Transplacental Transmission of Filarial Infections and Its Impact on Oxidative Stress and Immune Responses during Foetal Life in Bamenda, North West Cameroon

Background:Women commonly harbour filarial infections during their childbearing years, raising the possibility that the developing foetus may be exposed to filarial antigens in the uterus and thereby have altered immunity and susceptibility to infection during early childhood. However, there are no concrete proofs to justify the risk of infections in infants born from mothers having filarial infections during pregnancy. Aim:The purpose of this study was to assess the prevalence of microfilariae in umbilical cord blood and respective mothers and to evaluate the relationship between the cord blood filarial infection and the oxidative stress status and concentration of IL-2, IL-10, IL-13, INF-γ and IgG in umbilical cord blood.Methods:This was a nested case–control study of cords and mothers of normal gestational age (>250 days of gestation). A total of 316 pairs of umbilical cords and mothers were examined. The presence of microfilariae was assessed by microscopy in mothers and cords. Oxidative stress status (total oxidative stress and total oxidative defence) and nitric oxide of umbilical cord and mother’s blood were investigated by the colorimetric method. ELISA was carried out for IL-2, IL-10, IL-13, INF-γ in umbilical cord and mother’s blood. Equally, umbilical cords were subjected to ELISA for total IgG.Results:Results obtained showed that microfilariae had a prevalence of 32.9% and 29.7% in umbilical cord blood and womenat time of delivery respectively. High levels of total oxidative stress (TOS) with low total oxidative defence (TAD) was found in filarial infected (Mf +ve) umbilical cord and mother’s blood compared to controls or uninfected (Mf -ve) cords and mothers blood. IL-2 was lower in the blood of microfilariae infected cords and mothers, while INF-γ, IL-13 and IL-10 were higher as compared to microfilariae negative cords and mothers. Equally, plasma total IgG concentration was higher in microfilariae positive cords compared to the negative cords and positively correlated with IL-10.Conclusions: There is high frequency of transplacental transmission of microfilariae. Cord blood filarial infections were associated with a high TOS, a protective immune response with low IL-2 and high INF-γ, and a typical Th2 immune response that was associated with higher concentration of immune total IgG regulatory cytokine IL-10 and IL-13 in neonate

Microfilaremia by Cercopithifilaria bainae in a dog from the central western region of Brazil: case report / Microfilaremia por Cercopithifilaria bainae em um cão da região Centro-Oeste do Brasil: relato de caso

Cercopithifilaria bainae is a nematode belonging to the family Onchocercidae that parasitizes the subcutaneous tissue of dogs. Its transmission occurs through the tick Rhipicephalus sanguineus and its geographical distribution overlaps that of this vector. The present study reports the detection of microfilaremia by C. bainae in an eight-year-old male dog that presented anorexia, hyperthermia, motor incoordination, mydriasis, a nodule in the left testicle and concomitant infection by Ehrlichia sp. Blood samples were analyzed using microscopy, PCR and DNA sequencing. Microfilariae measuring 150±5.5µm in length and 7±1.8µm in width were retrieved. The DNA sequence exhibited 98% identity with C. bainae sequences available in Genbank. This is the first report of microfilaremia by C. bainae in a dog in the central western region of Brazil.(AU)

Cercopithifilaria bainae é um nematoide pertencente à família Onchocercidae, que parasita o tecido subcutâneo de cães. Sua transmissão ocorre pelo carrapato Rhipicephalus sanguineus, e sua distribuição geográfica se sobrepõe ao espalhamento desse vetor. O presente estudo relata a detecção de microfilaremia por C. bainae em um cão macho de oito anos que apresentava anorexia, hipertermia, incoordenação motora, midríase e nódulo no testículo esquerdo e infecção concomitante por Ehrlichia sp. A coleta de sangue foi realizada, e o material analisado por meio dos exames de microscopia, PCR e sequenciamento de DNA. Microfilárias medindo 150±5,5µm de comprimento e 7±1,8µm de largura foram recuperadas. A sequência de DNA obtida mostrou 98% de identidade com sequências de C. bainae disponíveis no Genbank. Este é o primeiro relato de microfilaremia de C. bainae em um cão na região Centro-Oeste do Brasil.(AU)

Microfilariae in bone marrow aspirate of a case of myelofibrosis: A cause or coincidence?

