Introduction

Hantaviruses are a group of human diseases that originate from viruses in rats and mice droppings, contaminating humans, either from direct contact or through their saliva, tissue or faecal matter causing the virus to become airborne. Typically these diseases spread in remote areas, resulting in sometimes severe illnesses such as haemorrhagic fever with renal syndrome (HFRS) or hantavirus pulmonary syndrome (HPS).¹ Although hantavirus cases historically emerged in endemic regions, there is an increasing appearance of this disease in newer areas, thus giving rise to a need for greater awareness.

Since many countries have not previously reported hantavirus cases, there are a number of unique challenges that can delay appropriate intervention, even by healthcare professionals. Consequently, this leads to possibly severe cases and unnecessary fatalities. As there may not traditionally be rodent exposure in certain areas, doctors may not think that this is the primary cause for illness, with misdiagnosis and delay in treatments leading to possible complications. In the following article, this will be explored in more depth, along with ways to remedy this issue.

Understanding Hantavirus

Hantavirus refers to a group of viruses that are primarily transmitted through contact with infected rodents and their waste products, such as droppings, urine, or saliva. Infections can result in two primary syndromes: HPS, which primarily impacts the lungs and is prevalent in the Americas, and HFRS, which is more commonly found in Europe and Asia.^1,2 Both types of hantavirus can lead to severe symptoms, including fever, muscle pain, and in more advanced cases, respiratory difficulties or kidney failure. Hantavirus cases are typically reported in rural regions, particularly areas populated with rodents. While these infections are usually linked to specific geographic areas, factors such as increased global travel and environmental changes have raised awareness of hantavirus risks in regions where it is not commonly found.² Diagnosing hantavirus in these non-endemic areas can be difficult due to its infrequent occurrence and the similarity of its symptoms to other respiratory diseases.

Symptoms and Diagnostic Challenges in Non-Endemic Areas

The diagnosis of hantaviruses in areas where it isn’t traditionally found can present many challenges, especially due to its rarity. Healthcare professionals are taught to explore the most common cause of symptoms first, and with hantavirus symptoms overlapping with many other common illnesses in its early stages, it is very possible that misdiagnosis can occur. Early symptoms, such as fever, fatigue, muscle aches, and chills, often resemble the flu, thus making hantavirus difficult to distinguish.³ 

Furthermore, disease progression can result in severe respiratory symptoms, like coughing and shortness of breath in HPS, mimicking illnesses like pneumonia and even COVID-19.³ Hantaviruses causing HFRS can also be diagnostically challenging in non-endemic areas as the abdominal pain and kidney complications can again point to a plethora of other health problems leading to potential misdiagnosis.

Without a clear history of rodent exposure, physicians may not necessarily suspect hantaviruses as the cause of common symptoms. This can lead to delays in diagnosis as hantavirus-specific tests may not be ordered until much later. Delays can develop into complications, decreasing the likelihood of effective intervention. Clinical awareness of hantaviruses can lead to more specific questioning when taking patient histories, with diagnostic test availability aiding in prompter diagnosis and treatment.

Lack of Awareness and Clinical Training

In regions unfamiliar with hantavirus, limited awareness and clinical training around hantavirus pose significant challenges to accurate diagnosis and timely treatment. Because hantavirus cases are rare in these areas, medical education and ongoing clinical training often focus on more common diseases, leaving infections like HPS and HFRS underrepresented. For example, a general practitioner in the city may have never encountered a hantavirus case in their career. As a result, it is possible to confuse the symptoms of hantavirus with those of pneumonia, or they may not consider asking about potential exposure to rodents. Only a few cases of hantavirus have been caused by direct, prolonged contact with rodents like mice. Most cases on the other hand are caused by exposure to the virus in contaminated aerosols, such as from rodent saliva or urine. In regions where hantavirus is rarely discussed, this lack of familiarity can delay suspicion and testing, causing the disease to go unrecognized until it reaches critical stages.

Beyond clinical knowledge, diagnostic resources for hantavirus are often limited in non-endemic regions. Most standard diagnostic panels do not include hantavirus testing, meaning healthcare providers need a high level of suspicion to test for it. Once hantavirus is suspected, testing often requires sending samples to specialized laboratories that can process hantavirus PCR (polymerase chain reaction) tests or antibody testing, which may only be available in national or state-level reference labs. This process can take days, delaying a definitive diagnosis and crucial early treatment. For instance, in smaller hospitals or community clinics without access to specialized tests, providers may have to send samples across state lines, extending wait times for results.

