The Journal of Infectious Diseases EDITORIAL COMMENTARY
Dengue Virus and Blood Transfusion José Eduardo Levi1,2,3 1
Fundação Pró-Sangue/Hemocentro de São Paulo, 2Hospital Israelita Albert Einstein, and 3Virology Laboratory, Instituto de Medicina Tropical da Universidade de São Paulo, Brazil
(See the major article by Sabino et al on pages 694–702.)
Keywords.
dengue virus; blood transfusion; mosquito bite; pathogenesis.
Received and accepted 2 June 2015. Correspondence: J. E. Levi, Fundação Pró-Sangue, Departamento de Biologia Molecular, Rua Dr Enéas de Carvalho Aguiar 155, 1° andar, CEP 05403-000, São Paulo–SP, Brazil ([email protected]). The Journal of Infectious Diseases® 2016;213:689–90 © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail [email protected]. DOI: 10.1093/infdis/jiv322
Performing such a TT study in a setting of high dengue endemicity provided an ideal situation to detect episodes of transmission, but it also demanded a thoughtful evaluation of the different patterns of reactivity demonstrated among donor/recipient pairs. This is illustrated by the classification of 5 viremic recipients as nonsusceptible to TT dengue, since they presented with either viral RNA or IgM antibody before undergoing transfusion, despite the fact that administered units harbored DENV RNA. Another 2 recipients were found to be viremic but underwent transfusion with viral RNA negative–units and were considered as vectorial cases. Moreover, several clinical manifestations associated with dengue are common among blood recipients, including fever, headache, and thrombocytopenia, which may hamper the establishment of a cause-effect relationship. Nevertheless, an increase in mortality up to 30 days after transfusion of viremic blood was demonstrated, although this increase was marginally statistically significant. The single DENV type detected in this epidemic was DENV-4, and the study by Sabino et al was performed during the initial introduction of this serotype in Recife and Rio de Janeiro. Considering that almost 90% of the population in these cities is currently seropositive for DENVspecific IgG, we can suppose that many recipients were exposed to heterotypic DENV RNA in transfusion components from asymptomatic donors, as the % of viremic donors peaked at 1%–2% in both cities. The absence of acute and moresevere symptomatic dengue cases among these recipients is an argument against the validity of the antibody-dependent
enhancement (ADE) theory [7] when the infectious source is a blood component, since proponents of the ADE theory suggest that preexisting heterotypic antibodies are responsible for the exacerbation of the clinical picture. Furthermore, it is common to transfuse dengue patients when their platelet levels are low [8]—one of the hallmarks of the disease—suggesting that the reverse situation is also not uncommon (ie, that viremic recipients are exposed to donor antibodies present in plasma). It is intriguing to contemplate that a tiny volume of virus in mosquito saliva injected in the skin can be much more harmful than 200–300 mL of virus in a blood bag from a viremic donor. This suggests that the amount of virus is less important than the form in which it is presented to the immune system. It has been shown that the structure of the viral particle changes according to body temperature [9], which differs between mosquitoes and humans. In addition, mosquito saliva, the vehicle for the viral particles injected in the skin, has important immunomodulatory and antigenic properties [10, 11], which are absent from the TT model. Moreover, the initial replication in keratinocytes and Langerhans cells may provide access to the lymphoid tissue and bone marrow, sites where intense viral replication takes place. A humanized animal model of dengue successfully demonstrated higher levels of and more-sustained viremia, larger erythema indices, and lower platelets count nadirs when the virus was delivered to mice by a mosquito bite, rather than when they were inoculated by intradermal injection, again reinforcing the key role played by the extrinsic replication phase in influencing the clinical course in humans [11]. Reasonably,
EDITORIAL COMMENTARY
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JID 2016:213 (1 March)
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689
Downloaded from http://jid.oxfordjournals.org/ by guest on February 17, 2016
In this issue of The Journal of Infectious Diseases, Sabino et al [1] present the results of the largest study to date on transfusion-transmitted (TT) dengue. Until now, TT dengue has been rarely reported, with 5 convincingly documented clusters [2–6]. This well-conducted investigation, performed during an outbreak of dengue virus 4 (DENV-4) infection in 2 large Brazilian cities, Recife and Rio de Janeiro, compiled compelling laboratorial and chronological evidence of another 6 TT cases judiciously sorted from 42 DENV RNA–positive units that were transfused to 35 recipients. These 6 cases, analyzed in the context of another 10 susceptible recipients exposed to viremic blood, which remained negative for virus RNA and immunoglobulin M (IgM) in the follow-up period, allowed the authors to estimate a transmissibility rate of 37.5%. Transmission was independent of the viral load, and, interestingly, all 3 components usually obtained from blood donations ( plasma, red blood cells, and platelets) were able to transmit DENV-4. This has also been previously observed in one of the clusters from Singapore [2], where 3 recipients were infected by DENV-2 from the same viremic donation, with one developing symptoms that would be today be classified as dengue with warning signs.
