Browsing by Subject "Zoonoses"

Now showing 1 - 12 of 12

Open Access
Brucellosis in low-income and middle-income countries.
(Curr Opin Infect Dis, 2013-10) Rubach, Matthew P; Halliday, Jo EB; Cleaveland, Sarah; Crump, John A
PURPOSE OF REVIEW: Human brucellosis is a neglected, underrecognized infection of widespread geographic distribution. It causes acute febrile illness and a potentially debilitating chronic infection in humans, and livestock infection has substantial socioeconomic impact. This review describes new information regarding the epidemiology of brucellosis in the developing world and advances in diagnosis and treatment. RECENT FINDINGS: The highest recorded incidence of human brucellosis occurs in the Middle East and Central Asia. Fever etiology studies demonstrate brucellosis as a cause of undifferentiated febrile illness in the developing world. Brucellosis is a rare cause of fever among returning travelers, but is more common among travelers returning from the Middle East and North Africa. Sensitive and specific rapid diagnostic tests appropriate for resource-limited settings have been validated. Randomized controlled trials demonstrate that optimal treatment for human brucellosis consists of doxycycline and an aminoglycoside. Decreasing the burden of human brucellosis requires control of animal brucellosis, but evidence to inform the design of control programs in the developing world is needed. SUMMARY: Brucellosis causes substantial morbidity in human and animal populations. While improvements in diagnostic options for resource-limited settings and stronger evidence for optimal therapy should enhance identification and treatment of human brucellosis, prevention of human disease through control in animals remains paramount.
Open Access
Characterization of Risk Factors for Inter- and Intraspecies Transmission of Respiratory Illness at Lola Ya, Democratic Republic of Congo
(2023) Hanberry, Daniel Austin
Zoonotic disease poses one of the greatest threats to both human and animal health in our world today. Recent pandemics such as Ebola, SARS-CoV2, and highly pathogenic Avian Influenza have shown the devastating consequences of infectious disease on both human and animal populations. Few studies have characterized the risk of interspecies pathogen transmission with one of our closest living relatives, Pan paniscus. This endangered species of great apes inhabits only rainforests of the Congo River Basin. Due to human encroachment, bushmeat trade, illegal pet trade, and deforestation, only 15,000-20,000 wild bonobos remain. The Lola Ya Bonobo Sanctuary (LYB) serves as the world’s only haven for orphaned and injured bonobos and presents a valuable opportunity to study the epidemiology of respiratory pathogens in a habituated population. This study aimed to characterize the risk factors for transmission of respiratory illness between bonobos and humans at LYB. Between 2014-2017 a cohort of 77 bonobos and 44 human staff were observed for signs of clinical illness and had their upper respiratory tract routinely sampled. We used a multiplex nucleic acid amplification assay to detect the presence of 18 viral and 3 bacterial respiratory pathogens. Of 282 total bonobo testing events, 93 (33%) returned positive results, primarily RSV-A (n = 41, 44.1%) and Rhinovirus/Enterovirus (n = 37, 39.8%). Although the point of entry into LYB could not be determined, RSV-A initially appeared in the infant and juvenile enclosures and spread serially through the older bonobo enclosures. Rhinovirus/Enterovirus appeared in diffuse clusters throughout the sanctuary. Although new bonobos are subject to a prolonged quarantine, current policy allows for relocation of bonobos between enclosures and frequent and sustained contact with human staff. Active surveillance for respiratory and other pathogens and additional infection control measures may benefit bonobo and human health.
Open Access
Comparing actual and perceived causes of fever among community members in a low malaria transmission setting in northern Tanzania.
(Trop Med Int Health, 2013-11) Hertz, Julian T; Munishi, O Michael; Sharp, Joanne P; Reddy, Elizabeth A; Crump, John A
OBJECTIVE: To compare actual and perceived causes of fever in northern Tanzania. METHODS: In a standardised survey, heads of households in 30 wards in Moshi, Tanzania, were asked to identify the most common cause of fever for children and for adults. Responses were compared to data from a local hospital-based fever aetiology study that used standard diagnostic techniques. RESULTS: Of 810 interviewees, the median (range) age was 48 (16, 102) years and 509 (62.8%) were women. Malaria was the most frequently identified cause of fever, cited by 353 (43.6%) and 459 (56.7%) as the most common cause of fever for children and adults, respectively. In contrast, malaria accounted for 8 (2.0%) of adult and 6 (1.3%) of paediatric febrile admissions in the fever aetiology study. Weather was the second most frequently cited cause of fever. Participants who identified a non-biomedical explanation such as weather as the most common cause of fever were more likely to prefer a traditional healer for treatment of febrile adults (OR 2.7, P < 0.001). Bacterial zoonoses were the most common cause of fever among inpatients, but no interviewees identified infections from animal contact as the most common cause of fever for adults; two (0.2%) identified these infections as the most common cause of fever for children. CONCLUSIONS: Malaria is perceived to be a much more common cause of fever than hospital studies indicate, whereas other important diseases are under-appreciated in northern Tanzania. Belief in non-biomedical explanations of fever is common locally and has important public health consequences.
