Ivermectin treatment response in two rural villages with a high prevalence of onchocerciasis and epilepsy, Mahenge Tanzania

Background: Despite 20 years of ivermectin mass distribution in the Mahenge area, Tanzania, the prevalence of onchocerciasis and epilepsy has remained high in rural villages. Objectives: We investigated the efficacy of ivermectin in reducing Onchocerca volvulus microfilariae and predictors for parasitic load following ivermectin treatment in persons with (PWE) and without epilepsy (PWOE). Methods: Between April and September 2019, 50 PWE and 160 randomly selected PWOE from Msogezi and Mdindo villages participated in a follow-up study. Skin snips were obtained pre (baseline) and three months post-ivermectin treatment. Results: The overall prevalence of O. volvulus positive skin snips at baseline was 49% (103/210), with no significant difference between PWE (58.0%) and PWOE (46.3%); p=0.197. The overall mean micro filarial density was significantly higher at baseline 1.45(95%CI:0.98-2.04)) than three-month post-ivermectin treatment (0.23(95%CI:0.11-0.37), p<0.001. Three months after ivermectin, the micro filarial density had decreased by ≥80% in 54 (81.8%, 95%CI: 72.3-91.4) of the 66 individuals with positive skin snips at baseline. High micro filarial density at baseline was the only significant predictor associated with higher micro filarial density in the post-ivermectin skin snips. Conclusion: Our study reports a decrease in micro filarial density following ivermectin treatment in most individuals. Optimizing ivermectin coverage will address the ongoing onchocerciasis transmission in Mahenge

COVID-19: The Ivermectin African Enigma / COVID-19: El enigma de la Ivermectina en Africa

Abstract Introduction: The low frequency of cases and deaths from the SARS-CoV-2 COVID-19 virus in some countries of Africa has called our attention about the unusual behavior of this disease. The ivermectin is considered a drug of choice for various parasitic and viral diseases and shown to have in vitro effects against SARS-CoV-2. Aims: Our study aimed to describe SARS-CoV2 infection and death rates in African countries that participated in an intensive Ivermectin mass campaign carried out to control onchocerciasis and compare them with those of countries that did not participate. Methods: Data from 19 countries that participated in the World Health Organization (WHO) sponsored African Programme for Onchocerciasis Control (APOC), from 1995 until 2015, were compared with thirty-five (Non-APOC), countries that were not included. Information was obtained from https://www.worldometers.info/coronavirus/ database. Generalized Poisson regression models were used to obtain estimates of the effect of APOC status on cumulative SARS-CoV-2 infection and mortality rates. Results: After controlling for different factors, including the Human Development Index (HDI), APOC countries (vs. non-APOC), show 28% lower mortality (0.72; 95% CI: 0.67-0.78) and 8% lower rate of infection (0.92; 95% CI: 0.91-0.93) due to COVID-19. Conclusions: The incidence in mortality rates and number of cases is significantly lower among the APOC countries compared to non-APOC countries. That a mass public health preventive campaign against COVID-19 may have taken place, inadvertently, in some African countries with massive community ivermectin use is an attractive hypothesis. Additional studies are needed to confirm it.

Resumen Introducción: La baja frecuencia de casos y muertes por el virus SARS-CoV-2 COVID-19 en algunos países de África llamó nuestra atención sobre el comportamiento inusual de esta enfermedad. La ivermectina se considera un fármaco de elección para diversas enfermedades parasitarias y virales, y se ha demostrado que tiene efectos in vitro contra el SARS-CoV-2. Objetivos: Nuestro estudio tiene el objetivo describir las tasas de infección y mortalidad del SARS-CoV-2 en los países africanos que participaron en una campaña intensiva masiva de ivermectina para el control de la oncocercosis y compararlas con las de los países que no participaron. Métodos: Los datos de 19 países que participaron en el Programa Africano para el Control de la Oncocercosis (APOC) patrocinado por la Organización Mundial de la Salud (OMS), desde 1995 hasta 2015, se compararon con 35 países que no fueron incluidos (NO APOC). La información sobre casos y muertes por COVID-19 se obtuvo de la base de datos https://www.worldometers.info/coronavirus/. Se utilizaron modelos de regresión de Poisson para obtener estimaciones del efecto del estado APOC sobre las tasas acumuladas de infección y mortalidad por SARS-CoV-2. Resultados: Después de controlar diferentes factores, incluido el Índice de Desarrollo Humano (IDH), los países APOC (frente a los no APOC) mostraron una mortalidad 28% menor (razón de tasas ajustada: RR= 0.72, IC 95%: 0.67-0.78) y una tasa de infección 8% menor (RR= 0.92, IC 95%: 0.91-0.93) por COVID-19. Conclusiones: Las tasas de mortalidad e infección son significativamente más bajas en países APOC en comparación con los países no APOC. Una campaña preventiva masiva de salud pública contra el COVID-19 pudo haber tenido lugar inadvertidamente en algunos países africanos con un uso masivo de ivermectina en la comunidad es una hipótesis atractiva. Se necesitan estudios adicionales para confirmarlo.