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was previously implemented in Puerto Rico, spurred by the observation that a transfusion recipient developed a hemorrhagic form of the disease [4]. More recently, blood collection was stopped in Puerto Rico because of the explosive outbreak of chikungunya virus (CHKV) infection there. At the moment, a few thousand autochthonous cases of CHKV infection have occurred in Brazil, and a future outbreak is predicted because of the abundance of the mosquito vectors (ie, Aedes aegypti and Aedes albopictus) shared with DENV [15]. Curiously, there has not yet been a single report of a TT case of CHKV infection, but the possibility of this happening led French blood authorities to implement pathogen-reduction procedures for platelet concentrates in Reunion Island during the 2006 outbreak [16] and, more recently, an in-house NAT for blood donations in their Caribbean territories, with the latter demonstrating a rate of 1:500 viremic units [17]. Certainly, a combined DENV/CHKV NAT assay would be valuable for blood and organ donor screening in Brazil and other involved countries, providing a higher level of safety, but, when available, it should be evaluated against the ever-growing list of health priorities in the country. Emerging and reemerging viruses will continue to threaten the blood supply. The current approach of creating a new test for each newly discovered agent increases the already high cost and complexity of blood screening. Two extremely promising alternatives for this dilemma are methods that would inactivate all nucleic acids in blood [18] or unbiased sequencing of donor cellfree plasma nucleic acids, revealing the whole microbial diversity [19] in addition to the human genome [20]. Notes Acknowledgments. I would like to thank Dr Cláudio Pannuti (Instituto de Medicina Tropical, Universidade de São Paulo) and Guido Levi for invaluable review of this manuscript. Potential conflict of interest. J. E. L. received a grant from Grifols for research of dengue in blood donors. The author has submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.
EDITORIAL COMMENTARY
References 1. Sabino EC, Loureiro P, Lopes ME, et al. Transfusionbased transmission of dengue virus and associated clinical symptoms during the 2012 epidemic in Brazil. J Infect Dis 2016; 213:694–702. 2. Tambyah PA, Koay ESC, Poon MLM, Lin RVTP, Ong BKC. Dengue hemorrhagic fever transmitted by blood transfusion. N Engl J Med 2008; 359: 1526–7. 3. Chuang VW, Wong TY, Leung YH, et al. Review of dengue fever cases in Hong Kong during 1998 to 2005. Hong Kong Med J 2008; 14:170–7. 4. Stramer SL, Linnen JM, Carrick JM, et al. Dengue viremia in blood donors identified by RNA and detection of dengue transfusion transmission during the 2007 dengue outbreak in Puerto Rico. Transfusion 2012; 52:1657–66. 5. Levi JE, Nishiya A, Félix AC, et al. Real-time symptomatic case of transfusion-transmitted dengue. Transfusion 2015; 55:961–4. 6. Oh HB, Muthu V, Daruwalla ZJ, Lee SY, Koay ES, Tambyah PA. Bitten by a bug or a bag? Transfusiontransmitted dengue: a rare complication in the bleeding surgical patient. Transfusion 2015; doi:10.1111/ trf.13054. 7. Halstead SB, O’Rourke EJ. Dengue viruses and mononuclear phagocytes. Infection enhancement by non-neutralizing antibody. J Exp Med 1977; 146: 201–7. 8. Fujimoto DE, Koifman S. Clinical and laboratory characteristics of patients with dengue hemorrhagic fever manifestations and their transfusion profile. Rev Bras Hematol Hemoter 2014; 36:115–20. 9. Rey FA. Dengue virus: two hosts, two structures. Nature 2013; 23:443–4. 10. Mores CN, Christofferson RC, Davidson SA. The role of the mosquito in a dengue human infection model. J Infect Dis 2014; 209(suppl 2):S71–8. 11. Cox J, Mota J, Sukupolvi-Petty S, Diamond MS, Rico-Hesse R. Mosquito bite delivery of dengue virus enhances immunogenicity and pathogenesis in humanized mice. J Virol 2012; 86:7637–49. 