Jorge Muñoz-jordán - Academia.edu (original) (raw)
Papers by Jorge Muñoz-jordán
Nature communications, Apr 11, 2018
The emergence and spread of Zika virus (ZIKV) presented a challenge to the diagnosis of ZIKV infe... more The emergence and spread of Zika virus (ZIKV) presented a challenge to the diagnosis of ZIKV infections in areas with transmission of dengue (DENV) and chikungunya (CHIKV) viruses. To facilitate detection of ZIKV infections, and differentiate these infections from DENV and CHIKV, we developed the Trioplex real-time RT-PCR assay (Trioplex assay). Here, we describe the optimization of multiplex and singleplex formats of the assay for a variety of chemistries and instruments to facilitate global standardization and implementation. We evaluated the analytical performance of all Trioplex modalities for detection of these three pathogens in serum and whole blood, and for ZIKV in urine. The limit of detection for the three viruses and in different RNA-extraction modalities is near 10 genome copy equivalents per milliliter (GCE/mL). Simultaneous testing of more than one specimen type from each patient provides a 6.4% additional diagnostic sensitivity. Overall, the high sensitivity of the Tr...
The American Journal of Tropical Medicine and Hygiene
Serological cross-reactivity has proved to be a challenge to diagnose Zika virus (ZIKV) infection... more Serological cross-reactivity has proved to be a challenge to diagnose Zika virus (ZIKV) infections in dengue virus (DENV) endemic countries. Confirmatory testing of ZIKV IgM positive results by plaque reduction neutralization tests (PRNTs) provides clarification in only a minority of cases because most individuals infected with ZIKV were previously exposed to DENV. The goal of this study was to evaluate the performance of a ZIKV/DENV DUO IgM antibody capture ELISA (MAC-ELISA) for discriminating between DENV and ZIKV infections in endemic regions. Our performance evaluation included acute and convalescent specimens from patients with real-time reverse transcription polymerase chain reaction (RT-PCR)-confirmed DENV or ZIKV from the Sentinel Enhanced Dengue Surveillance System in Ponce, Puerto Rico. The ZIKV/DENV DUO MAC-ELISA specificity was 100% for DENV (N = 127) and 98.4% for ZIKV (N = 275) when specimens were tested during the optimal testing window (days post-onset of illness [DP...
Emerging Infectious Diseases
We reconstructed the 2016-2017 Zika virus epidemic in Puerto Rico by using complete genomes to un... more We reconstructed the 2016-2017 Zika virus epidemic in Puerto Rico by using complete genomes to uncover the epidemic's origin, spread, and evolutionary dynamics. Our study revealed that the epidemic was propelled by multiple introductions that spread across the island, intricate evolutionary patterns, and ≈10 months of cryptic transmission.
MMWR. Morbidity and Mortality Weekly Report
On August 30, 2019, Yap State declared a public health crisis caused by concurrent outbreaks of d... more On August 30, 2019, Yap State declared a public health crisis caused by concurrent outbreaks of dengue and leptospirosis, two clinically similar illnesses, resulting in 545 suspected dengue cases and 515 suspected leptospirosis cases during January–August 2019. Dengue virus type 3 (DENV-3) was identified by reverse transcription–polymerase chain reaction (RT-PCR) for 38 patients. Leptospirosis is endemic in Yap State (pop. approximately 11,500) with an anecdotal baseline of 0–2 cases/month.* Dengue is a potentially fatal mosquitoborne acute febrile viral illness (1). Leptospirosis is caused by infection with Leptospira bacteria and commonly acquired from contact with water or soil contaminated with infected animal urine (2). Approximately 90% of patients with leptospirosis experience self-limiting acute febrile illness, and 10% develop severe, potentially life-threatening illness (3). Early antibiotic treatment is generally associated with less severe and shorter illness (4). A team of outbreak investigators from Yap State and CDC identified suspected dengue and leptospirosis cases among patients with dengue-like illness (DLI),† which is clinically compatible with both illnesses. The majority of patients with DLI were reported and tested as having suspected cases of both dengue and leptospirosis during the outbreak. Among 515 patients with DLI tested for leptospirosis, 115 (22%) had a positive immunoglobulin M (IgM) leptospirosis rapid diagnostic test (LRDT) result.§ Because anti-Leptospira IgM antibodies can persist ≥12 months postinfection (5), the team performed testing to confirm the LRDT results and assess whether a leptospirosis outbreak occurred during the dengue outbreak.
Emerging Infectious Diseases
F our genetically distinct but serologically related dengue viruses (DENV-1-4) cause dengue, an a... more F our genetically distinct but serologically related dengue viruses (DENV-1-4) cause dengue, an acute febrile illness common throughout the tropics (1). DENV is transmitted by Aedes mosquitoes and has a median incubation period of 6 days (2). Other routes of DENV transmission include perinatal (3), blood transfusion (4), needle stick (5), and laboratory exposure (6-8).
PLOS Neglected Tropical Diseases
Background Public health responses to outbreaks of dengue, chikungunya, and Zika virus have been ... more Background Public health responses to outbreaks of dengue, chikungunya, and Zika virus have been stymied by the inability to control the primary vector, Aedes aegypti mosquitos. Consequently, the need for novel approaches to Aedes vector control is urgent. Placement of three autocidal gravid ovitraps (AGO traps) in~85% of homes in a community was previously shown to sustainably reduce the density of female Ae. aegypti by >80%. Following the introduction of chikungunya virus (CHIKV) to Puerto Rico, we conducted a seroprevalence survey to estimate the prevalence of CHIKV infection in communities with and without AGO traps and evaluate their effect on reducing CHIKV transmission. Methods and findings Multivariate models that calculated adjusted prevalence ratios (aPR) showed that among 175 and 152 residents of communities with and without AGO traps, respectively, an estimated 26.1% and 43.8% had been infected with CHIKV (aPR = 0.50, 95% CI: 0.37-0.91). After stratification by time spent in their community, protection from CHIKV infection was strongest among residents who reported spending many or all weekly daytime hours in their community:10.3% seropositive in communities with AGO traps vs. 48.7% in communities without (PR = 0.21, 95% CI: 0.11-0.41). The age-adjusted rate of fever with arthralgia attributable to CHIKV infection was 58% (95% CI: 46-66%). The monthly number of CHIKVinfected mosquitos and symptomatic residents were diminished in communities with AGO traps compared to those without. Conclusions These findings indicate that AGO traps are an effective tool that protects humans from infection with a virus transmitted by Ae. aegypti mosquitos. Future studies should evaluate their protective effectiveness in large, urban communities.
