2024 dengue outbreak in Latin America and the Caribbean | |
---|---|
Disease | Dengue fever |
Virus strain | Dengue virus Serotypes: DENV1, DENV2, DENV3 and DENV4 |
Location | Mexico, North America (Florida only), Central America, South America, the Caribbean |
Suspected cases‡ | 11.5 million+ |
Severe cases | 8,361+ |
Deaths | 4,500+ |
Fatality rate | 0.048% |
Territories | South America: Brazil, Argentina, Paraguay, Peru, Ecuador, Colombia Central America: Honduras, Nicaragua, Belize, Panama, El Salvador, Guatemala North America: Mexico, United States (Florida only) |
‡Suspected cases have not been confirmed by laboratory tests as being due to this strain, although some other strains may have been ruled out. |
In the currently ongoing 2024 dengue outbreak in Latin America and the Caribbean, the number of reported infections surpassed historical records in several nations with a combined total of over 11.5 million suspected cases on 29 August 2024 and 4,500+ deaths. [1] 7,983+ severe cases from epidemiological week (EW) 19 were reported on 31 May 2024, while the 8,140,210 suspected cases at EW 19 reflect a 226% increase compared to 2023's outbreak up to EW 19, and a 416% increase compared to the annual average number of cases of the last 5 years. [2]
The impacted countries include Brazil, Argentina, Paraguay, Uruguay, Peru, Ecuador, and Colombia in South America; Honduras, Nicaragua, Belize, Panama, El Salvador, Costa Rica, and Guatemala in Central America; and Mexico in North America. [3]
A comprehensive multinational study published in Nature Communications found that climate change and increased human mobility were significant factors contributing to the rapid acceleration in the spread of dengue. Annual increases in temperatures, humidity levels, and rainfall amounts each provide more favorable conditions for the Aedes aegypti mosquito to breed and spread, and making it so previously unaffected regions gradually develop a climate more favorable for dengue spreading. [4]
The study also stated that rapid urbanization and population growth in cities led to poor urban planning, waste management, sanitation, and access to clean water further help incubate mosquito spread. [4]
Other studies indicate that the increased temperatures related to the El Niño weather pattern also contributed to the exceptionally high number of dengue fever cases and area covered. [5]
Four dengue virus serotypes: DENV1, DENV2, DENV3 and DENV4, were found to be simultaneously circulating in all of the impacted countries in Central America aside from El Salvador, which currently only had DENV1, DENV2, and DENV3 confirmed. [3]
The number of reported infections rapidly escalated in February to March to reach epidemic classification. The continued increase in rate of infection led to the national government issuing an epidemiological national emergency on 31 May 2024. As of 24 May 2024, based on a report made by the World Health Organization, 20,563 dengue cases were reported, of which 266 (1.29%) were classified as severe infections, with 27 deaths of which 11 deaths were confirmed to have been directly caused by the infection. From EW 19, there was a 445% increase in reported cases compared to EW 19 in Honduras's dengue outbreak in 2023, and 193% compared to the average number of annual dengue infections in the past 5 years. The greatest concentration of cases are currently ongoing in the departments of Tegucigalpa, Cortés, San Pedro Sula, Bay Islands, Atlántida, and La Paz. [6]
Reasons for the increase in cases from the prior year include logistical and personnel shortages in the national health secretariat, including shortages in chemical supplies, fumigation equipment, and vehicles. Another possible factor regards economic disparities in marginalized urban areas leading to delays in treatment allowing for the infection to spread in the densely populated environment. Poor waste management, water collection practices, and sanitation in part due to shortages of cleaning supplies prevented the disease from being contained. [6]