Open Access
Detection of Bartonella species in the blood of veterinarians and veterinary technicians: a newly recognized occupational hazard?
(Vector Borne Zoonotic Dis, 2014-08) Lantos, Paul M; Maggi, Ricardo G; Ferguson, Brandy; Varkey, Jay; Park, Lawrence P; Breitschwerdt, Edward B; Woods, Christopher W
BACKGROUND: Bartonella species are important emerging pathogens in human and veterinary medicine. In the context of their daily activities, veterinary professionals have frequent animal contact and arthropod exposures. Detection of Bartonella spp. using traditional culture methods has been limited by poor sensitivity, making it difficult to determine the prevalence of infection in this population. We have developed a detection method combining enrichment culture and molecular amplification, which increases testing sensitivity. METHODS: We performed a cross-sectional study to determine the prevalence of detectable Bartonella spp. in the blood of veterinary personnel and nonveterinary control subjects. Bartonella was detected by enrichment blood culture with conventional PCR followed by DNA sequencing. RESULTS were correlated with epidemiological variables and symptoms. RESULTS: We detected DNA from at least one Bartonella species in 32 (28%) of the 114 veterinary subjects. After DNA sequencing, the Bartonella species could be determined for 27 of the 32 infected subjects, including B. henselae in 15 (56%), B. vinsonii subsp. berkhoffii in seven (26%), B. koehlerae in six (22%), and a B. volans-like sequence in one (4%). Seventy percent of Bartonella-positive subjects described headache compared with 40% of uninfected veterinarians (p=0.009). Irritability was also reported more commonly by infected subjects (68% vs. 43%, p=0.04). CONCLUSIONS: Our study supports an emerging body of evidence that cryptic Bartonella bloodstream infection may be more frequent in humans than previously recognized and may induce symptoms. Longitudinal studies are needed to determine the natural course and clinical features of Bartonella infection.
Open Access
Ecology and economics for pandemic prevention.
(Science (New York, N.Y.), 2020-07) Dobson, Andrew P; Pimm, Stuart L; Hannah, Lee; Kaufman, Les; Ahumada, Jorge A; Ando, Amy W; Bernstein, Aaron; Busch, Jonah; Daszak, Peter; Engelmann, Jens; Kinnaird, Margaret F; Li, Binbin V; Loch-Temzelides, Ted; Lovejoy, Thomas; Nowak, Katarzyna; Roehrdanz, Patrick R; Vale, Mariana M
Open Access
Effects of land use, habitat characteristics, and small mammal community composition on Leptospira prevalence in northeast Madagascar.
(PLoS neglected tropical diseases, 2020-12-31) Herrera, James P; Wickenkamp, Natalie R; Turpin, Magali; Baudino, Fiona; Tortosa, Pablo; Goodman, Steven M; Soarimalala, Voahangy; Ranaivoson, Tamby Nasaina; Nunn, Charles L
Human activities can increase or decrease risks of acquiring a zoonotic disease, notably by affecting the composition and abundance of hosts. This study investigated the links between land use and infectious disease risk in northeast Madagascar, where human subsistence activities and population growth are encroaching on native habitats and the associated biota. We collected new data on pathogenic Leptospira, which are bacteria maintained in small mammal reservoirs. Transmission can occur through close contact, but most frequently through indirect contact with water contaminated by the urine of infected hosts. The probability of infection and prevalence was compared across a gradient of natural moist evergreen forest, nearby forest fragments, flooded rice and other types of agricultural fields, and in homes in a rural village. Using these data, we tested specific hypotheses for how land use alters ecological communities and influences disease transmission. The relative abundance and proportion of exotic species was highest in the anthropogenic habitats, while the relative abundance of native species was highest in the forested habitats. Prevalence of Leptospira was significantly higher in introduced compared to endemic species. Lastly, the probability of infection with Leptospira was highest in introduced small mammal species, and lower in forest fragments compared to other habitat types. Our results highlight how human land use affects the small mammal community composition and in turn disease dynamics. Introduced species likely transmit Leptospira to native species where they co-occur, and may displace the Leptospira species naturally occurring in Madagascar. The frequent spatial overlap of people and introduced species likely also has consequences for public health.