Update on parasitic dermatoses

Abstract These are cutaneous diseases caused by insects, worms, protozoa, or coelenterates which may or may not have a parasitic life. In this review the main ethological agents, clinical aspects, laboratory exams, and treatments of these dermatological diseases will be studied.

Knowledge, Attitude and Practice of People towards Onchocerciasis among Local People Living in Tafa Local Government Area of Niger State, Nigeria

The study is aimed atassessingthe knowledge, attitude and practice of peoplein Ija-Gwari and Kofa in Niger State towards onchocerciasis, structured questionnaires wereadministered to 300 respondents comprising 150 from each of the village, which is about 5% of the total population size of the two villages. The sampling technique used to administer the questionnaire was systemic sampling method. In Kofa and Ija-Gwari village, a high proportion 74 (49.3%) and 80 (53.3%) respectively thought it was both a blood and an eye infection while few of the respondents 8 (5.3%) and 2 (1.45%) respectively claimed to have no idea of river blindness. In Kofa village, out of 150 respondents, 146 (97.3%) said they accepted taking the drug and 4 (2.7%) did not accept taking the drug. In Ija-Gwari village out of 150 respondents, 144 (95.9%) said theyaccepted taking the drug and 6 (4.1%) did not accept taking the drug. In Kofa village, outof the 150 respondents, 148 (98.7%) use ivermectin as the type of treatment, while In Ija-Gwari village, out of the 150 respondents 149 (99.3%) use ivermectin as the type of treatment.Since lack of knowledge perpetuates disease, appropriate health education strategy will be necessary to improve the situation

Anti-Wolbachia therapy for onchocerciasis & lymphatic filariasis: Current perspectives

Onchocerciasis and lymphatic filariasis (LF) are human filarial diseases belonging to the group of neglected tropical diseases, leading to permanent and long-term disability in infected individuals in the endemic countries such as Africa and India. Microfilaricidal drugs such as ivermectin and albendazole have been used as the standard therapy in filariasis, although their efficacy in eliminating the diseases is not fully established. Anti-Wolbachia therapy employs antibiotics and is a promising approach showing potent macrofilaricidal activity and also prevents embryogenesis. This has translated to clinical benefits resulting in successful eradication of microfilarial burden, thus averting the risk of adverse events from target species as well as those due to co-infection with loiasis. Doxycycline shows potential as an anti-Wolbachia treatment, leading to the death of adult parasitic worms. It is readily available, cheap and safe to use in adult non-pregnant patients. Besides doxycycline, several other potential antibiotics are also being investigated for the treatment of LF and onchocerciasis. This review aims to discuss and summarise recent developments in the use of anti-Wolbachia drugs to treat onchocerciasis and LF.

