Biological Sciences
Lyme Disease
Lyme disease is a tick-borne illness caused by the bacterium Borrelia burgdorferi. It is characterized by flu-like symptoms, joint pain, and a distinctive rash. If left untreated, it can lead to more serious complications affecting the heart, nervous system, and joints. Prevention involves avoiding tick-infested areas and using insect repellent. Early diagnosis and antibiotic treatment are crucial for managing the disease.
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9 Key excerpts on "Lyme Disease"
eBook - ePubEmerging Infectious Diseases
A Guide to Diseases, Causative Agents, and Surveillance
- Lisa A. Beltz(Author)
- 2011(Publication Date)
- Jossey-Bass(Publisher)
PART II BACTERIAL INFECTIONS
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CHAPTER 3
Lyme Disease
LEARNING OBJECTIVES
- Define Lyme Disease
- Describe the spirochete responsible for causing this illness
- Discuss modes of infection
- Discuss the host’s response to infection
- Describe symptomatology and diagnosis
- Discuss methods of treatment
- Discuss methods of prevention
Lyme Disease was first reported in Connecticut in 1976 as an outbreak of arthritis in an unusually large number of children and adults. It was later found to result from infection by a tickborne spirochete bacterium. A spirochete is a spiral-shaped, rodlike bacterium that has caused diseases such as syphilis and relapsing fever. Nymphal and larval forms of the tick transmit the spirochete to humans. Disease incidence is highest during spring and summer when these ticks are seeking new hosts.SymptomsThe symptoms of Lyme Disease include a combination of a tick bite with or without the presence of a tick, an erythema migrans rash, fever, chills, fatigue, weight change, hair loss, swollen glands, sore throat, irritable bowel, chest pain, shortness of breath, heart palpitations, joint pain and stiffness, muscle pain, headache, tingling or numbness, facial paralysis, double vision, buzzing or ringing in the ears, dizziness, poor balance, light-headedness, difficulty walking, tremor, heart murmur, confusion, forgetfulness, poor short-term memory, mood swings, meningitis, sensitivity to light, recurring hepatitis, and adult respiratory distress syndrome. Lack of prompt treatment may lead to persistent fatigue or malaise, migratory musculoskeletal disorders, chronic encephalopathy and encephalomyelitis, peripheral neuropathy, and difficulty with concentration or memory.SettingLyme Disease in the United States occurs primarily in the Northeast along the coast from Maine to Maryland, in portions of the Midwest, and in parts of the Far West. It is also found in temperate areas of Canada, Europe, Africa, Asia, and Australia. Incidence of Lyme Disease has been on the rise due to increased habitats for the tick vectors and the mice and deer on which they feed. The rising incidence is also influenced by greater use of tick habitat by humans and an increase in the construction of human residences in these regions. Southern-tick-associated rash illness (STARI) is a similar disease found in the American Southeast. It results from infection with Borrelia lonestari
eBook - ePubConquering Lyme Disease
Science Bridges the Great Divide
- Brian A. Fallon, Jennifer Sotsky(Authors)
- 2017(Publication Date)
- Columbia University Press(Publisher)
1BASIC FACTSWHAT IS Lyme Disease?Lyme Disease (also known as Lyme borreliosis) is the most commonly reported vector-borne illness in the United States. The Centers for Disease Control and Prevention (CDC) estimates that more than 330,000 individuals are diagnosed with Lyme Disease each year in the United States alone. Although the illness was named after a town in Connecticut, Lyme Disease is not confined to the United States. In fact, more than eighty countries have reported cases, and the earliest reports come from Europe, not the United States.The causative pathogen, Borellia burgdorferi, is a spirochete or spiral-shaped bacterium that infects humans through the bite of the black-legged tick—sometimes referred to as a “deer tick.” During the initial blood meal by the tick, the B. burgdorferi bacteria are injected into the skin. Among most patients, this then triggers an inflammatory response that manifests as an expanding red rash known as erythema migrans. This is the most common presenting sign of the disease and usually develops within two to thirty days after infection. It is typically a round or oval, solid red rash that grows in size over time; sometimes it resembles a bull’s eye with a red perimeter and a paler central clearing. However, some patients never develop symptoms; the immune system clears the infection on its own and these individuals have no knowledge of having been infected with B. burgdorferi. Others don’t see the rash or have only mild symptoms, so they don’t seek medical attention; these patients may develop more serious manifestations weeks or a month later.As the B. burgdorferi