PLOS Neglected Tropical Diseases
Chikungunya, a mosquito-borne viral, acute febrile illness (AFI) is associated with polyarthralgi... more Chikungunya, a mosquito-borne viral, acute febrile illness (AFI) is associated with polyarthralgia and polyarthritis. Differentiation from other AFI is difficult due to the non-specific presentation and limited availability of diagnostics. This 3-year study identified independent clinical predictors by day post-illness onset (DPO) at presentation and age-group that distinguish chikungunya cases from two groups: other AFI and dengue. Specimens collected from participants with fever �7 days were tested for chikungunya, dengue viruses 1-4, and 20 other pathogens. Of 8,996 participants, 18.2% had chikungunya, and 10.8% had dengue. Chikungunya cases were more likely than other groups to be older, report a chronic condition, and present <3 DPO. Regardless of timing of presentation, significant positive predictors for chikungunya versus other AFI were: joint pain, muscle, bone or back pain, skin rash, and red conjunctiva; with dengue as the comparator, red swollen joints (arthritis), joint pain, skin rash, any bleeding, and irritability were predictors. Chikungunya cases were less likely than AFI and dengue to present with thrombocytopenia, signs of poor circulation, diarrhea, headache, and cough. Among participants presenting <3 DPO, predictors for chikungunya versus other AFI included: joint pain, skin rash, and muscle, bone or back pain, and absence of thrombocytopenia, poor circulation and respiratory or gastrointestinal symptoms; when
Open Forum Infectious Diseases
To evaluate potential enhancement of Zika virus (ZIKV) infection among patients with prior dengue... more To evaluate potential enhancement of Zika virus (ZIKV) infection among patients with prior dengue virus (DENV) infection, we compared viral RNA loads among patients infected with ZIKV (n=1,070), DENV-2 (n=312), or DENV-3 (n=260). Compared to patients without prior DENV infection, patients with prior DENV infection had significantly higher mean loads of viral RNA if infected with DENV-2 (10.6 vs. 11.6 log10 GCE/mL, respectively; t-test, p < 0.0001) or DENV-3 (10.3 vs. 10.9 log10 GCE/mL; p < 0.0001), but not ZIKV (4.7 vs. 4.7 log10 GCE/mL; p = 0.959). These findings provide evidence against in vivo enhancement of ZIKV by anti-DENV antibodies.
MMWR. Recommendations and Reports
Dengue and Zika viruses are closely related mosquitoborne flaviviruses with similar transmission ... more Dengue and Zika viruses are closely related mosquitoborne flaviviruses with similar transmission cycles, distribution throughout the tropics and subtropics, and disease manifestations including fever, rash, myalgia, and arthralgia. For patients with suspected dengue or Zika virus disease, nucleic acid amplification tests (NAATs) are the preferred method of diagnosis. Immunoglobulin M (IgM) antibody testing can identify additional infections and remains an important tool for the diagnosis of these diseases, but interpreting the results is complicated by cross-reactivity, and determining the specific timing of infection can be difficult. These limitations are a particular challenge for pregnant women in determining whether Zika virus infection occurred during or before the pregnancy. This report summarizes existing and new guidance on dengue and Zika virus diagnostic testing for patients with a clinically compatible illness who live in or recently traveled to an area where there is risk for infection with both viruses. CDC recommendations for screening of asymptomatic pregnant women with possible Zika virus exposure are unchanged. For symptomatic nonpregnant persons, dengue and Zika virus NAATs should be performed on serum collected ≤7 days after symptom onset. Dengue and Zika virus IgM antibody testing should be performed on NAAT-negative serum specimens or serum collected >7 days after onset of symptoms. For symptomatic pregnant women, serum and urine specimens should be collected as soon as possible within 12 weeks of symptom onset for concurrent dengue and Zika virus NAATs and IgM antibody testing. Positive IgM antibody test results with negative NAAT results should be confirmed by neutralizing antibody tests when clinically or epidemiologically indicated, including for all pregnant women. Data on the epidemiology of viruses known to be circulating at the location of exposure and clinical findings should be considered when deciding which tests to perform and for interpreting results. Patients with clinically suspected dengue should receive appropriate management to monitor and treat shock and hemorrhage. Women with laboratory evidence of possible Zika virus infection during pregnancy and their infants should be evaluated and managed for possible adverse outcomes. Dengue and Zika virus disease are nationally notifiable conditions, and cases should be reported to public health authorities.
Viruses, Jan 18, 2018
Dengue virus (DENV) is estimated to cause 390 million infections per year worldwide. A quarter of... more Dengue virus (DENV) is estimated to cause 390 million infections per year worldwide. A quarter of these infections manifest clinically and are associated with a morbidity and mortality that put a significant burden on the affected regions. Reports of increased frequency, intensity, and extended geographical range of outbreaks highlight the virus's ongoing global spread. Persistent transmission in endemic areas and the emergence in territories formerly devoid of transmission have shaped DENV's current genetic diversity and divergence. This genetic layout is hierarchically organized in serotypes, genotypes, and sub-genotypic clades. While serotypes are well defined, the genotype nomenclature and classification system lack consistency, which complicates a broader analysis of their clinical and epidemiological characteristics. We identify five key challenges: (1) Currently, there is no formal definition of a DENV genotype; (2) Two different nomenclature systems are used in paral...
