Last data update: Dec 09, 2024. (Total: 48320 publications since 2009)
Records 1-30 (of 48 Records) |
Query Trace: Herrera R[original query] |
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A collaboration to harmonize COVID-19 health messaging and fill communication gaps during initial U.S. refugee resettlement
Keaveney M , Le C , Steger K , Sood NJ , Bligh L , Kim C , Dicker S , Klosovsky A , Herrera H , Jentes E . Health Lit Commun Open 2024 2 (1) 2311402 To communicate with U.S.-bound refugees during travel to the United States during the onset of the COVID-19 pandemic, five federal and international organizations collaborated in a strategic work group to synergize COVID-19 prevention health messaging and COVID-19 considerations before, during, and after travel, as well as promote shared resources. This work group sought to establish consistent COVID-19 messaging, disseminate messages to partners, and identify message gaps as the pandemic evolved. In early Fall 2020, CDC released new communication materials, including a fact sheet, a welcome booklet, and infographics translated into 19 languages, to address refugee health partners' need for culturally and linguistically concordant educational materials for refugees. Rapidly changing health communications needs during the pandemic fostered opportunities for collaboration among federal and refugee health partners and highlighted a long-standing need among agencies to address health messaging across the continuum of care for refugees. |
Prior sexually transmitted infections and HIV in Mpox patients, Chicago, Illinois-(June 2022-March 2023
Faherty EAG , Holly T , Herrera K , Guidry T , Lyang J , Black S , Tabidze I . J Infect Dis 2024 229 S197-s202 HIV is associated with severe mpox. Sexually transmitted infections (STIs) could facilitate mpox transmission. We estimated HIV and STI frequency among patients with mpox and compared characteristics associated with mpox severity. Mpox cases during 1 June 2022 to 31 March 2023 were matched to Illinois HIV/AIDS surveillance data. Among 1124 patients with mpox, 489 (44%) had HIV and 786 (70%) had prior or concurrent STI; 307 (39%) had ≥3 STI episodes. More patients with mpox who were living with HIV were hospitalized than those without HIV (10.3% vs 4.1%, P < .001). STI screening visits are opportunities to vaccinate against mpox and provide HIV prophylaxis or treatment. |
Novel species of Triatoma (Hemiptera: Reduviidae) identified in a case of vectorial transmission of Chagas disease in northern Belize
Gunter SM , Nelson A , Kneubehl AR , Justi SA , Manzanero R , Zielinski-Gutierrez E , Herrera C , Thompson J , Mandage R , Desale H , Maliga A , Bautista K , Ronca SE , Morey F , Fuentes RC , Lopez B , Dumonteil E , Morazan GH , Murray KO . Sci Rep 2024 14 (1) 1412 Chagas disease is a leading cause of non-ischemic cardiomyopathy in endemic regions of Central and South America. In Belize, Triatoma dimidiata sensu lato has been identified as the predominate taxon but vectorial transmission of Chagas disease is considered to be rare in the country. We recently identified an acute case of vector-borne Chagas disease in the northern region of Belize. Here we present a subsequent investigation of triatomines collected around the case-patient's home. We identified yet undescribed species, closely related to Triatoma huehuetenanguensis vector by molecular systematics methods occurring in the peridomestic environment. The identification of a T. cruzi-positive, novel species of Triatoma in Belize indicates an increased risk of transmission to humans in the region and warrants expanded surveillance and further investigation. |
Advanced HIV disease in Homa Bay County, Kenya: Characteristics of newly-diagnosed and antiretroviral therapy-experienced clients
Masaba RO , Herrera N , Siamba S , Ouma M , Okal C , Mayi A , Kose J , Ndimbii J , Ochanda B , Mwangi E , Okomo G , Woelk G . Medicine (Baltimore) 2023 102 (51) e36716 Advanced HIV disease (AHD) remains a significant burden, despite the widespread use of antiretroviral therapy (ART) programs. Individuals with AHD are at a high risk of death even after starting ART. We characterized treatment naïve and treatment experienced clients presenting with AHD in western Kenya to inform service delivery and program improvement. We conducted a retrospective study using routinely collected program data from October 2016 to September 2019 for AHD clients in eight facilities in Homa Bay County, Kenya. Demographic and clinical data were abstracted from the medical records of AHD clients, defined as HIV-positive clients aged ≥ 5 years with documented CD4 count < 200 cells/mm3 and/or WHO clinical stage II/IV. Associations were assessed using Pearson's chi-square and Mann-Whitney Rank-Sum tests at 5% level of significance. Of the 19,427 HIV clients at the eight facilities, 6649 (34%) had a CD4 count < 200 cells/mm3 or a WHO III/IV stage. Of these, 1845 were randomly selected for analysis. Over half (991) of participants were aged 45 + years and 1040 (56%) were female. The median age was 46.0 years (interquartile range: 39.2-54.5); 1553 (84%) were in care at county and sub-county hospitals; and 1460 (79%) were WHO stage III/IV at enrollment. At ART initiation, 241 (13%) had tuberculosis, 192 (10%) had chronic diarrhea, and 94 (5%) had Pneumocystis jiroveci pneumonia. At the time of data collection, 89 (5%) participants had died and 140 (8%) were lost to follow-up. Eighteen percent (330) of participants were ART-experienced (on ART for ≥ 3 months). The proportions of ART-experienced and -naïve clients regarding age, sex and marital status were similar. However, a higher proportion of ART-experienced clients received care at primary care facilities, (93(28%) vs. 199 (13%); P < .001); were WHO stage 3/4 at AHD diagnosis, 273 (84%) vs. 1187 (79%) (P = .041); and had died or been LTFU, (124 (38%) vs. 105 (7%); P < .001). With increasing prevalence of patients on ART, the proportion of AHD treatment-experienced clients may increase without effective interventions to ensure that these patients remain in care. |
Extragenital gonorrhoea, chlamydia, and HIV co-infection in people with mpox