Filariasis is among the common parasitic infestations found in India, with Wuchereria bancrofti being the most common causative organism. Presentation ranges from clinically asymptomatic to profound elephantiasis. It is also detected incidentally in diagnostic samples such as body fluids, fine needle aspirates, peripheral blood smears, and other cytological smears. Its detection in bone marrow aspirates with an associated hematolymphoid neoplasm is rare, with only a few case reports. We report one such case of young male who presented with leukocytosis of 253 × 109/L with basophilia and massive splenomegaly. Bone marrow aspirate smears showed the presence of microfilariae along with other features of a myeloproliferative neoplasm (MPN). The present case is probably the first case of finding a microfilaria in a case of MPN

Microfilarae in malignant mesothelioma associated pleural effusion with blood microfilaremia: a rare association

Filariasis has a wide spectrum of presentation and usually involves the lung in the form of tropical pulmonary eosinophilia with pulmonary infiltrates and peripheral eosinophilia. Filariasis presenting with pleural effusion is an unusual presentation. Malignancy in association with filarial pleural effusion is extremely rare. In this context, we hereby report a case of 45 year old male who presented with right sided chest pain, cough, fever and generalized weakness. Pleural fluid cytology revealed microfilaria and pleural biopsies from pleural nodules confirmed malignant mesothelioma. Peripheral blood smears taken at night exhibited microfilaria with normal eosinophil counts, which is further uncommon. Role of filariasis in tumorigenesis is controversial.

Dirofilaria immitis infestation in imported police (K-9) dogs in Iraq: clinicopathological and molecular investigations study / Infecção por Dirofilaria immitis em cães policiais importados no Iraque: estudo clínico-patológico e de investigações moleculares

Dirofilaria immitis, the cause of heartworm infestation (HWI) or dirofilariasis, affects members of the Canidae and remains a worldwide clinical problem. In Iraq, dirofilariasis was believed absent until 2009, when the Karbala Governorate was reported as an endemic area for canine dirofilariasis. Consequently, this study intended to investigate the occurrence of Dirofilaria immitis in police dogs in one police academy in Iraq and to study the gross and histopathological changes in 5 dead dogs, as well as to identify the species of the causative parasite using PCR technique. Thirty-nine police dogs, aged between 6 months and 12 years were included in this study. For the microfilariae investigation, 5 ml blood samples were collected from all dogs in EDTA tubes and examined by Knott's method. The systemic necropsy performed in five dead dogs showed severe clinical signs of dirofilariasis and tissue specimens were sent for routine histopathological processing. For the molecular analysis, adult worms of the detected Dirofilaria spp. were used for DNA extraction and amplification of the cox1 gene. Fifteen of 39 (38.46%) dogs were diagnosed with moderate to severe microfilariasis. The dead dogs revealed typical severe clinical signs of dirofilariasis. Moreover, typical gross and histopathological changes were also seen, accompanied by generalized thromboembolic lesions, suggesting the occurrence of the caval syndrome. The PCR investigation confirmed that D. immitis was the species present in Iraq. In conclusion, this study establishes that Iraq is a newly reported endemic area for dirofilariasis. Moreover, the infestation occurring in these cases most probably happened inside Iraq. The authors recommend doing further epidemiological studies concerning the occurrence of D. immitis in local dogs as well as in the imported dogs in all Iraqi governorates to better understand the epidemiological map of this disease and to introduce an active treatment and preventive program. Awareness and education regarding this disease should be provided to the veterinarians, dog guiders and people in direct contact with dogs, as this disease is one of the important zoonotic diseases.(AU)

