Last data update: Jan 27, 2025. (Total: 48650 publications since 2009)
Records 1-15 (of 15 Records) |
Query Trace: Nakazawa YJ[original query] |
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Orthopoxvirus circulation in an endemic area in Brazil: Investigation of infections in small mammals during an absence of outbreaks
Domingos IJS , Rocha KLS , Graciano JM , Almeida LR , Doty JB , Paglia AP , Oliveira DB , Nakazawa YJ , Trindade GS . Viruses 2023 15 (4) ![]() Vaccinia virus (VACV) is the causative agent of an emerging viral zoonosis called bovine vaccinia (BV). Several studies have documented characteristics of VACV infections in Brazil; however, the manner in which this virus is maintained in wildlife remains unknown. This work investigated the presence of viral DNA and anti-orthopoxvirus (OPXV) antibodies in samples collected from small mammals in a VACV-endemic area in Minas Gerais, Brazil, in the absence of current outbreaks. Samples did not show amplification of OPXV DNA in molecular tests. However, 5/142 serum samples demonstrated the presence of anti-OPXV neutralizing antibodies in serological tests. These data reinforce the involvement of small mammals in the natural cycle of VACV, highlighting the need for further ecological studies to better understand how this virus is maintained in nature and to develop measures to prevent BV outbreaks. |
Modeling the impact of sexual networks in the transmission of monkeypox virus among gay, bisexual, and other men who have sex with men - United States, 2022
Spicknall IH , Pollock ED , Clay PA , Oster AM , Charniga K , Masters N , Nakazawa YJ , Rainisch G , Gundlapalli AV , Gift TL . MMWR Morb Mortal Wkly Rep 2022 71 (35) 1131-1135 What is already known about this topic? The 2022 monkeypox outbreak is associated with sexual and intimate contact. Survey data suggest that gay, bisexual, and other men who have sex with men (MSM), who have been disproportionately affected, are reducing one-time partnerships. What is added by this report? Modeling of sexual infection transmission between men indicates that one-time partnerships, which account for 3% of daily sexual partnerships and 16% of daily sex acts, account for approximately 50% of daily Monkeypox virus (MPXV) transmission. A 40% reduction in one-time partnerships might delay the spread of monkeypox and reduce the percentage of persons infected by 20% to 31%. What are the implications for public health practice? Reductions in one-time partnerships, already being reported by MSM, might significantly reduce MPXV transmission. © 2022 Department of Health and Human Services. All rights reserved. |
Activity patterns and burrowing ecology of the giant pouched rat (Cricetomys emini) in Tshuapa Province, D. R. Congo
Kalemba LN , Morgan CN , Nakazawa YJ , Mauldin MR , Malekani JM , Doty JB . Mammalia 2022 86 (6) 562-569 Rodents of the genus Cricetomys have been reported to be nocturnal with a bimodal activity pattern and to frequently change burrows. However, no studies to date have examined these ecological aspects with the use of radio-telemetry. Five C. emini were captured and radio-collared to study their activity patterns and burrowing ecology from 9 March to 15 April 2016. Nocturnal activity ranged between the hours of 18:00 and 05:00 with a probable reduction of activities between 20:00-23:00 and around 04:00 with diurnal activity between 06:00 and 17:00 h with a reduction of activity between 11:00 and 14:00. While the present study does confirm nocturnal activity and a bimodal pattern, this study also suggests greater diurnal activity as compared to previous studies. Additionally, data presented here also suggest that C. emini may not change burrows as frequently as previously reported. 2022 Walter de Gruyter GmbH, Berlin/Boston 2022. |
Educational Approach to Prevent the Burden of Vaccinia Virus Infections in a Bovine Vaccinia Endemic Area in Brazil
Barbosa Costa G , Silva de Oliveira J , Townsend MB , Carson WC , Borges IA , McCollum AM , Kroon EG , Satheshkumar PS , Reynolds MG , Nakazawa YJ , de Souza Trindade G . Pathogens 2021 10 (5) Bovine vaccinia (BV), caused by Vaccinia virus (VACV), is a zoonotic disease characterized by exanthematous lesions on the teats of dairy cows and the hands of milkers, and is an important public health issue in Brazil and South America. BV also results in economic losses to the dairy industry, being a burden to the regions involved in milk production. In the past 20 years, much effort has been made to increase the knowledge regarding BV epidemiology, etiologic agents, and interactions with the hosts and the environment. In the present study, we evaluated milking practices that could be associated with VACV infections in an endemic area in Brazil and proposed an educational tool to help prevent VACV