Babesiosis in Fairfield County, Connecticut

Expansion of zoonotic babesiosis and reported human cases, Connecticut, 2001-2010

To document the expansion of human babesiosis in Connecticut, we analyzed reservoir host sera for seroreactivity to Babesia microti Franca and reviewed Connecticut human surveillance case data collected during 2001-2010. Sera from white-footed mice, Peromyscus leucopus Rafinesque, from 10 towns in 5 counties, collected at 4-7-yr periods between 2001 and 2010, were tested for total immunoglobulins. The prevalence of B. microti-positive mice was compared with confirmed and probable human case reports tabulated by the Connecticut Department of Public Health. The highest babesiosis and rodent seroprevalence rates were in New London County, where this protozoan disease was first documented in the state. However, human cases and reservoir host infection increased significantly from 2001-2005 to 2005-2010 and in other parts of the state. Clinicians should be aware that the disease is not confined to long-established endemic areas of the state.

Efficacy and environmental persistence of nootkatone for the control of the blacklegged tick (Acari: Ixodidae) in residential landscapes

The ability of the plant-derived compound nootkatone to control nymphs of the blacklegged tick, Ixodes scapularis Say, was evaluated at lawn perimeter plots at homes in Lyme disease endemic areas of Connecticut. Three formulations of nootkatone ranging from 0.05 to 0.84% (0.06 - 1.03 g AI/m2) were applied by a hydraulic sprayer from 2008 to 2010. In 2008, the 0.84% emulsifiable nootkatone formulation provided 100% control of I. scapularis through week 1, but declined to 49 and 0% by 2 and 3 wk posttreatment, respectively. A combination of 0.05% nootkatone and entomopathogenic fungus, Metarhizium brunneum Petch F52, resulted in 50% control for the first week posttreatment and no control in subsequent weeks. The 0.84% emulsifiable nootkatone formulation was phytotoxic, although no damage was observed with the 0.05% formulation with Metarhizium. Residual analysis of nootkatone collected on filter paper disks showed that > or = 95% of the emulsified nootkatone for both formulations was lost within 7 d after application. A lignin-encapsulated nootkatone formulation (0.56 and 0.46% in 2009 and 2010, respectively) provided 100% control of I. scapularis for 8 wk in 2009 and, in 2010, 67% control at approximately 1 wk posttreatment with respect to the pretreatment counts, although there was no difference in tick abundance posttreatment. A 0.60% Maillard-reaction encapsulated nootkatone formulation in 2010 provided a similar level of control (62%). Nootkatone in the lignin and Maillard formulations were more persistent than the emulsifiable formulation. Little or no phytotoxicity was observed with the encapsulated formulations. Encapsulating nootkatone reduced phytotoxicity and appeared to reduce environmental loss. While nootkatone can provide effective tick control, further work is needed to refine formulations to address phytotoxicity, yet provide sufficient material to control ticks.

Babesiosis in Lower Hudson Valley, New York, USA

Cases were associated with tick bites and receipt of blood products.

Although Lyme disease has been endemic to parts of the Lower Hudson Valley of New York, United States, for >2 decades, babesiosis has emerged there only since 2001. The number of Lower Hudson Valley residents in whom babesiosis was diagnosed increased 20-fold, from 6 to 119 cases per year during 2001–2008, compared with an ≈1.6-fold increase for the rest of New York. During 2002–2009, a total of 19 patients with babesiosis were hospitalized on 22 occasions at the regional tertiary care center. Concurrent conditions included advanced age, malignancies, splenectomy, and AIDS. Two patients acquired the infection from blood transfusions and 1 from perinatal exposure, rather than from a tick bite. One patient died. Clinicians should consider babesiosis in persons with fever and hemolytic anemia who have had tick exposure or have received blood products.

Transfusion-transmitted Babesia spp.: bull's-eye on Babesia microti

Babesia spp. are intraerythrocytic protozoan parasites of animals and humans that cause babesiosis, a zoonotic disease transmitted primarily by tick vectors. Although a variety of species or types of Babesia have been described in the literature as causing infection in humans, the rodent parasite Babesia microti has emerged as the focal point of human disease, especially in the United States. Not only has B. microti become established as a public health concern, this agent is increasingly being transmitted by blood transfusion: estimates suggest that between 70 and 100 cases of transfusion-transmitted Babesia (TTB) have occurred over the last 30 years. A recent upsurge in TTB cases attributable to B. microti, coupled with at least 12 fatalities in transfusion recipients diagnosed with babesiosis, has elevated TTB to a key policy issue in transfusion medicine. Despite clarity on a need to mitigate transmission risk, few options are currently available to prevent the transmission of B. microti by blood transfusion. Future mitigation efforts may stress serological screening of blood donors in regionalized areas of endemicity, with adjunct nucleic acid testing during the summer months, when acute infections are prevalent. However, several hurdles remain, including the absence of a licensed blood screening assay and a thorough cost-benefit analysis of proposed interventions. Despite current obstacles, continued discussion of TTB without proactive intervention is no longer a viable alternative.

Babesia microti, upstate New York

Five cases of human babesiosis were reported in the Lower Hudson Valley Region of New York State in 2001. An investigation to determine if Babesia microti was present in local Ixodes scapularis ticks yielded 5 positive pools in 123 pools tested, the first detection of B. microti from field-collected I. scapularis in upstate New York.

Human babesiosis – an unrecorded reality

Human babesiosis, caused by parasitic protozoa of erythrocytes, has escaped usual associates--lower mammals. Thriving in tick guts, it has spread inland from the coasts of America, adopting mankind as a host. Babesia spp. threaten life quality of unsuspecting humans in quickly expanding territories worldwide, including the state of Pennsylvania, USA. The causative spirochetes of Lyme disease often similarly co-exist in ticks. Singly or together they may, by causing persistent and chronic infections, duplicate any symptom in the medical literature--including depression and hypochondriasis. Physicians practicing throughout Pennsylvania have identified patients with symptomatic babesiosis, but without governmental surveillance or health registries that require doctors to consider and report babesiosis, these cases have not prompted epidemiological concern. Misunderstandings such as, "Isn't that an obscure tropical disease?" are usual responses when doctors are asked about babesiosis, inadvertently trivializing patients and disease. Mandatory reporting of babesiosis should now be considered a medical necessity.