The Journal of infectious diseases, Jan 27, 2018
Zika virus (ZIKV) has recently caused a large epidemic in the Americas associated with birth defe... more Zika virus (ZIKV) has recently caused a large epidemic in the Americas associated with birth defects. Although ZIKV is primarily transmitted by Aedes spp. mosquitoes, ZIKV RNA is detectable in blood and semen of infected individuals for weeks or months, during which time sexual and other modes of transmission are possible. However, viral RNA is usually detectable for longer than infectious virus is present. We determined the frequency of isolation of infectious virus from semen and serum samples prospectively obtained from a cohort of patients in Puerto Rico. We confirmed positive isolation by tissue culture cytopathic effect, increase in virus genome copy equivalents (GCE), immunofluorescence, and quantitation of infected cells by flow cytometry. These criteria confirmed infectious virus in semen from 8 of 97 patients for up to 38 days after initial detection when virus loads are higher than 1.4x106 GCE/mL. Two serum isolates were obtained from 296 patients. These findings can help...
Transfusion, Mar 14, 2017
Zika virus (ZIKV) has spread rapidly in the Pacific and throughout the Americas and is associated... more Zika virus (ZIKV) has spread rapidly in the Pacific and throughout the Americas and is associated with severe congenital and adult neurologic outcomes. Nucleic acid amplification technology (NAT) assays were developed for diagnostic applications and for blood donor screening on high-throughput NAT systems. We distributed blinded panels to compare the analytical performance of blood screening relative to diagnostic NAT assays. A 25-member, coded panel (11 half-log dilutions of a 2013 French Polynesia ZIKV isolate and 2015 Brazilian donor plasma implicated in transfusion transmission, and 3 negative controls) was sent to 11 laboratories that performed 17 assays with 2 to 12 replicates per panel member. Results were analyzed for the percentage reactivity at each dilution and by probit analysis to estimate the 50% and 95% limits of detection (LOD50 and LOD95 , respectively). Donor-screening NAT assays that process approximately 500 µL of plasma into amplification reactions were comparab...
Clinical Infectious Diseases, 2016
We report two patients who developed severe thrombocytopenia after Zika virus infection. The firs... more We report two patients who developed severe thrombocytopenia after Zika virus infection. The first had 1,000 platelets/mm 3 , and died following multiple hemorrhages. The second had 2,000 platelets/mm 3 , melena, ecchymoses, and recovered after receiving intravenous immunoglobulin. Physicians should be aware that Zika virus may be associated with immunemediated severe thrombocytopenia.
Emerging Infectious Diseases, 2016
During a dengue epidemic in northern Mexico, enhanced surveillance identified 53 laboratory-posit... more During a dengue epidemic in northern Mexico, enhanced surveillance identified 53 laboratory-positive cases in southern Texas; 26 (49%) patients acquired the infection locally, and 29 (55%) were hospitalized. Of 83 patient specimens that were initially IgM negative according to ELISA performed at a commercial laboratory, 14 (17%) were dengue virus positive by real-time reverse transcription PCR performed at the Centers for Disease Control and Prevention. Dengue virus types 1 and 3 were identified, and molecular phylogenetic analysis demonstrated close identity with viruses that had recently circulated in Mexico and Central America. Of 51 household members of 22 dengue casepatients who participated in household investigations, 6 (12%) had been recently infected with a dengue virus and reported no recent travel, suggesting intrahousehold transmission. One household member reported having a recent illness consistent with dengue. This outbreak reinforces emergence of dengue in southern Texas, particularly when incidence is high in northern Mexico.
Journal of Infectious Diseases, 2016
Background. Anti-dengue virus (DENV) immunoglobulin M (IgM) seroconversion has been the reference... more Background. Anti-dengue virus (DENV) immunoglobulin M (IgM) seroconversion has been the reference standard for dengue diagnosis. However, paired specimens are rarely obtained, and the interval for this testing negates its usefulness in guiding clinical case management. The presence of DENV viremia and appearance of IgM during the febrile phase of dengue provides the framework for dengue laboratory diagnosis by using a single serum specimen. Methods. Archived paired serum specimens (n = 1234) from patients with laboratory-confirmed dengue from 2005 through 2011 were used to determine the diagnostic performance of real-time reverse transcription polymerase chain reaction (RT-PCR), for detection of DENV serotypes 1-4, and enzyme-linked immunosorbent assays (ELISAs), for detection of DENV nonstructural protein 1 (NS1) antigen and anti-DENV IgM. Results. During 1-3 days after illness onset, real-time RT-PCR and NS1 antigen testing detected 82%-69% and 90%-84% of cases, respectively, as viremia levels declined, while anti-DENV IgM ELISA detected 5%-41% of cases as antibody appeared. Over the 10-day period of the febrile phase of dengue, the cumulative effect of using these 3 types of tests in a diagnostic algorithm confirmed ≥90% of dengue cases. Conclusions. The use of molecular or NS1 antigen tests to detect DENV and one to detect anti-DENV IgM in a single serum specimen collected during the first 10 days of illness accurately identified ≥90% of dengue primary and secondary cases.
Virus Research, 2015
Dengue has emerged globally as a major human health problem since the 1950s and is now the most i... more Dengue has emerged globally as a major human health problem since the 1950s and is now the most important arboviral disease of humans, infecting nearly 400 million people annually. While some cases are asymptomatic, others can develop a febrile illness (dengue fever) or even progress to severe and fatal dengue. Dengue is caused by any of four closely related but distinct viruses, known as Dengue virus serotype 1 to 4 (DENV-1 to DENV-4) which are maintained in endemic transmission to humans in large urban centers of the tropics by Aedes mosquitoes. Since the early 1960s, Puerto Rico, a major metropolitan center in the Caribbean, has experienced increasingly larger and clinically more severe epidemics following the introduction of all four dengue serotypes. The first dengue hemorrhagic fever epidemic in 1986, and a particularly severe outbreak in 1998 were dominated by novel DENV-4 strains that evolved in Puerto Rico, replacing earlier strains and spreading throughout the region. Sequence characterization of 54 complete DENV-4 genomes and their comparative evolution against 74 previously published viral sequences from the region over several decades shows that DENV-4 strains from these periods were genetically distinct based on unique changes in the envelope and non-structural genes. Their replacement of earlier strains in Puerto Rico progressed rapidly, suggesting that strong natural selection played a role in their fixation. This study confirms that DENVs evolve through rapid lineage turnover driven in part by natural selection and genetic drift.