infections. In our survey, 124 individuals (51.7%) from a total of 240 had previously heard of BV, 94 of which knew about it through BV outbreaks. Although most individuals involved in dairy activities (n = 85/91) reported having good hygiene practices, only 29.7% used adequate disinfecting products to clean their hands and 39.5% disinfected cows' teats before and after milking. Furthermore, 46.7% of individuals reported having contact with other farm and domestic animals besides dairy cattle. We also evaluated the presence of IgG and IgM antibodies in the surveyed population. Overall, 6.1% of likely unvaccinated individuals were positive for anti-Orthopoxvirus IgG antibodies, and 1.7% of all individuals were positive for IgM antibodies. Based on our findings, we proposed educational materials which target individuals with permanent residence in rural areas (mainly farmers and milkers), providing an overview and basic information about preventive measures against VACV infections that could enhance BV control and prevention efforts, especially for vulnerable populations located in endemic areas. |
Laboratory infection of novel Akhmeta virus in CAST/EiJ mice
Morgan CN , Matheny AM , Nakazawa YJ , Kling C , Gallardo-Romero N , Seigler L , Barbosa Costa G , Hutson C , Maghlakelidze G , Olson V , Doty JB . Viruses 2020 12 (12) Akhmeta virus is a zoonotic Orthopoxvirus first identified in 2013 in the country of Georgia. Subsequent ecological investigations in Georgia have found evidence that this virus is widespread in its geographic distribution within the country and in its host-range, with rodents likely involved in its circulation in the wild. Yet, little is known about the pathogenicity of this virus in rodents. We conducted the first laboratory infection of Akhmeta virus in CAST/EiJ Mus musculus to further characterize this novel virus. We found a dose-dependent effect on mortality and weight loss (p < 0.05). Anti-orthopoxvirus antibodies were detected in the second- and third-highest dose groups (5 × 10(4) pfu and 3 × 10(2) pfu) at euthanasia by day 10, and day 14 post-infection, respectively. Anti-orthopoxvirus antibodies were not detected in the highest dose group (3 × 10(6) pfu), which were euthanized at day 7 post-infection and had high viral load in tissues, suggesting they succumbed to disease prior to mounting an effective immune response. In order of highest burden, viable virus was detected in the nostril, lung, tail, liver and spleen. All individuals tested in the highest dose groups were DNAemic. Akhmeta virus was highly pathogenic in CAST/EiJ Mus musculus, causing 100% mortality when ≥3 × 10(2) pfu was administered. |
Exportation of Monkeypox virus from the African continent.
Mauldin MR , McCollum AM , Nakazawa YJ , Mandra A , Whitehouse ER , Davidson W , Zhao H , Gao J , Li Y , Doty J , Yinka-Ogunleye A , Akinpelu A , Aruna O , Naidoo D , Lewandowski K , Afrough B , Graham V , Aarons E , Hewson R , Vipond R , Dunning J , Chand M , Brown C , Cohen-Gihon I , Erez N , Shifman O , Israeli O , Sharon M , Schwartz E , Beth-Din A , Zvi A , Mak TM , Ng YK , Cui L , Lin RTP , Olson VA , Brooks T , Paran N , Ihekweazu C , Reynolds MG . J Infect Dis 2020 225 (8) 1367-1376 ![]() ![]() BACKGROUND: The largest West African monkeypox outbreak began September 2017, in Nigeria. Four individuals traveling from Nigeria to the UK (2), Israel, and Singapore became the first human monkeypox cases exported from Africa, and a related nosocomial transmission event in the UK became the first confirmed human-to-human monkeypox transmission event outside of Africa. METHODS: Epidemiological and molecular data for exported and Nigerian cases were analyzed jointly to better understand the exportations in the temporal and geographic context of the outbreak. RESULTS: Isolates from all travelers and a Bayelsa case shared a most recent common ancestor and traveled to Bayelsa, Delta, or Rivers states. Genetic variation for this cluster was lower than would be expected from a random sampling of genomes from this outbreak, but data did not support direct links between travelers. CONCLUSIONS: Monophyly of exportation cases and the Bayelsa sample, along with the intermediate levels of genetic variation suggest a small pool of related isolates is the likely source for the exported infections. This may be the result of the level of genetic variation present in monkeypox isolates circulating within the contiguous region of Bayelsa, Delta, and Rivers states, or another more restricted, yet unidentified source pool. |
IMVAMUNE and ACAM2000 provide different protection against disease when administered postexposure in an intranasal monkeypox challenge prairie dog model