Herrera K , Lyang J , Holly T , Faherty EA , Luc C , Korban C , Kern D , Tabidze I . Lancet Infect Dis 2023 23 (9) e334-e336 High prevalence of sexually transmitted infections, including gonorrhoea (28%), chlamydia (25%), syphilis (8%), and HIV (38%) co-infections have been reported in the 2022 mpox outbreak,1 which has disproportionately affected men who have sex with men and minoritised racial and ethnic groups.2 Although the outbreak has receded, a modelling analysis predicts that most jurisdictions in the USA could be at risk of resurgence without continued vaccination efforts.3 In previous mpox outbreaks, co-infection with HIV has been associated with poor mpox health outcomes.1, 4 Furthermore, among people with mpox in eight jurisdictions in the USA in 2022, those with HIV co-infection were more likely to report severe symptoms compared with those without HIV co-infection.1 Unprotected anal intercourse confers a significant risk for HIV acquisition as the rectal membrane is susceptible to infection due to its thin and friable nature.5 Previous gonorrhoea and chlamydia diagnoses are also established risk factors for HIV acquisition.6 These findings, along with clinical manifestations of mpox at rectal, genital, and oral sites warrant further investigation. This Correspondence aims to explore predictors, including gonorrhoea and chlamydia sites of infection in the previous 12 months of mpox diagnosis, and HIV co-infection among people with mpox in Chicago, USA. It is hypothesised that a previous or current rectal site of gonorrhoea or chlamydia infection will be associated with an increased prevalence of HIV and mpox co-infection. |
Defining operational research priorities to improve malaria control and elimination in sub-Saharan Africa: Results from a country-driven research prioritization setting process
Tine R , Herrera S , Badji MA , Daniels K , Ndiaye P , Smith Gueye C , Tairou F , Slutsker L , Hwang J , Ansah E , Littrell M . Malar J 2023 22 (1) 219 BACKGROUND: In order to reignite gains and accelerate progress toward improved malaria control and elimination, policy, strategy, and operational decisions should be derived from high-quality evidence. The U.S. President's Malaria Initiative (PMI) Insights project together with the Université Cheikh Anta Diop of Dakar, Senegal, conducted a broad stakeholder consultation process to identify pressing evidence gaps in malaria control and elimination across sub-Saharan Africa (SSA), and developed a priority list of country-driven malaria operational research (OR) and programme evaluation (PE) topics to address these gaps. METHODS: Five key stakeholder groups were engaged in the process: national malaria programmes (NMPs), research institutions in SSA, World Health Organization (WHO) representatives in SSA, international funding agencies, and global technical partners who support malaria programme implementation and research. Stakeholders were engaged through individual or small group interviews and an online survey, and asked about key operational challenges faced by NMPs, pressing evidence gaps in current strategy and implementation guidance, and priority OR and PE questions to address the challenges and gaps. RESULTS: Altogether, 47 interviews were conducted with 82 individuals, and through the online survey, input was provided by 46 global technical partners. A total of 33 emergent OR and PE topics were identified through the consultation process and were subsequently evaluated and prioritized by an external evaluation committee of experts from NMPs, research institutions, and the WHO. The resulting prioritized OR and PE topics predominantly focused on generating evidence needed to close gaps in intervention coverage, address persistent challenges faced by NMPs in the implementation of core strategic interventions, and inform the effective deployment of new tools. CONCLUSION: The prioritized research list is intended to serve as a key resource for informing OR and PE investments, thereby ensuring future investments focus on generating the evidence needed to strengthen national strategies and programme implementation and facilitating a more coordinated and impactful approach to malaria operational research. |
Retrospective molecular investigation of Mayaro and Oropouche viruses at the human-animal interface in West-central Brazil, 2016-2018.
Dias HG , de Lima RC , Barbosa LS , Souza TMA , Badolato-Correa J , Maia LMS , Ferreira RDS , Neves Nads , Costa MCS , Martins LR , Souza EM , Carvalho MDS , Araujo-Oliveira A , Marques WA , Sabino-Santos G , Marques MS , Macedo GC , Nantes WAG , Santos FM , Netto CC , Morgado TO , Bianchini MA , Correa SHR , Almeida JR , Campos LP , Souza IM , Barreto WTG , Porfírio G , Alencar JAF , Herrera HM , Shlessarenko RD , Cunha RVD , Azeredo EL , Salyer SJ , Komar N , Pauvolid-Corrêa A , Dos Santos FB . PLoS One 2022 17 (11) e0277612 Mayaro virus (MAYV, Togaviridae) and Oropouche orthobunyavirus (OROV, Peribunyaviridae) are emerging enzootic arboviruses in Latin America. Outbreaks of febrile illness associated with MAYV and OROV have been reported among humans mainly in the northern region of Brazil since the 1980s, and recent data suggest these viruses have circulated also in more populated areas of western Brazil. MAYV shares mosquito vectors with yellow fever virus and it has been historically detected during yellow fever epidemics. Aiming to investigate the transmission of OROV and MAYV at the human-animal interface during a yellow fever, chikungunya and Zika outbreaks in Brazil, we conducted a retrospective molecular investigation in 810 wild and domestic animals, 106 febrile patients, and 22.931 vectors collected from 2016 to 2018 in Cuiaba and Campo Grande metropolitan regions, western Brazil. All samples tested negative for OROV and MAYV RNA by RT-qPCR. Findings presented here suggest no active circulation of MAYV and OROV in the sampled hosts. Active surveillance and retrospective investigations are instrumental approaches for the detection of cryptic and subclinical activity of enzootic arboviruses and together serve as a warning system to implement appropriate actions to prevent outbreaks. |
Diagnosis of Acute Chagas Disease in a Belizean Child with Evidence of a Multiclonal Trypanosoma cruzi Infection.