From the beginning of 2024 to EW 14, 12,570 cases were reported in Guatemala, of which 1,086 were lab-confirmed cases and 20 were severe cases. The number of cases increased to 480% relative to EW 14 in 2023 and 599% compared to the annual average across the last 5 years. 9 deaths have been reported, with a fatality rate of 0.072%. [7]
From the beginning of 2024 to EW 18, 5,882 dengue cases were reported, 4,141 (70%) were lab-confirmed, and 27 (0.45%) were severe cases. The number of cases increased to 155% relative to EW 18 in 2023, and 288% compared to the annual average across the last 5 years. 9 deaths have been reported, with a fatality rate of 0.153%. [7]
At EW 19 in Late May, Brazil made up the vast majority of cases of dengue fever reported in Latin America and the Caribbean in 2024, with 83% of suspected cases arising from Brazil, along with 79.4% of deaths. 6,803,727 cases were reported, and 2,897 deaths have been reported. [3]
Reasons for why Brazil has such a high number of cases include long-term underinvestment in water and sanitation infrastructure especially in poorer urban slums, forcing citizens to store water in open tanks that provides standing water for mosquitos to lay eggs in. [8]
In order to slow the spread of the disease and work to achieve herd immunity, Brazil preemptively purchased the entire global stock of Qdenga dengue two-dose vaccine made by the Japanese pharmaceutical company Takeda in January 2024. However, only six million doses were planned to be created for 2024, which would only be enough to vaccinate 1.5% of the population of Brazil. [9]
From the beginning of 2024 to EW 11, Colombia reported 69,837 cases, an increase of 262% relative to the annual average of cases up to EW 11 across the last 5 years. 9 deaths have been reported. The cumulative incidence rate was reported as 136 cases per 100,000 people. [7]
From the beginning of 2024 to EW 11, Ecuador reported 13,075 cases, an increase of 277% relative to the annual average of cases up to EW 11 across the last 5 years, and a cumulative incidence rate was reported as 136 cases per 100,000 people. [7] By EW 19, 31 deaths were reported. [3]
79,741 cases were reported from EW 1 to EW 11, a 471% increase relative to the 5-year average at EW 11 with a cumulative incidence rate of 239 cases per 100,000 people. [7]
65,758 cases of dengue fever have been reported up to EW 19 in Mexico, accounting for 0.8% of total cases in Latin America and the Caribbean in 2024. 405 severe cases and 20 deaths have been reported so far in Mexico, with a fatality rate of 0.03%. DENV1, DENV2, DENV3 and DENV4 serotypes have been detected in Mexico. [3] The states with the most cases were Guerrero, Tabasco, and Quintana Roo, as of EW 11. [7]
From the beginning of 2024 to EW 19, 21,458 suspected cases were reported, 3,633 (16.9%) were lab-confirmed, and 111 (0.51%) were severe cases. The number of cases increased to 468% relative to EW 19 in 2023. DENV1, DENV2, and DENV3 serotypes have been proven to be circulating in the region. [3]
Territory | Suspected Cases | Deaths | Proportion of Suspected Cases | Proportion of Deaths [3] |
Brazil | 6,803,727 | 2,897 | 83% | 79.4% |
Argentina | 475,743 | 325 | 6.0% | 9.0% |
Paraguay | 266,816 | 91 | 3.3% | 2.5% |
Peru | 222,950 | 174 | 2.7% | 4.7% |
Colombia | 137,175 | 62 | 1.6% | 1.6% |
Ecuador | 13,075 (EW 11) [7] | 31 (EW 19) | 0.8% |
Territory | Suspected Cases | Confirmed Cases | Severe Cases | Deaths | Yearly increase in suspected cases [3] |
Honduras | 20,563 | 1,248 (6.0%) | 266 (1.29%) | 27 (0.131%) | 445% |
Guatemala | 12,570 | 1,086 (8.6%) | 20 (0.16%) | 9 (0.072%) | 480% |
Panama | 5,882 | 4,141 (70%) | 27 (0.45%) | 9 (0.153%) | 155% |
State | Number of Cases [10] |
Tegucigalpa | 551 |
Cortés | 409 |
San Pedro Sula | 355 |
La Paz | 128 |
Atlántida | 115 |
Yellow fever is a viral disease of typically short duration. In most cases, symptoms include fever, chills, loss of appetite, nausea, muscle pains—particularly in the back—and headaches. Symptoms typically improve within five days. In about 15% of people, within a day of improving the fever comes back, abdominal pain occurs, and liver damage begins causing yellow skin. If this occurs, the risk of bleeding and kidney problems is increased.
