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1.
J Pediatr ; 232: 140-146, 2021 05.
Article in English | MEDLINE | ID: mdl-33453199

ABSTRACT

OBJECTIVE: To test feasibility of tele-clinic visits using parentally acquired vital signs and focused echocardiographic images in patients with Marfan syndrome. STUDY DESIGN: We included patients with Marfan syndrome aged 5-19 years followed in our clinic. We excluded patients with Marfan syndrome and history of previous aortic root (AoR) surgery, cardiomyopathy, arrhythmia, or AoR ≥4.5 cm. We trained parents in-person to acquire focused echocardiographic images on their children using a hand-held device as well as how to use a stadiometer, scale, blood pressure (BP) machine, and a digital stethoscope. Before tele-clinic visits, parents obtained the echocardiographic images and vital signs. We compared tele-clinic and on-site clinic visit data. Parental and clinic echocardiograms were independently analyzed. RESULTS: Fifteen patient/parent pairs completed tele-clinic visits, conducted at a median of 7.0 (IQR 3.0-9.9) months from the in-person training session. Parents took a median of 70 (IQR 60-150) minutes to obtain the height, weight, heart rate, BP, cardiac sounds, and echocardiographic images before tele-clinic visits. Systolic BP was greater on-site than at home (median +13 mm Hg, P = .014). Height, weight, diastolic BP, heart rate, and AoR measurements were similar. CONCLUSIONS: This study provides information for implementing tele-clinic visits using parentally acquired vital signs and echocardiographic images in patients with Marfan syndrome. The results show that tele-clinic visits are feasible and that parents were able to obtain focused echocardiographic images on their children. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03581682.


Subject(s)
Echocardiography/methods , Marfan Syndrome/diagnosis , Parents , Telemedicine/methods , Vital Signs , Adolescent , Blood Pressure Determination/methods , Body Height , Body Weight , Child , Child, Preschool , Feasibility Studies , Female , Follow-Up Studies , Heart Sounds , Humans , Male , Videoconferencing , Young Adult
3.
J Pediatr ; 203: 170-176.e1, 2018 12.
Article in English | MEDLINE | ID: mdl-30268404

ABSTRACT

OBJECTIVE: To evaluate whether the presence of patent ductus arteriosus (PDA) in preterm infants worsens long-term neurodevelopmental outcomes. STUDY DESIGN: This was a secondary observational analysis of data from 1090 preterm low-birthweight infants in the Infant Health and Development Program (IHDP), a multicenter longitudinal cohort study of outcomes assessed from 3 to 18 years of age. Multivariable analysis was adjusted for IHDP treatment group (intervention or follow-up), birth weight, maternal race, maternal education, infant sex, maternal preconception weight, Home Observation Measurement of the Environment (HOME) total score at 12 months, neonatal health index, and gestational age. RESULTS: Of the 1090 patients (49% male) included in the analysis, 135 had a PDA. Mean birth weight (1322 g vs 1871 g; P < .0001) and gestational age (30.2 weeks vs 33.4 weeks, P < .0001) were lower and mean ventilator days (11.8 vs 1.3; P < .0001), vasopressor use (12.6% vs 1.2%; P < .0001), and congestive heart failure (8.9% vs 0.1%; P < .0001) were higher in the PDA group. There were no differences between the PDA and no-PDA groups in maternal education level and HOME total score at age 12 months. Multivariable analysis demonstrated no between-group differences in cognitive development or behavioral competence at age 3, 8, and 18 years. CONCLUSIONS: The presence of a PDA in moderately preterm, low-birthweight infants does not impact long-term neurodevelopmental outcomes.