A century of onchocerciasis in Sierra Leone

In 1926, Blacklock first described onchocerciasis (OV) transmission by black fly, Simulium damnosum in Sierra Leone. In the 1950-1960's, high OV prevalence was demonstrated along the rivers and the existence of black flies nationwide except around the capital and the coastal plain of Bonthe. In 1957, control efforts started with insecticides along the river breeding sites. In 1974, the Onchocerciasis Control Programme focusing on vector control was launched, extending to Sierra Leone in the 1980s. From 1995, the African Programme for Onchocerciasis Control commenced community-directed treatment with ivermectin (CDTI) in hyper- [microfilaridermia (mf) prevalence≥40%] and meso- (nodule prevalence 20%-39%) sites. To be effective programme, coverage among the eligible population over five years of age needed be at least 80%. In the mid-1990s, the rebel war stopped vector control and effective CDTI was not established until 2006. Baseline data using skin snips from 39 sentinel villages found the average OV mf prevalence was 53.1% (28.9 mf/snip). From October 2008, albendazole was added in phases to CDTI for all communities in all 14 districts for lymphatic filariasis (LF) elimination. In 2010, after five rounds of effective MDA, OV mf prevalence was 21.1% (8.29 mf/snip). Males had higher prevalence and density than females in both studies. Since then, OV control (acknowledging transmission continues) has transitioned to OV elimination assuming transmission can be interrupted once mf prevalence is less than 5%. In 2017, a rapid assessment was integrated into LF-Transmission Assessment Survey and independently in 8 and 4 districts respectively, designed by the Survey Sample Builder. Children aged 5-9 years were randomly selected from 177 clusters and tested by OV-16 (Rapid Diagnostic Tests, SD BIOLINE) using finger-prick blood samples. Overall, 17 441 children participated and 347 (2.0%) were positive (M: 2.4% versus F: 1.6%) (P10%). The LF- Transmission Assessment Survey sampling methodology does not take cognizance of black fly breeding sites, but did demonstrate ongoing transmission and another 4-5 rounds were advisable. A technical advisory committee has been established with representation from international experts to help plan for accreditation of onchocerciasis elimination around 2025.

Presencia y distribución espacial de Simulium sp. (Díptera: Simuliidae) en dos provincias de Angola / Presence and spatial distribution of Simuliumsp.(Diptera: Simuliidae) in two provinces of Angola

En el oeste de África los miembros del complejo Simulium damnosum son los vectores de la oncocercosis. El objetivo es obtener datos sobre la presencia y distribución de simúlidos en dos provincias de Angola. El trabajo se realizó en las provincias de Huambo y Bié donde se muestrearon 24 cuerpos de agua entre julio y agosto, 2015. Todos los sitios se localizaron por encima de una altitud de 1 000 m y solo tres resultaron negativos a la presencia de simúlidos. Estos resultados constituyen los primeros que se obtienen sobre la presencia y distribución espacial de Simulium sp. en Angola de gran importancia, pues la superposición de los mapas de distribución de la infección humana y los vectores permiten localizar áreas con peligro de transmisión(AU)

In West Africa Simuliumdamnosum complex members are the main vectors of onchocerciasis. The objective of this paper was to collect data on the presence and spatial distribution of black flies in two provinces of Angola. The research work was conducted in Huambo and Bié provinces where 24 water bodies were sampled between July and August 2015. All the studied sites were located above 1 000 m of altitude and only three of them were found to be negative for the presence of black flies. These were the first results obtained on the presence and spatial distribution of Simulium sp. in Angola and are of great importance because overlapping the distribution maps of human infection and of vectors allows finding the areas at risk of transmission(AU)

Oncocercosis: de lo básico a lo clínico / Onchocerciasis: From basics to clinical / Oncocercose: do básico ao clínico

La oncocercosis es una de las enfermedades tropicales desatendidas, producida por el nemátodo filárico Onchocerca volvulus y transmitida por la picadura de la mosca negra del género Simulium. Es considerada la segunda causa mundial de ceguera prevenible y está presente en 35 naciones de tres continentes: África, América y Asia. Existen tres países declarados libres de oncocercosis: Colombia, Ecuador y México. Las principales manifestaciones clínicas son dermatológicas y oculares; sin embargo, también se han descrito alteraciones linfáticas y neurológicas. El diagnóstico se realiza por identificación de microfilarias en biopsia de piel o esclerocorneal, nodulectomía para buscar gusanos adultos o con lámpara de hendidura y observar el parásito en el ojo. Existe tratamiento farmacológico con ivermectina o quirúrgico con extracción directa de los nemátodos adultos de los oncocercomas. Los programas mundiales se basan en control vectorial y farmacoterapia. Con los conocimientos actuales y esfuerzos mundiales, la oncocercosis continúa siendo un grave problema de salud pública y causa de discapacidad. Por estas razones, se hace necesario una actualización en el tema.