Science, 2015
signal than nestin + cells in 6-week-old mice (Fig. 4, I and J). At 12 months, however, ubiquitin... more signal than nestin + cells in 6-week-old mice (Fig. 4, I and J). At 12 months, however, ubiquitin levels were not significantly different between NSCs and their neuronal progeny (Fig. 4, K and L) despite the general increase in ubiquitin levels in the older brain (fig. S5G). These findings establish that NSCs retain fewer damaged proteins during cell division and support the hypothesis that weakening of the diffusion barrier with age contributes to the more symmetric segregation of ubiquitinated proteins between NSCs and their neuronal progeny in vivo. Our results show how age affects protein segregation during mammalian NSC division by altering a diffusion barrier. The diffusion barrier facilitates asymmetric segregation of damaged proteins between daughter cells, keeping the selfrenewed stem cell free from damage. As in yeast, young rodent NSCs efficiently compartmentalize cellular damage, protecting the proliferative cell. Age reduces the efficiency of this compartmentalization, exposing the aged NSCs to excess cellular damage. Examining the role of the ER diffusion barrier in other mammalian cells will determine whether this represents a general mechanism for the asymmetric segregation of damage during cell divisions of somatic stem cells or other immortal cells, such as cancer cells. ACKNOWLEDGMENTS Data have been deposited in NCBI's Gene Expression Omnibus with accession number GSE61367. Supplement contains additional data. We thank M. Götz for providing support for pilot slice culture experiments and conceptual input; L.
Transfusion, 2015
In the absence of active blood donation screening, dengue viruses (DENV) have been implicated in ... more In the absence of active blood donation screening, dengue viruses (DENV) have been implicated in only a limited number of transfusion transmissions worldwide. This study attempted to identify if blood from donors testing negative by an NS1-antigen (Ag) enzyme-linked immunosorbent assay (ELISA) but confirmed positive for DENV RNA caused DENV-related disease in recipients during the epidemic years of 2010 to 2012 in Puerto Rico. Donation aliquots testing negative by an investigational NS1-Ag ELISA were stored frozen and retested retrospectively using a research transcription-mediated amplification assay (TMA) detecting DENV RNA. All RNA-reactive donations were subject to confirmatory RNA and antibody testing. Recipient tracing was conducted for all components manufactured from TMA-reactive components. Medical chart review, recipient interview, and follow-up sampling occurred for 42 recipients transfused with TMA-reactive components. Six of 42 recipients developed new-onset fever in the 2 weeks posttransfusion; three (50%) received RNA confirmed-positive, NS1-Ag-negative red blood cell (RBC) units. One recipient of a high-titer unit (7 × 10(7) DENV-4 RNA copies/mL) developed severe dengue, and a second recipient had only fever recorded but had a negative sepsis work-up. New fever attributable to DENV infection in a third recipient was confounded by fever potentially attributable to posttransfusion sepsis. In our retrospective study, NS1-Ag detected 20% of all RNA confirmed-positive donations demonstrating limitations of NS1-Ag ELISA for blood donation screening. We identified one recipient with a clinical syndrome compatible with severe dengue who had received an NS1-Ag-negative but RNA confirmed-positive RBC unit. This investigation illustrates the difficulty in confirming transfusion transmission in dengue-endemic areas among severely ill transfusion recipients.
Emerging Infectious Diseases, 2015
During the 2013 dengue epidemic in Luanda, Angola, 811 dengue rapid diagnostic test-positive case... more During the 2013 dengue epidemic in Luanda, Angola, 811 dengue rapid diagnostic test-positive cases were reported to the Ministry of Health. To better understand the magnitude of the epidemic and identify risk factors for dengue virus (DENV) infection, we conducted cluster surveys around households of case-patients and randomly selected households 6 weeks after the peak of the epidemic. Of 173 case cluster participants, 16 (9%) exhibited evidence of recent DENV infection. Of 247 random cluster participants, 25 (10%) had evidence of recent DENV infection. Of 13 recently infected participants who had a recent febrile illness, 7 (54%) had sought medical care, and 1 (14%) was hospitalized with symptoms consistent with severe dengue; however, none received a diagnosis of dengue. Behavior associated with protection from DENV infection included recent use of mosquito repellent or a bed net. These findings suggest that the 2013 dengue epidemic was larger than indicated by passive surveillance data.
Journal of NeuroVirology, 2014
The flaviviruses dengue, West Nile, and Japanese encephalitis represent three major mosquitoborne... more The flaviviruses dengue, West Nile, and Japanese encephalitis represent three major mosquitoborne viruses worldwide. These pathogens impact the lives of millions of individuals and potentially could affect non-endemic areas already colonized by mosquito vectors. Unintentional transport of infected vectors (Aedes and Culex spp.), traveling within endemic areas, rapid adaptation of the insects into new geographic locations, climate change, and lack of medical surveillance have greatly contributed to the increase in flaviviral infections worldwide. The mechanisms by which flaviviruses alter the immune and the central nervous system have only recently been examined despite the alarming number of infections, related deaths, and increasing global distribution. In this review, we will discuss the expansion of the geographic areas affected by flaviviruses, the potential threats to previously unaffected countries, the mechanisms of pathogenesis, and the potential therapeutic interventions to limit the devastating consequences of these viruses.
