Endemic Parasitic Disease Research Articles

Dirofilariose humaine : un nouveau cas français àDirofilaria repens

Dirofilariosis is an endemic filarial parasitic disease in the Mediterranean basin, unfamiliar in France. Its incidence and geographic area are increasing due to global warming. Dogs and cats are the usual hosts, but humans may be accidentally infected. We reported the 91st case of French dirofilariosis, contracted in Camargue (South France) which appeared as a subcutaneous abdominal nodule. Ultrasound strongly guided the diagnosis by showing a linear structure moving in a fibrocystic structure. Surgical excision confirmed the diagnosis of species (Dirofilaria repens) and this remains the only curative treatment.

Tratamento da hipertensão pulmonar esquistossomótica

A esquistossomose mansoni é a terceira doença parasitária endêmica mais prevalente do mundo. Estima-se que mais de 200 milhões de pessoas estejam infectadas com uma das espécies do parasita Schistosoma. Dessas, 270.000 pessoas (4,6%) são portadoras de hipertensão arterial pulmonar, que é associada à forma hepatoesplênica da doença. Essa alta prevalência coloca a hipertensão pulmonar esquistossomótica como a causa mais frequente de hipertensão pulmonar no mundo. Entretanto, o tratamento dirigido especificamente ao acometimento vascular pulmonar não está ainda estabelecido. Relatamos o caso de uma paciente portadora dessa doença que foi tratada com um inibidor de fosfodiesterase-5 (sildenafil) com resultados satisfatórios.

Biological invasions and the dynamics of endemic diseases in freshwater ecosystems

Summary1. Biological invasions, still occurring worldwide at an alarming rate, are widely acknowledged as threats to the integrity and functioning of ecosystems. In addition to introducing disease, biological invasions have also been linked to sudden increases in the incidence or severity of previously existing diseases. We review and illustrate the potential direct and indirect impacts of introduced species on the dynamics of endemic parasites in freshwater ecosystems.2. Introduced species may trigger and sustain disease emergence by acting as competent hosts for endemic parasites in which infection is amplified and then ‘spilled back’ to native hosts. In contrast, if introduced species are not suitable hosts for endemic parasites but become infected anyway, they may act as sinks for parasites and thus dilute disease risk for native hosts.3. Another mechanism by which introduced species can influence endemic parasitic diseases is by altering the relative abundance of one of the parasite’s hosts in ways that could either enhance or reduce disease transmission to other native hosts in the parasite’s life cycle.4. Introduced species may also alter disease incidence and severity in native hosts through trait‐mediated indirect effects. For example, the introduced species could change the exposure or susceptibility of native hosts to infection by causing alterations in their behaviour or immunocompetence. Also, by directly changing physicochemical conditions and modifying environmental stressors introduced species may indirectly affect native host exposure and/or resistance to disease.5. A survey of parasites infecting introduced freshwater fish in four distinct geographical areas revealed that use of non‐indigenous hosts by endemic parasites is widespread, mostly involving parasites transmitted via the food chain.6. We conclude by presenting a framework, based on risk assessment, for the prediction and possible mitigation of the impact of introduced species on endemic diseases and by calling for greater recognition of the potential role of invasive species as triggers of endemic disease emergence.

Response of Nkedi Zebu and Ankole cattle to tick infestation and natural tick-borne, helminth and trypanosome infections in Uganda