No longer available |Learn more- David P. Rakel(Author)
- 2017(Publication Date)
- Elsevier(Publisher)
3The principal vectors for transmission of B. burgdorferi in the United States are nymphal deer ticks (Ixodes scapularis and pacificus ) during the late spring or summer months.8 Infected ticks need to be attached for at least 24–48 hours to be able to transmit the organism.8 Bites from Ixodes ticks are usually painless and are often unrecognized. Fig. 23.2 illustrates stages in the life cycle of the deer tick.Ixodes ticks may also transmit Anaplasma phagocytophila , Babesia microti , Borrelia miyamotoi, Ehrlichia species, and Deer tick virus (a type of Powassan virus), either separately or in conjunction with B. burgdorferi. 9 The impact of coinfections on the clinical course of Lyme Disease can range from self-clearing fevers to life-threatening illnesses.2Infected persons do not transmit Lyme Disease to others; no epidemiological or clinical data currently confirm sexual or congenital transmission of B. Burgdorferi between humans,10 despite widespread concern. Uncomplicated Lyme Disease is generally treatable, with a favorable prognosis.3Clinical Course
Lyme Disease is classified into three stages; early localized Lyme Disease, early disseminated Lyme Disease, and late Lyme Disease.10 Early localized Lyme Disease is characterized by a rash (erythema migrans, see Fig. 23.3 ) appearing at the site of the tick bite typically between 7 and 14 days following the bite.10 Erythema migrans is usually asymptomatic but may become pruritic or painful.2 Systemic symptoms sometimes may accompany the rash and include fever, myalgia, headache, fatigue, and localized lymphadenopathy.10Early disseminated Lyme Disease may manifest as multiple erythema migrans, usually appearing 3–5 weeks following the tick bite. Neurological findings, including meningitis and cranial nerve palsies, may present. Other symptoms can include fatigue, flulike symptoms, carditis (manifested as heart block), and syncopal episodes.2 ,10
eBook - ePubCrypto-infections
Denial, censorship and repression - the truth about what lies behind chronic disease
- Christian Perronne(Author)
- 2020(Publication Date)
- Hammersmith Health Books(Publisher)
11 Chapter 1 The problem of Lyme and other crypto-infections Microbes have coexisted with human beings since the dawn of time and, for better or worse, they have contributed intimately to the organic balance, not to mention the structure and components, of our cells. However, understanding the role of microbes in the genesis of diseases is a long-term task that is far from complete. New microbes emerge regularly, such as the SARS-CoV-2, the new coronavirus responsible for the Covid-19 pandemic. Lyme Disease: a critical moment in understanding infectious processes The microbes that cause Lyme Disease have caused one of the greatest controversies in the history of medicine. Lyme Disease is (usually) the consequence of an infection by the Borrelia burgdorferi bacterium, a small spring-like microbe that can be transmitted by various routes, but most often through the bite of a tick. The colossal number of publications devoted to it shows the intensity of debate surrounding the disease and the crucial nature of the scientific and therapeutic issues to which they relate. Lyme Disease sits at the crossroads of different complementary approaches to understanding and treating infectious diseases in general. Such an understanding has never been more 12 pressing than it is today after decades in which it was assumed infectious diseases were a problem of the past. Epidemics, and especially pandemics, occur regularly to remind humanity that they always are a problem of the present and the future
eBook - ePub- Karen C. Carroll, Michael A. Pfaller, Marie Louise Landry, Alexander J. McAdam, Robin Patel, Sandra S. Richter, David W. Warnock(Authors)
- 2019(Publication Date)
- ASM Press(Publisher)
12 ). Recent estimates by the CDC suggest that the true incidence is closer to 300,000 cases/year. Although endemic throughout most of Europe, Lyme borreliosis is a notifiable disease in only a few of the countries in which it occurs; nonetheless, over 85,000 cases/year were reported from 18 countries in 2006, and significant increases in rates of incidence have been documented in parts of this region as well.TAXONOMY
Borreliae belong to the order Spirochaetales, which encompasses the families Spirochaetaceae and Leptospiraceae. Within the Spirochaetacea, two genera, Borrelia and Treponema, cause human disease. Borreliae are agents of LBRF and both tick-borne Lyme borreliosis and relapsing fever. The type species of the genus Borrelia is Borrelia anserina, which causes borreliosis in birds. Based on rrs (16S rRNA gene) sequence analyses, spirochetes form a distinct entity (division D) within the eubacterial kingdom. They are neither Gram positive nor Gram negative. In the case of the spirochetes, morphological criteria and DNA data produce concordant phylogenies, a rare trait in other bacterial groups.DESCRIPTION OF THE GENUS