12. Onlamoon N, Noisakran S, Hsiao H-M, et al. Dengue virus–induced hemorrhage in a nonhuman primate model. Blood 2010; 115:1823–34. 13. Stramer SL, Fang CT, Foster GA, Wagner AG, Brodsky JP, Dodd RY. West Nile virus among blood donors in the United States, 2003 and 2004. N Engl J Med 2005; 353:451–9. 14. Felix AC, Romano CM, Centrone CD, et al. Low sensitivity of NS1 tests evidenced during an dengue 2 outbreak in Santos, Brazil, 2010. Clin Vaccine Immunol 2012; 19:1972–6. 15. Nunes MRT, Faria NR, Vasconcelos JM, et al. Emergence and potential for spread of Chikungunya virus in Brazil. BMC Med 2015; 13:102. 16. Rasonglès P, Angelini-Tibert MF, Simon P, et al. Transfusion of platelet components prepared with photochemical pathogen inactivation treatment during a Chikungunya virus epidemic in Ile de La Réunion. Transfusion 2009; 49:1083–91. 17. Paturel C, Djoudi R, Leparc-Goffart I, et al. Prospective detection of Chikungunya virus in blood donors, Caribbean 2014. Blood 2014; 123:3679–81. 18. Snyder EL, Stramer SL, Benjamin RJ. The safety of the blood supply–time to raise the bar. N Engl J Med 2015; 372:1882–5. 19. De Vlaminck I, Khush KK, Strehl C, et al. Temporal response of the human virome to immunosuppression and antiviral therapy. Cell 2013; 155:1178–87. 20. Lo YMD, Chan KCA, Sun H, et al. Maternal plasma DNA sequencing reveals the genome-wide genetic and mutational profile of the fetus. Sci Transl Med 2010; 2:61ra91.
Downloaded from http://jid.oxfordjournals.org/ by guest on February 17, 2016
some experts argue that mosquito-improved DENV human infection models provide a more realistic approach for the study of dengue pathogenesis and the evaluation of vaccines and antiviral compounds [10]. Intriguingly, direct injection of DENV culture supernatant fluids intravenously into 6 Rhesus macaques provoked hemorrhagic manifestations in all [12]. Close follow-up of human recipients transfused with whole blood containing DENVs may show whether viral infectivity is reduced by modern techniques for processing blood and storing the resulting components. In contrast to the rapid response of blood banks to the West Nile virus (WNV) invasion of the United States, where a nucleic acid test (NAT) was promptly introduced and universally adopted for blood and organ donor screening [13], Brazil, which currently has one of the largest number of dengue cases in the world, has never implemented any specific measures toward halting TT dengue. This might suggest that TT dengue is not as harmful as TT WNV. However, our own experience shows that, when thoroughly investigated, TT dengue can cause symptomatic disease [5], and effective prevention measures should therefore be adopted. This must be balanced against a much higher risk of vectorial transmission during the dengue season, possibly rendering laboratory screening of donors not costeffective. Nevertheless, a select groups of patients may be more vulnerable to DENV infection and warrant targeted testing of a fraction of units. Importantly, if testing is to be performed, it must be done by methods targeting DENV RNA (ie, NAT), because of the short viremic phase that precedes seroconversion. The detection of nonstructural protein 1 (NS1) in the blood of suspicious cases is widespread in areas of endemicity. However, a remarkable decrease in the sensitivity of tests in experienced populations has been demonstrated [14], making it an unacceptable option for blood screening, a procedure demanding maximum sensitivity. In contrast, NAT for DENV
Dengue Virus and Blood Transfusion José Eduardo Levi1,2,3 1
Fundação Pró-Sangue/Hemocentro de São Paulo, 2Hospital Israelita Albert Einstein, and 3Virology Laboratory, Instituto de Medicina Tropical da Universidade de São Paulo, Brazil
(See the major article by Sabino et al on pages 694–702.)
