Introduction

Definition of bartonellosis

The word Bartonellosis refers to any infectious disease caused by the bacteria Bartonella.¹ Infection with any of these bacteria is referred to broadly as bartonellosis, however, some forms of infection have common names (for example, cat scratch disease).²

Common types of bartonella species

Bartonella henselae (Cat Scratch Disease): It can be transmitted through scratches or bites from infected cats, leading to symptoms such as fever, swollen lymph nodes.³ 

Bartonella bacilliformis (Carrion’s Disease): It is spread by sandflies, particularly in the Andean regions of South America, this disease has two phases: an Oroya fever (during this phase, fever, headache, muscle aches, abdominal pain, and severe anaemia may occur) and chronic skin lesions (verruga peruana).⁴

Bartonella quintana (Trench Fever): Due to the high number of cases among soldiers living in crowded trenches under unsanitary conditions in WWI, infection with B. quintana was known as "trench fever”. This infection is transmitted by body lice and presents with symptoms including fever, bone pain and skin lesions.⁵

Importance of prevention and control

Impact on Public Health: Bartonellosis can cause serious health problems, such as severe fevers and chronic diseases. These diseases have the potential to significantly damage both quality of life and public health resources.

Significance of Effective Measures to Reduce Incidence: Effective prevention and control methods are critical for lowering the risk of Bartonellosis, reducing the strain on healthcare systems, and improving overall public health.

Transmission pathways

Understanding how Bartonella species are transmitted is critical to establishing effective preventative and control measures:

Vector transmission

Fleas: Fleas are the primary vector for causing Bartonella henselae. Fleas infest cats and can spread the bacteria to humans through scratches or bites from infected animals.⁶

Sand flies: Bartonella bacilliformis, also known as South American bartonellosis, which spreads through the bites from infected sand flies. It is exclusively found in the Andes Mountains of western South America.⁷

Lice: The human body louse bites people and infects them with Bartonella quintana. Body lice are transmitted from person to person via close personal contact or shared clothing or bedding. B. quintana infection is most typically linked to body louse infestations in densely populated areas and poor sanitation.⁸

Animal-to-human transmission

Contact with infected cats: Bartonella henselae is usually transmitted through contact with infected cats. Infected cats can spread the infection by scratching, biting or licking a person's open wound.⁹ 

Human-to-human transmission

Human-to-human transmission of Bartonella species is rare, but it can happen in certain conditions, like blood transfusion, which has been recognised as a risk factor for the spread of Bartonella infections ¹⁰

Preventive measures

Personal protection

Avoiding contact with infected animals

Prevention of Bartonella henselae (Cat Scratch Disease) can be accomplished by avoiding contact with infected animals and avoiding being scratched or bitten. Taking appropriate care of the cats, regular treatment to eradicate cat fleas, washing hands after playing with them and keeping them indoors as much as possible will help reduce the spread of the disease.¹¹

Use of protective clothing and repellents

To avoid sand fly bites, use EPA (Environmental Protection Agency)-registered insect repellents and wear long-sleeved shirts and pants in locations where B. bacilliformis is abundant (South America).¹²

Personal hygiene

Avoid being exposed to human body lice. Body lice are often related to overcrowded living conditions and where there is limited access to bathing and clean clothing. Do not share beds, bedding, clothing or towels worn by someone who may have body lice. Access to regular showering and laundry services is crucial for preventing Bartonella quintana infection among persons living in communal shelters or without housing. When washing clothing or bedding that may be infested with body lice, use hot water above 55 degrees Celsius (130 degrees Fahrenheit) and dry on high heat to kill lice and their eggs.¹³

Environmental controls

Pet hygiene

Cats and dogs should be safeguarded from flea infestations all year long by regularly using acaricides (chemicals used to kill ticks and mites) in the form of collars, spot-on or spray-on treatments, or oral formulations. Furthermore, both humans and pets should avoid interacting with stray dogs and cats.

Vector control

As vaccines are not available to prevent infection, flea, sandfly, and lice control are the only effective measures for preventing this vector-borne infection in healthy animals, reducing the spread of these bacteria and lowering the risk of zoonotic pathogen transmission to humans.¹⁴

Education and awareness

Public education

Patients should be educated about Bartonellosis, including its symptoms, transmission routes, and prevention methods. For example, washing and cleansing any wounds immediately after a cat scratch or bite is necessary.¹⁵

Control measures for infected individuals

Diagnosis and treatment

Early diagnosis

Early identification of Bartonellosis is critical to effective treatment. Diagnosis is made through tests such as serology (scientific study or diagnostic examination of blood serum), PCR (Polymerase Chain Reaction), and blood cultures. Individuals with symptoms such as fever, swollen lymph nodes, or skin sores should seek medical assistance right away.¹⁶