Subject(s)
Ductus Arteriosus, Patent/diagnosis , Ductus Arteriosus, Patent/drug therapy , Infant, Low Birth Weight , Infant, Premature , Neurodevelopmental Disorders/diagnosis , Adolescent , Age Factors , Child , Child, Preschool , Cyclooxygenase Inhibitors/therapeutic use , Female , Follow-Up Studies , Humans , Ibuprofen/therapeutic use , Incidence , Indomethacin/therapeutic use , Infant , Infant, Newborn , Longitudinal Studies , Male , Neurodevelopmental Disorders/epidemiology , Risk Assessment , Time , Time Factors
5.
J Pediatr ; 165(5): 951-5, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25109242

ABSTRACT

OBJECTIVES: Angiotensin converting enzyme inhibitors (ACEI) have been shown to decrease aortic growth velocity (AGV) in Marfan syndrome (MFS). We sought to compare the effect of ß-blockers and ACEI on AGV in MFS. STUDY DESIGN: We retrospectively reviewed all data from all patients with MFS seen at Arkansas Children's Hospital between January 1, 1976 and January 1, 2013. Generalized least squares were used to evaluate AGV over time as a function of age, medication group, and the interaction between the 2. A mixed model was used to compare AGV between medication groups as a function of age, medication group (none, ß-blocker, ACEI), and the interaction between the 2. RESULTS: A total of 67 patients with confirmed MFS were identified (34/67, 51% female). Mean age at first encounter was 13 ± 10 years, with mean follow-up of 7.6 ± 5.8 years. There were 839 patient encounters with a median of 10 (range 2-42) encounters per patient. AGV was nearly normal in the ß-blocker group, and was less than either the ACEI or untreated groups. The AGV was higher than normal in ACEI and untreated groups (P < .001 for both). CONCLUSIONS: ß-blocker therapy results in near-normalization of AGV in MFS. ACEI did not decrease AGV in a clinically significant manner.


Subject(s)
Adrenergic beta-Antagonists/therapeutic use , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Aorta/pathology , Marfan Syndrome/drug therapy , Adolescent , Aorta/diagnostic imaging , Aorta/drug effects , Arkansas , Child , Child, Preschool , Echocardiography , Female , Follow-Up Studies , Humans , Male , Marfan Syndrome/pathology , Retrospective Studies , Treatment Outcome
6.
J Pediatr ; 156(2): 253-8.e1, 2010 Feb.
Article in English | MEDLINE | ID: mdl-19846117

ABSTRACT

OBJECTIVE: To determine the prevalence of cardiovascular abnormalities (CVA) and outcomes in patients with Williams syndrome presenting before 1 year of age. STUDY DESIGN: A retrospective review was undertaken of consecutive patients with WS at our institution from January 1, 1980, through December 31, 2007. WS was diagnosed by an experienced medical geneticist and/or by fluorescence in situ hybridization. CVA were diagnosed with the use of echocardiography, cardiac catheterization, or computerized tomographic angiography. Freedom from intervention was determined using Kaplan-Meier analysis. RESULTS: The study group was 129 patients with CVA. Age at presentation was 127 +/- 116 days, with follow-up of 8.0 +/- 7.5 years (0 to 42 years). The most common lesions were peripheral pulmonary artery stenosis (62%) and supravalvar aortic stenosis (57%). Other CVA were common. CV interventions were performed in 29%, with 58% of those before 1 year. Freedom from intervention was 85%, 73%, and 66% at 1, 5, and 25 years, respectively. Four patients died. CONCLUSIONS: CVA are the most common manifestations of infantile Williams syndrome and occur with greater frequency than previously reported. In those with CVA, interventions are common and usually occur by 5 years of age. Most of these patients do not require intervention on long-term follow-up, and overall mortality is low.


Subject(s)
Cardiovascular Abnormalities/epidemiology , Cardiovascular Abnormalities/therapy , Williams Syndrome/epidemiology , Williams Syndrome/therapy , Angioplasty, Balloon , Aortic Stenosis, Supravalvular/epidemiology , Aortic Stenosis, Supravalvular/surgery , Cardiovascular Abnormalities/surgery , Female , Humans , Infant , Infant, Newborn , Kaplan-Meier Estimate , Male , Prevalence , Prognosis , Proportional Hazards Models , Pulmonary Artery/abnormalities , Pulmonary Artery/surgery , Retrospective Studies , Stents , Treatment Outcome , United States/epidemiology , Williams Syndrome/surgery
10.
Trans R Soc Trop Med Hyg ; 99(3): 178-95, 2005 Mar.
Article in English | MEDLINE | ID: mdl-15653120

