The use of ivermectin to kill ixodes scapularis ticks feeding on humans.

OBJECTIVE: The purpose of this study was to determine whether 400 µg/kg oral ivermectin is able to kill Ixodes scapularis nymphs and adult female ticks feeding on humans. METHODS: Ten study subjects each wore 2 ostomy bags, the one containing 24 I scapularis nymphs, and the other containing 24 I scapularis adult females. Twenty-four hours after the ostomy bags were attached, study subjects received either 400 µg/kg ivermectin or placebo. Thirty hours after the ivermectin or placebo was consumed, the ticks were removed, and mortality determined in a double-blinded manner. RESULTS: Eleven percent of the I scapularis nymphs attached in the ivermectin group compared with 17% in the placebo. Mortality for the I scapularis nymphs that attached at the time of removal was 55% in the ivermectin group and 47% in the placebo group. Mortality for the I scapularis nymphs 5 days after removal was 92% in the ivermectin group and 88% for the placebo. Three percent of the I scapularis adults attached in the ivermectin group compared with 9% in the placebo group. Mortality for I scapularis adults was 0% on day 3 and 33% on day 8 for both the ivermectin and placebo groups. There were statistically insignificant differences in the mortality rates between I scapularis nymphs and adults exposed to ivermectin or placebo. CONCLUSIONS: There were a high number of ticks that died in both groups but the data do not support our hypothesis that ivermectin can kill I scapularis. The study was not designed to determine whether it could prevent the transmission of tick-borne illness.

Ivermectin causes Cimex lectularius (bedbug) morbidity and mortality.

BACKGROUND: Bedbug infestations are increasing across North America and Europe, with more people presenting to Emergency Departments for treatment. Physicians cannot provide substantive treatment for people affected by bedbugs. STUDY OBJECTIVE: To determine if ivermectin, a relatively inexpensive and safe, long-acting oral anti-parasitic drug is able to cause bedbug morbidity and mortality. METHODS: We evaluated the effects of ivermectin on bedbugs using an artificial feeding membrane and mice and humans. Bedbug morbidity, mortality, and nymph molting was recorded. RESULTS: Using an artificial feeding membrane, bedbug mortality was 98% (n = 81) for 260 ng/mL ivermectin and 0% for 0 ng/mL ivermectin (control; n = 90) after 13 days. Mortality for bedbugs fed on mice injected with the human equivalent of 200 µg/kg ivermectin was 86% (n = 22), vs. 0% in the 0 µg/kg ivermectin (control; n = 21). Of the surviving nymphs, 0% exposed to ivermectin molted by day 75, vs. 80% in the control group by day 8. Bedbugs that fed once on human study subjects 3 h after consuming 200 µg/kg of oral ivermectin had a 63% (n = 24) 20-day mortality rate, vs. 8% (n = 24) in the control group. Of the surviving nymphs, 0% (n = 5) in the 3-h ivermectin group molted, vs. 80% (n = 10) of the control group. CONCLUSIONS: It may be possible that ivermectin could help eradicate, suppress, or prevent a bedbug infestation.

Initial assessment of the ability of ivermectin to kill Ixodes scapularis and Dermacentor variabilis ticks feeding on humans.

OBJECTIVE: The purpose of this study was to determine Ixodes scapularis and Dermacentor variabilis tick mortality when fed on humans who have consumed 400 µg/kg oral ivermectin. METHODS: Six study subjects, 3 in each group, were randomly assigned to receive either 400 µg/kg ivermectin or placebo in a blinded manner. After consuming either ivermectin or placebo, each study subject had 2 colostomy bags attached to his or her abdomen. One of the colostomy bags contained 7 I scapularis nymphs and 7 adults. The other colostomy bag contained 7 D variabilis nymphs and 7 adults. Tick mortality was recorded over the next 24 hours. RESULTS: Fifty-five percent (6 of 11) of the attached I scapularis nymphs exposed to ivermectin had morbidity (3 of 11) or died (3 of 11), compared with 0% morbidity and mortality in the 2 I scapularis nymphs that attached in the placebo group. No I scapularis adults or D variabilis nymphs attached to feed. Among D variabilis adults that attached to feed, there was a 0% mortality rate for both the placebo group (0 of 6) and the ivermectin group (0 of 8). CONCLUSIONS: We demonstrate a novel method to confine ticks to human subjects to study tick-borne diseases. While there was a trend toward I scapularis morbidity and mortality in the ivermectin arm, the low number of ticks that attached in the placebo group limited our analysis. Most ticks began feeding in the last 12 hours of the experiment, significantly limiting their exposure to ivermectin. Ivermectin does not cause early death in D variabilis adults.

Neuropsychiatric and socioeconomic status impact antiretroviral adherence and mortality in rural Zambia.

We conducted a prospective cohort study of 496 adults starting antiretroviral treatment (ART) to determine the impact of neuropsychiatric symptoms and socioeconomic status on adherence and mortality. Almost 60% had good adherence based upon pharmacy records. Poor adherence was associated with being divorced, poorer, food insecure, and less educated. Longer travel time to clinic, concealing one's human immunodeficiency virus (HIV) status, and experiencing side effects predicted poor adherence. Over a third of the patients had cognitive impairment and poorer cognitive function was also associated with poor adherence. During follow-up (mean 275 days), 20% died-usually within 90 days of starting ART. Neuropsychiatric symptoms, advanced HIV, peripheral neuropathy symptoms, food insecurity, and poverty were associated with death. Neuropsychiatric symptoms, advanced HIV, and poverty remained significant independent predictors of death in a multivariate model adjusting for other significant factors. Social, economic, cognitive, and psychiatric problems impact adherence and survival for people receiving ART in rural Zambia.

Antiretroviral adherence in rural Zambia: the first year of treatment availability.

We conducted a retrospective chart review of antiretroviral therapy (ART) clinic patients treated during the first 12 months after clinics opened in rural Zambia and assessed adherence based on clinic attendance, patient report, and staff assessment. We identified 255 eligible patients (mean age, 39.7 years; 44.3% male; 56.5% married; and 45.5% with only primary school education). Twenty percent had partners known to be HIV positive. Twenty percent were widowed. Thirty-seven percent had disclosed their HIV status to their spouse. Disclosure was less likely among women (27.5% versus 49.6%, P = 0.0005); 36.5% had "clinic buddies" to provide adherence support. Adherence rates were good for 59.2%. Disclosure of HIV status to ones' spouse (P = 0.047), knowing spouses' HIV status (P = 0.02), and having a clinic buddy (P = 0.01) were associated with good adherence. Social support is a key patient-level resource impacting ART adherence in rural Zambia. Limited spousal disclosure affects women more than men. Clinic buddies are associated with better adherence.