Onchocerciasis is one of the neglected tropical diseases; it is produced by the filarial nematode Onchocerca volvulus and is transmitted through the bites of infected black flies of the Simulium genus. It is considered the second leading cause of preventable blindness and is present in 35 countries on three continents: Africa, America, and Asia. The following three countries have been declared free from onchocerciasis: Colombia, Ecuador, and Mexico. The main clinical manifestations are dermatological and ocular; however, lymphatic and neurological alterations have also been described. Diagnosis is made by identification of microfilariae in skin or sclerocorneal biopsy, by nodulectomy in search of adult worms, or by using a slit lamp to observe the parasite in the eye. There is pharmacological treatment through the use of ivermectin or surgical treatment by direct removal of adult nematodes from the onchocercomas. World programs are based on vector control and drug therapy. Despite current knowledge and global efforts, onchocerciasis remains a serious public health issue and an important cause of disability. Thus, an update on the topic is warranted.

A oncocercose é uma das doenças tropicais desatendidas, produzida pelo nemátodo filárico Onchocerca volvulus e transmitida pela picada da mosca negra do gênero Simulium. É considerada a segunda causa mundial de cegueira evitáveis e está presente em 35 nações de três continentes: África, América e Ásia. Existem três países declarados livres de oncocercose: Colômbia, Equador e México. As principais manifestações clínicas são dermatológicas e oculares; apesar disso, também se há descrito alterações linfáticas e neurológicas. O diagnóstico se realiza por identificação de microfilárias em biopsia da pele ou esclerocorneano, nodulectomia para buscar larva adultas ou com lâmpada de fenda e observar o parasita no olho. Existe tratamento farmacológico com ivermectina ou cirúrgico com extração direta dos nemátodos adultos dos oncocercomas. Os programas mundiais se baseiam no controle vectorial e farmacoterapia. Com os conhecimentos atuais e esforços mundiais, a oncocercose continua sendo um grave problema de saúde pública e causa de deficiência. Por estas razões, se faz necessário uma atualização no assunto.

Update on pathology of ocular parasitic disease.

Parasites are a group of eukaryotic organisms that may be free‑living or form a symbiotic or parasitic relationship with the hosts. Consisting of over 800,000 recognized species, parasites may be unicellular (Protozoa) or multicellular (helminths and arthropods). The association of parasites with human population started long before the emergence of civilization. Parasitic zoonotic diseases are prevalent worldwide including India. Appropriate epidemiological data are lacking on existing zoonotic parasitic diseases, and newer diseases are emerging in our scenario. Systemic diseases such as cysticercosis, paragonimiasis, hydatidosis, and toxoplasmosis are fairly common. Acquired Toxoplasma infections are rising in immune‑deficient individuals. Amongst the ocular parasitic diseases, various protozoas such as Cystoidea, trematodes, tissue flagellates, sporozoas etc. affect humans in general and eyes in particular, in different parts of the world. These zoonoses seem to be a real health related problem globally. Recent intensification of research throughout the world has led to specialization in biological fields, creating a conducive situation for researchers interested in this subject. The basics of parasitology lie in morphology, pathology, and with recent updates in molecular parasitology, the scope has extended further. The current review is to address the recent update in ophthalmic parasites with special reference to pathology and give a glimpse of further research in this field.

Knowledge, Attitude and Perception of Onchocerciasis and Ivermectin Treatment in Idogun Community, Ondo State, Nigeria.

Introduction: Onchocerciasis is a communicable parasitic disease caused by a nematode; Onchocerca volvulus and vectored by female Simulium blackfly. The disease is common among poor rural dwellers where it causes various degrees of skin and eye infections. Objectives: To evaluate the knowledge, attitude and perception of onchocerciasis and its treatment with ivermectin Methods: The study was undertaken in Idogun, an endemic community in Ose local government area, Ondo State. Structured questionnaire was administered to 384 respondents during personal interview and focus group discussion to obtain useful epidemiological information, while skin snip test was employed to determine the prevalence of the disease among the 384 respondents not below 10 years of age that were randomly selected for the study. Chi-square at 5% significance level was used to establish the significance of various parameters tested in the study. Results: The results revealed that 235 (61.2%) were ignorant of the disease while 149 (38.8%) respondents had adequate knowledge of the cause and mode of transmission of the disease. Meanwhile, skin snip test showed that the disease occurred more among the ignorant (22.9%) than the knowledgeable (5.2%). Ignorance of disease was further reflected in the response of the respondents to the cause and mode of infection. Most ignorant individuals in the community believed the disease can be contracted through sexual intercourse (4.6%), stepping on charms (3.9%), inherited from infected parents (6.3%), ageing (13.3%), lack of personal hygiene (7%) and too much farming (40.4%). Whereas, 15.6% of the study population had no idea of the cause and mode of the disease. The study further revealed that 24.7% of the respondents showed various side effects to the drug such as itching, rashes swelling wrinkles, dizziness and weakness. The side effects of the drug were observed to be more among the infected individuals (20.8%) than the uninfected individuals (3.9%). Conclusion: The study suggests that there is need for intensive public enlightment in the community to properly educate the community about the cause and mode of the disease.

