Dengue fever outbreaks

The first recognized dengue epidemics occurred almost simultaneously in Asia, Africa, and North America in the 1780s, shortly after the identification and naming of the disease in 1779.

A pandemic began in Southeast Asia in the 1950s, and by 1975 dengue haemorrhagic fever (DHF) had become a leading cause of death among children in the region.

Thus over time there remain large numbers of susceptible people in affected populations despite previous outbreaks due to the four different serotypes of dengue virus and the presence of unexposed individuals from childbirth or immigration.

[5] One model to explain this process is known as antibody-dependent enhancement (ADE), which allows for increased uptake and virion replication during a secondary infection with a different strain.

Cesar Maia, mayor of the city of Rio de Janeiro, denied that there was serious cause for concern, saying that the incidence of cases was in fact declining from a peak at the beginning of February.

[10][11] Dengue fever occurs widely in the tropics, including the southern United States,[12] northern Argentina, northern Australia,[13] Bangladesh, Barbados, Bolivia,[14] Belize, Brazil, Cambodia, Colombia, Costa Rica, Cuba, Dominican Republic, French Polynesia, Guadeloupe, El Salvador, Grenada, Guatemala, Guyana, Haiti, Honduras, India, Indonesia, Jamaica, Laos, Malaysia, Melanesia,[clarification needed] Mexico, Micronesia, Nicaragua, Pakistan, Panama, Paraguay,[15] the Philippines, Puerto Rico, Samoa,[16] Western Saudi Arabia, Singapore, Sri Lanka, Suriname, Taiwan, Thailand, Trinidad and Tobago, Venezuela and Vietnam, and increasingly in southern China.

Nearby Guadeloupe and Martinique, in the French Caribbean, were affected as well: over 40000 clinical cases in each island required medical assistance (the outbreak peaked in August 2010 and was practically over by October).

[23][24] The health risks and rapidly escalating costs to the United States of unmonitored, unvaccinated and disease carrying travelers, legal and illegal, has been recently considered.

On March 4, 2009, Queensland Health had confirmed an elderly woman had died from dengue fever in Cairns, in the first fatality since the epidemic began last year.

In 2009, in Argentina, a dengue outbreak was declared the northern provinces of Chaco, Catamarca, Salta, Jujuy, and Corrientes, with over 9673 cases reported as of April 11, 2009 by the Health Ministry.

There were information campaigns concerning prevention of the dengue fever; and the government is fumigating with insecticide in order to control the mosquito population.

"[30] In the Philippines where patients seek herbal medication in lieu of hospitals for treating dengue, death rates as evidenced, are statistically far greater than other affected areas.

[71] A notable case was that of Trinidad and Tobago's first female Prime Minister, Kamla Persad-Bissessar, who was diagnosed with dengue fever in August 2011,[72] prompting investigation into the possibility of an epidemic on the twin-island republic.

[74] Record dengue outbreaks reported in 2013 in many countries: Brazil (double deaths over 2012),[75] Singapore, and Thailand (worst in 20 years),[76] among others.

[91][92][93] With one sole exception, China's caseload has plunged to less than a tenth of the prior year due to massive releases of sterilized mosquitos.

[114] Brazil is facing a significant outbreak of dengue fever, with public health experts indicating that this surge is a precursor to an increase in cases across the Americas, including Puerto Rico.

While Brazil typically experiences fluctuations in dengue cases on a four-year cycle, experts attribute the intensified problem this year to factors such as El Niño and climate change.

[115] [116] Argentina is experiencing its worst dengue outbreak in history, with more than 100,000 positive cases in the first three months of the year, eleven times higher than the same period in 2023.

[117][118] Interviewed by Página/12, infectologist Leda Guzzi explained the outbreak with five main points: the exponential increase in the number of cases is up to 11 times higher than last year; the early timing of the outbreak was anticipated by at least four weeks; in 2023 the winter continued with viral transmission; there was co-circulation of three serotypes; and there have already been several epidemics in the last decade, which leads to an accumulation of people who have already had an episode of dengue fever.

[117] The new government of Javier Milei, who took office as president in December 2023, refused to carry out awareness campaigns or guarantee access to free vaccination against the disease (unlike Brazil), due to its intransigent policy of drastically reducing public spending.

[117][118] When asked about this, presidential spokesperson Manuel Adorni argued that "the effectiveness [of the vaccine] has not been proven", although it was approved in Argentina in April 2023.

[118] In general terms, the government's official position has been to ignore the epidemic and its health minister Mario Russo made almost no reference to the situation, centralizing communication with Adorni.

[117] Eventually, the severity of the epidemic led the government to launch its first advertising spot providing basic prevention information on March 21.