Central America: Dengue Outbreak Emergency Plan of Action Operation Update no. 1 (MDR42005)


Description of the disaster

Dengue is endemic in the Americas, and dengue outbreaks have occurred every three to five years over the past two decades. In several countries in 2019, the number of people affected equalled the previous averages in outbreak years prior to the habitual peak of the season. Severe dengue cases, which can result in death, and put children most at risk, are on the rise.

The cumulative incidence rate of dengue in the Central America region is higher than in the previous five previous years, with an incidence of more than 100 people with dengue per 100,000 people. To date in Central America, close to 250,000 people in Costa Rica, El Salvador, Guatemala, Honduras, and Nicaragua have been reported to have dengue in 2019. Considering that dengue cases are typically underreported (with a 14 to 28 time ratio), the number of people who have been infected with dengue is likely much higher.

Three countries in Central America have declared an Epidemiological Alert for the current outbreak: Honduras (14 June 2019), Guatemala (29 July 2019) and Nicaragua (31 July 2019). El Salvador and Costa Rica are reporting an increase in dengue cases compared to previous years, and ministries of health of both countries are implementing response activities to reduce the incidence of cases. Still, no epidemiological alert had been declared as of Epidemiological Week (EW) 40 (30 September to 6 October 2019).

In Costa Rica, the number of people with suspected dengue in 2019 is considerably higher than the incidence of cases compared to 2018 and 2017. As of EW 39, a total of 5,878 cases have been reported. The most affected areas are in the North Central and Caribbean regions in Sarapiquí, Guácimo, Pococí, and Turrialba. The Costa Rican Ministry of Health is actively seeking to reduce the presence of the mosquito vector using insecticides and partnering with Honduras on related activities.

In El Salvador, 21,377 dengue cases have been reported as of EW 39, including 11 deaths for severe dengue. According to the Salvadorean Ministry of Health, the most affected departments are Santa Ana, Ahuachapán, Sonsonate and Cabañas. The Salvadorean Red Cross Society (SRCS) has developed a strong relationship with the Ministry of Health over the last few years and constant coordination is ensured with regards to the ongoing dengue outbreak in the country.

In Guatemala, according to the latest information available, a total of 45 deaths out of 30,221 cases (67 severe dengue) have been reported as of EW 37. Among the deaths reported, over half were of children younger than 15 years, and most of those occurred in children aged 5 to 9 years. According to the Guatemalan Ministry of Health, the most affected departments are Huehuetenango, Quetzaltenango, Petén, Suroriente, Guatemala, and Las Verapaces. Though the trend of cases is now appearing to decline, it is unclear if this will be a sustained trend. The rainy season in Guatemala continues, and cases have remained higher than previous epidemic years, with 2014 reaching a peak of cases in EW 49 after an initial drop.

Honduras is experiencing the worst dengue outbreak in its history, with 142 deaths and a case fatality rate (CFR) of 0.18%. The country has reported 81,858 cases of dengue as of epidemiological week 38. Nearly one-quarter of the cases reported were classified as severe dengue. The Honduran Ministry of Health indicates that the most significant number of dengue cases are in the departments of Cortes, Santa Barbara, and Comayagua. However, all 20 health regions in the country have reported dengue cases. In Guatemala, deaths are concentrated in the younger population, with children between 5 to 9 years most severely impacted.

In Nicaragua, 130,243 dengue cases have been reported as of EW 38, including 19 deaths due to severe dengue. The government of Nicaragua has reported that the most affected departments are Leon, Carazo, Esteli, Chinandega, Masaya and Managua. The outbreak is primarily affecting children with the highest incidence rates among children 10 to 14 years old and 5 to 9 years old. There is an increasing risk of dengue infections since Central America is in its rainy season and this risk increases in more impoverished areas where improper waste disposal and water and sanitation systems generate stagnant water that is a breeding site for the Aedes aegypti mosquito. On 15 August, the Pan American Health Organization (PAHO) issued a report regarding the impact of dengue, especially for children for whom the mortality is highest. Populations where immunity is low and mobility is high (as is the case in Central America), small increases in mosquito populations produce potential rapid reproduction of an arboviral disease outbreak. The following factors and conditions contribute to the risk of a worsening outbreak exceeding endemic thresholds throughout the region:

• Increased rainfall leading to faster outbreak spread due to increased mosquito breeding sites.
• Typically, the highest incidence for dengue in Central America occurs from August through November and sometimes extends to January.
• Currently, the four dengue serotypes (DENV 1, DENV 2, DENV 3 and DENV 4) circulate simultaneously in Central America, which increases the risk of severe cases and the consequent burden of care for health services. Serotype 2 is one of the deadliest and is the one that is currently affecting children and adolescents in the region.
• Children under 15 are the most affected group. In Honduras, they constitute 66% of all confirmed deaths, while in Guatemala, they represent 52% of the total cases of severe dengue. According to PAHO, this heightened risk is the result of low exposure, and therefore, low immunity among this age range.
• There has been inadequate environmental management and limited access to water services in impoverished areas.
• The Central American region is experiencing a series of political and social challenges (restructuring of the Ministry of Health in El Salvador; health sector strikes and social mobilizations in Honduras, Nicaragua and Guatemala; etc.) that are hindering access to health services for the population affected by dengue fever.
• Migrants and internally displaced people in the region may find accessing health services challenging.

National Societies in Central America have supported community health outreach activities and used their unique access to cover gaps in service provision, including support for environmental approaches to health. They have worked in the past to overcome the issues outlined above and are well equipped with the skills to respond.