When Vector-Borne Infections Impact Entire Households: A One Health Case Study

A One Health Case Study

https://www.mdpi.com/2076-0817/14/2/110

Introduction

In a recent study, researchers investigated a family—including parents, two daughters, a son, two dogs, and a rabbit—all experiencing neurological symptoms. They discovered infections from bacteria like Bartonella quintana, Bartonella henselae, and Babesia divergens-like MO-1 across family members and pets. Notably, the youngest daughter suffered from prolonged heavy menstrual bleeding, which improved with antibiotics. One dog developed serious health issues, including a splenic hematoma and later, spinal cancer. This case underscores the importance of a One Health approach, which considers the interconnected health of humans, animals, and the environment.

Family-Wide Infection and Symptom Overview

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This family suffered from a range of neurological, systemic, and inflammatory symptoms, with each member displaying a unique pattern of infection. These infections were likely transmitted through household exposure, reinforcing the idea that when one family member is affected, others are at risk too—even if their infections manifest differently.

Symptoms and Infections by Family Member

• Father: Neck pain, shortness of breath, irritability, rage, anxiety attacks, depression, headaches, leg pain, and paresthesia.
  
  • Infections detected: Bartonella quintana, Babesia divergens
• Mother: Ocular migraines.
  
  • Infections detected: Bartonella quintana
• Older Daughter: Fatigue, confusion, memory loss, insomnia, headaches, prolonged menorrhagia (130 days), and weight gain.
  
  • Infections detected: Bartonella quintana, Babesia divergens
• Younger Daughter: Vertigo, joint pain (elbows and ankles).
  
  • Infections detected: Bartonella quintana, Babesia divergens
• Son: Memory loss, rage, aggression, irritability, anxiety, depression, ocular pain, leg pain, paresthesia, weight gain.
  
  • Infections detected: Bartonella quintana, Bartonella henselae, Bartonella spp.

Pets and Their Role in Disease Transmission

• Dog 1: Developed a splenic hematoma and later spinal cancer. Tested positive for Bartonella spp.
• Dog 2: No visible symptoms but tested positive for Bartonella spp.
• Rabbit: Tested positive for Bartonella spp.
• Foster puppy: Not tested.

Vectors Identified

Fleas collected from the home, dogs, and rabbit included:

• Ctenocephalides felis (cat flea)
• Ctenocephalides canis (dog flea)

Key Takeaways and Implications mirroring what I have seen in my own practice:

1. When one family member is impacted, it is very likely that others will also have infections—but these infections may not be identical. This study demonstrates the complexity of vector-borne diseases (VBIs), where each individual may have a different set of pathogens and symptoms.
2. Unfortuantely, people with pets are at higher risk for chronic VBIs, even without a history of flea infestations. Pets can serve as silent carriers of infections, contributing to long-term exposure within the household.
3. Treating the whole family—including pets—may be necessary for full recovery. Without addressing all reservoirs of infection, reinfection can prevent symptom resolution.
4. No one in this family tested positive for Borrelia (Lyme disease), despite significant symptoms. This highlights a crucial issue: many VBIs labeled as 'co-infections' may actually be the primary drivers of illness. Unfortunately, a negative Lyme test often leads to an assumption that vector-borne diseases are not present, preventing further investigation.

A One Health Approach is Essential

This case study reinforces the need for broader diagnostic strategies that go beyond Lyme disease and incorporate the full spectrum of vector-borne infections. A collaborative medical and veterinary approach can significantly improve health outcomes by preventing reinfection cycles and ensuring that all potential reservoirs of infection—both human and animal—are addressed.

Conclusion

By shifting the focus from Lyme disease alone to a comprehensive vector-borne infection model, we can better identify, treat, and prevent chronic infections. This case study serves as a compelling reminder that infectious diseases do not exist in isolation—they affect families, pets, and entire households. A One Health approach offers the best chance for successful treatment and long-term health improvement.

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