Nature communications, Apr 11, 2018
The emergence and spread of Zika virus (ZIKV) presented a challenge to the diagnosis of ZIKV infe... more The emergence and spread of Zika virus (ZIKV) presented a challenge to the diagnosis of ZIKV infections in areas with transmission of dengue (DENV) and chikungunya (CHIKV) viruses. To facilitate detection of ZIKV infections, and differentiate these infections from DENV and CHIKV, we developed the Trioplex real-time RT-PCR assay (Trioplex assay). Here, we describe the optimization of multiplex and singleplex formats of the assay for a variety of chemistries and instruments to facilitate global standardization and implementation. We evaluated the analytical performance of all Trioplex modalities for detection of these three pathogens in serum and whole blood, and for ZIKV in urine. The limit of detection for the three viruses and in different RNA-extraction modalities is near 10 genome copy equivalents per milliliter (GCE/mL). Simultaneous testing of more than one specimen type from each patient provides a 6.4% additional diagnostic sensitivity. Overall, the high sensitivity of the Tr...
The American Journal of Tropical Medicine and Hygiene
Serological cross-reactivity has proved to be a challenge to diagnose Zika virus (ZIKV) infection... more Serological cross-reactivity has proved to be a challenge to diagnose Zika virus (ZIKV) infections in dengue virus (DENV) endemic countries. Confirmatory testing of ZIKV IgM positive results by plaque reduction neutralization tests (PRNTs) provides clarification in only a minority of cases because most individuals infected with ZIKV were previously exposed to DENV. The goal of this study was to evaluate the performance of a ZIKV/DENV DUO IgM antibody capture ELISA (MAC-ELISA) for discriminating between DENV and ZIKV infections in endemic regions. Our performance evaluation included acute and convalescent specimens from patients with real-time reverse transcription polymerase chain reaction (RT-PCR)-confirmed DENV or ZIKV from the Sentinel Enhanced Dengue Surveillance System in Ponce, Puerto Rico. The ZIKV/DENV DUO MAC-ELISA specificity was 100% for DENV (N = 127) and 98.4% for ZIKV (N = 275) when specimens were tested during the optimal testing window (days post-onset of illness [DP...
Emerging Infectious Diseases
We reconstructed the 2016-2017 Zika virus epidemic in Puerto Rico by using complete genomes to un... more We reconstructed the 2016-2017 Zika virus epidemic in Puerto Rico by using complete genomes to uncover the epidemic's origin, spread, and evolutionary dynamics. Our study revealed that the epidemic was propelled by multiple introductions that spread across the island, intricate evolutionary patterns, and ≈10 months of cryptic transmission.
MMWR. Morbidity and Mortality Weekly Report
On August 30, 2019, Yap State declared a public health crisis caused by concurrent outbreaks of d... more On August 30, 2019, Yap State declared a public health crisis caused by concurrent outbreaks of dengue and leptospirosis, two clinically similar illnesses, resulting in 545 suspected dengue cases and 515 suspected leptospirosis cases during January–August 2019. Dengue virus type 3 (DENV-3) was identified by reverse transcription–polymerase chain reaction (RT-PCR) for 38 patients. Leptospirosis is endemic in Yap State (pop. approximately 11,500) with an anecdotal baseline of 0–2 cases/month.* Dengue is a potentially fatal mosquitoborne acute febrile viral illness (1). Leptospirosis is caused by infection with Leptospira bacteria and commonly acquired from contact with water or soil contaminated with infected animal urine (2). Approximately 90% of patients with leptospirosis experience self-limiting acute febrile illness, and 10% develop severe, potentially life-threatening illness (3). Early antibiotic treatment is generally associated with less severe and shorter illness (4). A team of outbreak investigators from Yap State and CDC identified suspected dengue and leptospirosis cases among patients with dengue-like illness (DLI),† which is clinically compatible with both illnesses. The majority of patients with DLI were reported and tested as having suspected cases of both dengue and leptospirosis during the outbreak. Among 515 patients with DLI tested for leptospirosis, 115 (22%) had a positive immunoglobulin M (IgM) leptospirosis rapid diagnostic test (LRDT) result.§ Because anti-Leptospira IgM antibodies can persist ≥12 months postinfection (5), the team performed testing to confirm the LRDT results and assess whether a leptospirosis outbreak occurred during the dengue outbreak.
Emerging Infectious Diseases
F our genetically distinct but serologically related dengue viruses (DENV-1-4) cause dengue, an a... more F our genetically distinct but serologically related dengue viruses (DENV-1-4) cause dengue, an acute febrile illness common throughout the tropics (1). DENV is transmitted by Aedes mosquitoes and has a median incubation period of 6 days (2). Other routes of DENV transmission include perinatal (3), blood transfusion (4), needle stick (5), and laboratory exposure (6-8).
PLOS Neglected Tropical Diseases
Background Public health responses to outbreaks of dengue, chikungunya, and Zika virus have been ... more Background Public health responses to outbreaks of dengue, chikungunya, and Zika virus have been stymied by the inability to control the primary vector, Aedes aegypti mosquitos. Consequently, the need for novel approaches to Aedes vector control is urgent. Placement of three autocidal gravid ovitraps (AGO traps) in~85% of homes in a community was previously shown to sustainably reduce the density of female Ae. aegypti by >80%. Following the introduction of chikungunya virus (CHIKV) to Puerto Rico, we conducted a seroprevalence survey to estimate the prevalence of CHIKV infection in communities with and without AGO traps and evaluate their effect on reducing CHIKV transmission. Methods and findings Multivariate models that calculated adjusted prevalence ratios (aPR) showed that among 175 and 152 residents of communities with and without AGO traps, respectively, an estimated 26.1% and 43.8% had been infected with CHIKV (aPR = 0.50, 95% CI: 0.37-0.91). After stratification by time spent in their community, protection from CHIKV infection was strongest among residents who reported spending many or all weekly daytime hours in their community:10.3% seropositive in communities with AGO traps vs. 48.7% in communities without (PR = 0.21, 95% CI: 0.11-0.41). The age-adjusted rate of fever with arthralgia attributable to CHIKV infection was 58% (95% CI: 46-66%). The monthly number of CHIKVinfected mosquitos and symptomatic residents were diminished in communities with AGO traps compared to those without. Conclusions These findings indicate that AGO traps are an effective tool that protects humans from infection with a virus transmitted by Ae. aegypti mosquitos. Future studies should evaluate their protective effectiveness in large, urban communities.
