Venezuelan national flag. Image credit: pedrucho, Pixabay

Categories: Sanger Science23 May 20196.6 min read

Infectious diseases make a comeback in Venezuela following healthcare crisis

The experiences of a friend of a Sanger Institute researcher reveal how parasites and bacteria are now threatening the country's population.

The crisis in Venezuela became all the more real to me when a colleague and friend shared her decision to leave the country. She has a condition that needs regular medication, which was becoming scarce. Her situation got worse when she fell ill with an infection. She was surprised to find that she had diphtheria - after all, it hadn’t been seen in the country for decades.

There were no antibiotics available anywhere to treat her, and she realised that if she stayed, she could die. So she left Venezuela and is now in Chile, under an undefined status. She teaches in a small university, though as she is only paid for the hours she teaches she works in a fruit packaging company over the summer to make ends meet. It is not what she studied for nor the life she wanted and she would certainly rather be home.

Bario houses in Venezuela. Image credit: skeeze, Pixabay

Her story is not uncommon as the deterioration of the Venezuelan economy takes its toll on the healthcare system. Recent years have witnessed the closure of 14 per cent of intensive care units, diminishing supplies of medicines, and a dramatic drop in vaccination programmes. Together with the disappearance of epidemiological surveillance, this has resulted in an unprecedented rise in infectious diseases, including diphtheria, measles and tuberculosis. These infections had previously been successfully controlled with a robust vaccination regime, but its interruption and the unavailability of treatments are causing fatality rates to climb.

The rise of malaria

Malaria is also on the rise. In 1961, Venezuela was the first country in the world to be certified malaria-free by the World Health Organisation (WHO). Now, the interruption of surveillance and follow-up of infections, together with the intermittent access to treatment, have caused malaria to spiral out of control.

Anopheles darlingi, one of the malaria-carrying mosquitoes found in Venzuela. Image credit: Fabio Medeiros da Costa, Flickr

Dr Julian Rayner, a malaria researcher and head of Connecting Science at the Wellcome Genome Campus, expresses his concerns about the increase of malaria in the region:

“The political stability that maintains a robust healthcare system is paramount to keeping a tight control of malaria.” As an example, he described the situation in the USA which is generally malaria-free, and any outbreaks that do occur are swiftly identified and effectively contained.

“A system that keeps track of cases and their origin is vital to avoid the parasite that causes malaria becoming established in a region,” Dr Rayner adds.

Particularly problematic in South America is the prevalence of Plasmodium vivax. This species of the malaria parasite can make ‘hypnozoites’, which hide in the liver in a dormant state and cause relapsing infections. It needs additional treatment to the standard antimalarial drugs, and close monitoring because the drugs have serious side effects, plus they are not always 100 per cent effective.

Compounding factors

The rise of infectious diseases is a great public health worry for Venezuela, particularly because the resources available to help and support its population are dwindling. Professors Stephen Bentley and Nick Thomson, from the Pathogens and Microbes programme at the Sanger Institute, emphasize that general living standards will have a great impact on the prevalence of bacterial diseases, particularly respiratory infections.

Shortages of water and electricity have become common, leading to unsanitary conditions. Keeping water in containers creates breeding sites for mosquitoes and other insects that transmit diseases. The water can also become a source of infection if it becomes contaminated with bacteria.

Malnutrition is an important factor too, particularly in children, as it weakens the immune defences and opens the way for infecting pathogens, including bacteria. The situation is compounded by the crumbling of vaccine programmes.

Professor Bentley says, “For infections like pneumonia, vaccination is essential to keep children disease-free.” This is not only for their own health but also to stop it spreading in the wider population.

He also warns that fluctuations in vaccination coverage have a lag period of several years, so it is possible that the worst of the health crisis in Venezuela is still to come. Professor Thomson adds that failures in vaccination programmes will have a long term impact, persisting in the population for a generation.

Beyond Venezuela

The health problems in Venezuela are rapidly expanding to neighbouring countries, as people flee in search of medical attention and better living standards. Epidemiological surveillance in Venezuela has collapsed, after the monthly Epidemiological Bulletins were stopped in 2014 and the Centre for Classification of Diseases closed in 2018. As people migrate, there is little information about the infectious diseases they carry and poor tracing of the pathogens that cause them.

Image credit: Kevin Keith, unsplash

Professor David Aanensen, director of the Centre for Genomic Pathogen Surveillance at the Sanger Institute, highlights how the understanding of bacterial populations and their movement through different regions of the world helps to identify strains with the potential to become predominant in communities. This information is important for local health authorities, so they can adapt their strategies to control the spread of infections. In the absence of surveillance, the appearance of new bacterial strains is difficult to predict and contain. The chaotic scenario of thousands of people flooding into new regions makes epidemics highly likely.

Malaria follows the same trend, as reports from Venezuela’s neighbours Colombia and Brazil state that 80 per cent of cases detected in the border areas originate from Venezuela. As a consequence, the control measures established in these countries are jeopardised.

“People move parasites more efficiently than mosquitoes do,” says Dr Rayner, who is concerned about the potential rise and spread of drug resistance in the region due to the mix of genetically diverse malaria parasites from different regions.

Dr Vladimir Corredor, a scientist in the Department of Public Health of the National University of Colombia, with whom Dr Rayner and I collaborate, adds that this potential is exacerbated by the sub-optimal use of drugs and the circulation of out of date or substandard medicines. Together with the complexity and informality of migration across borders, the danger of drug resistance appearing is very worrying.

Call for aid

The situation unravelling in Venezuela is watched with great concern by researchers and physicians around the world.

My friend does not know what her future holds nor whether she will be able to return home. Many people mirror her plight, and without urgent humanitarian aid to help Venezuelan people, many more across the continent will suffer.

The call for the restoration of the healthcare system is urgent in order to avoid catastrophic epidemics that could affect the whole continent.

Further reading

Published articles in scientific journals:

Grillet ME et al. Venezuela's humanitarian crisis, resurgence of vector-borne diseases, and implications for spillover in the region. Lancet Infect Dis. 2019 May; 19(5): e149-e161. doi: 10.1016/S1473-3099(18)30757-6. Epub 2019 Feb 21. Review. Erratum in: Lancet Infect Dis. 2019 Feb 27

Paniz-Mondolfi AE et al. Resurgence of Vaccine-Preventable Diseases in Venezuela as a Regional Public Health Threat in the Americas.
Emerg Infect Dis. 2019 Apr; 25(4): 625-632 doi: 10.3201/eid2504.181305

Doocy S et al. The food security and nutrition crisis in Venezuela.
Soc Sci Med. 2019 Apr; 226: 63-68. doi: 10.1016/j.socscimed.2019.02.007. Epub 2019 Feb 26. Erratum in: Soc Sci Med. 2019 May;228:293.


Shepherd A. Crisis in Venezuela. BMJ. 2019 Mar 20; 364: l1277. doi: 10.1136/bmj.l1277

The Lancet. Venezuelans' right to health crumbles amid political crisis.
Lancet. 2019 Mar 23; 393(10177): 1177. doi: 10.1016/S0140-6736(19)30729-9.

Page KR et al. Venezuela's public health crisis: a regional emergency.
Lancet. 2019 Mar 23; 393(10177): 1254-1260. doi: 10.1016/S0140-6736(19)30344-7. Epub 2019 Mar 11. Review

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