Murray KO , Saldaa MA , Gunter SM , Manzanero R , Zielinski-Gutierrez E , Herrera C , Thompson JM , Maliga A , Bautista K , Lino A , Hawes E , Ronca SE , Morey F , Fuentes RC , Lopez B , Dumonteil E , Morazan GH . Am J Trop Med Hyg 2022 107 (5) 992-995 In January 2020, we instituted acute febrile illness surveillance in 11 hospitals and clinics across Belize. Within 3 months, we diagnosed an acute case of Chagas disease by polymerase chain reaction in a 7-year-old child in the northern part of the country. Phylogenetic analyses of the parasite from the acute blood specimen revealed a multiclonal Trypanosoma cruzi infection, including parasites from the TcII (25.0% of haplotypes), TcIV (2.5% of haplotypes), and TcV (72.5% of haplotypes) discrete typing units. The family reported no history of travel, and three Triatoma species vectors were found within the home. The child's mother was seronegative for antibodies to T. cruzi, ruling out congenital transmission. Convalescent blood samples documented seroconversion and confirmed acute infection. The child was successfully treated with nifurtimox. This is the first known diagnosed case of acute Chagas infection in Belize, highlighting the need for further investigation and public health prevention measures. |
Standardized enhanced adherence counseling for improved HIV viral suppression among children and adolescents in Homa Bay and Turkana Counties, Kenya
Masaba RO , Woelk G , Herrera N , Siamba S , Simiyu R , Ochanda B , Okomo G , Odionyi J , Audo M , Mwangi E . Medicine (Baltimore) 2022 101 (40) e30624 Viral suppression is suboptimal among children and adolescents on antiretroviral therapy (ART) in Kenya. We implemented and evaluated a standardized enhanced adherence counseling (SEAC) package to improve viral suppression in children and adolescents with suspected treatment failure in Homa Bay and Turkana. The SEAC package, implemented from February 2019 to September 2020, included: standard procedures operationalizing the enhanced adherence counseling (EAC) process; provider training on psychosocial support and communication skills for children living with HIV and their caregivers; mentorship to providers and peer educators on EAC processes; and individualized case management. We enrolled children and adolescents aged 0 to 19 years with suspected treatment failure (viral load [VL] >1000 copies/mL) who received EAC before standardization as well as those who received SEAC in a pre-post evaluation of the SEAC package conducted in 6 high-volume facilities. Pre-post standardization comparisons were performed using Wilcoxon-Mann-Whitney and Pearson's chi-square tests at a 5% level of significance. Multivariate logistic regression was performed to identify factors associated with viral resuppression. The study enrolled 741 participants, 595 pre- and 146 post-SEAC implementation. All post-SEAC participants attended at least 1 EAC session, while 17% (n = 98) of pre-SEAC clients had no record of EAC attendance. Time to EAC following the detection of high VL was reduced by a median of 8 days, from 49 (interquartile range [IQR]: 23.0-102.5) to 41 (IQR: 20.0-67.0) days pre- versus post-SEAC (P = .006). Time to completion of at least 3 sessions was reduced by a median of 12 days, from 59.0 (IQR: 36.0-91.0) to 47.5 (IQR: 33.0-63.0) days pre- versus post-SEAC (P = .002). A greater percentage of clients completed the recommended minimum 3 EAC sessions at post-SEAC, 88.4% (n = 129) versus 61.1% (n = 363) pre-SEAC, P < .001. Among participants with a repeat VL within 3 months following the high VL, SEAC increased viral suppression from 34.6% (n = 76) to 52.5% (n = 45), P = .004. Implementation of the SEAC package significantly reduced the time to initiate EAC and time to completion of at least 3 EAC sessions, and was significantly associated with viral suppression in children and adolescents with suspected treatment failure. |
Principles and procedures for assessment of acute toxicity incorporating in silico methods
Zwickl CM , Graham JC , Jolly RA , Bassan A , Ahlberg E , Amberg A , Anger LT , Beilke L , Bellion P , Brigo A , Burleigh-Flayer H , Cronin MTD , Devlin AA , Fish T , Glowienke S , Gromek K , Karmaus AL , Kemper R , Kulkarni S , Lo Piparo E , Madia F , Martin M , Masuda-Herrera M , McAtee BL , Mestres J , Milchak L , Moudgal C , Mumtaz M , Muster W , Neilson L , Patlewicz G , Paulino A , Roncaglioni A , Ruiz P , Szabo DT , Valentin JP , Vardakou I , Woolley D , Myatt GJ . Comput Toxicol 2022 24 Acute toxicity in silico models are being used to support an increasing number of application areas including (1) product research and development, (2) product approval and registration as well as (3) the transport, storage and handling of chemicals. The adoption of such models is being hindered, in part, because of a lack of guidance describing how to perform and document an in silico analysis. To address this issue, a framework for an acute toxicity hazard assessment is proposed. This framework combines results from different sources including in silico methods and in vitro or in vivo experiments. In silico methods that can assist the prediction of in vivo outcomes (i.e., LD50) are analyzed concluding that predictions obtained using in silico approaches are now well-suited for reliably supporting assessment of LD50-based acute toxicity for the purpose of the Globally Harmonized System (GHS) classification. A general overview is provided of the endpoints from in vitro studies commonly evaluated for predicting acute toxicity (e.g., cytotoxicity/cytolethality as well as assays targeting specific mechanisms). The increased understanding of pathways and key triggering mechanisms underlying toxicity and the increased availability of in vitro data allow for a shift away from assessments solely based on endpoints such as LD50, to mechanism-based endpoints that can be accurately assessed in vitro or by using in silico prediction models. This paper also highlights the importance of an expert review of all available information using weight-of-evidence considerations and illustrates, using a series of diverse practical use cases, how in silico approaches support the assessment of acute toxicity. © 2022 Elsevier B.V. |
Rapid population-based surveillance of prenatal and postpartum experiences during public health emergencies, Puerto Rico, 20162018
Salvesen von Essen B , D'Angelo DV , Shulman HB , Virella WH , Kortsmit K , Herrera BR , Díaz PG , Taraporewalla A , Harrison L , Warner L , Vargas Bernal M . Am J Public Health 2022 112 (4) 574-578 The Pregnancy Risk Assessment Monitoring System-Zika Postpartum Emergency Response study, implemented in Puerto Rico during the Zika virus outbreak (2016-2017) and after Hurricanes Irma and María (2017-2018), collected pregnancy-related data using postpartum hospital-based surveys and telephone follow-up surveys. Response rates of 75% or more were observed across five study surveys. The study informed programs, increased the Puerto Rico Department of Health's capacity to conduct maternal‒infant health surveillance, and demonstrated the effectiveness of this methodology for collecting data during public health emergencies. (Am J Public Health. 2022;112(4):574-578. https://doi.org/10.2105/AJPH.2021.306687). |
SARS-CoV-2 B.1.1.529 (Omicron) Variant Transmission Within Households - Four U.S. Jurisdictions, November 2021-February 2022.