A Dirofilaria immitis, causadora da infestação pelo verme do coração (IVC) ou dirofilariose afeta os membros da família Canidae e ainda é um problema clínico mundial. Até o ano de 2009, acreditava-se que o Iraque fosse livre da dirofilariose, porém nessa ocasião a governadoria de Kerbala foi relatada como uma área endêmica de dirofilariose. Assim, o presente trabalho foi realizado para investigar a ocorrência da Dirofilaria immitis em cães policiais em uma academia de polícia do Iraque, estudar as alterações macroscópicas e histopatológicas em cinco cães mortos, bem como, identificar as espécies do parasita causador com o emprego da técnida de PCR. Trinta e nove cães policiais com 6 meses a 12 anos de idade foram incluídos no estudo. Amostras de sangue de cinco mililitros foram colhidas por animal, em tubos com EDTA e foram examinadas pelo método de Knott. A necropsia sistêmica foi realizada em cinco cães que haviam apresentado sinais clínicos severos de dirofilariose e espécimens dos seus tecidos foram enviados para o processamento histopatológico de rotina. Para a análise molecular dos vermes adultos de Dirofilaria spp, foi empregada a extração do DNA e a amplificação do gene cox1. Quinze de 39(38,46%) cães foram diagnosticados com uma microfilariase variável de moderada para severa. As alterações macroscópicas e histopatológicas foram acompanhadas por lesões generalizadas tromboembólicas sugestivas da ocorrência da síndrome da veia cava. A investigação de PCR confirmou que a D.immitisera a espécie presente no Iraque. A conclusão do estudo estabeleceu que o Iraque deve passar a ser considerado como uma nova área endêmica da dirofilariose. Além da infestação registrada nos casos descritos é provável que ela também esteja presente em outras regiões do Iraque. Os autores recomendam a realização de estudos epidemiológicos para investigar a ocorrência de D.immitis tanto nos cães locais bem como em cães importados em todas as governadorias do Iraque, para ser construído o mapa epidemiológico da distribuição da doença e implantadas as ações de tratamento e de um progrma preventivo. Ações de educação em saúde sobre a doença deverão ser dirigidas para os veterinários, tratadores de cães e para pessoas em geral que tenham contato com os cães, pois esta doença é uma importante zoonose.(AU)

Microfilaria In Bone Marrow Aspirate: A Case Report

Wuchereria bancrofti is the most common parasite causing lymphatic filariasis. Microfilariae are dem­onstrated in the peripheral blood, body fluids, fine needle aspirates and in onchial ushings but it is an uncommon finding in the bone marrow. We report a case of a 45-year old male who presented with pyrexia of unknown origin and on peripheral blood and bone marrow examination found to have pan­cytopaenia with megaloblastoid changes in the bone marrow and W. bancrofti microfilariae.

First report on surface aspects of Mansonella ozzardi (spirurida: onchocercidae) microfilariae by scanning electron microscopy: preliminary results

Blood samples from Mansonella ozzardi infected volunteers from Vila Antimary (Amazonas State) were processed and a protocol to isolate and prepare microfilariae was carried out in order to perform Scanning Electron Microscopy (SEM) analysis. Data obtained from ultrastructure showed some undescribed structural points of the parasite such as a dimple in the anterior end of the larva and small points ­orifice-like­ that may be related to amphidial structures or simply pores. Another interesting feature was the tip of the tail which is very similar to that found in the rodent parasite Dunnifilaria meningica

Antifilarial actions of green tea extract and a synthetic heterocyclic thiazolidine derivative, Im8 compound in experimental mouse model.

In spite of the advances in drug development and research against human lymphatic filariasis following the WHO mandate to address the disease-associated socioeconomic burden, diethylcarbamazine (DEC, N, N-diethyl-4-methyl-1-piperazine carboxamide) is the only available antifilarial drug to date. The major obstacle for further development of antifilarial drugs is the lack of validation of candidate drugs in the experimental animal models. Both, green tea extract and a synthetic heterocyclic thiazolidine derivative (Im8; 2-chloro-N-(4-phenylthiazol-2-yl), showed efficacy of antifilarial action in our earlier in vitro study and hence, they were screened in the present study for their antifilarial potential in the BALB/c mouse filariasis model. Mice were treated with 25 mg/kg dose of either Im8 or green tea extract or DEC or only with their respective vehicles. The untreated mice served as controls. Following insertion of the micropore chamber laden with microfilariae (Mf) of Brugia malayi, the drug or vehicle was administered s.c. in mice at 12 h intervals as 4 doses. After 12 h of administration of the last dose, the micropore chambers were removed to determine the action of the treatments as the loss of Mf motility. The green tea extract showed a significant antifilarial action and Im8 showed relatively less but significant antifilarial action as compared to the respective vehicle controls. Both the green tea extract and Im8 showed higher activity than that was exerted by DEC. These results revealed a greater efficacy of green tea and thiazolidine derivative, Im8 as the novelantifilarial agents in the experimental mouse model of filariasis.