A cross-sectional study was conducted in Soroti district of Uganda to establish important traits of Nkedi Zebu and Ankole cattle regarding their production performance responses to natural infections of trypanosomes, gastrointestinal nematodes, Theileria parva, Babesia bigemina, Anaplasma marginale and tick infestations. Over four visits between October 2006 to August 2007, tick counts were performed and blood, faecal samples and sera were collected from the Nkedi Zebu (295) and Ankole (165) cattle from 86 herds in six locations per visit. Low parasitological prevalence of trypanosome infection (<6%) and high prevalence of gastrointestinal nematode infections (>30%) with low faecal egg counts (110-300 eggs per gramme (EPG)) were observed in the Nkedi Zebu and Ankole cattle. Both breeds had high, moderate and low mean counts of Rhipicephalus appendiculatus (18.0-24.0), Rhipecephalus (Boophilus) decoloratus (3.6-10.3) and Amblyomma variegatum ticks (1.7-4.3), respectively. In addition, both breeds had similar mean packed cell volumes (26.4-31.2) and a similar percentage of animals were anaemic (14.5-36.6%). The Nkedi Zebu cattle further had higher mean optical density (OD) values for antibodies against T. parva (1.093-1.445) and A. marginale infections (0.573-0.583), and significantly (P < 0.001) higher mean OD values of antibodies against B. bigemina infections (1.07-2.175) than the Ankole cattle: T. parva (1.030-1.302); A. marginale (0.442-0.603) and B. bigemina infections (0.863-2.154). The Ankole cows produced significantly more (P < 0.001) milk per day (2.68L) than the Nkedi Zebu cows (1.98L), and the Ankole oxen had significantly higher (P < 0.05) draught power output (2.57days/acre) than the Nkedi Zebu oxen (2.93days/acre). Liveweights of calves aged 0-12months of both breeds were comparable, suggesting that the Nkedi Zebu and Ankole cattle under similar disease challenge exhibited similar growth rates. In conclusion, the Nkedi Zebu cattle seem to possess a higher degree of disease resistance against endemic parasitic diseases, while the Ankole cattle seem to possess a moderate degree of disease resistance coupled with a moderate production potential.

Esquistossomose em área de transição rural-urbana: reflexões epidemiológicas

The Schistosomiasis is an endemic parasitic disease of tropical areas found in 76 countries. It is also estimated that 779 million people are at risk of infection and 207 million are infected worldwide. In northeastern Brazil, this parasitosis reaches hyperendemic rates, particularly in the states of Pernambuco, Bahia, Alagoas and Sergipe. This study proposes to reflect about the epidemiology of schistosomiasis in a Housing Complex located in Sergipe. This study is characterized as descriptive; cross-sectional qualitative and quantitative with a convenience sample comprising 200 individuals, members of a population of 142 families. Secondary data analysis from 2003 to 2008 and primary data collected in 2009/2010, obtained through interviews were used. For data analysis it was used the chi-square test, assuming a significance level of 0.05%, from the SPSS 16.0 software. The studied area presents medium endemicity for schistosomiasis with an average prevalence of 13.98%, occurring more frequently among males of all age ranges, with a greater tendency among adolescent and adults and individuals of black and mulatto ethnicity with low level of education and low income.

A Case of Clonorchiasis with Focal Intrahepatic Duct Dilatation Mimicking an Intrahepatic Cholangiocarcinoma

Biliary strictures can be caused by various diseases. Intrahepatic duct (IHD) strictures are usually related to IHD stones and cholangitis. However, focal IHD strictures without IHD stones often create diagnostic problems. Parasitic diseases such as clonorchiasis can be a rare cause of an IHD stricture. Human clonorchiasis (Clonorchis sinensis infection) is an endemic parasitic disease in Eastern Asia, including Korea, and patients acquire the infestation by eating raw fish. On radiological examinations, clonorchiasis shows typically diffuse, minimal, or mild dilatation of the small IHD, particularly in the periphery, without dilatation of the extrahepatic duct. However, diagnosis of clonorchiasis can sometimes be difficult when radiological changes are atypical. We report a case of focal left IHD dilatation caused by clonorchiasis that was confused with a malignancy.

Primary hydatid cyst of the rib mimicking chest wall tumor: a case report

Hydatidosis, caused by Echinococcus granulosus, is still an endemic parasitic disease in the Mediterranean area, South America, North Africa, and Australia. The most common anatomic location of hydatid disease is the liver, followed by the lung. Hydatidosis is located in the bones in 0.5% to 2% of all cases. A hydatid cyst can be seen in any part of the body. However, primary hydatid cyst of the rib in childhood is exceedingly rare. We report the first case of a pediatric hydatid cyst of the rib mimicking chest wall tumor.