Dengue fever is a mosquito-borne disease caused by dengue virus, prevalent in tropical and subtropical areas. It is frequently asymptomatic; if symptoms appear they typically begin 3 to 14 days after infection. These may include a high fever, headache, vomiting, muscle and joint pains, and a characteristic skin itching and skin rash. Recovery generally takes two to seven days. In a small proportion of cases, the disease develops into severe dengue with bleeding, low levels of blood platelets, blood plasma leakage, and dangerously low blood pressure.
Chikungunya is an infection caused by the Alphavirus chikungunya (CHIKV). The disease was first identified in 1952 in Tanzania and named based on the Kimakonde words for "to become contorted".
Dengue virus (DENV) is the cause of dengue fever. It is a mosquito-borne, single positive-stranded RNA virus of the family Flaviviridae; genus Flavivirus. Four serotypes of the virus have been found, and a reported fifth has yet to be confirmed, all of which can cause the full spectrum of disease. Nevertheless, the mainstream scientific community's understanding of dengue virus may be simplistic as, rather than distinct antigenic groups, a continuum appears to exist. This same study identified 47 strains of dengue virus. Additionally, coinfection with and lack of rapid tests for Zika virus and chikungunya complicate matters in real-world infections.
Viral hemorrhagic fevers (VHFs) are a diverse group of animal and human illnesses. VHFs may be caused by five distinct families of RNA viruses: the families Filoviridae, Flaviviridae, Rhabdoviridae, and several member families of the Bunyavirales order such as Arenaviridae, and Hantaviridae. All types of VHF are characterized by fever and bleeding disorders and all can progress to high fever, shock and death in many cases. Some of the VHF agents cause relatively mild illnesses, such as the Scandinavian nephropathia epidemica, while others, such as Ebola virus, can cause severe, life-threatening disease.
Oropouche fever is a tropical viral infection which can infect humans. It is transmitted by biting midges and mosquitoes, from a natural reservoir which includes sloths, non-human primates, and birds. The disease is named after the region where it was first discovered and isolated in 1955, by the Oropouche River in Trinidad and Tobago. Oropouche fever is caused by the Oropouche virus (OROV), of the Bunyavirales order of viruses.
Adenovirus infection is a contagious viral disease, caused by adenoviruses, commonly resulting in a respiratory tract infection. Typical symptoms range from those of a common cold, such as nasal congestion, coryza and cough, to difficulty breathing as in pneumonia. Other general symptoms include fever, fatigue, muscle aches, headache, abdominal pain and swollen neck glands. Onset is usually two to fourteen days after exposure to the virus. A mild eye infection may occur on its own, combined with a sore throat and fever, or as a more severe adenoviral keratoconjunctivitis with a painful red eye, intolerance to light and discharge. Very young children may just have an earache. Adenovirus infection can present as a gastroenteritis with vomiting, diarrhoea and abdominal pain, with or without respiratory symptoms. However, some people have no symptoms.
The May 2004 Caribbean floods were a flood event that affected the Caribbean Islands and Hispaniola from May 18, 2004, to May 25, 2004. Moving quickly from Central America, a low-pressure area brought heavy rainfall and thunderstorms to Cuba, Jamaica, Haiti, and the Dominican Republic resulting in rainfall amounts exceeding 500 mm within a 7-day period. Cities in flood-plain areas like Mapou, Haiti, and Jimani, of the Dominican Republic, experienced over 250 mm of rain between May 24 and 25, causing the Solie River to overflow, resulting in devastating environmental and infrastructure damage. With hundreds dead and thousands more displaced in Mapou and Jimani, the death toll was at its highest in decades, partly because of deforestation. Steep valley ridges and barren hillsides channeled rainwater towards valleys, creating landslides that overwhelmed and flooded cities particularly in high-poverty areas where buildings were wooden or makeshift temporary homes. In addition, inhabitants residing on these flood plains were subject to increased risk from water-borne diseases due to inadequate waste removal management and contaminated water supply due to excessive debris caused by flooding.
Mosquito-borne diseases or mosquito-borne illnesses are diseases caused by bacteria, viruses or parasites transmitted by mosquitoes. Nearly 700 million people contract mosquito-borne illnesses each year, resulting in more than a million deaths.