Keywords.
dengue virus; blood transfusion; mosquito bite; pathogenesis.
Received and accepted 2 June 2015. Correspondence: J. E. Levi, Fundação Pró-Sangue, Departamento de Biologia Molecular, Rua Dr Enéas de Carvalho Aguiar 155, 1° andar, CEP 05403-000, São Paulo–SP, Brazil ([email protected]). The Journal of Infectious Diseases® 2016;213:689–90 © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail [email protected]. DOI: 10.1093/infdis/jiv322
Performing such a TT study in a setting of high dengue endemicity provided an ideal situation to detect episodes of transmission, but it also demanded a thoughtful evaluation of the different patterns of reactivity demonstrated among donor/recipient pairs. This is illustrated by the classification of 5 viremic recipients as nonsusceptible to TT dengue, since they presented with either viral RNA or IgM antibody before undergoing transfusion, despite the fact that administered units harbored DENV RNA. Another 2 recipients were found to be viremic but underwent transfusion with viral RNA negative–units and were considered as vectorial cases. Moreover, several clinical manifestations associated with dengue are common among blood recipients, including fever, headache, and thrombocytopenia, which may hamper the establishment of a cause-effect relationship. Nevertheless, an increase in mortality up to 30 days after transfusion of viremic blood was demonstrated, although this increase was marginally statistically significant. The single DENV type detected in this epidemic was DENV-4, and the study by Sabino et al was performed during the initial introduction of this serotype in Recife and Rio de Janeiro. Considering that almost 90% of the population in these cities is currently seropositive for DENVspecific IgG, we can suppose that many recipients were exposed to heterotypic DENV RNA in transfusion components from asymptomatic donors, as the % of viremic donors peaked at 1%–2% in both cities. The absence of acute and moresevere symptomatic dengue cases among these recipients is an argument against the validity of the antibody-dependent
enhancement (ADE) theory [7] when the infectious source is a blood component, since proponents of the ADE theory suggest that preexisting heterotypic antibodies are responsible for the exacerbation of the clinical picture. Furthermore, it is common to transfuse dengue patients when their platelet levels are low [8]—one of the hallmarks of the disease—suggesting that the reverse situation is also not uncommon (ie, that viremic recipients are exposed to donor antibodies present in plasma). It is intriguing to contemplate that a tiny volume of virus in mosquito saliva injected in the skin can be much more harmful than 200–300 mL of virus in a blood bag from a viremic donor. This suggests that the amount of virus is less important than the form in which it is presented to the immune system. It has been shown that the structure of the viral particle changes according to body temperature [9], which differs between mosquitoes and humans. In addition, mosquito saliva, the vehicle for the viral particles injected in the skin, has important immunomodulatory and antigenic properties [10, 11], which are absent from the TT model. Moreover, the initial replication in keratinocytes and Langerhans cells may provide access to the lymphoid tissue and bone marrow, sites where intense viral replication takes place. A humanized animal model of dengue successfully demonstrated higher levels of and more-sustained viremia, larger erythema indices, and lower platelets count nadirs when the virus was delivered to mice by a mosquito bite, rather than when they were inoculated by intradermal injection, again reinforcing the key role played by the extrinsic replication phase in influencing the clinical course in humans [11]. Reasonably,
EDITORIAL COMMENTARY
•
JID 2016:213 (1 March)
•
689
Downloaded from http://jid.oxfordjournals.org/ by guest on February 17, 2016
In this issue of The Journal of Infectious Diseases, Sabino et al [1] present the results of the largest study to date on transfusion-transmitted (TT) dengue. Until now, TT dengue has been rarely reported, with 5 convincingly documented clusters [2–6]. This well-conducted investigation, performed during an outbreak of dengue virus 4 (DENV-4) infection in 2 large Brazilian cities, Recife and Rio de Janeiro, compiled compelling laboratorial and chronological evidence of another 6 TT cases judiciously sorted from 42 DENV RNA–positive units that were transfused to 35 recipients. These 6 cases, analyzed in the context of another 10 susceptible recipients exposed to viremic blood, which remained negative for virus RNA and immunoglobulin M (IgM) in the follow-up period, allowed the authors to estimate a transmissibility rate of 37.5%. Transmission was independent of the viral load, and, interestingly, all 3 components usually obtained from blood donations ( plasma, red blood cells, and platelets) were able to transmit DENV-4. This has also been previously observed in one of the clusters from Singapore [2], where 3 recipients were infected by DENV-2 from the same viremic donation, with one developing symptoms that would be today be classified as dengue with warning signs.