Baker JM , Nakayama JY , O'Hegarty M , McGowan A , Teran RA , Bart SM , Mosack K , Roberts N , Campos B , Paegle A , McGee J , Herrera R , English K , Barrios C , Davis A , Roloff C , Sosa LE , Brockmeyer J , Page L , Bauer A , Weiner JJ , Khubbar M , Bhattacharyya S , Kirking HL , Tate JE . MMWR Morb Mortal Wkly Rep 2022 71 (9) 341-346 The B.1.1.529 (Omicron) variant, first detected in November 2021, was responsible for a surge in U.S. infections with SARS-CoV-2, the virus that causes COVID-19, during December 2021-January 2022 (1). To investigate the effectiveness of prevention strategies in household settings, CDC partnered with four U.S. jurisdictions to describe Omicron household transmission during November 2021-February 2022. Persons with sequence-confirmed Omicron infection and their household contacts were interviewed. Omicron transmission occurred in 124 (67.8%) of 183 households. Among 431 household contacts, 227 were classified as having a case of COVID-19 (attack rate [AR] = 52.7%).(†) The ARs among household contacts of index patients who had received a COVID-19 booster dose, of fully vaccinated index patients who completed their COVID-19 primary series within the previous 5 months, and of unvaccinated index patients were 42.7% (47 of 110), 43.6% (17 of 39), and 63.9% (69 of 108), respectively. The AR was lower among household contacts of index patients who isolated (41.2%, 99 of 240) compared with those of index patients who did not isolate (67.5%, 112 of 166) (p-value <0.01). Similarly, the AR was lower among household contacts of index patients who ever wore a mask at home during their potentially infectious period (39.5%, 88 of 223) compared with those of index patients who never wore a mask at home (68.9%, 124 of 180) (p-value <0.01). Multicomponent COVID-19 prevention strategies, including up-to-date vaccination, isolation of infected persons, and mask use at home, are critical to reducing Omicron transmission in household settings. |
Risk factors and clinical profile of sapovirus-associated acute gastroenteritis in early childhood: A Nicaraguan birth cohort study
Vielot NA , González F , Reyes Y , Zepeda O , Blette B , Paniagua M , Toval-Ruíz C , Diez-Valcarce M , Hudgens MG , Gutiérrez L , Blandón P , Herrera R , Cuadra EC , Bowman N , Vilchez S , Vinjé J , Becker-Dreps S , Bucardo F . Pediatr Infect Dis J 2021 40 (3) 220-226 BACKGROUND: Sapovirus is increasingly recognized as an important cause of acute gastroenteritis (AGE) in children. We identified risk factors and characterized the clinical profile of sapovirus AGE in a birth cohort in León, Nicaragua. METHODS: We conducted a case-control study nested within a birth cohort (n = 444). Fieldworkers conducted weekly household AGE surveillance. AGE stools were tested for sapovirus by reverse transcriptase quantitative polymerase chain reaction. For each first sapovirus episode, we selected 2 healthy age-matched controls and estimated independent risk factors of sapovirus AGE using conditional logistic regression. We compared clinical characteristics of sapovirus AGE episodes with episodes associated with other etiologies and identified co-infections with other enteric pathogens. RESULTS: From June 2017 to July 2019, we identified 63 first sapovirus AGE episodes and selected 126 controls. Having contact with an individual with AGE symptoms and vaginal delivery were independent risk factors for sapovirus AGE. All cases experienced diarrhea, lasting a median 6 days; 23% experienced vomiting. Compared to children with AGE due to another etiology, sapovirus AGE was similar in severity, with less reported fever. Most cases experienced co-infections and were more likely than controls to be infected with diarrheagenic Escherichia coli or astrovirus. CONCLUSIONS: Sapovirus was a commonly identified AGE etiology in this Central American setting, and symptoms were similar to AGE associated with other etiologies. The association between vaginal delivery and sapovirus is a novel finding. Gut microbiome composition might mediate this relationship, or vaginal delivery might be a proxy for other risk factors. Further investigation into more specific biological mechanisms is warranted. |
Preventing vector-borne transmission of Zika virus infection during pregnancy, Puerto Rico, USA, 2016-2017(1)
Kortsmit K , Salvesen von Essen B , Warner L , D'Angelo DV , Smith RA , Shapiro-Mendoza CK , Shulman HB , Virella WH , Taraporewalla A , Harrison L , Ellington S , Barfield WD , Jamieson DJ , Cox S , Pazol K , Garcia Díaz P , Herrera BR , Bernal MV . Emerg Infect Dis 2020 26 (11) 2717-2720 We examined pregnant women's use of personal protective measures to prevent mosquito bites during the 2016-2017 Zika outbreak in Puerto Rico. Healthcare provider counseling on recommended measures was associated with increased use of insect repellent among pregnant women but not with wearing protective clothing. |
Cytokine signatures of Plasmodium vivax infection during pregnancy and delivery outcomes.
Dobano C , Bardaji A , Arevalo-Herrera M , Martinez-Espinosa FE , Botto-Menezes C , Padilla N , Menegon M , Kochar S , Kochar SK , Unger H , Ome-Kaius M , Rosanas-Urgell A , Malheiros A , Castellanos ME , Hans D , Desai M , Casellas A , Chitnis CE , Severini C , Mueller I , Rogerson S , Menendez C , Requena P . PLoS Negl Trop Dis 2020 14 (5) e0008155 Plasmodium vivax malaria is a neglected disease, particularly during pregnancy. Severe vivax malaria is associated with inflammatory responses but in pregnancy immune alterations make it uncertain as to what cytokine signatures predominate, and how the type and quantity of blood immune mediators influence delivery outcomes. We measured the plasma concentrations of a set of thirty-one biomarkers, comprising cytokines, chemokines and growth factors, in 987 plasma samples from a cohort of 572 pregnant women from five malaria-endemic tropical countries and related these concentrations to delivery outcomes (birth weight and hemoglobin levels) and malaria infection. Samples were collected at recruitment (first antenatal visit) and at delivery (periphery, cord and placenta). At recruitment, we found that P. vivax-infected pregnant women had higher plasma concentrations of proinflammatory (IL-6, IL-1beta, CCL4, CCL2, CXCL10) and TH1-related cytokines (mainly IL-12) than uninfected women. This biomarker signature was essentially lost at delivery and was not associated with birth weight nor hemoglobin levels. Antiinflammatory cytokines (IL-10) were positively associated with infection and poor delivery outcomes. CCL11 was the only biomarker to show a negative association with P. vivax infection and its concentration at recruitment was positively associated with hemoglobin levels at delivery. Birth weight was negatively associated with peripheral IL-4 levels at delivery. Our multi-biomarker multicenter study is the first comprehensive one to characterize the immunological signature of P. vivax infection in pregnancy thus far. In conclusion, data show that while TH1 and pro-inflammatory responses are dominant during P. vivax infection in pregnancy, antiinflammatory cytokines may compensate excessive inflammation avoiding poor delivery outcomes, and skewness toward a TH2 response may trigger worse delivery outcomes. CCL11, a chemokine largely neglected in the field of malaria, emerges as an important marker of exposure or mediator in this condition. |
Zika Virus Surveillance at the Human-Animal Interface in West-Central Brazil, 2017-2018.
