Table 2.

Key Bartonella quintana Knowledge Gaps and Associated WHO Criteria for Classifying a Condition as a Neglected Tropical Disease

WHO Criteria for Neglected Tropical Disease Classification	Key Knowledge Gaps
1. Disproportionately affect populations living in poverty and cause important morbidity and mortality—including stigma and discrimination.	Risk factors for B quintana infection in LMICs are poorly defined and largely extrapolated from studies in high-income countries. Case-control studies in LMICs are lacking. Morbidity and mortality due to B quintana infection and endocarditis are poorly characterized in LMICs. Long-term cohort studies of B quintana infection and infective endocarditis are lacking, as well as prevalence studies among individuals with heart failure and embolization such as stroke. Qualitative research on pediculosis-related stigma and discrimination is absent. The effect of ectoparasitosis on employment, social mobility, and marriageability is not well studied.
2. Primarily affects populations living in tropical and subtropical areas.	While a Europe-Africa gradient has been proposed, comparative prevalence studies among countries do not exist. With few exceptions (eg, Tygerberg Endocarditis Cohort–South Africa), existing data predominantly rely on diagnostics performed outside LMICs, reflecting the need for diagnostic capacity in referral laboratories in LMICs.
3. Is immediately amenable to broad control, elimination, or eradication by applying ≥1 of the 5 public health strategies adopted by the Department for Control of Neglected Tropical Diseases.	Studies evaluating the role of oral chemotherapy to prevent the progression from infection to endovascular disease are lacking. Environmental stability of B quintana on shared bedding/clothing and its role in transmission is poorly defined. Transmission in LMICs is poorly characterized. Many case reports of patients with B quintana infective endocarditis acquired in LMICs deny previous pediculosis, suggesting alternate forms of transmission. Case-control, contact tracing, and additional vector studies are required.
4. Is relatively neglected by research—specifically, resource allocation is not commensurate with the magnitude of the problem.	Little to no investment in most aspects of Bartonella research—The Steven & Alexandra Cohen Foundation being a recent exception. Bartonella research needs, stakeholders, and existing projects have not been mapped.

Abbreviations: LMICs, low- and middle-income countries; WHO, World Health Organization.