690
•
JID 2016:213 (1 March)
•
was previously implemented in Puerto Rico, spurred by the observation that a transfusion recipient developed a hemorrhagic form of the disease [4]. More recently, blood collection was stopped in Puerto Rico because of the explosive outbreak of chikungunya virus (CHKV) infection there. At the moment, a few thousand autochthonous cases of CHKV infection have occurred in Brazil, and a future outbreak is predicted because of the abundance of the mosquito vectors (ie, Aedes aegypti and Aedes albopictus) shared with DENV [15]. Curiously, there has not yet been a single report of a TT case of CHKV infection, but the possibility of this happening led French blood authorities to implement pathogen-reduction procedures for platelet concentrates in Reunion Island during the 2006 outbreak [16] and, more recently, an in-house NAT for blood donations in their Caribbean territories, with the latter demonstrating a rate of 1:500 viremic units [17]. Certainly, a combined DENV/CHKV NAT assay would be valuable for blood and organ donor screening in Brazil and other involved countries, providing a higher level of safety, but, when available, it should be evaluated against the ever-growing list of health priorities in the country. Emerging and reemerging viruses will continue to threaten the blood supply. The current approach of creating a new test for each newly discovered agent increases the already high cost and complexity of blood screening. Two extremely promising alternatives for this dilemma are methods that would inactivate all nucleic acids in blood [18] or unbiased sequencing of donor cellfree plasma nucleic acids, revealing the whole microbial diversity [19] in addition to the human genome [20]. Notes Acknowledgments. I would like to thank Dr Cláudio Pannuti (Instituto de Medicina Tropical, Universidade de São Paulo) and Guido Levi for invaluable review of this manuscript. Potential conflict of interest. J. E. L. received a grant from Grifols for research of dengue in blood donors. The author has submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.
EDITORIAL COMMENTARY
References 1. Sabino EC, Loureiro P, Lopes ME, et al. Transfusionbased transmission of dengue virus and associated clinical symptoms during the 2012 epidemic in Brazil. J Infect Dis 2016; 213:694–702. 2. Tambyah PA, Koay ESC, Poon MLM, Lin RVTP, Ong BKC. Dengue hemorrhagic fever transmitted by blood transfusion. N Engl J Med 2008; 359: 1526–7. 3. Chuang VW, Wong TY, Leung YH, et al. Review of dengue fever cases in Hong Kong during 1998 to 2005. Hong Kong Med J 2008; 14:170–7. 4. Stramer SL, Linnen JM, Carrick JM, et al. Dengue viremia in blood donors identified by RNA and detection of dengue transfusion transmission during the 2007 dengue outbreak in Puerto Rico. Transfusion 2012; 52:1657–66. 5. Levi JE, Nishiya A, Félix AC, et al. Real-time symptomatic case of transfusion-transmitted dengue. Transfusion 2015; 55:961–4. 6. Oh HB, Muthu V, Daruwalla ZJ, Lee SY, Koay ES, Tambyah PA. Bitten by a bug or a bag? Transfusiontransmitted dengue: a rare complication in the bleeding surgical patient. Transfusion 2015; doi:10.1111/ trf.13054. 7. Halstead SB, O’Rourke EJ. Dengue viruses and mononuclear phagocytes. Infection enhancement by non-neutralizing antibody. J Exp Med 1977; 146: 201–7. 8. Fujimoto DE, Koifman S. Clinical and laboratory characteristics of patients with dengue hemorrhagic fever manifestations and their transfusion profile. Rev Bras Hematol Hemoter 2014; 36:115–20. 9. Rey FA. Dengue virus: two hosts, two structures. Nature 2013; 23:443–4. 10. Mores CN, Christofferson RC, Davidson SA. The role of the mosquito in a dengue human infection model. J Infect Dis 2014; 209(suppl 2):S71–8. 