ABSTRACT

The influence of spatial and temporal factors on onchocerciasis transmission by Simulium exiguum s.l. and S. quadrivittatum in Ecuador was investigated to help develop sampling protocols for entomological surveillance of ivermectin programmes. Flies were collected in alternate months (November 1995-November 1996) at four sites each in the hyperendemic communities of San Miguel and El Tigre. A fixed-effects analysis of variance was used to explore the influence on vector abundance of locality, site, month and hour. Infectivity rates detected by dissection and PCR assays were compared. Simulium exiguum s.l. predominated at El Tigre (75%) whereas S. quadrivittatum prevailed at San Miguel (62%). Vector abundance was highest on river banks and outside houses. Biting and infection rates peaked from March to July. Hourly activity patterns were bimodal in S. exiguum but unimodal in S. quadrivittatum. Annual transmission potentials (ATP) for both species combined were 385 and 733 third stage larvae/person in San Miguel and El Tigre respectively, with S. exiguum accounting for 80% of the combined ATP at both localities. We recommend protocols that may maximize detection of parasite transmission. Infection rates thus obtained must be linked with vector density estimates to assess meaningfully host exposure as treatment progresses.


Subject(s)
Bites and Stings/epidemiology , Insect Vectors , Onchocerciasis/transmission , Simuliidae , Animals , Anthelmintics/therapeutic use , Ecuador/epidemiology , Humans , Insect Vectors/parasitology , Ivermectin/therapeutic use , Onchocerca volvulus/isolation & purification , Onchocerciasis/epidemiology , Onchocerciasis/prevention & control , Polymerase Chain Reaction/methods , Seasons , Simuliidae/parasitology , Space-Time Clustering , Time Factors
11.
J Med Entomol ; 35(5): 745-57, 1998 Sep.
Article in English | MEDLINE | ID: mdl-9775604

ABSTRACT

Monthly samples of biting Simulium ochraceum s.l. Walker were collected before and after ivermectin treatment in southern Mexico and analyzed for Onchocerca volvulus Leuckart infection rates, infection intensity, and the characteristics of larval distribution among parous flies. The variance over mean ratio (VMR) indicated that in all cases this distribution departed from Poisson and was strongly aggregated (VMR > 1). The negative binomial was found to be an adequate model with a small value of the aggregation parameter k, but the degree of larval overdispersion increased as the mean larval load decreased, invalidating the use of a common kc value. A linear relationship between k and the mean (mu) was established, k(mu) = k1 mu, which permitted exploration of the relationship between the observed proportion of infected flies, p, and the estimated mean larval burden per fly, m (all larval stages in parous flies). This would allow mean numbers of larvae per parous fly to be predicted from presence-absence data (e.g., from infection rates provided by polymerase chain reaction methods applied to pools of flies), assuming that k1 is a known parameter. Given that both p and m are naturally low in S. ochraceum, their relationship was practically linear within the range of observed values. Predictions were tested with the Mexican data from which the clumping parameter was estimated as well as for Guatemalan data for which this information was not available. Results showed a highly satisfactory degree of agreement between predictions and observations. The sample sizes required to estimate mean larval loads from prevalence data for fixed levels of precision (defined as the ratio between SE[m] and m) were calculated for realistic S. ochraceum infection rates (those found in published pre- and postcontrol field surveys as well as in this work). For the special case in which the relationship between k and the mean is linear and goes through the origin, k(mu) = k1 mu, the number of flies to be examined for O. volvulus infections does not explicitly depend on the aggregation parameter, but rather on the unknown proportion of infected flies. Practical recommendations for the calculation of sample sizes are discussed. For infection levels < 0.2%, a minimum number between 6,000 and 13,000 parous flies would have to be examined to estimate the mean larval load with a precision between 0.20 and 0.30. The linearity between onchocercal infection rate and infection intensity in the fly population indicates that relationships between the former and onchocerciasis patterns in the human population should be further explored for the purposes of monitoring the impact of ivermectin control programs through entomological evaluations.


