Communicable diseases, also known as infectious diseases, are caused by germs, transferable living agents, mainly bacteria, viruses, fungi and protozoa. They are spread directly or indirectly from person to person. Sometimes, they are transmitted by bites from animals or insects that act as reservoirs. They account for more than 30 million outpatient visits and about 3 million emergency room visits.
Communicable diseases affect almost every organ system, causing different disease syndromes that range from the mild and self-limiting to the rapidly worsening and fatal. Vaccines are the major means of control. Specific anti-infective treatment has also contributed to the ever-changing profile of infectious diseases by drastically reducing the mortality and morbidity due to certain diseases.
Top 10 Communicable Diseases
Mortality and morbidity statistics from the Centers for Disease Control and Prevention provide information on the impact of various communicable diseases in the U.S. Case fatalities and hospitalization figures give an indication as to the severity of the illness and economic impact of the different diseases.
Topping the list as the only communicable disease in the top 10 list of all fatalities is the duo of influenza and pneumonia. Influenza virus--the flu--rages through the world in a seasonal blitz. In the U.S., it contributes to over 200,000 hospitalizations a year and about 36,000 deaths. The advent of the H1N1, or swine flu. has further deepened concerns over this disease this year. Usually riding on the back of the flu is bacterial pneumonia, mainly by the pneumococcus bacteria. Pneumococcal diseases account for more than 175,000 hospitalizations and 4,800 deaths.
HIV/AIDS, still without a cure, is the sixth killer of the backbone of the labor force, the 25-44 years age group in the U.S. There are more than 36,000 new cases each year and more than 12,000 deaths each year. Its propensity for striking in the most productive years has made it a nightmare in developing countries.
Viral hepatitis comes in with over 7,000 deaths per year. There are essentially four hepatitis virus types: A, B, C and E, each capable of fulminant disease with fatalities under peculiar conditions.
Tuberculosis, an age-old disease, recently staged a comeback with the rise of HIV/AIDS. With more than 13,000 cases and 652 deaths in 2006, it is definitely in the top 10 and can prevent entry into the U.S. by immigration services. Drug resistance poses a real problem here.
Other prominently fatal communicable diseases in the top 10 are meningiococcal meningitis, syphilis, non-typhoid salmonellosis, malaria and whooping cough, also called pertussis.
Other Important Communicable Diseases
Sexually transmitted diseases chlamydia--more than 1 million cases a year--and gonorrhea--more than 300,000 cases a year--are significant causes of morbidity and the leading causes of morbidity amongst notifiable diseases in the U.S. Another important notifiable disease is Lyme disease with almost 20,000 cases a year. Diarrheal diseases, especially Shigellosis, also account for a significant level of morbidity.
Another class of communicable diseases is not so prominent in morbidity and mortality but is of special interest for its possibility as an instrument of bioterrorism because of its virulence. Diseases in this class include anthrax, bubonic and pneumonic plague, botulism, small pox, tularemia and viral hemorrhagic fevers.
Communicable Disease Control
Many infectious agents have been drastically limited by vaccinations. This remains the backbone of communicable disease control. Specific vaccines have helped to curtail the spread of the agents they were developed for, sometimes leading to 'extinction' of clinical cases, such as smallpox.
Good personal hygiene, in terms of proper hand washing and sanitary practices, especially in waste disposal and food preparation, have also helped in infection control.
Prompt presentation for treatment and the public responsibility of staying away from public places when ill, have been shown to be crucial in the fight against communicable diseases.
