Terri L. Meinking

Aging, Acculturation, Salt Intake, and Hypertension in the Kuna of Panama

The indigenous Kuna who live on islands in the Panamanian Caribbean were among the first communities described with little age-related rise in blood pressure or hypertension. Our goals in this study were to ascertain whether isolated island-dwelling Kuna continue to show this pattern, whether migration to Panama City and its environs changed the patterns, and whether the island-dwelling Kuna have maintained their normal blood pressure levels despite partial acculturation, reflected in an increased salt intake. We enrolled 316 Kuna participants who ranged in age from 18 to 82 years. In 50, homogeneity was confirmed by documentation of an O+ blood group. In 92 island dwellers, diastolic hypertension was not identified and blood pressure levels were as low in volunteers over 60 years of age as in those between 20 and 30 years of age. In Panama City, conversely, hypertension prevalence was 10.7% and exceeded 45% in those over 60 years of age (P < .01), blood pressure levels were higher in the elderly, and there was a statistically significant positive relationship between age and blood pressure (P < .01). In Kuna Nega, a Panama City suburb designed to maintain a traditional Kuna lifestyle but with access to the city, all findings were intermediate. Sodium intake and excretion assessed in 50 island-dwelling Kuna averaged 135 +/- 15 mEq/g creatinine per 24 hours, exceeding substantially other communities free of hypertension and an age-related rise in blood pressure. Despite partial acculturation, the island-dwelling Kuna Indians are protected from hypertension and thus provide an attractive population for examining alternative mechanisms.

Community control of scabies: a model based on use of permethrin cream

For 18 years treatment with lindane or crotamiton products has failed to stem the epidemic of scabies among the Kuna Indians in the San Blas islands of the Republic of Panama. Permethrin 5% cream was introduced as the only treatment in a programme to control scabies on an island of 756 inhabitants and involving workers recruited locally. Prevalence fell from 33% to less than 1% after every person was treated. As long as continued surveillance and treatment of newly introduced cases was maintained, prevalence of scabies remained below 1.5% for over 3 years. When supply of medication was interrupted for 3 weeks, prevalence rose to 3.6%. When control was lost after the US invasion of Panama, prevalence rose to 12% within 3 months. Bacterial skin infections decreased dramatically when scabies was controlled. Permethrin is safe and effective even in areas where this disease has become resistant to lindane.

Comparison of crotamiton 10% cream (Eurax) and permethrin 5% cream (Elimite) for the treatment of scabies in children.

Permethrin 5% cream (Elimite) was approved as a treatment for scabies by the U.S. Food and Drug Administration in September 1989. in a doubie‐biinded, randomized study, it was compared with crotamiton 10% cream (Eurax) for the treatment of scabies in children 2 months to 5 years of age. Two weeks after a singie overnight treatment, 14 (30%) of 47 chiidren were cured with permethrin 5% cream, in contrast to oniy 6 of 47 (13%) of subjects treated with Eurax. Four weeks after treatment the figures were 89% and 60% cured for the two agents, respectively. In 10 of the 19 patients whose treatment failed, the condition became worse after therapy. The difference in efficacy in favor of permethrin was significant (P = 0.002). That agent also demonstrated greater effectiveness in reducing pruritus and secondary bacterial infections. Eilmite offers a safe, efficacious, and cosmetically elegant aiternative to Eurax in the treatment of scabies in chiidren.

Permethrin 5% dermal cream: A new treatment far scabies

Permethrin 5% dermal cream (Burroughs Wellcome Co.) was compared in an investigator-blinded, randomized study against lindane 1% lotion (Kwell) for the treatment of microscopically confirmed scabies. Eleven of twenty-three patients treated with permethrin cream were cured in 2 weeks (48%). Only two patients had scabies 1 month following a single treatment with this product, giving a cure rate of 91%. One of these two patients was considered to have a reinfestation. Only three of twenty-three (13%) patients treated with 1% lindane lotion (Kwell) were free of scabies 2 weeks after a single treatment and fifteen of twenty-three (65%) were cured at 1 month. The unusually high percentage of treatment failures (35%) following lindane therapy may have been related to extensive use of this agent for head lice and scabies in this village during the preceding 5 years. The higher cure rate at 1 month seen with permethrin cream was significant (p less than 0.025). Permethrin 5% dermal cream offers a new, cosmetically elegant alternative to lindane therapy and was effective in a community in which lindane demonstrated an unacceptable level of treatment failures.

