Increased close contact leads to spread of Andes virus in Argentina

1. Extensive person to person contact demonstrated high viral titer load of Andes orthohantavirus (ANDV) in Argentina.

2. The results indicated that epidemic possibility should be evaluated along with a biological risk assessment of the orthohantavirus genus.

Evidence Rating Level: 2 (Good)

Study Rundown: A rare disease, namely Hantavirus Pulmonary Syndrome, has been the main cause of death for 11 people in Argentina over the span of one year between 2018 to 2019. This syndrome is caused by the Andes orthohantavirus (ANDV), which has been the source of an outbreak in the past as well back in 1996. Past studies have revealed that person-to-person contact is one of the factors that leads to the super-spreading of this virus. However, there is a lack of reported social gatherings among the cases over the past twenty years in South America. This study further investigated all the people that were in contact with the symptomatic individuals that were reported during the recent outbreak and further analyzed the laboratory and clinical data to find linkages to further reduce the transmission of ANDV. This study successfully analyzed all 34 cases of ANDV hantavirus pulmonary syndrome.

Click to read the study in NEJM

Relevant Reading: Epidemiological description, case‐fatality rate, and trends of Hantavirus Pulmonary Syndrome: 9 years of surveillance in Argentina

In-Depth [systematic review]: This study took place in Argentina where patient reports were analyzed followed by contact tracing, analysis of clinical and laboratory data, testing and analysis using the reverse-transcriptase-qualitative polymerase-chain-reaction (RT-qPCR) method and next generation sequencing were performed for data collected between November 2018 to February 2019. The results indicated that ANDV transmission may have resulted from nosocomial spread such as droplet inhalation or aerosolized virions. Furthermore, three cases were the main source of majority of the secondary cases, where all three patients were part of a large get-together at the time of transmission. Therefore, the study displayed that ANDV spread was a result of person-to-person contact. The laboratory results indicated that those with compromised liver function may be a potential target of the virus since the blood reports showed increasing ALT levels, decreasing prothrombin index and longer prothrombin response times. Similarly, a dysregulated immune response was also noted but did not add indicate an association of any disease pathway. However, the contact tracing concluded that social factors played a key role in the transmission of this virus. The analysis indicated a mean time of 6.7 days from symptom onset to death and the case fatality rate of 32%.

Image: PD

©2020 2 Minute Medicine, Inc. All rights reserved. No works may be reproduced without expressed written consent from 2 Minute Medicine, Inc. Inquire about licensing here. No article should be construed as medical advice and is not intended as such by the authors or by 2 Minute Medicine, Inc.