Canine heartworm disease in a brazilian non-endemic area / Dirofilariose canina em uma aréa não endêmica brasileira / Dirofilariosis canina en una zona no endémica brasileña

Canine Heartworm Disease (CHD) is a mosquito-borne disease caused by Dirofilaria immitis. In this study, two mature adult-senior dogs from a non-endemic area to CHD presented clinical signs suggestive to the disease. The first one presented skin lesions, loss of appetite, weakness, pale mucosa membrane, and hyperthermia, whereas the second one presented severe ascites, anorexia and exercise intolerance, lateral decumbency, and marked heart murmurs. Both presented tachypnea, thrombocytopenia, leukocytosis, and microfilaremia. Multiplex-PCR (COI gene) resulted positive to D. immitis research in both cases, confirmed by sequencing, with 98% homology to D. immitis (Gen Bank accession n.AJ537512-1). In addition, both animals have never had any prophylactic treatment to CHD, and no reports about traveling to coastal areas. This study reported two unusual cases of D. immitis infection in non-endemic area from Brazil.

A dirofilariose canina (CHD) é uma doença transmitida por mosquitos e causada por Dirofilaria immitis. No presente estudo, dois cães de idade adulta a idoso de área não endêmica apresentaram sinais clínicos sugestivos da doença. O primeiro apresentou lesões de pele, perda de apetite, fraqueza, mucosas pálidas e hipertermia, enquanto o segundo apresentou severo quadro de ascite, anorexia e intolerância ao exercício, decúbito lateral, e murmúrios cardíacos acentuados. Ambos apresentaram taquipneia, trombocitopenia, leucocitose e microfilaremia. A pesquisa por D. immitis pela multiplex-PCR (COI gene) resultou positiva em ambos os casos, confirmada pelo sequenciamento, com 98% de homologia com D. immitis (Gen Bank n. AJ537512-1). Nenhum dos animais havia sido submetido a tratamento profilático para CHD e não havia relatos de viagens para regiões litorâneas. Assim, o presente estudo reporta dois casos raros de infecção por D. immitis em área brasileira não endêmica para a doença.

La dirofilariosis canina (CHD) es una enfermedad transmitida por mosquitos y causada por Dirofilaria immitis. En este estudio, dos perros de edad adulta a anciano, de área no endémica presentaron signos clínicos de la enfermedad. El primero presentó lesiones en la piel, pérdida del apetito, debilidad, palidez de mucosas e hipertermia, mientras el otro presentó severa ascitis, anorexia e intolerancia al ejercicio, decúbito lateral, y soplos cardíacos acentuados. Ambos presentaron taquipnea, trombocitopenia, leucocitosis y microfilaremia. La investigación de D. immitis por multiplex-PCR (gen COI) resultó positivo en ambos casos, confirmados por la técnica de secuenciación, con 98% de homología con D. immitis (Gen Bank n.AJ537512-1). Ninguno de los animales había sido sometido al tratamiento profiláctico para CHD, y sin relatos de viajes a regiones costeras. El presente estudio reporta dos casos raros de la infección por D. immitis en zona no endémica de Brasil.

Effects of filaricidal drugs on longevity and enzyme activities of the microfilariae of Setaria cervi in white rats

To analyse the efficacy of diethylcarbamazine (DEC), tetramisole and chlorpromazine on the longevity and activity of glucose-6-phosphatase and succinate dehydrogenase in the microfilariae recovered from the peripheral circulation of the rats before and after the treatment. Methods: Setaria cervi worms were implanted in white rats via laparotomy and microfilaraemic rats were divided into 4 groups. Groups 1, 2 and 3 were treated with DEC, tetramisole and chlorpromazine respectively, while Group 4 served as infected control. Longevity of microfilariae and differential leucocyte counts were recorded till the disappearance of microfilariae from peripheral blood. Glucose-6-phosphatase and succinate dehydrogenase enzymes were localized in the microfilariae recovered from normal and treated rats. Results: The microfilariae survived for 48 days in untreated rats while survival was reduced to 15, 21 and 27 days after treatment with DEC, tetramisole and chlorpromazine, respectively. Eosinophils and neutrophils increased during 2nd and 3rd weeks, whereas the lymphocytes increased during 4-7 weeks. DEC treatment resulted in slight decrease in the localization of succinate dehydrogenase but not in glucose-6-phosphatase. Tetramisole and chlorpromazine treatment did not show any appreciable change in the localization of both the above enzymes. Conclusions: DEC proved the most effective drug which cleared the microfilaraemia within 15 days and reduced the activity of succinate dehydrogenase to some extent followed by tetramisole and chlorpromazine which took more time for the clearance of microfilariae and had no effect on the localization of both glucose-6-phosphatase and succinate dehydrogenase.

Effects of filaricidal drugs on longevity and enzyme activities of the microfilariae of Setaria cervi in white rats

Objective: To analyse the efficacy of diethylcarbamazine (DEC), tetramisole and chlorpromazine on the longevity and activity of glucose-6-phosphatase and succinate dehydrogenase in the microfilariae recovered from the peripheral circulation of the rats before and after the treatment. Methods: Setaria cervi worms were implanted in white rats via laparotomy and microfilaraemic rats were divided into 4 groups. Groups 1, 2 and 3 were treated with DEC, tetramisole and chlorpromazine respectively, while Group 4 served as infected control. Longevity of microfilariae and differential leucocyte counts were recorded till the disappearance of microfilariae from peripheral blood. Glucose-6-phosphatase and succinate dehydrogenase enzymes were localized in the microfilariae recovered from normal and treated rats. Results: The microfilariae survived for 48 days in untreated rats while survival was reduced to 15, 21 and 27 days after treatment with DEC, tetramisole and chlorpromazine, respectively. Eosinophils and neutrophils increased during 2nd and 3rd weeks, whereas the lymphocytes increased during 4-7 weeks. DEC treatment resulted in slight decrease in the localization of succinate dehydrogenase but not in glucose-6-phosphatase. Tetramisole and chlorpromazine treatment did not show any appreciable change in the localization of both the above enzymes. Conclusions: DEC proved the most effective drug which cleared the microfilaraemia within 15 days and reduced the activity of succinate dehydrogenase to some extent followed by tetramisole and chlorpromazine which took more time for the clearance of microfilariae and had no effect on the localization of both glucose-6-phosphatase and succinate dehydrogenase.

Tropical pulmonary eosinophilia - A review.

Tropical pulmonary eosinophilia (TPE) is a syndrome of wheezing, fever and eosiniphilia seen predominantly in the Indian subcontinent and other tropical areas. Its etiological link with Wuchereria bancrofti and Brugia malayi has been well established. The pathogenesis is due to an exaggerated immune response to the filarial antigens which includes type I, type III and type IV reactions with eosinophils playing a pivotal role. Peripheral blood eosinophilia is usually striking with levels over 3000/μl being common. High serum levels of IgE and filarial-specific IgE and IgG are also found. The pathology may vary from an acute eosinophilic alveolitis to histiocytic infiltration depending on the stage of the disease. While earlier studies had suggested that the disease runs a benign course, more recent work has shown that untreated TPE could result in a fair degree of respiratory morbidity. Pulmonary function tests may show a mixed restrictive and obstructive abnormality with a reduction in diffusion capacity. The bronchoalveolar lavage (BAL) eosinophil count has a negative correlation with the diffusion capacity. Treatment consists of diethylcarbamazine (DEC) for at least three weeks. Despite treatment with DEC, about 20 per cent of patients may relapse. Steroids have shown to have a beneficial effect but the exact dose and duration is yet to be confirmed by randomized controlled trials. A specific and easily available marker is required for TPE in order to distinguish it from other parasitic and non-parasitic causes of pulmonary eosinophilia.