Pauvolid-Correa A , Goncalves Dias H , Marina Siqueira Maia L , Porfirio G , Oliveira Morgado T , Sabino-Santos G , Helena Santa Rita P , Teixeira Gomes Barreto W , Carvalho de Macedo G , Marinho Torres J , Arruda Gimenes Nantes W , Martins Santos F , Oliveira de Assis W , Castro Rucco A , Mamoru Dos Santos Yui R , Bosco Vilela Campos J , Rodrigues Leandro ESilva R , da Silva Ferreira R , Aparecido da Silva Neves N , Charlles de Souza Costa M , Ramos Martins L , Marques de Souza E , Dos Santos Carvalho M , Goncalves Lima M , de Cassia Goncalves Alves F , Humberto Guimaraes Riquelme-Junior L , Luiz Batista Figueiro L , Fernandes Gomes de Santana M , Gustavo Rodrigues Oliveira Santos L , Serra Medeiros S , Lopes Seino L , Hime Miranda E , Henrique Rezende Linhares J , de Oliveira Santos V , Almeida da Silva S , Araujo Lucio K , Silva Gomes V , de Araujo Oliveira A , Dos Santos Silva J , de Almeida Marques W , Schafer Marques M , Junior Franca de Barros J , Campos L , Couto-Lima D , Coutinho Netto C , Strussmann C , Panella N , Hannon E , Cristina de Macedo B , Ramos de Almeida J , Ramos Ribeiro K , Carolina Barros de Castro M , Pratta Campos L , Paula Rosa Dos Santos A , Marino de Souza I , de Assis Bianchini M , Helena Ramiro Correa S , Ordones Baptista Luz R , Dos Santos Vieira A , Maria de Oliveira Pinto L , Azeredo E , Tadeu Moraes Figueiredo L , Augusto Fonseca Alencar J , Maria Barbosa de Lima S , Miraglia Herrera H , Dezengrini Shlessarenko R , Barreto Dos Santos F , Maria Bispo de Filippis A , Salyer S , Montgomery J , Komar N . Viruses 2019 11 (12) Zika virus (ZIKV) was first discovered in 1947 in Uganda but was not considered a public health threat until 2007 when it found to be the source of epidemic activity in Asia. Epidemic activity spread to Brazil in 2014 and continued to spread throughout the tropical and subtropical regions of the Americas. Despite ZIKV being zoonotic in origin, information about transmission, or even exposure of non-human vertebrates and mosquitoes to ZIKV in the Americas, is lacking. Accordingly, from February 2017 to March 2018, we sought evidence of sylvatic ZIKV transmission by sampling whole blood from approximately 2000 domestic and wild vertebrates of over 100 species in West-Central Brazil within the active human ZIKV transmission area. In addition, we collected over 24,300 mosquitoes of at least 17 genera and 62 species. We screened whole blood samples and mosquito pools for ZIKV RNA using pan-flavivirus primers in a real-time reverse-transcription polymerase chain reaction (RT-PCR) in a SYBR Green platform. Positives were confirmed using ZIKV-specific envelope gene real-time RT-PCR and nucleotide sequencing. Of the 2068 vertebrates tested, none were ZIKV positive. Of the 23,315 non-engorged mosquitoes consolidated into 1503 pools tested, 22 (1.5%) with full data available showed some degree of homology to insect-specific flaviviruses. To identify previous exposure to ZIKV, 1498 plasma samples representing 62 species of domestic and sylvatic vertebrates were tested for ZIKV-neutralizing antibodies by plaque reduction neutralization test (PRNT90). From these, 23 (1.5%) of seven species were seropositive for ZIKV and negative for dengue virus serotype 2, yellow fever virus, and West Nile virus, suggesting potential monotypic reaction for ZIKV. Results presented here suggest no active transmission of ZIKV in non-human vertebrate populations or in alternative vector candidates, but suggest that vertebrates around human populations have indeed been exposed to ZIKV in West-Central Brazil. |
A second case of human conjunctival infestation with Thelazia gulosa and a review of T. gulosa in North America
Bradbury RS , Gustafson DT , Sapp SGH , Fox M , de Almeida M , Boyce M , Iwen P , Herrera V , Ndubuisi M , Bishop HS . Clin Infect Dis 2019 70 (3) 518-520 We describe a second case of human infection caused by Thelazia gulosa (the cattle eye worm), likely acquired in California. For epidemiologic purposes, it is important to identify all Thelazia recovered from humans in North America to the species level. |
Preventing sexual transmission of Zika virus infection during pregnancy, Puerto Rico, USA, 2016
Salvesen von Essen B , Kortsmit K , Warner L , D'Angelo DV , Shulman HB , Virella WH , Taraporewalla A , Harrison L , Ellington S , Shapiro-Mendoza C , Barfield W , Smith RA , Jamieson DJ , Cox S , Pazol K , Diaz PG , Herrera BR , Bernal MV . Emerg Infect Dis 2019 25 (11) 2115-2119 We examined condom use throughout pregnancy during the Zika outbreak in Puerto Rico during 2016. Overall, <25% of women reported consistent condom use during pregnancy. However, healthcare provider counseling was associated with a 3-fold increase in consistent use, reinforcing the value of provider counseling in Zika prevention efforts. |
Effect of glove decontamination on bacterial contamination of healthcare personnel hands
Kpadeh-Rogers Z , Robinson GL , Alserehi H , Morgan DJ , Harris AD , Herrera NB , Rose LJ , Noble-Wang J , Johnson JK , Leekha S . Clin Infect Dis 2019 69 S224-s227 We examined the effect of glove decontamination prior to removal on bacterial contamination of healthcare personnel hands in a laboratory simulation study. Glove decontamination reduced bacterial contamination of hands following removal. However, hand contamination still occurred with all decontamination methods, reinforcing the need for hand hygiene following glove removal. |
Blood cytokine, chemokine and growth factor profiling in a cohort of pregnant women from tropical countries
Dobano C , Bardaji A , Kochar S , Kochar SK , Padilla N , Lopez M , Unger HW , Ome-Kaius M , Castellanos ME , Arevalo-Herrera M , Hans D , Martinez-Espinosa FE , Botto-Menezes C , Malheiros A , Desai M , Casellas A , Chitnis CE , Rogerson S , Mueller I , Menendez C , Requena P . Cytokine 2019 125 154818 The immune status of women changes during and after pregnancy, differs between blood compartments at delivery and is affected by environmental factors particularly in tropical areas endemic for multiple infections. We quantified the plasma concentration of a set of thirty-one TH1, TH2, TH17 and regulatory cytokines, pro-inflammatory and anti-inflammatory cytokines and chemokines, and growth factors (altogether biomarkers), in a cohort of 540 pregnant women from five malaria-endemic tropical countries. Samples were collected at recruitment (first antenatal visit), delivery (periphery, cord and placenta) and postpartum, allowing a longitudinal analysis. We found the lowest concentration of biomarkers at recruitment and the highest at postpartum, with few exceptions. Among them, IL-6, HGF and TGF-beta had the highest levels at delivery, and