Keckler MS , Salzer JS , Patel N , Townsend MB , Nakazawa YJ , Doty JB , Gallardo-Romero NF , Satheshkumar PS , Carroll DS , Karem KL , Damon IK . Vaccines (Basel) 2020 8 (3) The protection provided by smallpox vaccines when used after exposure to Orthopoxviruses is poorly understood. Postexposu re administration of 1st generation smallpox vaccines was effective during eradication. However, historical epidemiological reports and animal studies on postexposure vaccination are difficult to extrapolate to today's populations, and 2nd and 3rd generation vaccines, developed after eradication, have not been widely tested in postexposure vaccination scenarios. In addition to concerns about preparedness for a potential malevolent reintroduction of variola virus, humans are becoming increasingly exposed to naturally occurring zoonotic orthopoxviruses and, following these exposures, disease severity is worse in individuals who never received smallpox vaccination. This study investigated whether postexposure vaccination of prairie dogs with 2nd and 3rd generation smallpox vaccines was protective against monkeypox disease in four exposure scenarios. We infected animals with monkeypox virus at doses of 10(4) pfu (2× LD(50)) or 10(6) pfu (170× LD(50)) and vaccinated the animals with IMVAMUNE(®) or ACAM2000(®) either 1 or 3 days after challenge. Our results indicated that postexposure vaccination protected the animals to some degree from the 2× LD(50), but not the 170× LD(5) challenge. In the 2× LD(50) challenge, we also observed that administration of vaccine at 1 day was more effective than administration at 3 days postexposure for IMVAMUNE(®), but ACAM2000(®) was similarly effective at either postexposure vaccination time-point. The effects of postexposure vaccination and correlations with survival of total and neutralizing antibody responses, protein targets, take formation, weight loss, rash burden, and viral DNA are also presented. |
Risk modeling of bat rabies in the Caribbean Islands
Morgan CN , Wallace RM , Vokaty A , Seetahal JFR , Nakazawa YJ . Trop Med Infect Dis 2020 5 (1) Rabies surveillance and control measures vary significantly between Caribbean islands. The Centers for Disease Control and Prevention currently recommends certain groups of U.S. travelers to any Caribbean island receive pre-exposure rabies immunization. However, most islands self-declare as "rabies free", and have never publicly released data to support rabies-free claims. We used the Analytic Hierarchy Process to create pairwise comparison values among five risk factors determined by subject matter experts. Risk factor weights were calculated and used in a geospatial analysis to calculate a risk value for each island nation (higher values indicate higher risk). Risk values ranged from 8.73 (Trinidad) to 1.57 (The Bahamas, Turks and Caicos Islands). All four countries that have documented occurrences of laboratory confirmed rabid bats were ranked highest (Trinidad and Tobago, Grenada, Cuba, Dominican Republic), as well as Haiti. The top five highest risk countries that currently have no reports of bat rabies include St. Vincent and the Grenadines, Jamaica, Puerto Rico, the Cayman Islands, and Dominica. This study reviews the inter-island movement potential of bats, designates areas of high risk for bat-associated rabies within the Caribbean islands, and demonstrates a need for further surveillance efforts in bat populations within islands that self-declare as rabies free. |
Field identification key and guide for bats of the United States of America
Morgan CN , Ammerman LK , Demere KD , Doty JB , Nakazawa YJ , Mauldin MR . Occas Pap Tex Tech Univ Mus 2019 360 Bats are the second most speciose lineage of mammals with more than 1,300 recognized species. Overall, bats are extremely ecologically and morphologically diverse, making them of interest to a wide variety of biologists. Bats are also known reservoirs for an assortment of zoonotic diseases, including rabies, for which they are commonly tested if identified as sick, behaving abnormally, or in instances where there has been a significant human exposure. In these cases, proper identification of bat species is important to public health experts as it will inform future testing procedures and management practices, as well as broaden our understanding of rabies virus bat variant distributions and disease ecology. Despite the multiple disciplines interested in bats, no key has been developed which includes all species found within the United States. For this reason, a dichotomous key and bat identification guide, designed to differentiate bats to species level, has been developed. This document can be used by people with a variety of backgrounds to morphologically identify bats quickly and accurately using only a scale, a ruler, and attention to detail. |
Understanding orthopoxvirus host range and evolution: from the enigmatic to the usual suspects.
