Central America: Dengue Outbreak Emergency Plan of Action Operation Update no. 2 (MDR42005)
A. SITUATION ANALYSIS
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 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.
The cumulative incidence rate of dengue in the Central America region is higher than in the previous five years, with an incidence of more than 100 cases of dengue per 100,000 people. In Central America, as of epidemiological week (EW) 45 (4 to 10 November 2019), 349,076 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 with 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 EW 44.
In Costa Rica, the number of suspected dengue cases in 2019 is considerably higher than the number of cases in 2018 and 2017. As of EW 45, a total of 7,900 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. There has been an increase of the cases of dengue during the last 7 weeks, from 5,729 reported from EW 37 (September 10 to 17, 2019) to 7,900 cases reported in EW 45. The has been a worrying increase in the number of sever dengue cases, from 2 to 10 in the reporting period.
In El Salvador, 25,686 dengue cases have been reported as of EW 45. Fourteen people have died as a result of 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. Recent rains have increased the cases of dengue, especially in regions located in Bajo Lempa and San Salvador as well. The combination of high temperatures and rainfall increases the proliferation of mosquitoes. As such, it is expected that the number of cases might increase during the months of November and December. Currently, there are 105 laboratory-confirmed dengue cases in the country.
In Guatemala, according to the latest information available, a total of 54 deaths out of 44,616 cases (of which 85 were classified as severe dengue) have been reported as of EW 45 (4 to 10 November 2019).
Among the deaths reported, over half were children below 15 years of age, of whom the majority were children aged from 5 to 9. According to the Guatemalan Ministry of Health, the most affected departments are Huehuetenango, Quetzaltenango, Petén, Suroriente, Guatemala, and Las Verapaces. Though the trend 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 in cases in EW 49 (which this year will be 1 to 7 December, 2019) after an initial drop. From EW 37 to 44, there has been an increase of around 20% in the number of reported cases. October rains will contribute to the proliferation of mosquitoes and therefore an increase in cases is to be expected. Beyond the dengue outbreak, there have also been newly reported cases of malaria in the operational areas. The current dengue operation is contributing to respond to malaria vector control as well.
Honduras is experiencing the worst dengue outbreak in its history, with 157 deaths and a case fatality rate (CFR) of 0.20%.2 The country has reported 96,779 cases of dengue as of EW 45. 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.
The increase in the number of dengue cases started in April 2019. As of EW 45, 96,379 dengue cases have been reported, of which 77,744 (80.7%) are classified as dengue and 18,635 (19.3%) are classified as severe dengue.3 Dengue: Among the 79,826 cases accumulated up to EW 45 of 2019, 93.3% occurred in 12 health regions: Yoro, Central District, Cortes, Olancho, Atlantis, Colon, Choluteca, Santa Barbara, Copán, MSPS, Comayagua and La Paz.
Severe dengue: Up to EW 44, 18,635 cases have been reported, representing an increase of 18,099 cases when compared with EW 44 of 2018 (in which 536 cases had been reported). Among the 18,635 cumulative cases of Severe Dengue up to EW 44 of 2019, 92.0% occurred in six health regions: Cortes, Metropolitana de San Pedro Sula, Santa Barbara, Metropolitan MDC, Valle and Yoro.
Deaths: Up to EW 44, there were 253 deaths suspected to be caused by dengue. Of those, 156 deaths were confirmed to be dengue-related by laboratory tests and 46 were determined to have no relation to dengue. There are an additional 38 cases in the process of confirmation. 57.8% (89) of those deceased were under the age of 15, of which 52.8% (47) were between 5 and 9 years of age.
In Nicaragua, 172,095 dengue cases have been reported as of EW 46, including 26 deaths due to severe dengue4 . 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 seen among 10 to14 year-old children as well as among 5 to 9 year-old children. During the last 7 weeks there has been an increase of over 32% in the number of cases reported, from 116,381 cases reported in EW 37 to 172,095 number of cases reported in EW 46 (10 to 16 November 2019).
From a regional point of view, 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, which is a breeding site for the Aedes aegypti mosquito.
On 11 November, the Pan American Health Organization (PAHO) issued a report regarding the impact of dengue in the Americas region. Between EW 1 and EW 42 of 2019, a total of 2,733,635 cases of dengue (280 cases per 100,000 population) have been reported in the region, including 1,206 deaths. Of the total cases, 1,217,196 (44.5%) were laboratory-confirmed and 22,127 (0.8%) were classified as severe dengue.
The reported case-fatality rate was 0.044%. The number of cases reported in 2019 as of EW 42 (2,733,635) is the largest recorded in the history of dengue in the Americas, exceeding by 13% the number of cases reported in the epidemic year of 2015. In 2019, the proportion of severe dengue (0.8%) has exceeded that observed in the previous four years.
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 a higher number of 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 needed to respond.