Vectors With a Vengeance: How Venezuela’s Political Crisis Opens Doors to Disease

Reasons for the Resurgence

Political and economic instability in Venezuela has resulted in a multitude of challenges over the last decade, including the re-emergence of vector-borne diseases. Recent research points to a variety of factors for the resurgence, including:^1,4,6

• Fraying healthcare infrastructure
• Lack of trained medical providers
• Lack of public health programs
• Lack of medications and prevention tools, such as antimalaria nets
• Inadequate disease surveillance, education, and awareness
• Urbanization
• Overcrowding
• Inadequate funding
• Poverty
• Social inequality
• Interruptions in water supplies and electricity
• Illegal mining activities, including deforestation
• Environmental changes
• Contaminated food and water

Effect on Neighboring Countries

An estimated 5500 people left Venezuela daily in 2018, significantly affecting neighboring countries.⁵ By March 2018, 40,000 Venezuelans were estimated to be living in Brazil, and at least 600,000 of the country’s citizens have sought shelter in Colombia.¹ Of note, these numbers are likely underestimated as a result of informal border crossings.

This diaspora has led to increases in vector diseases in bordering countries. Regions of Brazil, which neighbors Venezuela to the south, have seen an increase in malaria cases; the state of Roraima reported a rise in the number of imported cases of malaria, from 1538 in 2014 to 3129 in 2017.¹ From 2012 to 2013, the island of Madeira had an outbreak of dengue, which was directly linked with a DENV-1 serotype from Venezuela.¹ In addition, cases of leishmaniasis have historically been tied to migrations, and several cases of cross-border dispersal of Leishmania spp from Venezuelan migrants in Colombia have been documented in the past 6 months.¹The researchers of TheLancet study cautioned that increasing air travel and human migration will continue to contribute to the re-emergence of vector-borne diseases in Brazil, Colombia, most of Latin American, the Caribbean, and even cities in the United States like Miami and Houston, which have welcomed a large population of Venezuelan ex-patriots in recent years.¹ Further, an increase in international travel and trade means that new vectors and pathogens will be introduced in new regions, where they were previously confined to specific localites.⁴

An Environment for Outbreak

One possible exacerbating factor to the effects that political, economic, and social unrest are having on the health of Venezuelans is climate variability.

Dengue has emerged as one of the most important public health problems in the country’s urban areas, which has seen frequent epidemics since 2001.⁶ A study published in Scientific Reports determined that dengue outbreak cycles correlated with local climate and El Niño Southern Oscillation (ENSO) variation. Specifically, dengue incidence peaks were more prevalent during the warmer and dryer years of El Niño, indicating that ENSO and its effect on Venezuela’s climate — namely, above-normal temperatures and below-normal rainfall — have been important drivers in spikes in the incidence of the disease in the last 16 years.⁶The study’s authors contended that future research should investigate the connection between regional and local climate and viral transmission with an added focus on behavioral and socioeconomic factors.⁶

Reversing the Spread of Vector-Borne Diseases

Vector-borne diseases significantly affect the morbidity and mortality rates of less-developed nations.⁴ Presently, vector control relies heavily on insecticidal interventions, but these are not deployed consistently on a sufficiently wide scale.⁴ Further, insect vectors are becoming increasingly resistant to public health insecticides.⁴ There is an urgent need for new approaches — and perhaps a return to methods that have previously been successful — to control these diseases.Researchers believe that there are several possible solutions, even with Venezuela’s restricted resources. Solutions include:^1,4

• Applying pressure to Venezuelan and regional authorities to recognize the growing crisis and accept international humanitarian assistance and medical interventions
• Sharing resources, such as information, personnel, medication, and insecticides
• Strengthening surveillance through relevant international health authorities, such as the WHO Global Outbreak Alert and Response Network, to provide robust, nonpartisan evidence to authorities
• Regional coordination to curtail cross-border spillover, which is expected to increase
• Training public health providers to collect blood from febrile individuals in border communities to spur rapid diagnosis, case definition, and treatment
• Mobilizing citizen scientists and informal networks of healthcare professionals to spearhead efforts
• Investing in technologies to facilitate low-cost sample preservation, passive sampling, and in-situ diagnostics
• Ramping up education to raise awareness within at-risk communities using social media, initiatives at schools, and information campaigns at public centers
• Scaling up the use of interventions like long-lasting insecticidal nets, which were responsible for 68% of the 663 million malaria cases averted worldwide between 2000 and 2015

While it is unclear when Venezuela will stabilize as a country, the data shows that the health of its citizens, and those in bordering countries, is suffering.

Reference

1. Grillet ME, Hernández-Villena JV, Llewellyn MS, et al. Venezuela’s humanitarian crisis, resurgence of vector-borne diseases, and implications for spillover in the region [published on February 21, 2019]. Lancet Infect Dis. doi: 10.1016/s1473-3099(18)30757-6
2. Herrero AV. After U.S. backs Juan Guaidó as Venezuela’s leader, Maduro cuts ties. The New York Times. https://www.nytimes.com/2019/01/23/world/americas/venezuela-protests-guaido-maduro.html. Published January 23, 2019. Accessed February 28, 2019.
3. Parasites – Leishmaniasis. Centers for Disease Control and Prevention website. https://www.cdc.gov/parasites/leishmaniasis/index.html. Published July 26, 2018. Accessed February 28, 2019.
4. Wilson AL, Davies M, Lindsay SW. Revisiting an old idea: engineering against vector-borne diseases in the domestic environment. Trans R Soc Trop Med Hyg. 2018;113(2):53-55.
5. Dengue, malaria, chikungunya resurgence in strife torn Venezuela: Lancet. MediBulletin website. Published February 23, 2019. Accessed February 28, 2019.
6. Vincenti-Gonzalez MF, Tami A, Lizarazo EF, Grillet ME. ENSO-driven climate variability promotes periodic major outbreaks of dengue in Venezuela. Sci Rep. 2018;8(1):5727.