PLOS Neglected Tropical Diseases
Chikungunya, a mosquito-borne viral, acute febrile illness (AFI) is associated with polyarthralgi... more Chikungunya, a mosquito-borne viral, acute febrile illness (AFI) is associated with polyarthralgia and polyarthritis. Differentiation from other AFI is difficult due to the non-specific presentation and limited availability of diagnostics. This 3-year study identified independent clinical predictors by day post-illness onset (DPO) at presentation and age-group that distinguish chikungunya cases from two groups: other AFI and dengue. Specimens collected from participants with fever �7 days were tested for chikungunya, dengue viruses 1-4, and 20 other pathogens. Of 8,996 participants, 18.2% had chikungunya, and 10.8% had dengue. Chikungunya cases were more likely than other groups to be older, report a chronic condition, and present <3 DPO. Regardless of timing of presentation, significant positive predictors for chikungunya versus other AFI were: joint pain, muscle, bone or back pain, skin rash, and red conjunctiva; with dengue as the comparator, red swollen joints (arthritis), joint pain, skin rash, any bleeding, and irritability were predictors. Chikungunya cases were less likely than AFI and dengue to present with thrombocytopenia, signs of poor circulation, diarrhea, headache, and cough. Among participants presenting <3 DPO, predictors for chikungunya versus other AFI included: joint pain, skin rash, and muscle, bone or back pain, and absence of thrombocytopenia, poor circulation and respiratory or gastrointestinal symptoms; when
Open Forum Infectious Diseases
To evaluate potential enhancement of Zika virus (ZIKV) infection among patients with prior dengue... more To evaluate potential enhancement of Zika virus (ZIKV) infection among patients with prior dengue virus (DENV) infection, we compared viral RNA loads among patients infected with ZIKV (n=1,070), DENV-2 (n=312), or DENV-3 (n=260). Compared to patients without prior DENV infection, patients with prior DENV infection had significantly higher mean loads of viral RNA if infected with DENV-2 (10.6 vs. 11.6 log10 GCE/mL, respectively; t-test, p < 0.0001) or DENV-3 (10.3 vs. 10.9 log10 GCE/mL; p < 0.0001), but not ZIKV (4.7 vs. 4.7 log10 GCE/mL; p = 0.959). These findings provide evidence against in vivo enhancement of ZIKV by anti-DENV antibodies.
MMWR. Recommendations and Reports
Dengue and Zika viruses are closely related mosquitoborne flaviviruses with similar transmission ... more Dengue and Zika viruses are closely related mosquitoborne flaviviruses with similar transmission cycles, distribution throughout the tropics and subtropics, and disease manifestations including fever, rash, myalgia, and arthralgia. For patients with suspected dengue or Zika virus disease, nucleic acid amplification tests (NAATs) are the preferred method of diagnosis. Immunoglobulin M (IgM) antibody testing can identify additional infections and remains an important tool for the diagnosis of these diseases, but interpreting the results is complicated by cross-reactivity, and determining the specific timing of infection can be difficult. These limitations are a particular challenge for pregnant women in determining whether Zika virus infection occurred during or before the pregnancy. This report summarizes existing and new guidance on dengue and Zika virus diagnostic testing for patients with a clinically compatible illness who live in or recently traveled to an area where there is risk for infection with both viruses. CDC recommendations for screening of asymptomatic pregnant women with possible Zika virus exposure are unchanged. For symptomatic nonpregnant persons, dengue and Zika virus NAATs should be performed on serum collected ≤7 days after symptom onset. Dengue and Zika virus IgM antibody testing should be performed on NAAT-negative serum specimens or serum collected >7 days after onset of symptoms. For symptomatic pregnant women, serum and urine specimens should be collected as soon as possible within 12 weeks of symptom onset for concurrent dengue and Zika virus NAATs and IgM antibody testing. Positive IgM antibody test results with negative NAAT results should be confirmed by neutralizing antibody tests when clinically or epidemiologically indicated, including for all pregnant women. Data on the epidemiology of viruses known to be circulating at the location of exposure and clinical findings should be considered when deciding which tests to perform and for interpreting results. Patients with clinically suspected dengue should receive appropriate management to monitor and treat shock and hemorrhage. Women with laboratory evidence of possible Zika virus infection during pregnancy and their infants should be evaluated and managed for possible adverse outcomes. Dengue and Zika virus disease are nationally notifiable conditions, and cases should be reported to public health authorities.
Viruses, Jan 18, 2018
Dengue virus (DENV) is estimated to cause 390 million infections per year worldwide. A quarter of... more Dengue virus (DENV) is estimated to cause 390 million infections per year worldwide. A quarter of these infections manifest clinically and are associated with a morbidity and mortality that put a significant burden on the affected regions. Reports of increased frequency, intensity, and extended geographical range of outbreaks highlight the virus's ongoing global spread. Persistent transmission in endemic areas and the emergence in territories formerly devoid of transmission have shaped DENV's current genetic diversity and divergence. This genetic layout is hierarchically organized in serotypes, genotypes, and sub-genotypic clades. While serotypes are well defined, the genotype nomenclature and classification system lack consistency, which complicates a broader analysis of their clinical and epidemiological characteristics. We identify five key challenges: (1) Currently, there is no formal definition of a DENV genotype; (2) Two different nomenclature systems are used in paral...