11. Cox J, Mota J, Sukupolvi-Petty S, Diamond MS, Rico-Hesse R. Mosquito bite delivery of dengue virus enhances immunogenicity and pathogenesis in humanized mice. J Virol 2012; 86:7637–49. 12. Onlamoon N, Noisakran S, Hsiao H-M, et al. Dengue virus–induced hemorrhage in a nonhuman primate model. Blood 2010; 115:1823–34. 13. Stramer SL, Fang CT, Foster GA, Wagner AG, Brodsky JP, Dodd RY. West Nile virus among blood donors in the United States, 2003 and 2004. N Engl J Med 2005; 353:451–9. 14. Felix AC, Romano CM, Centrone CD, et al. Low sensitivity of NS1 tests evidenced during an dengue 2 outbreak in Santos, Brazil, 2010. Clin Vaccine Immunol 2012; 19:1972–6. 15. Nunes MRT, Faria NR, Vasconcelos JM, et al. Emergence and potential for spread of Chikungunya virus in Brazil. BMC Med 2015; 13:102. 16. Rasonglès P, Angelini-Tibert MF, Simon P, et al. Transfusion of platelet components prepared with photochemical pathogen inactivation treatment during a Chikungunya virus epidemic in Ile de La Réunion. Transfusion 2009; 49:1083–91. 17. Paturel C, Djoudi R, Leparc-Goffart I, et al. Prospective detection of Chikungunya virus in blood donors, Caribbean 2014. Blood 2014; 123:3679–81. 18. Snyder EL, Stramer SL, Benjamin RJ. The safety of the blood supply–time to raise the bar. N Engl J Med 2015; 372:1882–5. 19. De Vlaminck I, Khush KK, Strehl C, et al. Temporal response of the human virome to immunosuppression and antiviral therapy. Cell 2013; 155:1178–87. 20. Lo YMD, Chan KCA, Sun H, et al. Maternal plasma DNA sequencing reveals the genome-wide genetic and mutational profile of the fetus. Sci Transl Med 2010; 2:61ra91.
Downloaded from http://jid.oxfordjournals.org/ by guest on February 17, 2016
some experts argue that mosquito-improved DENV human infection models provide a more realistic approach for the study of dengue pathogenesis and the evaluation of vaccines and antiviral compounds [10]. Intriguingly, direct injection of DENV culture supernatant fluids intravenously into 6 Rhesus macaques provoked hemorrhagic manifestations in all [12]. Close follow-up of human recipients transfused with whole blood containing DENVs may show whether viral infectivity is reduced by modern techniques for processing blood and storing the resulting components. In contrast to the rapid response of blood banks to the West Nile virus (WNV) invasion of the United States, where a nucleic acid test (NAT) was promptly introduced and universally adopted for blood and organ donor screening [13], Brazil, which currently has one of the largest number of dengue cases in the world, has never implemented any specific measures toward halting TT dengue. This might suggest that TT dengue is not as harmful as TT WNV. However, our own experience shows that, when thoroughly investigated, TT dengue can cause symptomatic disease [5], and effective prevention measures should therefore be adopted. This must be balanced against a much higher risk of vectorial transmission during the dengue season, possibly rendering laboratory screening of donors not costeffective. Nevertheless, a select groups of patients may be more vulnerable to DENV infection and warrant targeted testing of a fraction of units. Importantly, if testing is to be performed, it must be done by methods targeting DENV RNA (ie, NAT), because of the short viremic phase that precedes seroconversion. The detection of nonstructural protein 1 (NS1) in the blood of suspicious cases is widespread in areas of endemicity. However, a remarkable decrease in the sensitivity of tests in experienced populations has been demonstrated [14], making it an unacceptable option for blood screening, a procedure demanding maximum sensitivity. In contrast, NAT for DENV