Topical 0.5% Ivermectin Lotion for Treatment of Head Lice

BACKGROUND The emergence of resistance to treatment complicates the public health problem of head-louse infestations and drives the need for continuing development of new treatments. There are limited data on the activity of ivermectin as a topical lousicide. METHODS In two multisite, randomized, double-blind studies, we compared a single application of 0.5% ivermectin lotion with vehicle control for the elimination of infestations without nit combing in patients 6 months of age or older. A tube of topical ivermectin or vehicle control was dispensed on day 1, to be applied to dry hair, left for 10 minutes, then rinsed with water. The primary end point was the percentage of index patients (youngest household member with ≥3 live lice) in the intention-to-treat population who were louse-free 1 day after treatment (day 2) and remained so through days 8 and 15. RESULTS A total of 765 patients completed the studies. In the intention-to-treat population, significantly more patients receiving ivermectin than patients receiving vehicle control were louse-free on day 2 (94.9% vs. 31.3%), day 8 (85.2% vs. 20.8%), and day 15 (73.8% vs. 17.6%) (P<0.001 for each comparison). The frequency and severity of adverse events were similar in the two groups. CONCLUSIONS A single, 10-minute, at-home application of ivermectin was more effective than vehicle control in eliminating head-louse infestations at 1, 7, and 14 days after treatment. (Funded by Topaz Pharmaceuticals [now Sanofi Pasteur]; ClinicalTrials.gov numbers, NCT01066585 and NCT01068158.).

A comparative trial of three treatment schedules for the eradication of scabies.

A trial of three treatment schedules, consisting of 1% gamma benzene hexachloride (GBH) lotion applied head to toe and left on the body for 2, 6, or 12 to 24 hours was conducted on an island of 2,076 persons, approximately 70% of whom had clinical evidence of scabies. The island is situated off the north coast of the Republic of Panama. Examination at 1 month after therapy showed that both the 6-hour and 12- to 24-hour cure rate was high (96% and 98%). There was a significantly lower cure rate in the 2-hour group, in which only 82% were cured. Eleven to twelve percent of the subjects became infested in all groups, presumably due to contact with untreated persons with scabies on the island. A single 6-hour application of 1% GBH lotion appears to be adequate therapy for scabies if properly applied. The entire population at risk should be treated at the same time if possible to reduce or eliminate the risk of infestation. No adverse reactions to 1% GBH lotion were observed.

The Clinical Trials Supporting Benzyl Alcohol Lotion 5% (UlesfiaTM): A Safe and Effective Topical Treatment for Head Lice (Pediculosis Humanus Capitis)

Abstract:  Benzyl alcohol lotion 5% (BAL 5%) is a non‐neurotoxic topical head lice treatment that is safe and effective in children as young as 6 months of age. The safety and efficacy of this pediculicide has been studied in 695 (confirm number) subjects in all phases of clinical development. Scanning electron micrographs (SEM) demonstrated that the active agent appears to stun the breathing spiracles open, enabling the vehicle to penetrate the respiratory mechanism (spiracles), therefore asphyxiating the lice. Initial phase II trials compared this novel product to RID® using identical volumes of treatment (4 oz/application) and yielding, almost, identical efficacy. This outcome pointed to the significant importance of completely saturating the hair with the product in order to achieve maximum treatment success. A second phase II trial, which allowed the use of sufficient product to saturate the hair, resulted in 100% efficacy after both 10 and 30 minute treatments. A third phase II trial verified an effective dose. Phase III trials compared BAL 5% to vehicle placebo for two 10‐minute applications. It proved to be safe and effective (p < 0.001) for treatment of head lice and is the first FDA‐approved non‐neurotoxic lice treatment, now available in the United States as UlesfiaTM lotion.