even higher concentrations in the placenta compared to peripheral blood. Placental concentrations were generally higher than peripheral, except for eotaxin that was lower. We also compared plasma biomarker concentrations between the tropical cohort and a control group from Spain at delivery, presenting overall higher biomarker levels the tropical cohort, particularly pro-inflammatory cytokines and growth factors. Only IL-6 presented lower levels in the tropical group. Moreover, a principal component analysis of biomarker concentrations at delivery showed that women from Spain grouped more homogenously, and that IL-6 and IL-8 clustered together in the tropical cohort but not in the Spanish one. Plasma cytokine concentrations correlated with Plasmodium antibody levels at postpartum but not during pregnancy. This basal profiling of immune mediators over gestation and in different compartments at delivery is important to subsequently understand response to infections and clinical outcomes in mothers and infants in tropical areas. |
House screening with insecticide-treated netting provides sustained reductions in domestic populations of Aedes aegypti in Merida, Mexico
Che-Mendoza A , Medina-Barreiro A , Koyoc-Cardena E , Uc-Puc V , Contreras-Perera Y , Herrera-Bojorquez J , Dzul-Manzanilla F , Correa-Morales F , Ranson H , Lenhart A , McCall PJ , Kroeger A , Vazquez-Prokopec G , Manrique-Saide P . PLoS Negl Trop Dis 2018 12 (3) e0006283 BACKGROUND: There is a need for effective methods to control Aedes aegypti and prevent the transmission of dengue, chikungunya, yellow fever and Zika viruses. Insecticide treated screening (ITS) is a promising approach, particularly as it targets adult mosquitoes to reduce human-mosquito contact. METHODOLOGY/PRINCIPAL FINDINGS: A cluster-randomised controlled trial evaluated the entomological efficacy of ITS based intervention, which consisted of the installation of pyrethroid-impregnated long-lasting insecticide-treated netting material fixed as framed screens on external doors and windows. A total of 10 treatment and 10 control clusters (100 houses/cluster) were distributed throughout the city of Merida, Mexico. Cross-sectional entomological surveys quantified indoor adult mosquito infestation at baseline (pre-intervention) and throughout four post-intervention (PI) surveys spaced at 6-month intervals corresponding to dry/rainy seasons over two years (2012-2014). A total of 844 households from intervention clusters (86% coverage) were protected with ITS at the start of the trial. Significant reductions in the indoor presence and abundance of Ae. aegypti adults (OR = 0.48 and IRR = 0.45, P<0.05 respectively) and the indoor presence and abundance of Ae. aegypti female mosquitoes (OR = 0.47 and IRR = 0.44, P<0.05 respectively) were detected in intervention clusters compared to controls. This high level of protective effect was sustained for up to 24 months PI. Insecticidal activity of the ITS material declined with time, with ~70% mortality being demonstrated in susceptible mosquito cohorts up to 24 months after installation. CONCLUSIONS/SIGNIFICANCE: The strong and sustained entomological impact observed in this study demonstrates the potential of house screening as a feasible, alternative approach to a sustained long-term impact on household infestations of Ae. aegypti. Larger trials quantifying the effectiveness of ITS on epidemiological endpoints are warranted and therefore recommended. |
Nuclear and radiological emergencies: Building capacity in medical physics to support response
Berris T , Nusslin F , Meghzifene A , Ansari A , Herrera-Reyes E , Dainiak N , Akashi M , Gilley D , Ohtsuru A . Phys Med 2017 42 93-98 Medical physicists represent a valuable asset at the disposal of a structured and planned response to nuclear or radiological emergencies (NREs), especially in the hospital environment. The recognition of this fact led the International Atomic Energy Agency (IAEA) and the International Organization for Medical Physics (IOMP) to start a fruitful collaboration aiming to improve education and training of medical physicists so that they may support response efforts in case of NREs. Existing shortcomings in specific technical areas were identified through international consultations supported by the IAEA and led to the development of a project aiming at preparing a specific and standardized training package for medical physicists in support to NREs. The Project was funded through extra-budgetary contribution from Japan within the IAEA Nuclear Safety Action Plan. This paper presents the work accomplished through that project and describes the current steps and future direction for enabling medical physicists to better support response to NREs. |
Implementing impact evaluations of malaria control interventions: Process, lessons learned, and recommendations
Hershey CL , Bhattarai A , Florey LS , McElroy PD , Nielsen CF , Ye Y , Eckert E , Franca-Koh AC , Shargie E , Komatsu R , Smithson P , Thwing J , Mihigo J , Herrera S , Taylor C , Shah J , Mouzin E , Yoon SS , Salgado SR . Am J Trop Med Hyg 2017 97 20-31 As funding for malaria control increased considerably over the past 10 years resulting in the expanded coverage of malaria control interventions, so did the need to measure the impact of these investments on malaria morbidity and mortality. Members of the Roll Back Malaria (RBM) Partnership undertook impact evaluations of malaria control programs at a time when there was little guidance in terms of the process for conducting an impact evaluation of a national-level malaria control program. The President's Malaria Initiative (PMI), as a member of the RBM Partnership, has provided financial and technical support for impact evaluations in 13 countries to date. On the basis of these experiences, PMI and its partners have developed a streamlined process for conducting the evaluations with a set of lessons learned and recommendations. Chief among these are: to ensure country ownership and involvement in the evaluations; to engage stakeholders throughout the process; to coordinate evaluations among interested partners to avoid duplication of efforts; to tailor the evaluation to the particular country context; to develop a standard methodology for the evaluations and a streamlined process for completion within a reasonable time; and to develop tailored dissemination products on the evaluation for a broad range of stakeholders. These key lessons learned and resulting recommendations will guide future impact evaluations of malaria control programs and other health programs. |
Burden and impact of Plasmodium vivax in pregnancy: A multi-centre prospective observational study.
