PAHO/WHO Makes an Appeal to Fight Dengue


PAHO/WHO’s Director, Dr. Mirta Roses appealed to all countries in the Americas to increase efforts and to ensure preventive measures to respond to the growing number of cases of dengue in the region, given that in 2009 past trends could be repeated whereby serious outbreaks have been reported each three to five years.

Dengue outbreaks in Bolivia, Paraguay, Argentina and Brazil as well as significant numbers of cases in other countries should place the entire Region on alert, said Dr. Roses. “Governments need to strengthen surveillance, the monitoring of sites which incite the breeding of mosquitoes and the clinical management of patients; the first priority is to avoid deaths,” indicated Dr. Roses.

There is no vaccine or treatment for dengue, but appropriate medical attention can save the lives of patients who are suffering from the most serious form of the illness, haemorrhagic dengue.

PAHO/WHO has indicated that in order to reinforce the fight against dengue, an integrated and multidisciplinary approach is needed, since it requires action on the part of individuals (prevention of the disease and avoidance of self-medication); of locally-based groups and of civil society organizations; of local governments and communications media; of the central government, including the sectors responsible for the collection of waste and environmental sanitation, potable water services and, naturally, the health services with the guarantee of timely treatment.

The appeal from the director comes at the time when Bolivia is experiencing the worst epidemic in recent decades. As of April, there were over 55,000 cases, of which more than 10 were of haemorrhagic dengue, the most lethal form of the illness. The epidemic which is concentrated in the Department of Santa Cruz, has put the national health system to the test to respond to the emergency and has totally absorbed resources.

Dengue is an endemic disease in almost all countries in the region. In 2008 alone, 850,000 cases were recorded, including over 38,000 of haemorrhagic dengue, which caused at least 584 deaths. To date this year, almost 175,000 cases have been recorded, with over 3,000 cases of haemorrhagic dengue fever and 74 deaths.

The disease is endemic in over 100 countries in Africa, the Americas, the Eastern Mediterranean, South East Asia and the Western Pacific. Before 1970, only nine countries had had haemorrhagic dengue epidemics, a figure which by 1995 had been mulitiplied more than four times over. Today, cases of dengue have been reported to PAHO/WHO in 42 countries of the Americas.
As the illness reaches new areas, not only does the number of cases increase, but explosive outbreaks are occurring. For example, in 2007 in Venezuela more than 80,000 cases were reported, amongst which over 6,000 were of haemorrhagic dengue fever. In 2008, Brazil reported 585,769 cases of dengue and 478 deaths, mostly due to a dengue fever outbreak in Rio de Janeiro.
The spread of dengue has been attributed to the geographical distribution of the four dengue viruses and the mosquito vector, the most significant of which is the aedes aegypti, a predominanly urban species.

Climatic variability with an increase in temperature, an increase in the intensity and duration of the rainy season and the uncontrolled population growth in urban areas wthout basic potable water and environmental sanitation services favor the reproduction of mosquitoes. The most effective way to prevent the spread of dengue is to fight the mosquitoes which transmit the illness, destroying potential breeding sites, such as tires, vases and other recipients in which water can accumulate, both within the house and in surrounding areas.

Dengue is common in tropical climates, in particular in cities and peri-urban areas. More information on this issue can be found in the page; see “epidemiological alerts” and Dr. Mirta Roses’ blog.

Dengue rate and cases reported until 3 April by subregion
Americas Subregion
Cases of dengue/acute dengue
Incidence rate
by 100,000 hab.
Cases of acute dengue
Central America and Mexico
Andean Subregion
Southern Cone
Spanish-speaking Caribbean
Caribbean (rest)

*The figures used in this note are based on statistics from the month of April.

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