Additionally, logistical issues, such as the limited availability of staff trained in proper sample collection and handling for hantavirus, can cause further delays. Hantavirus is biohazardous, and mishandling samples can risk exposure.⁴ In some cases, the need to wait for biohazard-approved transportation services to ship samples to distant laboratories further complicates the process.

The Role of Public Health and Surveillance in Emerging Cases

Following the COVID-19 pandemic, it has become publicly evident that public health departments play a big role in tracking and tracing the spread of certain contagious diseases. In areas where hantavirus is traditionally not found, public health institutions play a vital role in tracing its presence, especially as physicians may not be equipped to deal with it. In line with this, should hantavirus begin to become more common in an area, medical education within the country should also reflect the changing sphere of prevalent illnesses to ensure that the public can be treated as quickly and accurately as possible to prevent complications.

Specific hantavirus protocols may not be in place in non-endemic areas, therefore not resulting in case flagging within hospitals. One way in which spread can be monitored is if national protocols are implemented, thus limiting unknown spread of the virus and permitting tracking of disease spread. In local areas without previous hantavirus cases, rapid testing kits may not be available to diagnose the disease due to limited resources. Centralised test resources that can be deployed when necessary may help combat budget issues. Having national protocols that permit early detection can also aid in preventing the spread of the virus in this way, and local health warnings may be issued in a timely fashion, alongside possible pest-control units to prevent larger outbreaks.

Strategies for Improving Hantavirus Diagnosis in Non-Endemic Areas

Improving the diagnosis of a disease where it has never previously been encountered by healthcare professionals is quite challenging, and a multifaceted approach is required. Although difficult, early diagnosis is important to prevent large outbreaks and control severe complications. 

Increasing clinical awareness

One essential strategy is increasing clinical awareness among healthcare providers. As they may have never encountered the disease, they may exclude it from their differential diagnosis. As previously mentioned, improving medical education and holding educational development programs for registered healthcare professionals on hantavirus can improve symptom recognition and diagnosis. Additionally, ensuring that emergency staff and public health officials are also able to recognise the disease can improve exposure risks and help ensure that there are protocols to prevent large outbreaks. Learning from previous case studies is a cornerstone of medical education, and this can aid in educating everyone about the dangers of hantaviruses. An example illustrating an outbreak, such as the Yosemite National Park hantavirus outbreak in 2012, could serve as a problem-based learning tool to retrospectively analyse why several visitors contracted the virus, how it could have been prevented and what could have been done to contain the outbreak.⁵ Another case which illuminated the need for greater clinical awareness could be the 1993 HPS outbreak in the United States of America which resulted in multiple deaths due to complications⁶ This led to greater educational efforts of local physicians and helped strengthen diagnostic capabilities.

Better access to testing facilities

Many non-endemic areas lack access to specialized laboratories that can conduct hantavirus testing. Nationally organised protocols which group local, regional and state departments can lead to centralised testing facilities within each region, streamlining diagnosis with minimal costs. Although this was implemented globally during the COVID-19 pandemic, in 2019, New Mexico also increased laboratory testing to expedite diagnosis, identifying cases quickly during its hantavirus outbreak to permit effective responses from public health officials.⁷

Improving surveillance systems

Another vital component is improving surveillance systems. As previously mentioned, integrating hantavirus into existing public health reporting frameworks can facilitate the early detection of cases. Public health agencies should consider implementing routine monitoring of rodent populations in areas with a history of hantavirus cases, enabling proactive measures to mitigate risks.

Be prepared

Real-world case studies also illuminate the importance of preparedness. In 1993, a significant outbreak of HPS occurred in the Four Corners region of the United States, resulting in multiple fatalities.³ This incident underscored the need for enhanced training and awareness among healthcare providers in that area. Following this outbreak, efforts were made to educate local physicians about hantavirus, improving diagnosis in subsequent cases.

Ultimately, by prioritising education, expanding testing resources, and strengthening surveillance systems, non-endemic regions can enhance their capacity to diagnose and respond to hantavirus effectively, thereby reducing the risk of severe health outcomes for affected individuals.

Summary

There are many challenges in diagnosing hantaviruses in areas where it has not previously been found, mainly the lack of awareness. It is also important to consider the role that public health departments play in coordinating responses between different response teams. Ultimately, by understanding the significance of education and public health surveillance in preventing large outbreaks and taking preemptive measures, more lives can be saved and the public protected.