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.

Identificación morfológica y molecular de filarías caninas en una comuna semi-rural de la Región Metropolitana, Chile / Morphological and molecular identification of canine filariae in a semi-rural district of the Metropolitan Region in Chile

Introduction: To date, there has been no definitive confirmation of the presence of zoonotic dirofilariasis in dogs in Chile. Objectives: To study the presence of dirofilarias in blood samples from dogs collected in a semi-rural district near Santiago and to compare their frequency in dogs with and without dermatological manifestations. Methods: We examined 100 blood samples for dog filariae infections using microscopic methods (modified Knott technique). 50 dogs presented dermatological symptoms or signs compatible with filarial infections and 50 were asymptomatic. ITS-2 and 12s rDNA gene amplification by PCR and sequencing were performed in samples microscopically positive for microfilariae. Results. We observed microfilariae in 22 dogs (22%). Of these, 16/50 (32%) were symptomatic and 6/50 (12%) were asymptomatic (p = 0.02). Morphologically, the majority of micro-filariae were similar to Dirofilaria repens, although many had a bigger size than previously described. Nucleotide sequencing of the amplified genes showed no more than 95% homology with the D. repens sequences available for comparison. D. reconditum and D. dracunculoides infections were also identified. Conclusions: These features might indicate the presence of new species of Dirofilaria or a D. repens close related variant in Chile.

Introducción: A la fecha no hay datos concluyentes en Chile respecto a la presencia de dirofilariasis zoonótica en perros. Objetivos: Identificar la presencia de dirofilarias en sangre de perros de una comuna semi-rural cercana a Santiago y comparar su frecuencia en animales con y sin manifestaciones dermatológicas. Materialy Métodos. Se examinó un frotis sanguíneo de 100 perros en busca de microfilarias mediante observación microscópica (técnica de Knott modificada). Cincuenta perros presentaban síntomas o signos dermatológicos que se han asociado a esta parasitosis y 50 eran asintomáticos. Se amplificaron los genes ITS-2 y 12s ADNr de filarías en las muestras con microfilarias al frotis, secuenciando los fragmentos amplificados. Resultados: Se observaron microfilarias en 22 perros (22%), 16/50 (32%) sintomáticos y 6/50 (12%) asintomáticos (p = 0,02). Morfológicamente, la mayoría de las microfilarias observadas fueron similares a D. repens; sin embargo, una gran proporción mostró un tamaño mayor al descrito para esta especie. Las secuencias nucleotídicas de los genes amplificados mostraron una homología no mayor al 95% con las secuencias de D. repens disponibles para comparación. Se identificaron además dos especies poco patógenas, D. reconditum por morfología y secuenciación genética y D. dracunculoides por morfología. Conclusiones: Los resultados indican la existencia de una nueva especie de Dirofilaria cercanamente relacionada a D. repens o de una variante de esta especie.

Investigation of the occurrence of Mansonella ozzardi in the State of Rondônia, Western Amazonia, Brazil / Investigação da ocorrência da Mansonella ozzardi no Estado de Rondônia, Amazônia Ocidental

INTRODUCTION: Mansonella ozzardi, a human filarial nematode transmitted by Diptera Simuliidae flies (black flies), is widely spread in the Amazon, while the occurrence of mansonelliasis in the State of Rondônia (Western Amazonia) has not been reported thus far. The existence of this parasitic disease in this state is investigated in this study. METHODS: A total of 4,452 people who lived alongside the Madeira, Mamore, Guapore, Machado and Preto Rivers, in the State of Rondônia, were examined using the thick blood smear method. Alongside the Machado and Guapore rivers, 2,112 adult simuliid specimens were captured. RESULTS: Infected people were not reported, although simuliids with vector potential such as Cerqueirellum pydanielli, C. argentiscutum and C. amazonicum were found. CONCLUSIONS: This study registered no infected people. This finding may be explained by the individuals' low level of microfilaremia that is below the limit of detection of the diagnostic method used in the study or insufficient migration of people infected with M. ozzardi from endemic areas, making it impossible to introduce the disease into Rondônia. Further studies using more sensitive diagnostic techniques could shed light on this question.