Reynolds MG , Guagliardo SAJ , Nakazawa YJ , Doty JB , Mauldin MR . Curr Opin Virol 2017 28 108-115 ![]() ![]() In general, orthopoxviruses can be considered as falling into one of three host-utilization categories: highly specialized, single-host; broad host range; or 'cryptic', the last encompassing those viruses about which very little is known. Single-host viruses tend to exploit abundant hosts that have consistent patterns of interaction. For these viruses, observed genome reduction and loss of presumptive host-range genes is thought to be a consequence of relaxed selection. In contrast, the large genome size retained among broad host range orthopoxviruses suggests these viruses may depend on multiple host species for persistence in nature. Our understanding of the ecologic requirements of orthopoxviruses is strongly influenced by geographic biases in data collection. This hinders our ability to predict potential sources for emergence of orthopoxvirus-associated infections. |
Ecological niche model for predicting distribution of disease-vector mosquitoes in Yucatan State, Mexico
Baak-Baak CM , Moo-Llanes DA , Cigarroa-Toledo N , Puerto FI , Machain-Williams C , Reyes-Solis G , Nakazawa YJ , Ulloa-Garcia A , Garcia-Rejon JE . J Med Entomol 2017 54 (4) 854-861 The majority of the Yucatan State, Mexico, presents subtropical climate that is suitable for many species of mosquitoes that are known to be vectors of diseases, including those from the genera Aedes and Culex. The objective of this study is to identify the geographic distribution of five species from these two genera and estimate the human population at risk of coming in contact with them. We compiled distributional data for Aedes aegypti (L.), Aedes (Howardina) cozumelensis (Diaz Najera), Culex coronator Dyar and Knab, Culex quinquefasciatus Say, and Culex thriambus Dyar from several entomological studies in Yucatan between March 2010 and September 2014. Based on these data, we constructed ecological niche models to predict the spatial distribution of each species using the MaxEnt algorithm. Our models identified areas with suitable environments for Ae. aegypti in most of Yucatan. A similar percentage of urban (97.1%) and rural (96.5%) populations were contained in areas of highest suitability for Ae. aegypti, and no spatial pattern was found (Moran's I = 0.33, P = 0.38); however, we found an association of abundance of immature forms of this species with annual mean temperature (r = 0.19, P ≤ 0.001) and annual precipitation (r = 0.21, P ≤ 0.001). Aedes cozumelensis is also distributed in most areas of the Yucatan State; Cx. quinquefasciatus, Cx. coronator, and Cx. thriambus are restricted to the northwest. The information generated in this study can inform decision-making to address control measures in priority areas with presence of these vectors. |
Endemic orthopoxvirus circulating in procyonids in Mexico
Gallardo-Romero NF , Arechiga-Ceballos N , Emerson GL , Martinez-Martinez FO , Doty JB , Nakazawa YJ , Rendon-Franco E , Munoz-Garcia CI , Villanueva-Garcia C , Ramirez-Cid C , Gama-Campillo LM , Gual-Sill F , Aguilar-Setien A , Carroll DS . J Wildl Dis 2016 52 (3) 609-15 Limited serosurveillance studies suggested that orthopoxviruses (OPXV) are widespread in the US (e.g., Raccoonpox virus, Skunkpox virus, Volepox virus) and Brazil (Vaccinia virus); however, their animal reservoir(s) remain unconfirmed. Mexican mammal diversity includes several species related to those in which evidence for OPXV infections has been found (Oryzomys, Peromyscus, Microtus, and Procyonidae). The presence of these groups of mammals in Mexico and the evidence of their possible involvement in the maintenance of OXPV in nature suggest the same or similar OPXV are circulating in Mexico. We tested 201 sera from 129 procyonids via modified enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) to estimate OPXV antibody prevalence in these animals. We detected a prevalence of 16.67% in Nasua narica (white-nosed coati), 35% in Procyon lotor (raccoon), and 30.4% in Bassariscus astutus (ring-tailed cat) when tested by either ELISA or WB. Western blot results presented protein bands consistent with the size of some OXPV immunodominant bands (14, 18, 32, 36, and 62 kDa). These results support the hypothesis that OPXV circulate in at least three genera of Procyonidae in Central and Southeast Mexico. |
Laboratory investigations of African pouched rats (Cricetomys gambianus) as a potential reservoir host species for Monkeypox virus