Parasitosis intestinales en Altragracia de la Montaña, Estado Miranda, Venezuela: Influencia del programa para la eliminación de oncocercosis / Intestinal parasites in Altragracia de la Montaña, Miranda State, Venezuela: Influence of the program for onchocerciasis elimination

El objetivo general de este trabajo fue determinar la prevalencia de parasitosis intestinales y sus características epidemiológicas en cuatro comunidades de la parroquia Altagracia de la Montaña, Estado Miranda (Venezuela). Se desarrolló un estudio de corte transversal con una muestra constituida por 492 en su mayoría niños, en febrero de 2011. Previo consentimiento informado, se realizó una encuesta clínico-epidemiológica, extracción de sangre y exámenes coproparasitológicos con los métodos directo, Kato y cultivo en agar. El 60% de la población tenía al menos un parásito de transmisión hídrica y/o alimentos contaminados por heces de humanos y/o animales. La elevada frecuencia de protozoarios intestinales, especialmente Blastocystis sp., con predominio entre quienes viven con fallas en la disposición de excretas y baja calidad del agua para consumo humano, demuestran la persistencia de parasitosis intestinales como problema de salud pública; sin embargo, la influencia indirecta de la administración semestral de ivermectina y educación sanitaria con visión etnográfica impartida por el Programa para la Eliminación de Oncocercosis en Bucarito, una de las comunidades evaluadas, tuvo como efecto colateral no sólo disminuir la prevalencia de helmintos intestinales, sino de los protozoarios, a pesar de estar sometida a los mismos factores de riesgo que las comunidades restantes.

The aim of this study was to determine the prevalence of intestinal parasites and their epidemiological characteristics in four rural communities from Altagracia de la Montaña, Miranda State (Venezuela). A cross sectional study was conducted in February 2011 where 492 subjects were evaluated, mostly children. Informed consent was previously obtained. A clinical and epidemiological survey was done. Patients voluntarily brought a fresh stool sample for analysis with direct smear, Kato and agar culture; blood was extracted for eosinophil count. 60% of the evaluated people had at least one parasite transmitted by water or food contaminated by human or animal feces. The high prevalence of protozoa, specially Blastocystis sp., among those who live under poor living conditions such as inadequate feces disposal and low quality of drinking water, shows the persistence of intestinal parasites as a public health problem; nevertheless, indirect influence of ivermectin treatment every six months and health education with an ethnographic orientation given by the Onchocerciasis Elimination Programme in Bucarito, one of the evaluated communities, had an unexpected outcome not only diminishing the prevalence of helminthes but also the prevalence of intestinal protozoa, being this community under the same risk factors as the rest of the evaluated communities.

Oncocercosis de la mandíbula: a propósito de un caso / Onchocercosis of the jaw: about a case

Fundamento: la oncocercosis, enfermedad de Robles, es una enfermedad parasitaria crónica causada por un gusano nematodo; la filaria Onchocerca volvulus transmitida por moscas negras de la familia Simuliidae, cuyo único hospedero definitivo es el hombre. Es la segunda causa infecciosa de ceguera en el mundo. Objetivo: describir un caso de una paciente portadora de la enfermedad con un nódulo en la rama ascendente del maxilar derecho. Caso clínico: paciente africana, femenina, que acude a consulta por presentar aumento de volumen de la mandíbula derecha de varios meses de evolución y tumoración de seis centímetros de diámetro, a nivel del ángulo y rama horizontal derecha del maxilar inferior. En la citología se diagnosticó microfilariasis. Conclusiones: el parásito se trasmitió en esta enferma, como ocurre en todos los casos, por la picadura de una mosca del género Simulium, que al succionar la sangre de la paciente depositó sus larvas desencadenando la enfermedad.