Open Access
Epidemiology of Leptospirosis in Africa: A Systematic Review of a Neglected Zoonosis and a Paradigm for 'One Health' in Africa.
(PLoS Negl Trop Dis, 2015) Allan, Kathryn J; Biggs, Holly M; Halliday, Jo EB; Kazwala, Rudovick R; Maro, Venance P; Cleaveland, Sarah; Crump, John A
BACKGROUND: Leptospirosis is an important but neglected bacterial zoonosis that has been largely overlooked in Africa. In this systematic review, we aimed to summarise and compare current knowledge of: (1) the geographic distribution, prevalence, incidence and diversity of acute human leptospirosis in Africa; and (2) the geographic distribution, host range, prevalence and diversity of Leptospira spp. infection in animal hosts in Africa. METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, we searched for studies that described (1) acute human leptospirosis and (2) pathogenic Leptospira spp. infection in animals. We performed a literature search using eight international and regional databases for English and non-English articles published between January 1930 to October 2014 that met out pre-defined inclusion criteria and strict case definitions. RESULTS AND DISCUSSION: We identified 97 studies that described acute human leptospirosis (n = 46) or animal Leptospira infection (n = 51) in 26 African countries. The prevalence of acute human leptospirosis ranged from 2 3% to 19 8% (n = 11) in hospital patients with febrile illness. Incidence estimates were largely restricted to the Indian Ocean islands (3 to 101 cases per 100,000 per year (n = 6)). Data from Tanzania indicate that human disease incidence is also high in mainland Africa (75 to 102 cases per 100,000 per year). Three major species (Leptospira borgpetersenii, L. interrogans and L. kirschneri) are predominant in reports from Africa and isolates from a diverse range of serogroups have been reported in human and animal infections. Cattle appear to be important hosts of a large number of Leptospira serogroups in Africa, but few data are available to allow comparison of Leptospira infection in linked human and animal populations. We advocate a 'One Health' approach to promote multidisciplinary research efforts to improve understanding of the animal to human transmission of leptospirosis on the African continent.
Open Access
Fever, bacterial zoonoses, and One Health in sub-Saharan Africa.
(Clinical medicine (London, England), 2019-09) Carugati, Manuela; Kilonzo, Kajiru G; Crump, John A
Although often underappreciated, a number of bacterial zoonoses are endemic in Africa. Of these, brucellosis, leptospirosis, Q fever, and rickettsioses are responsible for a substantial proportion of febrile illness among patients seeking hospital care. In this paper, we discuss the aetiology, epidemiology, clinical presentation, diagnosis, treatment and prevention of these bacterial zoonoses. To prevent and control bacterial zoonoses, strategies targeting both animals and humans are crucial. These may lead to better outcomes than strategies based exclusively on treatment of human infections. Such strategies are referred to as the 'One Health' approach; the collaborative effort of multiple disciplines to attain optimal health for people, animals and the environment.
Open Access
From Hendra to Wuhan: what has been learned in responding to emerging zoonotic viruses.
(Lancet (London, England), 2020-02) Wang, Lin-Fa; Anderson, Danielle E; Mackenzie, John S; Merson, Michael H
Open Access
Mixed Methods Survey of Zoonotic Disease Awareness and Practice among Animal and Human Healthcare Providers in Moshi, Tanzania.
