Dengue fever outbreak may occur due to prolonged El Nino

According to the US Climate Prediction Center (NOAA), 2015 could be the strongest and most destructive El Nino year on record.

This year, according to NOAA's report, in Vietnam, Laos, Cambodia, the Philippines, Malaysia,... the hot and warm climate will last until the end of the year due to being in the area affected by El Nino, thus leading to the risk of outbreaks and prolongation of dengue fever compared to previous years in these countries.

Scientific statistics show that the cyclical nature of El Nino is also logical with the observations of infectious disease epidemiologists that dengue fever epidemics occur every 3-5 years.

In Vietnam, the peak of dengue fever is during the rainy season, because this is the time when humidity is high, and the epidemic is also related to each time and each region. Usually, there are two notable peaks in April - May and September - October in the three regions of the North, Central and South.

According to information from the Ministry of Health, the dengue fever situation in Vietnam is currently complicated, with the number of cases increasing in most provinces and cities. In recent weeks, the number of cases has slowed down but there are no clear signs of a decrease. Since the beginning of the year, the country has recorded more than 54,000 cases of dengue fever, with at least 34 deaths.

At Bach Mai Hospital, the number of severe dengue fever cases requiring inpatient treatment at the Department of Infectious Diseases from May 2015 to present is 412 cases (10 times higher than the whole year of 2014). In October and the first half of November this year alone, the number of dengue fever patients treated at the department was 310 (accounting for 75% of the total number of cases), many of which were severe cases with complications, however, there have been no deaths.

Dr. Do Duy Cuong - Deputy Head of the Department of Infectious Diseases, Bach Mai Hospital, said that this year the epidemic appeared and broke out in larger numbers than previous years and although the weather has entered autumn and winter, the number of cases has not shown signs of decreasing.

At Bach Mai Hospital, patients are mainly from Hoang Mai, Hai Ba Trung, Cau Giay, and Dong Da districts of Hanoi. These are places where many student dormitories are located with unsanitary conditions and poor accommodation.

In particular, according to Dr. Cuong, this year due to the influence of El Nino, the prolonged hot and humid weather has created favorable conditions for the disease to develop.

The strongest El Nino phenomenon in history at this time is a condition for disease-causing mosquitoes to thrive, the life and lifespan of mosquitoes tend to be longer, meaning they have more conditions to complete their disease-causing cycle, because disease-causing insects are often metamorphic vectors, easily changed by environmental and natural factors.

Treatment for children with dengue fever at the Emergency Department, Ca Mau Maternity and Pediatrics Hospital. (Photo: Kim Ha/VNA)

In addition, according to the United Nations Children's Fund (UNICEF), El Nino can also lead to a significant increase in other diseases for young children, including malaria, dengue fever, diarrhea, and cholera - diseases that can easily cause death if not prevented and treated promptly.

- El Nino is the gradual warming of the sea water in the eastern Pacific Ocean, mainly along the Equator. El Nino occurs every 2-7 years with varying intensities and causes the atmosphere to warm, thereby significantly affecting the disease structure in affected countries. Typically, malaria and dengue fever can increase in countries that are warmed by El Nino.

The cause of the above situation is due to the development of Anopheles minimus and Anopheles dirus (the main hosts transmitting malaria) and Aedes Aegypti mosquitoes (the intermediate host transmitting Dengue fever and dengue hemorrhagic fever-DHF) which will have an ideal development environment at a temperature of 25 - 32 degrees Celsius.

According to VIETNAM+