Background: onchocercosis, also known as Robles’ disease, is a chronic parasitic disease caused by a nematode worm of the genus filaria onchocerca volvulus that is transmitted by black flies of the simuliidae family and the only host of which is man. It is the second infectious cause of blindness in the world. Objective: to describe the case of a patient carrier of the disease who present a nodule in the right ascending ramus of the lower jaw. Clinical case: an African female patient who came to consultation for presenting an increase in volume of the right area of the lower jaw of some months of evolution and a tumor of six centimeters in diameter at the level of the right horizontal angle and ramus of the lower jaw. Microfilariasis was diagnosed in the cytology. Conclusions: the parasite was transmitted to the patient like it happens in all the cases, by the sting of a fly of the genus simulium that sucks the blood of the person and lays the larvae causing the disease.

Monitoring of Human Onchocerciasis in Delta State, Nigeria.

Background: In Delta State, free doses of ivermectin are distributed annually to communities through the Community Directed Treatment with Ivermectin (CDTI). Despite this intervention approach, pockets of endemic foci still exits. Updated information of the epidemiology of human onchocerciasis is essential for planning effective control strategies. Thus this study aimed at investigating the current prevalence and distribution of human onchocerciasis in endemic communities of Delta State, Nigeria. Methods: A cross-sectional study was carried out in three local government areas (Aniocha North, Aniocha South and Oshimili) comprising of 41 communities in Delta State, Nigeria. A total of 1,201 consented subjects were examined by skin snips biopsy. A pre-validated well structure questionnaire was used in collecting epidemiological information. Results: The general prevalence of onchocerciasis in the studied communities was 11.5%. The prevalence did not vary among the three local government areas (P>0.05) though, the infection rate was highest in Aniocha North (12.5%), followed by Oshimili South (11.5%) and Aniocha South (10.7%). With respect to gender, the prevalence was insignificantly higher in males (12.2%) than in female (9.9%). Age-wise, the general pattern showed that the prevalence increased significantly with age. The prevalence of onchocerciasis generally differed widely among the various occupational groups sampled. The prevalence was almost two-fold among farmers (19.3%) compared to drivers and bike riders group (10.2%). Conclusion: Although the prevalence of onchocerciasis has decreased, the infection still remainsa public health concern in the area. Occupation and age were significant risk factors that affected the prevalence of onchocerciasis. Thus, there is need for control measures to be tailored towards these high risk groups. Also, intensifying community treatment with ivermectin will help eliminate onchocerciasis in the studied communities.

Outstanding insecurities concerning the use of an Ov16-based ELISA in the Amazonia onchocerciasis focus

In a recent issue of Memórias do Instituto Oswaldo Cruz, published in Rio de Janeiro in February 2014 (109: 87-92), Adami et al. have published a survey reporting Mansonella parasite prevalence in the Amazon Region. This report makes a useful contribution to the existing knowledge of filarial parasite distribution within the Amazon area, parasite prevalence rates in relation to age and occupation and provides observations on the possible clinical impact of Mansonella ozzardi. Their publication also provides an account of what appears to be a novel ELISA that has recently been used in the Simuliidae and Onchocerciasis Laboratory of the Oswaldo Cruz Institute, Rio de Janeiro, Brazil. We are concerned that the publication of this ELISA may have created an excessively positive impression of the effectiveness of the onchocerciasis recrudescence serological surveillance tools that are presently available for use in the Amazonia onchocerciasis focus. In this letter we have, thus, sought to highlight some of the limitations of this ELISA and suggest how continuing insecurities concerning the detection of antibodies to Onchocerca volvulus within the Amazonia onchocerciasis focus might be minimised.

Nodding Syndrome (NS) in Northern Uganda: A Probable Metabolic Disorder.

Aims: To conduct an epidemiological study to establish the association between malnutrition, metabolic disorder and Onchocerciasis to Nodding Syndrome (NS) in Northern Uganda. Study Design: Case-control study design. Place and Duration of Study: Odek and Atiak sub counties in Gulu and Amuru districts between 10th to 20th June 2012. Methodology: We recruited consecutively 101 children with probable NS in the 2 sub counties in Gulu and Amuru districts. Controls were from the same population but without symptoms of NS and were matched by age, sex and residents. History and physical examinations were conducted; anthropometry, blood samples and skin snips were obtained from cases and controls. Researchers were pediatricians, psychiatrists, nurses, laboratory scientists and epidemiologists. The research proposal was approved by the Ministry of Health and the IRB of Gulu University. Results: There was a statistically significant association between NS with malnutrition (t=0.142; p=0.044), Onchocerciasis (Χ 2 = 152.74, p<0.001; OR 7.025 95% CI 3.891, 12.682) and High Anion Gap (Χ 2=146.752, p<0.001; OR 6.313 95%CI 4.027, 9.895). Conclusion: Nodding syndrome is associated with metabolic disorder in young children who are malnourished and infected with Onchocerciasis.

Ivermectin: pharmacology and therapeutic applications.

Ivermectin is an antiparasitic drug with a broad spectrum of activity, high efficacy as well as a wide margin of safety. It belongs to the family of avermectins. It binds to glutamate-gated chloride iron channels, which are present in invertebrate nerve and muscle cells, and causes the paralysis and death of the parasite. Ivermectin is approved by the US Food and Drug Administration, and used worldwide to treat patients with onchocerciasis and strongyloidiasis. It is also used against a wide range of endoparasites (nematodes) and ectoparasites (insects, acarine) of animals and humans.

Biting on human body parts of Simulium vectors and its implication for the manifestation of Onchocerca nodules along Osun River, southwestern Nigeria.

Background: The biting preference of Simulium vectors has been known to influence the distribution of Onchocerca nodules and microfilariae in human body. There is, however, variation in biting pattern of Simulium flies in different geographical locations. This study investigates the biting pattern on human parts by Simulium vectors along Osun river system where Simulium soubrense Beffa form has been implicated as the dominant vector and its possible implication on the distribution of Onchocerca nodules on human body along the river. Methods: Flies were collected by consented fly capturers on exposed human parts namely head/neck region, arms, upper limb and lower limb in Osun Eleja and Osun Budepo along Osun river in the wet season (August– September) and the dry season (November–December) in 2008. The residents of the communities were also screened for palpable Onchocerca nodules. Results: The results showed that number of flies collected below the ankle region was significantly higher than the number collected on other exposed parts (p <0.05) while the least was collected on head/neck region in both seasons. The lower trunk was the most common site (60%) for nodule location at Osun Eleja followed by upper trunk (40%). Nodules were not found in the head and limb regions. At Osun Budepo, the upper trunk was the most common site of the nodule location (53.8%) followed by the lower trunk (38.5%) and head region (7.7%). Conclusion: Though, most of the flies were caught at the ankle region, the biting of other parts coupled with the presence of nodules at the head and upper trunk regions showed that Simulium vectors could obtain microfilariae from any part of the body, thus increasing the risk of onchocerciasis transmission.

Impacto de la ivermectina sobre las geohelmintiasis en el foco de oncocercosis en Colombia / The effect of ivermectin on geohelminth frequency (i.e. as used in the onchocerciasis control program in Colombia)

Objetivo: Evaluar el efecto de la ivermectina sobre la frecuencia de infección por geohelmintos en una población colombiana incluida en el Programa para la Eliminación de la Oncocercosis en las Américas. Métodos: Estudio de evaluación de impacto con enfoque longitudinal como punto referente inicial, la población de Naicioná (1996) y como control, sujetos de la misma población (2008). Para el enfoque transversal se usó como referente la población de Naicioná en 2008 y como control, sujetos de Dos Quebradas en 2008. El procesamiento de las muestras de materia fecal se hizo por Ritchie-Frick modificado. Resultados: Ascaris lumbricoides fue el parásito más frecuente 49,6 % (60/121; IC 95 %:37,8-63,8) en Naicioná y 47,4 % (36/76; IC 95 %: 33,2-65,6) en Dos Quebradas. El mayor efecto de la ivermectina en mayores de 5 años fue la disminución del riesgo de infección, para Trichiuris trichiura, de 86 % (IC95 %:74-93) en la evaluación longitudinal y 63 % (IC 95 %:24-82) en la evaluación transversal. La disminución en la frecuencia de Strongyloides stercoralis fue 93 % (IC 95 %: 45-99), en la evaluación longitudinal y 85 % (IC95 %:-031 - 99) en la evaluación transversal. Conclusiones: El uso de la ivermectina en el contexto del Programa para la Eliminación de la Oncocercosis en las Américas no es suficiente para el control de la morbilidad de todas las geohelmintiasis, se requiere de programas integrales que incluyan los componentes de educación y saneamiento básico.

