While Ebola garners the bulk of the headlines, other serious disease threats like Chikungunya and Dengue continue their inexorable spread across the globe, infecting hundreds of times more people than does Ebola, albeit with a far lower morality rate.
In 2013, dengue behaved like a classic epidemic for the Americas region, with the largest historical cases reported. In total, countries in the Americas reported more than 2.3 million cases of dengue, with 37,692 cases of severe dengue and 1,280 deaths, for a mortality rate of about 0.05%.
This year, for the first time, the Americas are also dealing with Chikungunya – which arrived late last fall in the Caribbean, and has spread rapidly since then. PAHO’s most recent report (Week 34) indicates just over 650,000 CHKV infections in the Americas, and 37 deaths.
The arrival of Chikungunya to the Americas has been anticipated for some time, and the CDC & PAHO produced a 161 page guide on preparing for its arrival 3 years ago (see Preparedness and Response for Chikungunya Virus Introduction in the Americas).
Last May, in Florida Prepares For Chikungunya we looked at local preparations for its arrival. Given its climate, its position as the gateway to the Caribbean, and that it receives millions of tourists every year - Florida was considered a likely first US battleground against any CHKV invasion.
And indeed, the first first locally acquired case in Florida was reported in July.
For now, the major concern is in the Caribbean, Central & South America where both Dengue and CHKV co-circulate, and where the burden of these diseases is infinitely higher than it is in the United States. As the height of the Dengue season generally occurs in the second half the year, the next few months are considered a critical time for mosquito control programs.
Yesterday PAHO and the World Health Organization released an 8-page PDF Epidemiological Alert for the Americas on these co-circulating mosquito-borne diseases. Follow the link to read the entire document:
29 August 2014
The first evidence of autochthonous chikungunya transmission in the Americas was recorded in December 2013, since then, autochthonous transmission has been detected in 33 countries and territories of the Americas (27 countries and territories in the Caribbean, 3 countries in Central America, 1 country and 1 territory in South America and 1 country in North America).1,2 As of epidemiological week (EW) 35 of 2014, the Pan American Health Organization / World Health Organization (PAHO/WHO) has been informed of a total of 659,367 cases, including 37 deaths, in the Americas.
Usually during the second semester of the year, Central America, Mexico and the Caribbean experience a seasonal increase in dengue fever transmission. Currently, the Dominican Republic, El Salvador, Guatemala, and Honduras, are recording increases in cases coinciding with this period of greater transmission.
The threats posed by the seasonal increase of dengue transmission and the introduction, or risks of introduction of the chikungunya virus in the Region require an integrated approach of prevention and vector control activities of both diseases. With the rapid spread of the chikungunya virus observed in some countries of the Americas, simultaneous dengue and chikungunya outbreaks may occur, which would result in increased health care demand. Accordingly, health care services must be prepared to meet expected increased demand without compromising quality of care; preparations should be guided by the PAHO/WHO recommendations for clinical management of patients with dengue or chikungunya.
With the rapid expansion of both Dengue and Chikungunya around the globe, Europe and the United States are seeing signifcant increases in the number of imported cases every year – each with at least the potential to seed local mosquito populations with the virus. So far locally acquired infections in both regions remain relatively rare.
The lack of an abundant non-human animal reservoir for the virus is likely partly responsible. But in 2003, a CDC EID study also found that economics and lifestyle may have a lot to do to with our lack of locally transmitted Dengue (see Texas Lifestyle Limits Transmission of Dengue Virus).
But given the availability of two competent mosquito vectors (Aedes Aegypti & Aedes Albopictus), and repeated introductions of the virus from travelers coming from regions where the virus is endemic, our luck in this matter may not last forever.
The good news is that these mosquito-borne illnesses (and others, including WNV, SLEV, EEE, etc.) are largely preventable.
Florida’s Health department reminds people to always follow the `5 D’s’: