Hantavirus Pulmonary Syndrome
Hantavirus pulmonary syndrome is a disease that results from infection by one of the Hantaviruses, which are carried by rodents. It is marked by multiple respiratory symptoms due to pulmonary edema, and it may be fatal.
Presentation
Hantavirus pulmonary syndrome (HPS) is an infectious disease that is acquired through exposure to rodents carrying the causative virus, the Hantavirus. A few cases have been documented, where the infection was acquired through human to human contact [1] [2].
HPS usually occurs in specific geographical locations, such as north and south America. The disease appears to affect all individuals equally, although men may have a higher incidence rate due to more recurrent exposure to the vector. For the same reason, HPS typically does not present in young children or the elderly.
HPS is one of many syndromes that can arise from Hantavirus infection [3] [4]. The affected organ systems depend on the specific type of Hantavirus an individual has come in contact with. The severity of illness varies greatly between cases, ranging from mild to severe. Furthermore, it demonstrates significantly high case mortality rates, estimated at up to 50%. This syndrome is characterized by severe respiratory compromise. The illness has several stages entailing a prodromal phase, respiratory phase, and convalescent phase. The disease has an incubation period of one week to one month, after which prodromal symptoms manifest.
Prodromal symptoms are often nonspecific and may involve gastrointestinal discomfort, vomiting, headache, and muscle pain [5]. These individuals also experience pyrexia. The typical signs usually last up to 5 days.
Subsequently, the host immune system attacks endothelial cells lining the lungs, displaying viral antigens. This process leads to increased permeability of the endothelium and thus pulmonary edema. The cardiopulmonary phase lasts up to 48 hours and is characterized by the emergence of respiratory findings such as coughing, tachypnea, crepitations, and dyspnea. Patients frequently require mechanical ventilation during this time. Some individuals may develop hypotension and circulatory collapse due to cardiogenic shock, the latter being the main cause of death in HPS [6] [7] [8]. Oliguria is not an uncommon observation during this phase, and in a few cases, may lead to renal failure.
The third stage is preceded by an episode of diuresis and is made evident by the resolution of cardiopulmonary features.
Entire Body System
Intravenous Drugs
- HPS treatment with an experimental antiviral intravenous drug, ribavirin, is under investigation.[ncbi.nlm.nih.gov]
Respiratoric
Exertional Dyspnea
- Temporary exertional dyspnea and reduced expiratory flow are common in early convalescence after HPS but resolves in almost all patients.[ncbi.nlm.nih.gov]
Workup
Upon presentation, baseline blood tests, as well as more specific laboratory testing should be carried out. Often requested laboratory studies include:
- Complete blood count (CBC), urea and electrolytes, peripheral smear, and arterial blood gas analysis (ABGA).
- Immunochemistry.
- Serology.
- PCR (polymerase chain reaction).
CBC may reveal low platelets and elevated white blood cells, with an unusually high proportion of immature cells [9]. Serum lactate dehydrogenase (LDH) is also high. Other parameters may reflect the distributive shock experienced in Hantavirus pulmonary syndrome [6] [7]. One such finding is hemoconcentration. A peripheral blood smear, in addition to the above, may reveal the presence of atypical immune cells, as well as immunoblasts [9]. Once these findings are observed, HPS can be diagnosed.
Imaging studies are usually carried out in the form of a chest radiograph. Signs of pulmonary edema that may be visualized include increased hilar markings, diffuse bilateral infiltrates, Kerley B lines, and peribronchial thickening. The cardiac silhouette is of normal size, and pleural effusions might also be present.
X-Ray
Pulmonary Infiltrate
- We identified three groups of patients, which included the following: 1) those with the least severe form who had prodromic symptoms without pulmonary involvement; 2) those with moderate illness who had interstitial pulmonary infiltrates, usually needed[ncbi.nlm.nih.gov]
- Thrombocytopenia, elevated white blood cell (WBC) count, and pulmonary infiltrates were observed in all five children; elevated hematocrit was observed in three.[ncbi.nlm.nih.gov]
- A chest radiograph revealed bilateral diffuse pulmonary infiltrates with pleural effusions. HPS was suspected, and the boy was treated with intravenous fluids, ceftriaxone, and azithromycin.[jamanetwork.com]
Kerley B Lines
- Signs of pulmonary edema that may be visualized include increased hilar markings, diffuse bilateral infiltrates, Kerley B lines, and peribronchial thickening. The cardiac silhouette is of normal size, and pleural effusions might also be present.[symptoma.com]
Treatment
- The high rate of mortality could be reduced if effective therapeutics could be discovered for treatment of this illness.[ncbi.nlm.nih.gov]
- Likewise, treatment with 20,000 NAU/kg starting 5 days after challenge with SNV protected immunocompromised hamsters from lethal HPS, protecting five of eight animals.[ncbi.nlm.nih.gov]
- HPS treatment with an experimental antiviral intravenous drug, ribavirin, is under investigation.[ncbi.nlm.nih.gov]
- These data provide in vivo evidence supporting the potential use of ribavirin as a post-exposure treatment to prevent HPS after exposure by the respiratory route.[ncbi.nlm.nih.gov]
- This article reviews the nature of the viruses that cause hantavirus pulmonary syndrome, the epidemiology and ecology of disease transmission, and disease recognition, treatment, and prevention. Copyright 2010 Elsevier Inc. All rights reserved.[ncbi.nlm.nih.gov]
Prognosis
- The prognosis for HPS is ominous and misdiagnoses may increase mortality. Better chances of survival depend on prompt intensive care support.[ncbi.nlm.nih.gov]
- Early recognition of HPS and admission to an intensive care setting offers the best prognosis. Hantavirus pulmonary syndrome was first recognized during the 1993 outbreak in the Four Corners region of the southwestern United States.[en.wikipedia.org]
- What Is the Prognosis? About 45% of patients with HPS die from the infection. However, early identification and supportive care in the hospital will help the majority of infected people recover from this dangerous syndrome.[healthychildren.org]
Etiology
- These findings underscore the need for systematic archiving and analysis of clinical information and specimens from patients with diseases of unknown etiology to facilitate the study of new clinical entities and their associated etiologic agents.[ncbi.nlm.nih.gov]
- However, the etiological agent was PUUV, as proved by serological testing, real-time polymerase chain reaction (PCR), and sequencing.[ncbi.nlm.nih.gov]
- Abstract In 1978, hantaviruses were first described as the etiological agent of hemorrhagic fever with renal syndrome (HFRS) in Korea.[ncbi.nlm.nih.gov]
- From these evaluations, it is clear that, in order to allow a precise risk assessment of acquiring HPS, we must first understand the host-virus cycle and we must have data regarding more exact conditions of human behaviors and exposure to the etiologic[ncbi.nlm.nih.gov]
- The etiologic agents in those cases have been closely related to each other, based upon comparisons of their genetic sequences.[ncbi.nlm.nih.gov]
Epidemiology
- KEYWORDS: Brazil; epidemiological surveillance; hantavirus; hantavirus pulmonary syndrome; outbreak; respiratory infections; viruses[ncbi.nlm.nih.gov]
- Our findings help elucidate the epidemiology of HPS in Brazil, where mast seeding of bamboo can trigger rodent population eruptions and subsequent human HPS outbreaks.[ncbi.nlm.nih.gov]