(PLoS Negl Trop Dis, 2016-03) Zhang, Helen L; Mnzava, Kunda W; Mitchell, Sarah T; Melubo, Matayo L; Kibona, Tito J; Cleaveland, Sarah; Kazwala, Rudovick R; Crump, John A; Sharp, Joanne P; Halliday, Jo EB
BACKGROUND: Zoonoses are common causes of human and livestock illness in Tanzania. Previous studies have shown that brucellosis, leptospirosis, and Q fever account for a large proportion of human febrile illness in northern Tanzania, yet they are infrequently diagnosed. We conducted this study to assess awareness and knowledge regarding selected zoonoses among healthcare providers in Moshi, Tanzania; to determine what diagnostic and treatment protocols are utilized; and obtain insights into contextual factors contributing to the apparent under-diagnosis of zoonoses. METHODOLOGY/RESULTS: We conducted a questionnaire about zoonoses knowledge, case reporting, and testing with 52 human health practitioners and 10 livestock health providers. Immediately following questionnaire administration, we conducted semi-structured interviews with 60 of these respondents, using the findings of a previous fever etiology study to prompt conversation. Sixty respondents (97%) had heard of brucellosis, 26 (42%) leptospirosis, and 20 (32%) Q fever. Animal sector respondents reported seeing cases of animal brucellosis (4), rabies (4), and anthrax (3) in the previous 12 months. Human sector respondents reported cases of human brucellosis (15, 29%), rabies (9, 18%) and anthrax (6, 12%). None reported leptospirosis or Q fever cases. Nineteen respondents were aware of a local diagnostic test for human brucellosis. Reports of tests for human leptospirosis or Q fever, or for any of the study pathogens in animals, were rare. Many respondents expressed awareness of malaria over-diagnosis and zoonoses under-diagnosis, and many identified low knowledge and testing capacity as reasons for zoonoses under-diagnosis. CONCLUSIONS: This study revealed differences in knowledge of different zoonoses and low case report frequencies of brucellosis, leptospirosis, and Q fever. There was a lack of known diagnostic services for leptospirosis and Q fever. These findings emphasize a need for improved diagnostic capacity alongside healthcare provider education and improved clinical guidelines for syndrome-based disease management to provoke diagnostic consideration of locally relevant zoonoses in the absence of laboratory confirmation.
Open Access
Primate malarias as a model for cross-species parasite transmission.
(eLife, 2022-01) Voinson, Marina; Nunn, Charles L; Goldberg, Amy
Parasites regularly switch into new host species, representing a disease burden and conservation risk to the hosts. The distribution of these parasites also gives insight into characteristics of ecological networks and genetic mechanisms of host-parasite interactions. Some parasites are shared across many species, whereas others tend to be restricted to hosts from a single species. Understanding the mechanisms producing this distribution of host specificity can enable more effective interventions and potentially identify genetic targets for vaccines or therapies. As ecological connections between human and local animal populations increase, the risk to human and wildlife health from novel parasites also increases. Which of these parasites will fizzle out and which have the potential to become widespread in humans? We consider the case of primate malarias, caused by Plasmodium parasites, to investigate the interacting ecological and evolutionary mechanisms that put human and nonhuman primates at risk for infection. Plasmodium host switching from nonhuman primates to humans led to ancient introductions of the most common malaria-causing agents in humans today, and new parasite switching is a growing threat, especially in Asia and South America. Based on a wild host-Plasmodium occurrence database, we highlight geographic areas of concern and potential areas to target further sampling. We also discuss methodological developments that will facilitate clinical and field-based interventions to improve human and wildlife health based on this eco-evolutionary perspective.
Open Access
Zoonotic causes of febrile illness in malaria endemic countries: a systematic review.
(The Lancet. Infectious diseases, 2020-02) Halliday, Jo EB; Carugati, Manuela; Snavely, Michael E; Allan, Kathryn J; Beamesderfer, Julia; Ladbury, Georgia AF; Hoyle, Deborah V; Holland, Paul; Crump, John A; Cleaveland, Sarah; Rubach, Matthew P
Fever is one of the most common reasons for seeking health care globally and most human pathogens are zoonotic. We conducted a systematic review to describe the occurrence and distribution of zoonotic causes of human febrile illness reported in malaria endemic countries. We included data from 53 (48·2%) of 110 malaria endemic countries and 244 articles that described diagnosis of 30 zoonoses in febrile people. The majority (17) of zoonoses were bacterial, with nine viruses, three protozoa, and one helminth also identified. Leptospira species and non-typhoidal salmonella serovars were the most frequently reported pathogens. Despite evidence of profound data gaps, this Review reveals widespread distribution of multiple zoonoses that cause febrile illness. Greater understanding of the epidemiology of zoonoses in different settings is needed to improve awareness about these pathogens and the management of febrile illness.

Browsing by Subject "Zoonoses"

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