Bardaji A , Martinez-Espinosa FE , Arevalo-Herrera M , Padilla N , Kochar S , Ome-Kaius M , Botto-Menezes C , Castellanos ME , Kochar DK , Kochar SK , Betuela I , Mueller I , Rogerson S , Chitnis C , Hans D , Menegon M , Severini C , Del Portillo H , Dobano C , Mayor A , Ordi J , Piqueras M , Sanz S , Wahlgren M , Slutsker L , Desai M , Menendez C . PLoS Negl Trop Dis 2017 11 (6) e0005606 BACKGROUND: Despite that over 90 million pregnancies are at risk of Plasmodium vivax infection annually, little is known about the epidemiology and impact of the infection in pregnancy. METHODOLOGY AND PRINCIPAL FINDINGS: We undertook a health facility-based prospective observational study in pregnant women from Guatemala (GT), Colombia (CO), Brazil (BR), India (IN) and Papua New Guinea PNG). Malaria and anemia were determined during pregnancy and fetal outcomes assessed at delivery. A total of 9388 women were enrolled at antennal care (ANC), of whom 53% (4957) were followed until delivery. Prevalence of P. vivax monoinfection in maternal blood at delivery was 0.4% (20/4461) by microscopy [GT 0.1%, CO 0.5%, BR 0.1%, IN 0.2%, PNG 1.2%] and 7% (104/1488) by PCR. P. falciparum monoinfection was found in 0.5% (22/4463) of women by microscopy [GT 0%, CO 0.5%, BR 0%, IN 0%, PNG 2%]. P. vivax infection was observed in 0.4% (14/3725) of placentas examined by microscopy and in 3.7% (19/508) by PCR. P. vivax in newborn blood was detected in 0.02% (1/4302) of samples examined by microscopy [in cord blood; 0.05% (2/4040) by microscopy, and 2.6% (13/497) by PCR]. Clinical P. vivax infection was associated with increased risk of maternal anemia (Odds Ratio-OR, 5.48, [95% CI 1.83-16.41]; p = 0.009), while submicroscopic vivax infection was not associated with increased risk of moderate-severe anemia (Hb<8g/dL) (OR, 1.16, [95% CI 0.52-2.59]; p = 0.717), or low birth weight (<2500g) (OR, 0.52, [95% CI, 0.23-1.16]; p = 0.110). CONCLUSIONS: In this multicenter study, the prevalence of P. vivax infection in pregnancy by microscopy was overall low across all endemic study sites; however, molecular methods revealed a significant number of submicroscopic infections. Clinical vivax infection in pregnancy was associated with maternal anemia, which may be deleterious for infant's health. These results may help to guide maternal health programs in settings where vivax malaria is endemic; they also highlight the need of addressing a vulnerable population such as pregnant women while embracing malaria elimination in endemic countries. |
Severe neurologic disorders in 2 fetuses with Zika virus infection, Colombia
Acosta-Reyes J , Navarro E , Herrera MJ , Goenaga E , Ospina ML , Parra E , Mercado M , Chaparro P , Beltran M , Gunturiz ML , Pardo L , Valencia C , Huertas S , Rodriguez J , Ruiz G , Valencia D , Haddad LB , Tinker SC , Moore CA , Baquero H . Emerg Infect Dis 2017 23 (6) 982-984 We report the results of pathologic examinations of 2 fetuses from women in Colombia with Zika virus infection during pregnancy that revealed severe central nervous system defects and potential associated abnormalities of the eye, spleen, and placenta. Amniotic fluid and tissues from multiple fetal organs tested positive for Zika virus. |
Defining the next generation of Plasmodium vivax diagnostic tests for control and elimination: Target product profiles.
Ding XC , Ade MP , Baird JK , Cheng Q , Cunningham J , Dhorda M , Drakeley C , Felger I , Gamboa D , Harbers M , Herrera S , Lucchi N , Mayor A , Mueller I , Sattabongkot J , Ratsimbason A , Richards J , Tanner M , Gonzalez IJ . PLoS Negl Trop Dis 2017 11 (4) e0005516 The global prevalence of malaria has decreased over the past fifteen years, but similar gains have not been realized against Plasmodium vivax because this species is less responsive to conventional malaria control interventions aimed principally at P. falciparum. Approximately half of all malaria cases outside of Africa are caused by P. vivax. This species places dormant forms in human liver that cause repeated clinical attacks without involving another mosquito bite. The diagnosis of acute patent P. vivax malaria relies primarily on light microscopy. Specific rapid diagnostic tests exist but typically perform relatively poorly compared to those for P. falciparum. Better diagnostic tests are needed for P. vivax. To guide their development, FIND, in collaboration with P. vivax experts, identified the specific diagnostic needs associated with this species and defined a series of three distinct target product profiles, each aimed at a particular diagnostic application: (i) point-of-care of acutely ill patients for clinical care purposes; (ii) point-of-care asymptomatic and otherwise sub-patent residents for public health purposes, e.g., mass screen and treat campaigns; and (iii) ultra-sensitive not point-of-care diagnosis for epidemiological research/surveillance purposes. This report presents and discusses the rationale for these P. vivax-specific diagnostic target product profiles. These contribute to the rational development of fit-for-purpose diagnostic tests suitable for use the clinical management, control and elimination of P. vivax malaria. |
Naturally acquired binding-inhibitory antibodies to Plasmodium vivax Duffy binding protein in pregnant women are associated with higher birth weight in a multicenter study
Requena P , Arevalo-Herrera M , Menegon M , Martinez-Espinosa FE , Padilla N , Botto-Menezes C , Malheiro A , Hans D , Castellanos ME , Robinson L , Samol P , Kochar S , Kochar SK , Kochar DK , Desai M , Sanz S , Quintó L , Mayor A , Rogerson S , Mueller I , Severini C , Del Portillo HA , Bardají A , Chitnis CC , Menéndez C , Dobaño C . Front Immunol 2017 8 163 A vaccine to eliminate malaria would need a multi-stage and multi-species composition to achieve robust protection, but the lack of knowledge about antigen targets and mechanisms of protection precludes the development of fully efficacious malaria vaccines, especially for Plasmodium vivax (Pv). Pregnant women constitute a risk population who would greatly benefit from a vaccine preventing the adverse events of Plasmodium infection during gestation. We hypothesized that functional immune responses against putative targets of naturally acquired immunity to malaria and vaccine candidates will be associated with protection against malaria infection and/or poor outcomes during pregnancy. We measured (i) IgG responses to a large panel of Pv and Plasmodium falciparum (Pf) antigens, (ii) the capacity of anti-Pv ligand Duffy binding protein (PvDBP) antibodies to inhibit binding to Duffy antigen, and (iii) cellular immune responses to two Pv antigens, in a subset of 1,056 pregnant women from Brazil, Colombia, Guatemala, India, and Papua New Guinea (PNG). There were significant intraspecies and interspecies correlations for most antibody responses (e.g., PfMSP119 versus PfAMA1, Spearman's rho = 0.81). Women from PNG and Colombia had the highest levels of IgG overall. Submicroscopic infections seemed sufficient to boost antibody responses in Guatemala but not antigen-specific cellular responses in PNG. Brazil had the highest percentage of Duffy binding inhibition (p-values versus Colombia: 0.040; Guatemala: 0.047; India: 0.003, and PNG: 0.153) despite having low anti-PvDBP IgG levels. Almost all antibodies had a positive association with present infection, and coinfection with the other species increased this association. Anti-PvDBP, anti-PfMSP1, and anti-PfAMA1 IgG levels at recruitment were positively associated with infection at delivery (p-values: 0.010, 0.003, and 0.023, respectively), suggesting that they are markers of malaria exposure. Peripheral blood mononuclear cells from Pv-infected women presented fewer CD8+IFN-gamma+ T cells and secreted more G-CSF and IL-4 independently of the stimulus used in vitro. Functional anti-PvDBP levels at recruitment had a positive association with birth weight (difference per doubling antibody levels: 45 g, p-value: 0.046). Thus, naturally acquired binding-inhibitory antibodies to PvDBP might confer protection against poor outcomes of Pv malaria in pregnancy. |