Common Characteristics
Borreliae (Fig. 2 and 3 ) are similar in length (8 to 30 μm) to, but wider (0.2 to 0.5 μm) than, the two other human-pathogenic spirochetes, the treponemes and the leptospires (13 ). They are highly motile organisms, with corkscrew and oscillating motility enabling movement through highly viscous mediums, such as connective tissue. In contrast to the exoflagella of other bacteria, the flagella of spirochetes are endoflagella. The endoflagella (7 to 20 per terminus) are localized beneath the outer membrane and insert subterminally at one end or the other of the protoplasmic cylinder. The protoplasmic cylinder consists of a peptidoglycan layer and an inner membrane which encloses the internal components of the cell (13 ). If cultivable, borreliae grow slowly under microaerophilic (14 ) or anaerobic (15
eBook - ePub- Debra C. Sellon, Maureen Long(Authors)
- 2013(Publication Date)
- Saunders(Publisher)
Chapter 33Lyme Disease
Thomas J. DiversEtiology
Lyme Disease is caused by at least three strains of the spirochete Borrelia burgdorferi sensu lato complex,1 ,2which includes several worldwide species and multiple variants of each species. The North American strain is B. burgdorferi sensu stricto,3 which may have several strain variations.4 In Europe, B. afzelii and B. garinii are responsible for most cases of Lyme Disease.5 In Asia, B. garinii is most common. Borrelia burgdorferi organisms are helical-shaped, gram-negative, unicellular spirochetes with flagellar projections.6 Borrelia burgdorferi bacteria are not free-living organisms and quickly die outside a host. They are maintained in a 2-year enzootic life cycle that involves ixodid ticks (Ixodes scapularis in the eastern United States and I. pacificus on the west coast of North America) and mammals.6 The white-footed mouse, which provides a continual source of the spirochete, and deer, which maintain the tick vector, are the most common mammals involved in maintaining the life cycle of this spirochete (Fig. 33-1 ).Figure 33-1 Two-year enzootic cycle of Borrelia burgdorferi and distinguishing features of Ixodes species ticks. Inset, Female ventral abdomen.Epidemiology
The seroprevalence of B. burgdorferi in horses in the United States is not known but is likely much higher than in humans but with similar geographic distribution (Fig. 33-2 ). The mid-Atlantic and northeastern states have a high seroprevalence, as do areas of Minnesota and Wisconsin extending into southern Canada. Seropositive horses are rare in the Rocky Mountain states, the Dakotas, Nebraska, and some other areas of the United States. In one New England survey, 45% of horses had Borrelia antibodies.7 In a Wisconsin study, 118 of 190 horses were serologically positive.8 In central Europe, there is a high level of antibody positive horses.9 –11
eBook - ePub- Peter Lydyard, Michael Cole, John Holton, Will Irving, Nino Porakishvili, Pradhib Venkatesan, Kate Ward(Authors)
- 2023(Publication Date)
- CRC Press(Publisher)
B. burgdorferi.- ■ B. burgdorferi undergoes antigenic variation and modulates the expression of Osps on the cell surface during infection.
- ■ The pathogenesis of Lyme Disease is not well understood.
- ■ Tissue injury results from the inflammatory response mounted against the borreliae.
- ■ Chemokines may be the principal mediators of inflammation in Lyme Disease.
3. WHAT IS THE TYPICAL CLINICAL PRESENTATION AND WHAT COMPLICATIONS CAN OCCUR?- ■ Lyme Disease can be divided into three stages: (1) erythema migrans and some associated symptoms; (2) intermittent arthritis, cranial nerve palsies and nerve pain, atrioventricular node block, and severe malaise and fatigue; (3) prolonged arthritis, chronic encephalitis, myelitis, and parapareses (partial paralysis of the lower limbs).
- ■ The manifestations of Lyme Disease are related to the particular genospecies of Borrelia involved.
4. HOW IS THE DISEASE DIAGNOSED, AND WHAT IS THE DIFFERENTIAL DIAGNOSIS?- ■ In patients with signs and symptoms consistent with Lyme Disease, a diagnosis is confirmed by antibody detection tests comprising an enzyme immunoassay (EIA) or immunofluorescence assay (IFA) followed by a Western immunoblot.
- ■ All specimens positive or equivocal by the EIA or IFA should be tested by a standardized Western immunoblot. Specimens negative by the EIA or IFA do not require further testing.
- ■ The following conditions should be considered in the differential diagnosis: calcium pyrophosphate deposition disease, fibromyalgia, gonococcal arthritis, gout, meningitis, psoriatic arthritis, rheumatoid arthritis, syncope, systemic lupus erythematosus, and urticaria.