Isolation, Amplification, and Sequencing of Human Mitochondrial DNA Obtained from Human Crab Louse, Pthirus Pubis (L.), Blood Meals

The ability to identify individual human hosts based on analyses of blood recovered from the digestive tract of hematophagous arthropods has been a long-term pursuit in both medical and forensic entomology. Blood meal individualization techniques can bring important advancements to studies of vector-borne disease epidemiology. Forensically, these analyses may aid in assailant identification in violent crime cases where blood-feeding insects or their excreta are recovered from victims or at crime scenes. Successful isolation, amplification, and sequencing of human mitochondrial DNA obtained from adult human crab lice fed on human volunteers are reported. Adult lice were removed from recruited volunteers frequenting inner city health clinics. Live lice were killed by freezing and subsequently air dried at ambient temperature. A saliva sample was obtained from each volunteer and served as a DNA reference sample. Volunteers were afforded free, approved pediculosis treatment. Individual lice were subsequently processed using procedures developed for the extraction of mitochondrial DNA from human hair, teeth, and bone. The resulting DNA was amplified by the polymerase chain reaction and sequenced. Our results point to valuable avenues for future entomological research.

Age, renal perfusion and function in island-dwelling indigenous Kuna Amerinds of Panama.

Background/Aims: Among possible contributors to a progressive fall in renal perfusion and function with increasing age, some hypotheses have invoked the rise in blood pressure that occurs with age, and a high-protein diet typical of urban cultures. Kuna Amerinds residing in isolated islands off the Panamanian Coast have a very low protein intake and show no tendency for blood pressure to rise with age, thus providing an opportunity to test these hypotheses. Methods: We measured renal plasma flow and glomerular filtration rate (PAH and inulin clearance) in 16 Kuna Indians ranging in age from 18 to 86 years (51 ± 6 years) who have resided on Ailigandi, an isolated Panamanian island for all of their lives. Inulin and PAH were infused with a battery-driven pump for 60 min, and a metabolic clearance rate used to calculate inulin and PAH clearance. For comparison, we employed identical techniques in 29 residents of Boston, ranging in age from 19 to 79 years (52 ± 4 years), all normotensive and free of disease or medication use. Twenty-four were Caucasian. Results: The Bostonian controls showed the anticipated fall in PAH clearance with age (y = 806 – 4.9x; r = –0.82; f = 38.0; p < 0.0001). Our hypothesis was that the absence of a blood pressure rise with age and the low protein intake would flatten the slope relating renal perfusion to Kuna age. Our finding was a numerically steeper slope relating age and renal plasma flow in the Kuna (y = 936 – 6.48x; r = –0.81; p < 0.001). Filtration fraction rose with age in both populations, and again the rise was steeper in the Kuna. GFR in the Kuna, on the other hand, was very much higher at any age (139 ± 4 ml/min/1.73 m2) than in Bostonians (112 ± 3 ml/min/1.73 m2; p < 0.001). Conclusion: The findings are not in accord with the hypothesis that age-related changes in renal perfusion and glomerular filtration rate reflect an important contribution from blood pressure rise and a high protein intake, typical of modern, urban life.

Efficacy of a Reduced Application Time of Ovide Lotion (0.5% Malathion) Compared to Nix Creme Rinse (1% Permethrin) for the Treatment of Head Lice

Abstract:  Our objective was to conduct a randomized, investigator‐blinded evaluation of the pediculicidal and ovicidal activity of a reduced application time (20 minutes) of Ovide (0.5% malathion) compared to Nix (1% permethrin) in a south Florida population infested with Pediculus humanus capitis. Either Ovide or Nix was applied according to the label instructions. However, Ovide application time was reduced to 20 minutes. At day 8, subjects with live lice were re‐treated with the same product and procedure as on day 1. Ovicidal and pediculicidal efficacy were evaluated at days 8 and 15. A subject free of lice and viable eggs at day 15 was considered to be a treatment success. Percent efficacy was calculated using the number of subjects free of lice and viable eggs per total number of subjects treated. We found that a 20‐minute application of Ovide was significantly more pediculicidal and ovicidal (98%) compared to Nix (55%) at day 15 (p < 0.0001). The percentage of Ovide subjects who required treatment at day 8 was half that of the Nix group. The reinfestation rate was 0% with Ovide and 33% with Nix. In conclusion, a 20‐minute treatment with Ovide, instead of the approved 8‐ to 12‐hour application, cured 40 of 41 subjects (98%), demonstrating superior efficacy to Nix. The poor efficacy of Nix confirms the resistance of head lice to permethrin in south Florida.