While the number of confirmed cases of H1N1 influenza remain in the hundreds in Mexico and the scores in the United States, the number of confirmed cases of dengue fever numbers in the many thousands in several states in Brazil. In late April the Brazilian government released statistics on confirmed cases of dengue fever and dengue hemorrhagic fever (a worse version).
The rapid increase in cases was attributed to heavy rains and large amounts of trash accumulating in cities.
The most recent totals released by the Ministry of Health in early April 2009 said that throughout the country dengue virus infected 161,414 people, which many believe is lower than the true number of infections. The state secretariat statistics are typically higher and more accurate that the ministry’s.
One example is Bahia. In the totals of the federal government were 41,093 dengue cases. The government of Bahia said that it reached 55,483 cases in Bahia through April 17, 2009, which represents a 220 percent increase compared to the same period in 2008. Of that total, 47 people have died of dengue.
The municipalities of Jequie, Itabuna, Porto Seguro, Ilheus, and Salvador had nearly half of the confirmed dengue cases in Bahia. Of that total, 389 people were victims of dengue hemorrhagic fever (DHF). According to the bulletin, 82 percent of the municipalities in Bahia recorded dengue cases.
The rapid increase in cases was attributed to heavy rains and large amounts of trash accumulating in and around the cities, which leads to increased mosquito breeding. The disease is spread through mosquito bites.
Complicating matters and leading to an increase in the incidence of DHF is a tendency among the population to self-medicate with acetaminophen (Tylenol) at the first sign of a fever rather than seek medical attention. As a result, the government estimates more than 220,000 dengue cases nationwide.
So, unlike H1N1 flu, which is spread from person to person via bodily fluids, dengue has a known vector (method of infection) — mosquitoes — an environment that fosters the breeding of the vector, and a reluctance of infected humans to seek proper medical attention, thus remaining sources of infection.
In Bolivia since October there have been 56,000 unconfirmed cases of dengue with 25 deaths. Argentina currently has an estimated 100,000-plus cases dengue, though some believe the actual figure to be as much as five times that. On the other side of the world in Sri Lanka they are also experiencing a dengue fever outbreak with smaller numbers but still with 200 percent more cases than during the same period last year.
In Saudi Arabia they’re trying to stem an outbreak of dengue, as well, caused by the Aedes aegypti species of mosquito, the most common dengue vector, which breeds in household water sources such as buckets and plant holders.
Looked at in this context, H1N1 doesn’t appear to be so bad, though it does have the potential to become a pandemic much more quickly than dengue fever. Those of us who live in mosquito-plagued places like Miami that also serves as a destination for many South Americans should take pause, however, as summer is nigh here and we could see dengue fever become endemic to the entire South Florida region.
But wait — it’s worse than that!
Aedes aegypti mosquitoes indeed breed here in southern Florida year-round, but they also breed year-round in North Carolina, New York, Upper Peninsula of Michigan, Missouri and — bad news, Jon — California. Trish only has to worry about contracting dengue fever from an Aedes aegypti from mid-January through mid-December (gee, that sounds like almost year-round, don’t it?).
Most of the east, extending all the way to north Texas has the mosquito breeding between six and eight moths of the year, so if dengue does get introduced into the U.S., it could rapidly become nasty for about half the country.
Just something to think about when you’re considering pandemics.