Subject(s)
Anthelmintics/therapeutic use , Diptera/parasitology , Insect Bites and Stings , Ivermectin/therapeutic use , Onchocerca volvulus , Onchocerciasis/prevention & control , Animals , Female , Guatemala , Humans , Larva , Mexico/epidemiology , Onchocerca volvulus/isolation & purification , Onchocerciasis/epidemiology , Prevalence , Sample Size
12.
Rev. panam. salud pública ; 3(6): 367-374, jun. 1998. tab
Article in English | LILACS | ID: lil-220199

ABSTRACT

The decision in 1987 by the pharmaceutical firm Merck & Co. to provide Mectizan (ivermectin) free of charge to river blindness control programs has challenged the international public health community to find effective ways to distribute the drug to rural populations most affected by onchocerciasis. In the Americas, PAHO responded to that challenge by calling for the elimination of all morbidity from onchocerciasis from the Region by the year 2007 through mass distribution of ivermectin. Since 1991, a multinational, multiagency partnership (consisting of PAHO, the endemic countries, nongovernmental development organizations, the Centers for Disease Control and Prevention in Atlanta, Georgia, as well as academic institutions and funding agencies) has developed the political, financial, and technical support needed to move toward the realization of that goal. This partnership is embodied in the Onchocerciasis Elimination Program for the Americas (OEPA), which is supported by the River Blindness Foundation (RBF) and now by the Carter Center. OEPA was conceived as a means of maintaining a regional initiative to eliminate what is otherwise a low priority disease. Since its inception in 1993, the OEPA has provided more than US$2 million in financial, managerial, and technical assistance to stimulate and/or support programs in Brazil, Colombia, Ecuador, Guatemala, Mexico and Venezuela, so as to take full advantage of the Merck donation. Now halfway into a five-year, US$ 4 million grant provided through the Inter-American Development Bank, the OEPA's capacity to support the regional initiative is assured through 1999


La decisión tomada en 1987 por la Merck & Co., fabricante de productos farmacéuticos, de proveer Mectizan® (ivermectina) gratuitamente a los programas de control de la oncocercosis ha obligado a la comunidad sanitaria internacional a buscar formas de distribuir el medicamento a las poblaciones rurales que se ven más afectadas por la enfermedad. En las Américas, la OPS respondió al reto con un llamado a eliminar de la Región toda morbilidad por oncocercosis para el año 2007 mediante la distribución de ivermectina al público. Desde 1991, una alianza multinacional de diversas entidades (la OPS, países con oncocercosis endémica, agencias de desarrollo no gubernamentales, los Centros para el Control y la Prevención de Enfermedades en Atlanta, Georgia, instituciones académicas y agencias de financiamiento) ha generado el apoyo político, económico y técnico necesario para tratar de alcanzar esa meta. Esta alianza está representada por el Programa de Eliminación de la Oncocercosis en las Américas (OEPA), subvencionado por la Fundación Ceguera de los Ríos y actualmente por el Centro Carter. El OEPA se creó como iniciativa de alcance regional destinada a eliminar una enfermedad que no merece atención prioritaria. Desde su aparición en 1993, el OEPA ha aportado más de US$ 2 millones en ayuda económica, administrativa y técnica para fomentar y subvencionar programas en Brasil, Colombia, Ecuador, Guatemala, México y Venezuela, logrando así aprovechar al máximo la donación de la Merck & Co. Ahora que hemos llegado a la mitad de una subvención de 5 años y US$ 4 millones aportada por el Banco Interamericano de Desarrollo, se sabe que el OEPA tiene la capacidad para apoyar la iniciativa regional hasta fines de 1999


Subject(s)
Onchocerciasis , Ivermectin/pharmacology , Economic Cooperation , Technical Cooperation , Rural Population , Health Policy , Latin America
13.
Rev. panam. salud publica ; 3(6): 367-74, Jun.1998. maps
Article in English | MedCarib | ID: med-16902

