Infectious Diseases

September 4, 2014


zangenehAs humans, we are constantly in contact with numerous people, objects, environments and thus, diseases. Viruses, bacteria, parasites, or fungi can cause infectious diseases. They can be spread via other humans, food, water, healthcare-associated infections, insects, and shared common areas in highly populated environments. Here to answer a few questions about infectious diseases is Tirdad T. Zangeneh, DO. Dr. Zangeneh is board certified in Internal Medicine and Infectious Diseases and is an Assistant Professor of Clinical Medicine at the University of Arizona, College of Medicine.

Q-What are infectious diseases?

They are diseases caused by organisms including bacteria, viruses, fungi, or parasites; they are generally transferred from one organism to another organism.

Q-Why do people end up in your care?

Consultations or referrals are due to a variety of reasons including established infections with challenging management issues, infections in immunocompromised hosts, travel related infections, sexually transmitted infections, fever of unknown etiology, second opinions, or finally the patient or provider is uncertain about the diagnosis.

Q-What are the most common types of infectious disease that you see?

Solid Organ Transplant and HSCT related infections, HIV/AIDS, endocarditis and endovascular infections, osteomyelitis and complicated diabetic foot infections, Coccidioidomycosis (commonly known as "valley fever"), Sexually Transmitted Infections (STIs), Hospital Acquired Infections (HAI), infections related to travel, and vector-borne and zoonotic diseases.

Q-What are the most common ways that people contract infectious diseases?

Most are divided into contagious and non-contagious categories. Specific examples include Immunosuppression, post-antibiotic exposure, hospital acquired, pregnancy associated, vector-borne or zoonotic, sexually transmitted, food-borne, contact, oral-fecal, airborne, and droplet.

Q-Are there any infectious diseases particular to Southern Arizona?needles

Mainly Coccidioidomycosis (commonly known as "valley fever") and Nocardia is common as well. There have been a recent increase in Rocky Mountain Spotted Fever (RMSF) in certain parts of the state, and other vector-borne and zoonotic infections such as Hantavirus and rabies are present here as well.

Q- Are drugs used to treat all infectious diseases?

No, some infections resolve without needing therapy and unfortunately for some infectious diseases, there are no available treatment options. Many infections are simply prevented by immunizations and public health measures. Some organisms colonize us without causing an infection.

Q-What level of concern should people have regarding Methicillin-Resistant Staphylococcus aureus (MRSA)?

patientMRSA can be acquired in the community or healthcare setting. Each year MRSA related infections result in significant morbidity and mortality. According to the Centers for Disease Control and Prevention (CDC), invasive hospital acquired MRSA infections declined 54% between 2005 and 2011.

Q-How often is it that people acquire infectious diseases from hospital visits/stays?

According to the CDC, about 1 in 25 hospital patients has at least one healthcare-associated infection (HAI) on any given day. 722,000 HAIs occurred in acute care hospitals in 2011. About 75,000 hospital patients died during their hospitalizations due to one of these infections.

1) Magill S.S., Edwards J.R., Bamberg W., et al Multistate Point-Prevalence Survey of Health Care-Associated Infections, NEJM, 2014; 370:1198-1208.
2) The Centers for Disease Control and Prevention (CDC).

Photos (stock): Dynamic Graphics, The Professional Series. Health & Medicine 2, Vol. 46.


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