The 2009 Bolivian dengue fever epidemic was an epidemic of dengue fever which struck Bolivia in early 2009, escalating into a national emergency by February. The BBC described it as the worst outbreak of dengue fever in the country's history. At least 18 people died and 31,000 were infected by the mosquito-transmitted arbovirus.
As of 2010, dengue fever is believed to infect 50 to 100 million people worldwide a year with 1/2 million life-threatening infections. It dramatically increased in frequency between 1960 and 2010, by 30 fold. This increase is believed to be due to a combination of urbanization, population growth, increased international travel, and global warming. The geographical distribution is around the equator with 70% of the total 2.5 billion people living in endemic areas from Asia and the Pacific. Many of the infected people during outbreaks are not virally tested, therefore their infections may also be due to chikungunya, a coinfection of both, or even other similar viruses.
In the 2013 dengue outbreak in Singapore, a significant rise in the number of dengue fever cases was reported in Singapore. The outbreak began in January, with the number of infections beginning to surge in April, before eventually reaching a peak of 842 dengue cases in the week of 16–22 June 2013. This figure was far beyond the highest number of cases per week in the previous three years. Although there were concerns that the rate of infection could exceed 1,000 per week, these fears did not materialize.
Dengue vaccine is a vaccine used to prevent dengue fever in humans. Development of dengue vaccines began in the 1920s, but was hindered by the need to create immunity against all four dengue serotypes. As of 2023, there are two commercially available vaccines, sold under the brand names Dengvaxia and Qdenga.
In the 2017 dengue outbreak in Peshawar, Pakistan, hundreds of incidents of dengue fever were reported in Peshawar in mid-2017. Initially, according to the health department of Khyber Pakhtunkhwa, 4,320 suspected cases were received by Khyber Teaching Hospital Peshawar and 831 were positive. About a dozen people died of dengue, starting in July. Punjab healthcare experts and Peshawar experts worked together to control the dengue epidemic, using health workers going door-to-door to educate residents, as well as fumigation of the city to suppress mosquito populations.
The 2019–2020 dengue fever epidemic was an epidemic of the infectious disease dengue fever in several countries of Southeast Asia, including the Philippines, Malaysia, Vietnam, and Bangladesh, Pakistan, India, Thailand, Singapore, and Laos. The spread of the disease was exacerbated by falling vaccination levels in certain areas, and by a growing population of mosquitoes, which are the primary carriers of the disease, and which are able to reproduce in larger numbers where humans have littered the environment with plastic containers, which provide an ideal breeding ground for mosquitoes. Affected countries have sought to control the epidemic through increased vaccination efforts, and through efforts to control the mosquito population.
In 2017, there was a rise in the number of dengue fever cases reported in the island country of Sri Lanka. The peak of the outbreak occurred during the mid-year monsoon season with more than 40,000 cases reported in July alone, far exceeding historical highs. By the end of the year, the total number of dengue cases had risen to 186,101.
In the 2020 dengue outbreak in Singapore, a record-breaking number of dengue fever cases was reported in Singapore. This was part of the wider 2019–2020 dengue fever epidemic which also affected several neighbouring countries in Southeast Asia.
In Bangladesh's ongoing 2023 dengue epidemic season, the country has been witnessing the deadliest outbreak of dengue fever ever since the first outbreak in Bangladesh in 2000. As of 31 December 2023, the Directorate General of Health Services (DGHS) has reported 321,179 hospitalizations and 1,705 deaths due to the Aedes mosquito-borne tropical disease in the 2023 outbreak year. Like previous years, the outbreak started in Summer (April–May), spread and surged nationwide in the monsoons (July–August). On 3 August, the number of deaths surpassed previous years; and on 21 August, the tally of hospitalization surpassed the previous highest record of the 2019 outbreak. Dhaka is the worst-hit area and the epicentre of the outbreak, with more than half of the cases being reported in the megacity. On 25 July, hospitalizations were reported in all districts; and the tally of hospitalizations outside Dhaka city surpassed the figure of the capital on 14 August.
The 2024 dengue epidemic in Argentina is an outbreak of this disease, transmitted by the Aedes aegypti mosquito. It is considered to date as the largest dengue outbreak in Argentine history.