ABSTRACT

The decision in 1987 by the pharmaceutical firm Merck & Co. to provide Mectizan (ivermectin) free of charge to river blindness control programs has challenged the international public health community to find effective ways to distribute the drug to rural populations most affected by onchocerciasis. In the Americas, PAHO responded to that challenge by calling for the elimination all morbidity from onchocerciasis from the region by the year 2007 through mass distribution of ivermectin. Since 1991, a multinational, multiagency partnership (consisting of PAHO, the endemic countries, nongovernmental development organizations, the Centers for Disease Control and Prevention in Atlanta, Georgia, as well as academic institutions and funding agencies) has developed the political, financial, and technical support needed to move toward the realization of that goal. This partnership is embodied in the Onchocerciasis Elimination Program for the Americas (OEPA), which is supported by the River Blindness Foundation (RBF) and now by the Carter Center, OEPA was conceived as a means of maintaining a regional initiative to eliminate what is otherwise a low priority disease. Since its inception in 1993, the OEPA has provided more than US$ 2 million in financial, managerial, and technical assistance to stimulate and/or support programs in Brazil, Colombia, Ecuador, Guatemala, Mexico, and Venezuela, so as to take full advantage of the Merck donation, Now halfways into a five-year, US$ 4 million grant provided through the Inter-American Development Bank, the OEPA's capacity to support the regional initiative is assured through 1999 (AU)


Subject(s)
Humans , Onchocerca volvulus , Americas , Onchocerciasis, Ocular/drug therapy , Latin America , Disease Management , Ivermectin/administration & dosage , Ivermectin/therapeutic use
14.
Br J Obstet Gynaecol ; 105(3): 286-92, 1998 Mar.
Article in English | MEDLINE | ID: mdl-9532988

ABSTRACT

OBJECTIVE: To determine whether prophylactic, low dose controlled-release aspirin improves outcome for pregnant women and their babies in Barbados. DESIGN: Randomised placebo-controlled trial. SETTING: The Queen Elizabeth Hospital, Barbados. POPULATION: All women attending antenatal clinics between 12 and 32 weeks of gestation were eligible, if without specific contraindications to aspirin and unlikely to deliver immediately. METHODS: Randomisation was computer-generated in the antenatal clinic; 1822 women were allocated to receive 75 mg controlled-release aspirin and 1825 matching placebo. MAIN OUTCOME MEASURES: Proteinuric pre-eclampsia, other pregnancy-induced hypertension, pregnancy duration, birthweight, stillbirths and neonatal deaths, major neonatal events. RESULTS: All but three women from each group were followed up successfully. Forty-four percent were primigravid, and 8% had previous obstetric complications. There were no significant differences between the allocated treatment groups in the incidence of proteinuric pre-eclampsia (40 [2.2%] of those allocated aspirin, compared with 46 [2.5%] allocated placebo), of preterm delivery (255 [14.0%] vs 270 [14.8%]), of birthweight < 1500 g (32 [1.7%] vs 33 [1.8%]) or of stillbirth and neonatal death (44 [2.4%] vs 38 [2.1%]). Aspirin was not associated with excess risk of maternal or fetal bleeding. CONCLUSIONS: The results of this study in Barbados do not support the routine use of low dose aspirin for prevention of pre-eclampsia or its complications, confirming results of previous large trials in other settings.


PIP: The effect of administration of a prophylactic dose of controlled-release aspirin on the prevention of pre-eclampsia was investigated in a randomized placebo-controlled trial conducted at the Queen Elizabeth Hospital in Barbados in 1992-94. All women attending hospital antenatal clinics between 12 and 32 weeks of gestation were eligible for the study; enrolled were 1822 cases allocated to receive 75 mg of aspirin per day and 1825 matched controls who received a placebo. Study participants represented about 60% of women who gave birth during the enrollment period. Aspirin administration was not associated with any excessive risk of infant or maternal bleeding. However, there were no significant differences between cases and controls in terms of the incidence of proteinuric pre-eclampsia (2.2% vs. 2.5%), preterm delivery (14.0% vs. 14.8%), birth weight under 1500 g (1.7% vs. 1.8%), or stillbirth and neonatal death (2.4% vs. 2.1%). These results were not affected by the time of pregnancy at which aspirin prophylaxis was initiated or parity. The Barbados findings are consistent with previous studies and fail to support the routine use of low-dose aspirin for the prevention of pre-eclampsia and its complications.