Medical management

Treatment varies according to the specific Bartonella species involved:

Cat Scratch Fever: Cat scratch disease normally goes away on its own, therefore, therapy is usually to alleviate your symptoms in the meantime. Your doctor may give the antibiotic azithromycin to try to get rid of the bacteria. This is normally only done if you have a weakened immune system or if your symptoms persist for more than a few months.¹⁷

Carrion’s Disease: The treatment of choice for Carrion disease in the systemic phase is ciprofloxacin and chloramphenicol for 14 days in adults and amoxicillin plus clavulanic acid for 14 days in children. In the cutaneous (relating to or affecting the skin) phase of Carrion disease, the treatment of choice is azithromycin as a first-line treatment and erythromycin, ciprofloxacin, and rifampicin as second-line treatment.¹⁸

Trench Fever: The recommended treatment for trench fever is oral Doxycycline 200 mg once daily for four weeks and intravenous gentamicin 3 mg/kg for two weeks.¹⁹

Isolation and care

Guidelines for managing infected individuals

While Bartonellosis is not very contagious, providing appropriate care to sick persons is critical, which includes appropriately covering wounds or skin lesions and exercising excellent hygiene to prevent transmission, particularly in healthcare settings. If immunosuppressed people or young children's pets are found to be bacteremic (presence of bacteria in the bloodstream), antibiotic treatment and routine acaricide use are recommended.²⁰

Future strategies

Advancements in vaccines

In the framework of One Health, the authors support the future development of vaccinations to protect pets against infection with B. henselae, reducing reservoir potential and zoonotic concerns.²¹

Frequently asked questions (FAQs)

Q1. What is bartonellosis?

A1. Bartonellosis refers to diseases caused by bacteria of the Bartonella genus. Common types include Cat Scratch Fever (Bartonella henselae), Carrion’s Disease (Bartonella bacilliformis), and Trench Fever (Bartonella quintana). Each variety has unique symptoms and transmission routes.

Q2. How is bartonella transmitted?

A2. Bartonellosis can be transmitted through:

• Vector transmission: Fleas transmit Bartonella henselae, sand flies transmit Bartonella bacilliformis, and lice transmit Bartonella quintana
• Animal-to-human transmission: Bartonella henselae is commonly transmitted from cats to humans through scratches or bites
• Human-to-human transmission: Rare, but possible through blood transfusions or organ transplants from infected individuals

Q3. What are the main preventive measures for Bartonellosis?

A3. Preventive measures include:

• Avoid contact with infected animals: Especially cats showing symptoms of illness
• Using protective clothing and repellents: Wear long sleeves and pants, and apply insect repellents
• Maintaining pet hygiene: Regular grooming and flea control for pets
• Controlling vectors: Reducing flea, sandfly, and lice populations in the environment
• Public education and professional training: Raising awareness and educating healthcare providers

Q4. What are the symptoms of bartonellosis?

A4. Symptoms vary depending on the type of Bartonellosis:

• Cat Scratch Disease: Fatigue, swollen lymph nodes, and fever
• Carrion’s Disease: Acute fever, anaemia, and skin lesions (verruga peruana) in the chronic phase
• Trench Fever: Periodic fevers, severe headache, and muscle and bone pain

Q5. How is bartonellosis diagnosed and treated?

A5. Diagnosis is made through tests such as serology, PCR, and blood cultures. Treatment typically involves antibiotics like doxycycline, azithromycin, or rifampin, depending on the Bartonella species and clinical presentation.

Q6. Are there any vaccines for bartonellosis?

A6. Currently, there are no vaccines available for Bartonellosis. The ongoing research goal is to develop vaccines. Supporting research and advancements in vaccine development are essential for long-term prevention.

Q7. What are the challenges in preventing and controlling bartonellosis?

A7. Challenges include antibiotic resistance, which complicates treatment, and limitations in current vector control methods. Addressing these challenges requires ongoing research, innovative prevention strategies, and improved vector management.

Q8. What should individuals do if they suspect they have bartonellosis?

A8. Individuals who suspect they have Bartonellosis should seek medical attention promptly. Early diagnosis and treatment are important for managing symptoms and preventing complications. Healthcare providers will conduct appropriate tests and recommend the necessary treatment.

Summary

Bartonellosis, caused by numerous Bartonella species, poses important public health issues due to its multiple transmission mechanisms and risk of chronic illness. Effective prevention and control necessitate a multimodal approach that includes personal safety, environmental controls, public education, and timely medical care. Addressing the issues of rising resistance and limits in current methods is critical to future success. Continued research and development are critical for enhancing preventative tactics and treatment options. Working collaboratively, we can lower the prevalence of Bartonellosis and improve outcomes for those who are affected.