Global Infectious Diseases Update

From SARS to swine flu: Checking the status of recent outbreaks around the world.

On March 15, 2003, The New York Times ran its first article on SARS (severe acute respiratory syndrome), titled “Mystery Respiratory Illness Afflicts Hundreds Globally.” It’s a familiar pattern: A new disease prompts dramatic headlines and international anxiety. Then the threat diminishes, the news moves on, and the panic becomes a memory. But what happened to SARS? Or bird flu? We looked at seven recent outbreaks to assess their impact today. (For current advisories, go to or

West Nile virus made its Western Hemisphere debut in 1999, in the New York City suburbs. Since then it has spread throughout North America, causing fever and serious illnesses like encephalitis and meningitis, and has expanded to Central and South America. The risk of catching the virus increases in late summer and early fall. The CDC recommends using insect repellent when outdoors.

Swine flu The H1N1 virus was first detected in Mexico in March 2009, and by late April the CDC called for U.S. citizens to avoid all nonessential travel to the country. But the WHO soon announced that containment was no longer possible and recommended against closing borders. The CDC ban was lifted on May 15, having been in effect for only two weeks. As of November the flu was still spreading at an increasing pace, and production delays had slowed distribution of the vaccine.

Mad cow disease The human version of bovine spongiform encephalopathy (BSE) was first identified in 1996 in the UK. More than 80 percent of cases were contracted there, mostly from eating beef tainted with the central nervous tissue of infected cattle. Per the CDC, new public health measures have reduced the risk in the UK to roughly one case per ten billion servings.

Monkeypox hit the United States in 2003, when 37 human cases were linked to pet prairie dogs who had contracted the virus from African rodents they had been housed with at a pet store. The virus itself is highly treatable, but the 2003 outbreak showed how quickly international animal transportation can spread infectious diseases.

Ebola virus Discovered in 1976, when outbreaks occurred in Sudan and Zaire, the Ebola virus kills an average of 90 percent of those it infects. Transmitted through bodily fluids, the most dangerous strains have remained in Africa. The strand that caused the 1989 Reston, Virginia, scare affected only monkeys, and no human cases have been reported in the States.

SARS originated in southern China in late 2002. It reached Hong Kong in February 2003, and within days there were outbreaks in Singapore, Toronto, and Hanoi. By summer a total of 810 deaths had been reported in 29 countries. No humans have been infected since 2004, but scientists warn that even one new case could cause another epidemic.

Avian flu Since the first human outbreak, in 1997 in Hong Kong, 442 cases of bird flu have been reported worldwide. Human-to-human transmission remains rare, but if contracted, the disease has a high mortality rate. Travelers to affected countries—Indonesia, Vietnam, and Thailand have had the most cases—should get a seasonal flu shot.