Key ethical issues discussed at CDC-sponsored international, regional meetings to explore cultural perspectives and contexts on pandemic influenza preparedness and response
Lor A , Thomas JC , Barrett DH , Ortmann LW , Herrera Guibert DJ . Int J Health Policy Manag 2016 5 (11) 653-662 BACKGROUND: Recognizing the importance of having a broad exploration of how cultural perspectives may shape thinking about ethical considerations, the Centers for Disease Control and Prevention (CDC) funded four regional meetings in Africa, Asia, Latin America, and the Eastern Mediterranean to explore these perspectives relevant to pandemic influenza preparedness and response. The meetings were attended by 168 health professionals, scientists, academics, ethicists, religious leaders, and other community members representing 40 countries in these regions. METHODS: We reviewed the meeting reports, notes and stories and mapped outcomes to the key ethical challenges for pandemic influenza response described in the World Health Organization's (WHO's) guidance, Ethical Considerations in Developing a Public Health Response to Pandemic Influenza: transparency and public engagement, allocation of resources, social distancing, obligations to and of healthcare workers, and international collaboration. RESULTS: The important role of transparency and public engagement were widely accepted among participants. However, there was general agreement that no "one size fits all" approach to allocating resources can address the variety of economic, cultural and other contextual factors that must be taken into account. The importance of social distancing as a tool to limit disease transmission was also recognized, but the difficulties associated with this measure were acknowledged. There was agreement that healthcare workers often have competing obligations and that government has a responsibility to assist healthcare workers in doing their job by providing appropriate training and equipment. Finally, there was agreement about the importance of international collaboration for combating global health threats. CONCLUSION: Although some cultural differences in the values that frame pandemic preparedness and response efforts were observed, participants generally agreed on the key ethical principles discussed in the WHO's guidance. Most significantly the input gathered from these regional meetings pointed to the important role that procedural ethics can play in bringing people and countries together to respond to the shared health threat posed by a pandemic influenza despite the existence of cultural differences. |
Plasmodium vivax VIR proteins are targets of naturally-acquired antibody and T cell immune responses to malaria in pregnant women
Requena P , Rui E , Padilla N , Martinez-Espinosa FE , Castellanos ME , Botto-Menezes C , Malheiro A , Arevalo-Herrera M , Kochar S , Kochar SK , Kochar DK , Umbers AJ , Ome-Kaius M , Wangnapi R , Hans D , Menegon M , Mateo F , Sanz S , Desai M , Mayor A , Chitnis CC , Bardaji A , Mueller I , Rogerson S , Severini C , Fernandez-Becerra C , Menendez C , Del Portillo H , Dobano C . PLoS Negl Trop Dis 2016 10 (10) e0005009 P. vivax infection during pregnancy has been associated with poor outcomes such as anemia, low birth weight and congenital malaria, thus representing an important global health problem. However, no vaccine is currently available for its prevention. Vir genes were the first putative virulent factors associated with P. vivax infections, yet very few studies have examined their potential role as targets of immunity. We investigated the immunogenic properties of five VIR proteins and two long synthetic peptides containing conserved VIR sequences (PvLP1 and PvLP2) in the context of the PregVax cohort study including women from five malaria endemic countries: Brazil, Colombia, Guatemala, India and Papua New Guinea (PNG) at different timepoints during and after pregnancy. Antibody responses against all antigens were detected in all populations, with PNG women presenting the highest levels overall. P. vivax infection at sample collection time was positively associated with antibody levels against PvLP1 (fold-increase: 1.60 at recruitment -first antenatal visit-) and PvLP2 (fold-increase: 1.63 at delivery), and P. falciparum co-infection was found to increase those responses (for PvLP1 at recruitment, fold-increase: 2.25). Levels of IgG against two VIR proteins at delivery were associated with higher birth weight (27 g increase per duplicating antibody levels, p<0.05). Peripheral blood mononuclear cells from PNG uninfected pregnant women had significantly higher antigen-specific IFN-gamma TH1 responses (p=0.006) and secreted less pro-inflammatory cytokines TNF and IL-6 after PvLP2 stimulation than P. vivax-infected women (p<0.05). These data demonstrate that VIR antigens induce the natural acquisition of antibody and T cell memory responses that might be important in immunity to P. vivax during pregnancy in very diverse geographical settings. |
Antibiotic failure mediated by a resistant subpopulation in Enterobacter cloacae
Band VI , Crispell EK , Napier BA , Herrera CM , Tharp GK , Vavikolanu K , Pohl J , Read TD , Bosinger SE , Trent MS , Burd EM , Weiss DS . Nat Microbiol 2016 1 (6) 16053 Antibiotic resistance is a major public health threat, further complicated by unexplained treatment failures caused by bacteria that appear antibiotic susceptible. We describe an Enterobacter cloacae isolate harbouring a minor subpopulation that is highly resistant to the last-line antibiotic colistin. This subpopulation was distinct from persisters, became predominant in colistin, returned to baseline after colistin removal and was dependent on the histidine kinase PhoQ. During murine infection, but in the absence of colistin, innate immune defences led to an increased frequency of the resistant subpopulation, leading to inefficacy of subsequent colistin therapy. An isolate with a lower-frequency colistin-resistant subpopulation similarly caused treatment failure but was misclassified as susceptible by current diagnostics once cultured outside the host. These data demonstrate the ability of low-frequency bacterial subpopulations to contribute to clinically relevant antibiotic resistance, elucidating an enigmatic cause of antibiotic treatment failure and highlighting the critical need for more sensitive diagnostics. |
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