The Journal of infectious diseases, Jan 27, 2018
Zika virus (ZIKV) has recently caused a large epidemic in the Americas associated with birth defe... more Zika virus (ZIKV) has recently caused a large epidemic in the Americas associated with birth defects. Although ZIKV is primarily transmitted by Aedes spp. mosquitoes, ZIKV RNA is detectable in blood and semen of infected individuals for weeks or months, during which time sexual and other modes of transmission are possible. However, viral RNA is usually detectable for longer than infectious virus is present. We determined the frequency of isolation of infectious virus from semen and serum samples prospectively obtained from a cohort of patients in Puerto Rico. We confirmed positive isolation by tissue culture cytopathic effect, increase in virus genome copy equivalents (GCE), immunofluorescence, and quantitation of infected cells by flow cytometry. These criteria confirmed infectious virus in semen from 8 of 97 patients for up to 38 days after initial detection when virus loads are higher than 1.4x106 GCE/mL. Two serum isolates were obtained from 296 patients. These findings can help...
Transfusion, Mar 14, 2017
Zika virus (ZIKV) has spread rapidly in the Pacific and throughout the Americas and is associated... more Zika virus (ZIKV) has spread rapidly in the Pacific and throughout the Americas and is associated with severe congenital and adult neurologic outcomes. Nucleic acid amplification technology (NAT) assays were developed for diagnostic applications and for blood donor screening on high-throughput NAT systems. We distributed blinded panels to compare the analytical performance of blood screening relative to diagnostic NAT assays. A 25-member, coded panel (11 half-log dilutions of a 2013 French Polynesia ZIKV isolate and 2015 Brazilian donor plasma implicated in transfusion transmission, and 3 negative controls) was sent to 11 laboratories that performed 17 assays with 2 to 12 replicates per panel member. Results were analyzed for the percentage reactivity at each dilution and by probit analysis to estimate the 50% and 95% limits of detection (LOD50 and LOD95 , respectively). Donor-screening NAT assays that process approximately 500 µL of plasma into amplification reactions were comparab...
Clinical Infectious Diseases, 2016
We report two patients who developed severe thrombocytopenia after Zika virus infection. The firs... more We report two patients who developed severe thrombocytopenia after Zika virus infection. The first had 1,000 platelets/mm 3 , and died following multiple hemorrhages. The second had 2,000 platelets/mm 3 , melena, ecchymoses, and recovered after receiving intravenous immunoglobulin. Physicians should be aware that Zika virus may be associated with immunemediated severe thrombocytopenia.
Emerging Infectious Diseases, 2016
During a dengue epidemic in northern Mexico, enhanced surveillance identified 53 laboratory-posit... more During a dengue epidemic in northern Mexico, enhanced surveillance identified 53 laboratory-positive cases in southern Texas; 26 (49%) patients acquired the infection locally, and 29 (55%) were hospitalized. Of 83 patient specimens that were initially IgM negative according to ELISA performed at a commercial laboratory, 14 (17%) were dengue virus positive by real-time reverse transcription PCR performed at the Centers for Disease Control and Prevention. Dengue virus types 1 and 3 were identified, and molecular phylogenetic analysis demonstrated close identity with viruses that had recently circulated in Mexico and Central America. Of 51 household members of 22 dengue casepatients who participated in household investigations, 6 (12%) had been recently infected with a dengue virus and reported no recent travel, suggesting intrahousehold transmission. One household member reported having a recent illness consistent with dengue. This outbreak reinforces emergence of dengue in southern Texas, particularly when incidence is high in northern Mexico.
Journal of Infectious Diseases, 2016
Background. Anti-dengue virus (DENV) immunoglobulin M (IgM) seroconversion has been the reference... more Background. Anti-dengue virus (DENV) immunoglobulin M (IgM) seroconversion has been the reference standard for dengue diagnosis. However, paired specimens are rarely obtained, and the interval for this testing negates its usefulness in guiding clinical case management. The presence of DENV viremia and appearance of IgM during the febrile phase of dengue provides the framework for dengue laboratory diagnosis by using a single serum specimen. Methods. Archived paired serum specimens (n = 1234) from patients with laboratory-confirmed dengue from 2005 through 2011 were used to determine the diagnostic performance of real-time reverse transcription polymerase chain reaction (RT-PCR), for detection of DENV serotypes 1-4, and enzyme-linked immunosorbent assays (ELISAs), for detection of DENV nonstructural protein 1 (NS1) antigen and anti-DENV IgM. Results. During 1-3 days after illness onset, real-time RT-PCR and NS1 antigen testing detected 82%-69% and 90%-84% of cases, respectively, as viremia levels declined, while anti-DENV IgM ELISA detected 5%-41% of cases as antibody appeared. Over the 10-day period of the febrile phase of dengue, the cumulative effect of using these 3 types of tests in a diagnostic algorithm confirmed ≥90% of dengue cases. Conclusions. The use of molecular or NS1 antigen tests to detect DENV and one to detect anti-DENV IgM in a single serum specimen collected during the first 10 days of illness accurately identified ≥90% of dengue primary and secondary cases.
Virus Research, 2015
Dengue has emerged globally as a major human health problem since the 1950s and is now the most i... more Dengue has emerged globally as a major human health problem since the 1950s and is now the most important arboviral disease of humans, infecting nearly 400 million people annually. While some cases are asymptomatic, others can develop a febrile illness (dengue fever) or even progress to severe and fatal dengue. Dengue is caused by any of four closely related but distinct viruses, known as Dengue virus serotype 1 to 4 (DENV-1 to DENV-4) which are maintained in endemic transmission to humans in large urban centers of the tropics by Aedes mosquitoes. Since the early 1960s, Puerto Rico, a major metropolitan center in the Caribbean, has experienced increasingly larger and clinically more severe epidemics following the introduction of all four dengue serotypes. The first dengue hemorrhagic fever epidemic in 1986, and a particularly severe outbreak in 1998 were dominated by novel DENV-4 strains that evolved in Puerto Rico, replacing earlier strains and spreading throughout the region. Sequence characterization of 54 complete DENV-4 genomes and their comparative evolution against 74 previously published viral sequences from the region over several decades shows that DENV-4 strains from these periods were genetically distinct based on unique changes in the envelope and non-structural genes. Their replacement of earlier strains in Puerto Rico progressed rapidly, suggesting that strong natural selection played a role in their fixation. This study confirms that DENVs evolve through rapid lineage turnover driven in part by natural selection and genetic drift.
