NMSU branding

Human Infectious Diseases


Ebola hemorrhaghic fever is a severe, often fatal disease in humans and other primates that has appeared sporadically since its was first seen in 1976 in Zaire, where it killed 318 people. It is caused by infection with the Ebola virus, named after a river near where it was first identified.

Where does Ebola occur?

The exact origin and location of the Ebola virus is unknown. But researchers believe the virus is maintained in an animal host in Africa. Confirmed cases of Ebola in humans have been reported in Uganda, the Democratic Republic of Congo, Gabon, Sudan and the Ivory Coast. Ebola-Reston virus, a strain that causes disease in nonhuman primates but not people, sparked a scare when it caused severe illness and death in monkeys imported to research facilities in the United States from the Phillipines. Several laboratory researchers became infected with the virus but did not become ill.

How does the disease spread?

Infections with Ebola virus are acute. There is no carrier state. Because the natural reservoir of the virus is unknown, the manner in which the virus first appears in a human at the start of an outbreak has not been determined. However, researchers have hypothesized that the first patient becomes infected through contact with an infected animal.


Patients usually experience high fever, headache, muscle aches, stomach pain, fatigue and diarrhea. They may also experience less common symptoms such as a sore throat, hiccups, rash, red and itchy eyes, vomiting blood and bloody diarrhea. Within one week of infection, patients often experience chest pain, shock and death. Other symptoms may include blindness and bleeding.


There is no standard treatment for Ebola fever. Currently, patients receive supportive therapy, including balancing their fluids and electrolytes, maintaining their blood pressure and breathing, and treating them for any complicating infections.

Source: Centers for Disease Control and Prevention

West Nile virus

  • EDEN Network
    As we approach peak season for West Nile Virus transmission and time being spent outdoors, there is a West Nile Virus Issue Page on the EDEN website – link above. This page is also useful as many are concerned about the relationship between flooding and the increased mosquitoes being seen in these communities/states.

The West Nile virus is a mosquito-borne flavivirus common in Africa, West Asia and the Middle East. It was first seen in the eastern United States in the summer of 1999.

Where is the disease found?

Nearly 3,000 human cases of the West Nile virus have been reported this year, with nearly one-third of them in Colorado. Nationwide, the death toll is 54. The only states without a single human case of West Nile are Oregon and Nevada as of September 11, 2003.


Many people who are infected experience no symptoms while others may experience mild symptoms. Syptoms include low-grade fever, headache and body aches, skin rash or swollen lymph nodes, within three to 15 days. The elderly, children or people with weak immune systems are more vulnerable to the disease. The virus can cause encephalitis (inflammation of the brain tissue), which can result in permanent neurological damage and, in rare cases, death. Encephalitis symptoms can include the rapid onset of severe headache, high fever, stiff neck, muscle weakness and coma.

Reduce your risk to West Nile Virus

When dealing with West Nile virus, prevention is your best bet. Fighting mosquito bites reduces your risk of getting this disease, along with others that mosquitoes can carry. Take the commonsense steps below to reduce your risk:

  • Clean out the mosquitoes from the places where you work and play;
  • Help your community control the disease.
  • From April to October, minimize time spent outdoors at dawn, dusk and in the early evening.
  • Wear long-sleeved shirts and long pants when outdoors.
  • Apply insect repellent sparingly to exposed skin and clothing, according to manufacturer's directions. Repellent may irritate the eyes and mouth so avoid applying it to the hands of children.
  • Make sure your door and window screens fit tightly.
  • Remove standing water, which serves as breeding grounds for mosquitoes.
  • Change the water in bird baths at least once a week.

Source: Centers for Disease Control and Prevention

Severe acute respiratory syndrome (SARS)

Severe acute respiratory syndrome (SARS) is a viral respiratory illness that was recognized as a global threat in March 2003, after first appearing in Southern China in November 2002.

What is the cause of SARS?

SARS is caused by a previously unrecognized coronavirus, called SARS-associated coronavirus (SARS-CoV). It is possible that other infectious agents might have a role in some cases of SARS.

How does it spread?

The primary way that SARS appears to spread is by close person-to-person contact. SARS-CoV is thought to be transmitted most readily by respiratory droplets (droplet spread) produced when an infected person coughs or sneezes. Droplet spread can happen when droplets from the cough or sneeze of an infected person are propelled a short distance (generally up to 3 feet) through the air and deposited on the mucous membranes of the mouth, nose, or eyes of persons who are nearby. The virus also can spread when a person touches a surface or object contaminated with infectious droplets and then touches his or her mouth, nose, or eye(s). In addition, it is possible that SARS-CoV might be spread more broadly through the air (airborne spread) or by other ways that are not now known.

What does "close contact" mean?

Close contact is defined as having cared for or lived with a person known to have SARS or having a high likelihood of direct contact with respiratory secretions and/or body fluids of a patient known to have SARS. Examples include kissing or embracing, sharing eating or drinking utensils, close conversation (within 3 feet), physical examination, and any other direct physical contact between people. Close contact does not include activities such as walking by a person or briefly sitting across a waiting room or office.


The illness usually begins with a high fever (measured temperature greater than 100.4°F [>38.0°C]). The fever is sometimes associated with chills or other symptoms, including headache, general feeling of discomfort, and body aches. Some people also experience mild respiratory symptoms at the outset. Diarrhea is seen in approximately 10 percent to 20 percent of patients. After 2 to 7 days, SARS patients may develop a dry, nonproductive cough that might be accompanied by or progress to a condition in which the oxygen levels in the blood are low (hypoxia). In 10 percent to 20 percent of cases, patients require mechanical ventilation. Most patients develop pneumonia.

Source: Centers for Disease Control and Prevention

Centers for Disease Control and Prevention web site

Diseases and Conditions: A-Z

Pandemic Influenza