Cuba Confirms that US Introduced Dengue Fever in Cuba in 1981

Cuban scientists sequenced the complete genome of viral strains collected at different stages of the epidemic, to demonstrate that it was not a laboratory contamination

An epidemic of dengue hemorrhagic fever occurred in Cuba in 1981, which caused 158 deaths, including 101 children, was deliberately introduced in the country by the United States, confirms an investigation that reflected Cuban magazine Bohemia Monday.

The publication says on his website that the article “First Epidemic of Dengue Hemorrhagic Fever in the Americas, 1981 offers new knowledge about the causal agent and scientific evidence that corroborate the accusation made by Cuba.

Its main author, Doctor in Sciences Rosmari Rodríguez, researcher at the Pedro Kouri Tropical Medicine Institute (IPK), was awarded the Grand Award in the annual public health contest in 2015 by such an outcome.

Rodriguez noted that in the 1990s, IPK, along with similar institutions from other countries, carried out studies to characterize the causative strain of the 1981 DHF epidemic.

These investigations allowed to obtain the sequence of about 300 basic data pairs, of the almost 11,000 having the viral genome complete, with the use of methodologies for manual sequencing and bioinformatics very simple, available tools then.

This was sufficient to demonstrate that the causative strain of the epidemic in 1981 had great similarity with the laboratory New Guinea C, isolated in 1944, first time that dengue fever was isolated in the world, he explained.

Cuban scientists sequenced the complete genome of viral strains collected at different stages of the epidemic, to demonstrate that it was not a laboratory contamination.

In 1983, Bohemia reminds, scientist Gustavo Kourí denounced this biological aggression against Cuba during a Congress of Tropical Medicine in Calgary, Canada.

The Cubans showed evidence in 1995 about the similarity of the circulating strain in 1981 in Cuba, with the first of dengue 2 isolated in the world, known as reference or prototype.

The IPK acquired in 2008 modern automatic sequencing technology, to return to the strains of 1981, preserved for more than 30 years in a refrigerator at – 80ºC, and make the entire process for the first time in Cuba.

Cuban researchers were able to amplify and sequence the full genome of the original strains obtained in different moments of the epidemic in 1981, using bioinformatic tools that allowed you to define with high certainty the genetic relatedness of the 81 Cuban strains with New Guinea C.

After analyzing the sequences of strains of different moments of the epidemic they noticed that, even though all were similar in New Guinea in 1944, there were differences between Cuban strains. That is, that the virus underwent changes during the epidemic period.

That fact rejects the hypothesis of contamination of laboratory, as if it were that all strains tested should have the same sequence.

Also, it supports the fact that the epidemic broke out at three points in the country at the same time the Cuban complaint: Eastern, Central, and West.

Dengue outbreaks are detected usually from an index case in a given area, around which new patients appear.

Then they expand to other territories with the movement of infected persons, and a gradual increase of patients reaching epidemic peaks, which largely depend on the density of mosquitoes is observed.