Science, 2015
signal than nestin + cells in 6-week-old mice (Fig. 4, I and J). At 12 months, however, ubiquitin... more signal than nestin + cells in 6-week-old mice (Fig. 4, I and J). At 12 months, however, ubiquitin levels were not significantly different between NSCs and their neuronal progeny (Fig. 4, K and L) despite the general increase in ubiquitin levels in the older brain (fig. S5G). These findings establish that NSCs retain fewer damaged proteins during cell division and support the hypothesis that weakening of the diffusion barrier with age contributes to the more symmetric segregation of ubiquitinated proteins between NSCs and their neuronal progeny in vivo. Our results show how age affects protein segregation during mammalian NSC division by altering a diffusion barrier. The diffusion barrier facilitates asymmetric segregation of damaged proteins between daughter cells, keeping the selfrenewed stem cell free from damage. As in yeast, young rodent NSCs efficiently compartmentalize cellular damage, protecting the proliferative cell. Age reduces the efficiency of this compartmentalization, exposing the aged NSCs to excess cellular damage. Examining the role of the ER diffusion barrier in other mammalian cells will determine whether this represents a general mechanism for the asymmetric segregation of damage during cell divisions of somatic stem cells or other immortal cells, such as cancer cells. ACKNOWLEDGMENTS Data have been deposited in NCBI's Gene Expression Omnibus with accession number GSE61367. Supplement contains additional data. We thank M. Götz for providing support for pilot slice culture experiments and conceptual input; L.
Transfusion, 2015
In the absence of active blood donation screening, dengue viruses (DENV) have been implicated in ... more In the absence of active blood donation screening, dengue viruses (DENV) have been implicated in only a limited number of transfusion transmissions worldwide. This study attempted to identify if blood from donors testing negative by an NS1-antigen (Ag) enzyme-linked immunosorbent assay (ELISA) but confirmed positive for DENV RNA caused DENV-related disease in recipients during the epidemic years of 2010 to 2012 in Puerto Rico. Donation aliquots testing negative by an investigational NS1-Ag ELISA were stored frozen and retested retrospectively using a research transcription-mediated amplification assay (TMA) detecting DENV RNA. All RNA-reactive donations were subject to confirmatory RNA and antibody testing. Recipient tracing was conducted for all components manufactured from TMA-reactive components. Medical chart review, recipient interview, and follow-up sampling occurred for 42 recipients transfused with TMA-reactive components. Six of 42 recipients developed new-onset fever in the 2 weeks posttransfusion; three (50%) received RNA confirmed-positive, NS1-Ag-negative red blood cell (RBC) units. One recipient of a high-titer unit (7 × 10(7) DENV-4 RNA copies/mL) developed severe dengue, and a second recipient had only fever recorded but had a negative sepsis work-up. New fever attributable to DENV infection in a third recipient was confounded by fever potentially attributable to posttransfusion sepsis. In our retrospective study, NS1-Ag detected 20% of all RNA confirmed-positive donations demonstrating limitations of NS1-Ag ELISA for blood donation screening. We identified one recipient with a clinical syndrome compatible with severe dengue who had received an NS1-Ag-negative but RNA confirmed-positive RBC unit. This investigation illustrates the difficulty in confirming transfusion transmission in dengue-endemic areas among severely ill transfusion recipients.
Emerging Infectious Diseases, 2015
During the 2013 dengue epidemic in Luanda, Angola, 811 dengue rapid diagnostic test-positive case... more During the 2013 dengue epidemic in Luanda, Angola, 811 dengue rapid diagnostic test-positive cases were reported to the Ministry of Health. To better understand the magnitude of the epidemic and identify risk factors for dengue virus (DENV) infection, we conducted cluster surveys around households of case-patients and randomly selected households 6 weeks after the peak of the epidemic. Of 173 case cluster participants, 16 (9%) exhibited evidence of recent DENV infection. Of 247 random cluster participants, 25 (10%) had evidence of recent DENV infection. Of 13 recently infected participants who had a recent febrile illness, 7 (54%) had sought medical care, and 1 (14%) was hospitalized with symptoms consistent with severe dengue; however, none received a diagnosis of dengue. Behavior associated with protection from DENV infection included recent use of mosquito repellent or a bed net. These findings suggest that the 2013 dengue epidemic was larger than indicated by passive surveillance data.
Journal of NeuroVirology, 2014
The flaviviruses dengue, West Nile, and Japanese encephalitis represent three major mosquitoborne... more The flaviviruses dengue, West Nile, and Japanese encephalitis represent three major mosquitoborne viruses worldwide. These pathogens impact the lives of millions of individuals and potentially could affect non-endemic areas already colonized by mosquito vectors. Unintentional transport of infected vectors (Aedes and Culex spp.), traveling within endemic areas, rapid adaptation of the insects into new geographic locations, climate change, and lack of medical surveillance have greatly contributed to the increase in flaviviral infections worldwide. The mechanisms by which flaviviruses alter the immune and the central nervous system have only recently been examined despite the alarming number of infections, related deaths, and increasing global distribution. In this review, we will discuss the expansion of the geographic areas affected by flaviviruses, the potential threats to previously unaffected countries, the mechanisms of pathogenesis, and the potential therapeutic interventions to limit the devastating consequences of these viruses.