- This article reviews the nature of the viruses that cause hantavirus pulmonary syndrome, the epidemiology and ecology of disease transmission, and disease recognition, treatment, and prevention. Copyright 2010 Elsevier Inc. All rights reserved.[ncbi.nlm.nih.gov]
- By using molecular epidemiologic methods, we show that rice rats (Oryzomys palustris) are frequently infected with Bayou virus and that viral RNA sequences from HPS patients are similar to those from nearby rice rats.[ncbi.nlm.nih.gov]
- Abstract This report describes the epidemiological and clinical-evolutive characteristics of eight patients with hantavirus pulmonary syndrome (HPS) in Uberaba, Minas Gerais, Brazil.[ncbi.nlm.nih.gov]
Pathophysiology
- The hantavirus pulmonary syndrome (HPS) is an acute, rapidly progressive disease transmitted by rodent excreta, with endothelial damage playing a central role in the pathophysiology. It usually affects rural workers.[ncbi.nlm.nih.gov]
- Following infection with Andes virus, hamsters develop HPS-like disease which faithfully mimics the human condition with respect to incubation period and pathophysiology of disease.[ncbi.nlm.nih.gov]
- Loin pain haematuria syndrome Chapter 48 Nutcracker syndrome and phenomenon Chapter 49 Exercise-related pseudonephritis Chapter 50 Proteinuria Chapter 51 Postural proteinuria (benign orthostatic proteinuria) Chapter 52 Nephrotic syndrome Chapter 53 Pathophysiology[oxfordmedicine.com]
- There is acute renal failure, but the precise pathophysiologic lesion producing renal failure is uncertain. Mortality is usually from shock or hemorrhage. Pulmonary edema is a frequent finding (Powell, 1954).[web.archive.org]
Prevention
- The findings suggest an association between a household's accurate HPS knowledge and its respective use of HPS preventive measures.[ncbi.nlm.nih.gov]
- We tested three different concentrations of ribavirin for their capability to prevent HPS in the ANDV hamster model following an intranasal challenge.[ncbi.nlm.nih.gov]
- Because no specific therapies are available for the disease, prevention and early recognition play an important role in reducing mortality from the disease.[ncbi.nlm.nih.gov]
- These cases emphasize the need to educate the public throughout the United States regarding risks and prevention measures for hantavirus infection.[ncbi.nlm.nih.gov]
- Prevention of this new syndrome centers on avoidance of contact with and inhalation of saliva, urine, and feces of infected rodents.[ncbi.nlm.nih.gov]
References
Article
- Martinez VP, Bellomo CM, Cacace ML, Suarez P, Bogni L, Padula PJ. Hantavirus pulmonary syndrome in Argentina, 1995-2008. Emerg Infect Dis. 2010;16(12):1853-1860.
- Padula PJ, Edelstein A, Miguel SD, López NM, Rossi CM, Rabinovich RD. Hantavirus pulmonary syndrome outbreak in Argentina: molecular evidence for person-to-person transmission of Andes virus. Virology. 1998;241(2):323-330.
- Khan A, Khan AS. Hantaviruses: a tale of two hemispheres. Panminerva Med. 2003;45(1):43-51.
- Peters CJ, Khan AS. Hantavirus pulmonary syndrome: the new American hemorrhagic fever. Clin Infect Dis. 2002;34(9):1224-1231.
- Vinh DC, Embil JM. Hantavirus pulmonary syndrome: a concise clinical review. South Med J. 2009;102(6):620–625.
- Jonsson CB, Figueiredo LT, Vapalahti O. A global perspective on hantavirus ecology, epidemiology, and disease. Clin Microbiol Rev. 2010;23(2):412–441.
- Watson DC, Sargianou M, Papa A, Chra P, Starakis I, Panos G. Epidemiology of Hantavirus infections in humans: a comprehensive, global overview. Crit Rev Microbiol. 2014;40(3):261–272.
- Verity R, Prasad E, Grimsrud K, et al. Hantavirus pulmonary syndrome in Northern Alberta, Canada: clinical and laboratory findings for 19 cases. Clin Infect Dis. 2000;31(4):942–946.
- Dvorscak L, Czuchlewski DR. Successful triage of suspected hantavirus cardiopulmonary syndrome by peripheral blood smear review—a decade of experience in an endemic region. Am J Clin Pathol. 2014;142(2):196–201.