Subject(s)
Aspirin/administration & dosage , Platelet Aggregation Inhibitors/administration & dosage , Pre-Eclampsia/prevention & control , Adult , Barbados/epidemiology , Birth Weight , Delayed-Action Preparations , Female , Fetal Death , Gestational Age , Hospitalization , Humans , Infant , Infant Mortality , Infant, Newborn , Pregnancy , Pregnancy Outcome , Prenatal Care , Time Factors
16.
Am J Trop Med Hyg ; 52(3): 213-8, 1995 Mar.
Article in English | MEDLINE | ID: mdl-7694961

ABSTRACT

In the transmission of human onchocerciasis, competence of the black fly vector influences intensity of transmission by regulating how many infective-stage larvae are produced. The disease is intensifying in Ecuador where Simulium exiguum is a highly efficient limitation-type vector comparable with African forest species in terms of the percentage of flies developing infective-stage larvae and the numbers of larvae per infected fly. In contrast, the endemic foci in Guatemala and southern Mexico have remained stable and closely circumscribed around larval development sites for S. ochraceum, a vector that exhibits a facilitation type of competence and must feed on people with comparatively high microfiladeremia to develop significant numbers of infective-stage larvae. This comparison indicates that assessments of vector competence should be included when planning regional control programs for onchocerciasis.


Subject(s)
Insect Vectors/parasitology , Onchocerca volvulus/growth & development , Onchocerciasis/transmission , Simuliidae/parasitology , Adult , Animals , Ecuador/epidemiology , Guatemala , Humans , Larva/growth & development , Male , Microfilariae/growth & development , Onchocerciasis/epidemiology , Regression Analysis , Skin/parasitology
17.
Trans R Soc Trop Med Hyg ; 86(6): 663-6, 1992.
Article in English | MEDLINE | ID: mdl-1287939

ABSTRACT

Male and female residents on a Guatemalan coffee plantation where Onchocerca volvulus infections were hyperendemic were offered oral ivermectin (100-200 micrograms/kg) as part of a community-wide treatment programme for onchocerciasis. Forty-five persons were treated and then questioned daily for 28 d about changes in their health. Those with complaints were monitored until all signs and symptoms had resolved. Sixty-seven percent complained of some adverse event after treatment; 60% developed observable adverse reactions attributed clinically to ivermectin. No reaction was life-threatening; the most common were oedema (53%) and fever (47%). Expulsion of intestinal helminths was reported by 38%. Almost all reactions began 24-48 h after treatment; their mean duration was 5 d, despite treatment with acetaminophen and antihistamines. Three patients had oedematous changes lasting over 2 weeks. Incidence, but not severity, of reactions was related to the pretreatment density of microfilariae in skin.


Subject(s)
Edema/chemically induced , Ivermectin/adverse effects , Onchocerca volvulus , Onchocerciasis/drug therapy , Adolescent , Adult , Animals , Child , Child, Preschool , Female , Fever/chemically induced , Guatemala , Humans , Longitudinal Studies , Male , Middle Aged
18.
Am J Trop Med Hyg ; 47(2): 147-55, 1992 Aug.
Article in English | MEDLINE | ID: mdl-1503184

ABSTRACT

Wild Simulium ochraceum females, both blood engorged and non-blood engorged, were collected from human volunteers infected with Onchocerca volvulus, marked with fluorescent dyes, and released from the same locality as they were collected during February and March 1989. A small hyperendemic village located within 0.5 km of streams supporting large populations of S. ochraceum larvae served as the site for both collection and release of adult females. Fifteen sites for the recapture of flies were located within this same village, within two other villages located 1.0 and 3.7 km from it, and at other places spaced approximately 0.25-3.5 km within a coffee agroecosystem. Flies from both groups were recaptured at distances ranging to 3.5 km from the point of release. Non-blood-engorged flies, however, exhibited a greater tendency to disperse away from the release site. Of the total number of blood-engorged flies recaptured, 51.9% were collected at the release point, 25.7% at 1.0 km, and 1.6% at 3.3-3.5 km. The corresponding percentages for non-blood-engorged flies were 26.9%, 40.4%, and 4.4%, respectively. No flies from either group were recaptured at the most distant site, a large village that was 3.7 km away. Marked flies from both groups were recaptured 12-14 days after release, which was sufficient time for the development of infective O. volvulus larvae. A survival rate (4.7%) of marked, blood-engorged flies over the second and third gonotrophic cycles was estimated from the slope of the regression line of the log number of flies recaptured.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Insect Vectors/parasitology , Onchocerca/isolation & purification , Onchocerciasis/transmission , Simuliidae/parasitology , Animals , Female , Guatemala/epidemiology , Humans , Insect Vectors/physiology , Ivermectin/therapeutic use , Onchocerciasis/drug therapy , Onchocerciasis/epidemiology , Simuliidae/physiology , Time Factors
19.
Am J Trop Med Hyg ; 47(2): 156-69, 1992 Aug.
Article in English | MEDLINE | ID: mdl-1503185

