased risk for infection, for anyone at increased risks for complications from Hepatitis A, and for anyone wishing to be protected. The Hepatitis A vaccination is recommended for the following groups:

  • All children at age 1 year (i.e., 12–23 months). Children who have not been vaccinated by age 2 can be vaccinated at any time.
  • Persons traveling to or working in countries that have higher risks of Hepatitis A. People from the United States who travel to developing countries are at high risk for Hepatitis A. The risk for Hepatitis A exists even for travelers to urban areas, those who stay in luxury hotels, and those who report that they are careful about what they drink and eat. Some experts feel that travel to any country is a risk and recommend Hepatitis A vaccination for any international travel.
  • Men who have sex with men. Sexually active men (both adolescents and adults) who have sex with men should be vaccinated.
  • Users of illegal injection and noninjection drugs (included pain killers). During the past two decades, outbreaks of Hepatitis A have been reported with increasing frequency among users of both injection and noninjection drugs in North America, Europe, and Australia. In fact, several large outbreaks are occurring around the country, including Southeastern Michigan, which appears to be linked at least in part to drug use.
  • Persons who have occupational risk for infection. Persons who work with HAV-infected primates or with HAV in a research laboratory setting should be vaccinated. No other groups have been shown to be at increased risk for HAV infection because of occupational exposure.
    • Also, it is currently being recommended that healthcare workers caring for patients in outbreak areas be vaccinated, primarily those in contact with high risk populations, such as workers in emergency departments, janitorial staff, EMS, paramedics, and other first responders.
    • Although they are not necessarily at higher risk for infection, it is being recommended that food handlers in outbreak areas be vaccinated. This is due to the risk a hepatitis A-infected food handler has in spreading disease to a large number of people due to contamination of food.
  • Persons who have chronic liver disease. Persons with chronic liver disease who have never had Hepatitis A should be vaccinated, as they have a higher rate of serious and life-threatening Hepatitis A. Persons who are either awaiting or have received liver transplants also should be vaccinated.
  • Persons who have clotting-factor disorders. Persons who have never had Hepatitis A and who are getting clotting-factor concentrates, especially solvent detergent-treated preparations, should be vaccinated.
  • Household members and other close personal contacts of adopted children newly arriving from countries with high prevalence of Hepatitis A.

​Where can I go to get a Hepatitis A vaccine?

Your local health department, primary care provider, or visit An appointment may be necessary


​Quick Links

Hepatitis A Vaccination Guidance
CDC – Viral Hepatitis
Hepatitis A Vaccine:  Reasons to Consider Vaccination
Hepatitis A Vaccination Priority Levels for Hospital Personnel