Hutson CL , Nakazawa YJ , Self J , Olson VA , Regnery RL , Braden Z , Weiss S , Malekani J , Jackson E , Tate M , Karem KL , Rocke TE , Osorio JE , Damon IK , Carroll DS . PLoS Negl Trop Dis 2015 9 (10) e0004013 Monkeypox is a zoonotic disease endemic to central and western Africa, where it is a major public health concern. Although Monkeypox virus (MPXV) and monkeypox disease in humans have been well characterized, little is known about its natural history, or its maintenance in animal populations of sylvatic reservoir(s). In 2003, several species of rodents imported from Ghana were involved in a monkeypox outbreak in the United States with individuals of three African rodent genera (Cricetomys, Graphiurus, Funisciurus) shown to be infected with MPXV. Here, we examine the course of MPXV infection in Cricetomys gambianus (pouched Gambian rats) and this rodent species' competence as a host for the virus. We obtained ten Gambian rats from an introduced colony in Grassy Key, Florida and infected eight of these via scarification with a challenge dose of 4X104 plaque forming units (pfu) from either of the two primary clades of MPXV: Congo Basin (C-MPXV: n = 4) or West African (W-MPXV: n = 4); an additional 2 animals served as PBS controls. Viral shedding and the effect of infection on activity and physiological aspects of the animals were measured. MPXV challenged animals had significantly higher core body temperatures, reduced activity and increased weight loss than PBS controls. Viable virus was found in samples taken from animals in both experimental groups (C-MPXV and W-MPXV) between 3 and 27 days post infection (p.i.) (up to 1X108 pfu/ml), with viral DNA found until day 56 p.i. The results from this work show that Cricetomys gambianus (and by inference, probably the closely related species, Cricetomys emini) can be infected with MPXV and shed viable virus particles; thus suggesting that these animals may be involved in the maintenance of MPXV in wildlife mammalian populations. More research is needed to elucidate the epidemiology of MPXV and the role of Gambian rats and other species. |
Estimating the geographic distribution of human Tanapox and potential reservoirs using ecological niche modeling
Monroe BP , Nakazawa YJ , Reynolds MG , Carroll DS . Int J Health Geogr 2014 13 (1) 34 BACKGROUND: Tanapox virus is a zoonotic infection that causes mild febrile illness and one to several nodular skin lesions. The disease is endemic in parts of Africa. The principal reservoir for the virus that causes Tanapox is unknown, but has been hypothesized to be a non-human primate. This study employs ecological niche modeling (ENM) to determine areas of tropical Africa suitable for the occurrence of human Tanapox and a list of hypothetical reservoirs. The resultant niche model will be a useful tool to guide medical surveillance activities in the region. METHODS: This study uses the Desktop GARP software to predict regions where human Tanapox might be expected to occur based on historical human case locations and environmental data. Additional modeling of primate species, using occurrence data from museum records was performed to determine suitable disease reservoirs. RESULTS: The final ENM predicts a potential distribution of Tanapox over much of equatorial Africa, exceeding the borders of Kenya and Democratic Republic of Congo (DRC) where it has been historically reported. Five genera of non-human primates were found to be potential reservoir taxa. CONCLUSIONS: Validity testing suggests the model created here is robust (p < 0.04). Several genera of primates were identified as having ENMs overlapping with that of Tanapox and are suggested as potential reservoirs, mainly members of the Genus Cercopithecus. The ENM modeling technique has several limitations and results should be interpreted with caution. This study may increase knowledge and engage further research in this neglected disease. |
The pox in the North American backyard: Volepox virus pathogenesis in California mice (Peromyscus californicus)
Gallardo-Romero NF , Drew CP , Weiss SL , Metcalfe MG , Nakazawa YJ , Smith SK , Emerson GL , Hutson CL , Salzer JS , Bartlett JH , Olson VA , Clemmons CJ , Davidson WB , Zaki SR , Karem KL , Damon IK , Carroll DS . PLoS One 2012 7 (8) e43881 ![]() Volepox virus (VPXV) was first isolated in 1985 from a hind foot scab of an otherwise healthy California vole (Microtus californicus). Subsequent surveys in San Mateo County, CA, revealed serological evidence suggesting that VPXV is endemic to this area, and a second viral isolate from a Pinyon mouse (Peromyscus truei) was collected in 1988. Since then, few studies have been conducted regarding the ecology, pathology, and pathogenicity of VPXV, and its prevalence and role as a potential zoonotic agent remain unknown. To increase our understanding of VPXV disease progression, we challenged 24 California mice (Peromyscus californicus) intranasally with 1.6x10(3) PFU of purified VPXV. By day five post infection (pi) we observed decreased activity level, conjunctivitis, ruffled hair, skin lesions, facial edema, and crusty noses. A mortality rate of 54% was noted by day eight pi. In addition, internal organ necrosis and hemorrhages were observed during necropsy of deceased or euthanized animals. Viral loads in tissues (brain, gonad, kidney, liver, lung, spleen, submandibular lymph node, and adrenal gland), bodily secretions (saliva, and tears), and excretions (urine, and/or feces) were evaluated and compared using real time-PCR and tissue culture. Viral loads measured as high as 2x10(9) PFU/mL in some organs. Our results suggest that VPXV can cause extreme morbidity and mortality within rodent populations sympatric with the known VPXV reservoirs. |
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