ABSTRACT

Residents of five hyperendemic communities located in the central focus of onchocerciasis in Guatemala were treated with ivermectin (Mectizan) or placebo every six months for 30 months. The effects of treatment on prevalence and the intensity of skin infection (microfilarial skin density [MFD]) were evaluated. Significant and persistent reductions in both of these indices were achieved by coverage of 80.7% of the eligible populations. The highest proportionate reductions in both indicators of infection occurred after the first treatment, followed by more gradual decreases through the fourth treatment. In one community in which the mean coverage was 92.7%, prevalence decreased from 74.0% at pretreatment to 34.9% after four treatments, while the MFD decreased from 7.8 to 2.0; reductions of 52.8% and 74.3% from pretreatment values, respectively. In every ivermectin-treated community except one, in which drug acceptance was low, the mean community MFD values were reduced to the level associated with low infectiousness for the vector, Simulium ochraceum. Moreover, the category of MFD associated with high vector infectiousness was reduced at least ten-fold over the pretreatment level. One community had low participation during the first two treatments (32.8% and 22.7% of those eligible). This increased to 55.2% at the third treatment because of implementation of an educational program describing both the disease and the beneficial effects of ivermectin and because skin biopsies and nodulectomies were not performed. Secondary reaction rates for all communities were 29.5%, 9.9%, 10.3%, 8.2%, and 7.1% for the first through fifth treatments, respectively. Pruritus was the most common (34.0%) secondary reaction, followed by facial edema (31.8%). All reactions were classified as mild to moderate. Recommendations for mass distribution of ivermectin in Guatemala are given.


Subject(s)
Ivermectin/therapeutic use , Onchocerca/isolation & purification , Onchocerciasis/drug therapy , Skin/parasitology , Adolescent , Adult , Age Factors , Animals , Child , Female , Guatemala/epidemiology , Humans , Ivermectin/adverse effects , Male , Microfilariae/growth & development , Microfilariae/isolation & purification , Onchocerca/growth & development , Onchocerciasis/epidemiology , Onchocerciasis/parasitology , Prevalence , Treatment Refusal
20.
Am J Trop Med Hyg ; 47(2): 170-80, 1992 Aug.
Article in English | MEDLINE | ID: mdl-1503186

ABSTRACT

The effects of biannual ivermectin treatment at the community level on transmission of Onchocerca volvulus during the dry season were measured over a 30-month period in Guatemala. In the Los Tarrales Transmission Zone, an area encompassing three villages, significant changes occurred in both the prevalence and quantity of infection in the Simulium ochraceum vector population. These included a 76% reduction in females with infective stage larvae (L3S) and an 80% reduction in number of L3S per 1,000 parous flies. Significant reductions in both the mean infective biting density (IBD) and mean transmission potential (TP) also occurred. In Santa Emilia, the prevalence of infection with L3S in S. ochraceum was significantly reduced by 77% from the baseline value. The number of O. volvulus L3S per 1,000 parous flies was also reduced by 92%. Changes in both the IBD and TP were substantial but not significant due to the high degree of variance in the occurrence of O. volvulus L3S in the vector population. This was due, in part, to the movement of infected migrant workers into the finca (coffee farm). In Los Andes, four recurrent treatments successfully blocked transmission of infective stage larvae. Prevalence (flies with all stages of developing larvae) in the vector population was reduced by 89% over the two-year period; yearly reductions in both the IBD and TP were also highly significant, ultimately ending in zero values. This finding is particularly striking since prior to treatment, Los Andes exhibited the highest IBD of the three study locations and the second highest TP.


Subject(s)
Insect Vectors/parasitology , Ivermectin/therapeutic use , Onchocerca/isolation & purification , Onchocerciasis/transmission , Simuliidae/parasitology , Animals , Female , Guatemala , Humans , Larva/isolation & purification , Onchocerciasis/drug therapy , Seasons
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