Objective: Evaluating the effect of ivermectin on soil-transmitted helminthes (STH) infection frequency in a Colombian population included in the Onchocerciasis Elimination Program for the Americas (OEPA). Methods: This was an impact evaluation study which adopted a longitudinal approach using the population of Naicioná (1996) as baseline for comparison to people from the same population as controls (2008). The cross-sectional approach involved comparing the reference population of Naicioná (2008) to the population of Dos Quebradas (2008) used as controls. Fecal samples were processed by a modified Ritchie-Frick method. Results: Ascaris lumbricoides was the most frequently found parasite in Naicioná (60/121; 49.6 %: 37.8-63.895%CI) and in Dos Quebradas (36/76; 47.4 %: 33.2-65.6 95 % CI). Ivermectin’s main effect on the population aged over 5 years was a decreased risk of Trichiuris trichiura infection in both longitudinal assessment (86 % reduction: 74-93 95 % CI) and cross-sectional assessment (63 %:24-82 95 % CI). A 93 % reduction (45-99 95 % CI) in Strongyloides stercoralis frequency was found in longitudinal assessment, compared to 85 % in cross-sectional assessment (-031-99 95 % CI). Conclusions: Ivermectin use in the OEPA is not sufficient for STH morbidity control. Integrated programs including education and basic sanitation are required.

Epidemiological evaluation of onchocerciasis along Ogun River System, southwest Nigeria.

Background & objective: Epidemiological studies were carried out to assess the prevalence and community microfilarial load (CMFL) of onchocerciasis after repeated annual treatment with ivermectin along Ogun river System, southwest Nigeria. Method: Skin snips were taken from consented participants in 11 selected communities along the River system. The microfilarial load of the community was estimated. Results: The prevalence and CMFL varied significantly in the communities (p <0.05). The prevalence of onchocerciasis ranged from 19.1 to 45.6%, while the CMFL ranged from 0.11 to 1.03 microfilariae per skin snip. The CMFL recorded was <5 microfilariae per skin snip, i.e. recognized by WHO as threshold value in certifying the communities to be free of onchocerciasis as public health problem, thus, signifying the possibility of onchocerciasis elimination in the study area. Conclusion: Efforts should therefore be intensified to achieve improved ivermectin coverage and compliance in annual ivermectin treatment in order to completely eliminate onchocerciasis as a public health problem in the studied communities.

Multiple filarial species microfilaraemia: a comparative study of areas with endemic and sporadic onchocerciasis.

Background & objectives: The study was aimed at determining the pattern of co-occurrence of species of microfilaraemia between onchocerciasis endemic and sporadic populations. Methods: From every consenting person of one year and above, 50 μl of day and night blood samples were collected and processed respectively with Haemotoxylin and Giemsa as vital stains. Two skin snips (one each from the waist and the shoulder) were also taken from these individuals and processed. Results: Results showed single species microfilaraemia (86.4 and 82.3%), double species microfilaraemia (12.2 and 16.9%) and triple species microfilaraemia (1.4 and 0.7%) for endemic and sporadic populations respectively. All the species had single species microfilaraemia mostly, but Mansonella perstans and Loa loa showed greatest tendency towards double and triple species microfilaraemia. The prevalence of Wuchereria bancrofti microfilaraemia among those positive for Onchocerca volvulus was significantly lower than the overall prevalence of Wuchereria bancrofti. Wuchereria bancrofti microfilaraemia was most common among those who had L. loa microfilaraemia. Wuchereria bancrofti microfilarial intensity was higher among those with M. perstans microfilaraemia than among those positive for any of the other filarial species. Similarly, the intensity of M. perstans microfilaraemia among those positive for W. bancrofti exceeded the overall intensity of M. perstans. Conclusion: It is concluded that there was no definite pattern in mf densities discernible from co-occurrence infections either in the onchocerciasis endemic or sporadic population. There could be varied outcomes of onchocerciasis infection attributable to positive or negative regulatory effects of other pathogens harbored by the victims.