Description of the disaster
Dengue is an endemic disease in the Americas, and dengue outbreaks have occurred every three to five years over the past decades. In several countries in 2019, the number of cases before peak season was already equal or above the total number of cases in previous years. Additionally, potentially deadly severe dengue cases are on the rise, with children being the demographic most at-risk.
According to the World Health Organization (WHO), 3,139,335 cases of dengue (incidence of 321.58 cases per 100,000 inhabitants) and 1,538 deaths were reported in the Americas in 2019 between epidemiological week (EW) 1 and EW 52. Of the total number of reported cases, 1,367,353 (43.6 per cent) were laboratory-confirmed and 28,169 (0.9 per cent) were classified as severe dengue. The case-fatality rate was 0.049 per cent.
The number of cases reported (3,139,335) by week 52 was the highest ever recorded in the history of dengue in the Americas, exceeding by 30 per cent the number of cases reported in the epidemic year of 2015 (Figure 1). The proportion of severe dengue (0.9 per cent) has exceeded that observed in the previous four years but is still below what was observed between 2010 and 2014 (variation of between 1.35 and 3.05 per cent).
A comparison of accumulated incidence rates by sub-region between 2019 (EW 52) and the previous epidemic period (2015-2016, EW 52) shows that, with the exception of the Andean sub-region, incidence rates in the other sub-regions are higher than in the previous epidemic cycle (Figure 2).
In the first 4 weeks of 2020 in the Region of the Americas countries such as Bolivia, Honduras, Mexico and Paraguay have reported an increase of two to three times more cases of dengue fever compared to the same period of the previous year. Between EW 1 and EW 12 in 2020, 248,665 cases of dengue were reported, including 232 deaths. Of the total confirmed cases, 2,374 were severe dengue.
Three Central American countries have declared an Epidemiological Alert for the current outbreak: Honduras (14 June 2019), Guatemala (29 July 2019) and Nicaragua (31 July 2019). No formal alerts have been declared in El Salvador and Costa Rica, but the number of cases there have been notably higher than in previous years, and continue to rise as of the drafting of this report.
In Costa Rica, the number of suspected cases of dengue in 2019/2020 is considerably higher than the number of cases in 2018 and 2017. A total of 9,400 cases were reported in 2019 and 1,051 cases have been reported as of EW 8 2020, for a cumulative total of 10,451 cases of dengue in the country. The most affected areas are Huetar Caribe, Pacifico Central, Huetar Norte, Chorotega, Brunca, Central Norte, Sur, Este and Occidente.
In El Salvador, 27,470 cases of dengue and 14 deaths were reported in 2019 and 2,042 new cases have been reported as of EW 11 2020, for a cumulative total of 29,512 cases. According to the Salvadoran Ministry of Health, the most affected departments are Santa Ana, Ahuachapán, Sonsonate and Cabañas.
In Guatemala, a total of 50,432 cases of dengue and 90 deaths were reported in 2019 and 2,203 cases and 15 deaths have been reported as of EW 8 2020, for a cumulative total of 52,635 cases and 105 deaths. More than half of those reported dead were children under the age of 15, most between the ages of five and nine. According to the Guatemalan Ministry of Health, the most affected departments are Huehuetenango, Quetzaltenango, Petén, Suroriente, Guatemala and Las Verapaces. The cumulative total as of EW 8 is 66.7 per cent higher compared to this same period the year before.
Honduras experienced the worst dengue outbreak in its history. A total of 112,708 cases and 266 deaths were reported in 2019 and a total of 7,084 new cases and 13 deaths have been reported as of EW 7 2020, for a cumulative total of 119,792 cases and 279 deaths from dengue. According to the Honduran Ministry of Health, the most affected areas are Cortés, San Pedro Sula, Santa Bárbara, the Central District, Olancho, Yoro and Atlántida.
In Nicaragua, 186,173 cases of dengue and 30 deaths were reported in 2019 and a total of 15,772 cases have been reported as of EW 10 2020, for a total of 201,946 cases as of the drafting of this report. The Nicaraguan government has reported that the most affected departments are León, Carazo, Estelí, Chinandega, Masaya and Managua. The outbreak primarily affects children - the highest incidence rates are seen in children between the ages of 10 and 14 and between the ages of 5 and 9.
The following factors and conditions contribute to the risk of a worsening outbreak exceeding endemic thresholds throughout the region:
• The presence of COVID-19 in all Central American countries has significantly affected the activities of health service providers. Activities have been affected by measures related to preventive and mandatory quarantines taken by governments, which has reduced the number of people in common spaces.
• Increased rainfall leading to faster outbreak spread due to a higher number of mosquito breeding sites.
• Four dengue serotypes (DENV 1, DENV 2, DENV 3 and DENV 4) are currently circulating 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 the age of 15 are the most affected group. According to PAHO, this heightened risk is the result of low exposure, and therefore, low immunity among this age range.
• Poor environmental management and limited access to water services in impoverished areas.
• Migrants and internally displaced persons in the region may find it difficult to access health services.
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. hey have worked in the past to overcome the issues outlined above and are well equipped with the skills needed to respond.