5. HOW IS THE DISEASE MANAGED AND PREVENTED?
eBook - ePubHot Science
Battling infection in the modern world
- Meera Senthilingam(Author)
- 2020(Publication Date)
- Icon Books(Publisher)
122 bitten her without her knowing. Not all ticks carry the infectious bacteria, just ones that have recently bitten animals infected with the disease, such as deer, mice and squirrels. The risk of Lyme Disease has increased over time, with the disease now present in the United States, most of Europe and forested areas in Asia. Around 30,000 cases of Lyme Disease are reported to the US Centers for Disease Control and Prevention each year, but the agency estimates as many as ten times that number may get the disease annually. In Europe, it’s estimated that 360,000 people have contracted the disease over the last two decades.The case of the woman from Virginia highlights the ease with which Lyme Disease transmits, as she had simply gone for a walk in the woods, something she may do regularly, and had not felt a tick embed into her skin as it bit her. People rarely do. But her case also highlights another crucial point about infectious diseases today – the sheer number of them we contract from animals, either directly or through vectors such as ticks or mosquitoes. These pathogens humans share with animals, known as zoonoses, are responsible for more than 60 per cent of the infectious diseases we see in humans and, importantly, some of the worst epidemics and pandemics we have experienced to date: HIV, Ebola, swine flu. It’s estimated that three out of every four new or emerging infectious diseases in people are contracted from animals, mostly wildlife, meaning global health experts must keep a close eye on the animals we find ourselves in the company of. ‘All diseases that are endemic today in humans, likely came from an animal,’ says Dr David Heymann, Professor of Infectious Disease Epidemiology at the London School of Hygiene and Tropical Medicine, adding that if we look at the diseases we know today, they probably got into human populations 123 from an animal, circulated for a while and became endemic. Heymann explains that there are typically three pathways that can occur when an animal infection reaches humans: the first is that an infection enters some humans and goes no further, like rabies; the second is that an infection emerges and spreads between people but doesn’t prolong, like Ebola or avian influenza; and the third is when a disease goes into populations and becomes endemic, like HIV.Today, the boundaries between animals and humans are dissolving, making the crossover of infections more common. Human populations are growing in size and people are moving further into new or unknown territories; communities are becoming more dense and more mobile; animal farming practices have become both wider in scale and more poorly managed and monitored; forests are being cleared, bringing humans closer to the wildlife within them; and many populations are increasingly relying on wild animals, or bush meat, for food. These factors all play a part, for example, in how Ebola outbreaks begin: people enter forests and come into contact with animals infected with the virus, promptly contracting it through contact with the animals’ bodily fluids or by consuming their meat.
- Ian D Penman, Stuart H. Ralston, Mark W J Strachan, Richard Hobson(Authors)
- 2022(Publication Date)
- Elsevier(Publisher)
burgdorferi, which occurs in the USA, Europe, Russia, China, Japan and Australia. In Europe, two additional genospecies are also encountered, B. afzelii and B. garinii. The reservoir of infection is ixodid (hard) ticks that feed on a variety of large mammals, particularly deer. Birds spread ticks over a wide area. The organism is transmitted to humans via the bite of larval, nymphal or adult ticks. Ehrlichiosis is a common co-infection with Lyme Disease. Two forms occur: Anaplasma phagocytophilum, human granulocytic anaplasmosis (HGA); and Ehrlichia chaffeensis, human monocytic ehrlichiosis (HME). Clinical features There are three stages of disease. Progression may be arrested at any stage. • Early localised disease. The characteristic feature is a skin reaction around the site of the tick bite, known as erythema migrans (Fig. 13.24). Initially, a red ‘bull’s eye’ macule or papule appears 2–30 days after the bite. It then enlarges peripherally with central clearing and may persist for months. Atypical forms are common. The lesion is not pathognomonic of Lyme Disease since similar lesions can occur after tick bites. Acute manifestations, such as fever, headache and regional lymphadenopathy, may develop with or without the rash. • Early disseminated disease. Dissemination occurs via the blood stream and lymphatics. There may be a systemic reaction with malaise, arthralgia and, occasionally, metastatic areas of erythema migrans (see Fig. 13.24). Neurological involvement may follow weeks or months after infection. Common features include lymphocytic meningitis, cranial nerve palsies (especially unilateral or bilateral facial nerve palsy) and peripheral neuropathy. Radiculopathy, often painful, may present a year or more after initial infection. Carditis, sometimes accompanied by atrioventricular conduction defects, occurs in the USA but is rare in Europe. • Late disease. Late manifestations include arthritis, polyneuritis and encephalopathy
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