INTRODUÇÃO: Mansonella ozzardi é uma filária humana que tem como vetor dípteros simulídeos e é amplamente distribuída na Amazônia. Não há informações sobre a ocorrência de casos de mansonelose no Estado de Rondônia, e neste trabalho procurou-se investigar a situação epidemiológica desta parasitose em áreas urbanas e ribeirinhas na Amazônia Ocidental. MÉTODOS: Foram examinados 4.452 moradores às margens dos rios Madeira, Mamoré, Guaporé, Machado e Preto em Rondônia, através da técnica da gota espessa de sangue. Capturou-se às margens do rio Machado e Guaporé 2.112 simulídeos adultos das espécies Cerqueirellum pydanieli e Chirostilbia pertinax. RESULTADOS: Não foram encontradas pessoas infectadas com M. ozzardi e foram encontradas diferentes espécies de simulídeos com potencial de transmissão da mansonelose. CONCLUSÕES: Não foram encontrados indivíduos infectados com M. ozzardi neste estudo. Este fato pode ser explicado pela existência de pacientes com baixas microfilaremias, associado à técnica diagnóstica de baixa sensibilidade utilizada no estudo. Pode-se ainda aventar a possibilidade de ter ocorrido migração insuficiente de pacientes infectados de áreas endêmicas, impossibilitando a implantação da endemia. Estudos posteriores com técnicas diagnósticas mais sensíveis podem ajudar a esclarecer esta questão.

Studies on amino acids in microfilariae of periodic Brugia malayi before and after cytotoxicity / 中华传染病杂志

Objective To study the mechanism of killing microfilariae in host by detecting the change of amino acids in Brugia malayi microfilariae. Methods The composition and contents of amino acid in microfilariae of periodic Brugia malayi before and after the effect of cytotoxicity were analyzed with automatic amino acid analyzer. Results The result showed that microfilariae contained 17 kinds of amino acids, but lacked Tryptophan. The total amount of amino acids of the microfilariae after cytotoxicity was lower than that before cytotoxicity( P

Immunoprophylaxis against filarial parasite, Brugia malayi: potential of excretory-secretory antigens in inducing immunity.

The role of excretory-secretory antigens in inducing immunity in the host against Brugia malayi microfilariae and infective larvae was studied by in vitro antibody dependent cell-mediated reaction as well as in vivo inoculation of filarial parasites within a microchamber in the host. The immune sera of jirds raised against Brugia malayi microfilarial and infective larval excretory-secretory antigens (Bm Mf ESA and Bm L3 ESA) promoted the adherence of peritoneal exudate cells to Brugia malayi microfilariae and infective larvae in vitro and induced cytotoxicity to the parasites within 48 h. The anti Bm Mf ESA serum was more effective than anti Bm L3 ESA serum in inducing cytotoxicity to microfilariae and both antisera had a similar cytotoxic effect on infective larvae. In the microchambers implanted in the immune jirds, host cells could migrate and adhere to the microfilariae and infective larvae and kill them within 48–72 h. Further, Mastomys natalensis immunized against Bm Mf ESA and L3 ESA generated a high degree of protective response against circulating microfilariae. These results suggest that excretorysecretory antigens are effective in inducing resistance against filarial parasites and thus have potential in immunoprophylaxis.

Sharing of antigens among filarial species revealed by antibody dependent cell-mediated reactions.

Antisera raised in albino rats against microfilariae of Litomosoides carinii, Brugia pahangi, Brugia malayi and sera from Bancroftian elephantiasis patients promoted rat neutrophil-mediated adherence and cytotoxicity to the microfilariae. Pre-treatment of the immune sera, with microfilarial antigen at a final concentration of 5 and 25 μg per ml blocked cellular adherence and cytotoxicity to the microfilariae indicating the presence of crossreactive antibodies. The heterologous immune sera were effective in eliminating the circulating Litomosoides carinii microfilariae in Mastomys natalensis.