Crystal Structures of TbCatB and Rhodesain, Potential Chemotherapeutic Targets and Major Cysteine Proteases of Trypanosoma brucei

Background Trypanosoma brucei is the etiological agent of Human African Trypanosomiasis, an endemic parasitic disease of sub-Saharan Africa. TbCatB and rhodesain are the sole Clan CA papain-like cysteine proteases produced by the parasite during infection of the mammalian host and are implicated in the progression of disease. Of considerable interest is the exploration of these two enzymes as targets for cysteine protease inhibitors that are effective against T. brucei.Methods and FindingsWe have determined, by X-ray crystallography, the first reported structure of TbCatB in complex with the cathepsin B selective inhibitor CA074. In addition we report the structure of rhodesain in complex with the vinyl-sulfone K11002.ConclusionsThe mature domain of our TbCat•CA074 structure contains unique features for a cathepsin B-like enzyme including an elongated N-terminus extending 16 residues past the predicted maturation cleavage site. N-terminal Edman sequencing reveals an even longer extension than is observed amongst the ordered portions of the crystal structure. The TbCat•CA074 structure confirms that the occluding loop, which is an essential part of the substrate-binding site, creates a larger prime side pocket in the active site cleft than is found in mammalian cathepsin B-small molecule structures. Our data further highlight enhanced flexibility in the occluding loop main chain and structural deviations from mammalian cathepsin B enzymes that may affect activity and inhibitor design. Comparisons with the rhodesain•K11002 structure highlight key differences that may impact the design of cysteine protease inhibitors as anti-trypanosomal drugs.

Antiprotozoal Agents: An Overview

The therapy of parasitic diseases has relied, until recently, on the use of a very limited number of drugs, most of them of low efficacy, leading to side effects and in certain cases with high toxicity. This review focuses on the chemotherapy to treat diseases caused by Trypanosoma cruzi (Chagas disease), Trypanosoma b. gambiense and Trypanosoma b. rhodesiense (sleeping sickness), Plasmodium (malaria) and Leishmania (leishmaniasis). Therefore, we will summarize drugs currently available and future specific chemotherapy against these neglected diseases under clinical evaluation. The most advanced antichagasic candidates are represented by posaconazole, TAK-187 and albaconazole, which have completed their pre-clinical development as anti-T. cruzi agents, while new quinines concerning to ferroquine, tafenoquine and AQ-13 are in phase I or II of clinical trials as promising candidates for the treatment of malaria. Although parafuramidine has been under phase III clinical trials to treat Human African Trypanosomiasis (HAT), its development was discontinued due to liver problems. Finally, new approaches for the treatment of leishmaniasis were achieved by using miltefosine and, more recently, the aminoglycoside paromomycin, which was approved after clinical trials and, owing to its milder adverse effects and low cost, is being considered as a potential first-choice treatment for the disease. Thus, this review aims to highlight the available drugs to treat four endemic parasitic diseases, as well as promising therapeutic approaches and their corresponding targets under development, but it is not intended to be an exhaustive survey on the subject.

Integrating global animal health, public health and tropical animal health issues into the veterinary curriculum: a South African/African perspective

The globalisation of trade and food, the increased volume and speed of international travel, climate change, and the related escalation of emerging and re-emerging infectious diseases mean that countries are now more interconnected and interdependent than ever before. Africa is beleaguered by a range of endemic infectious and parasitic tropical diseases which, due to its diverse wildlife populations and indigenous livestock, can serve as a reservoir of high-impact or transboundary diseases and play a role in the emergence of disease, particularly at the wildlife, domestic animal and human interfaces. It is therefore essential to integrate animal and public health issues into the veterinary curriculum. Veterinary training in most parts of sub-Saharan Africa has focused on producing veterinarians to serve the livestock sector although socio-economic changes and privatisation of Veterinary Services have caused curriculum adjustments, as have globalisation and the increased risk of the spread of transboundary diseases. In South Africa, undergraduate veterinary training is more clinically oriented than in other regions. Animal and public health issues are covered in the curriculum, although their global relevance is not emphasised. The authors describe the undergraduate veterinary curriculum and summarise post-graduate programmes in South Africa. They also discuss a more comprehensive core-elective approach to the current curriculum and the need to adapt to new challenges facing the profession. Finally, they examine the potential use of innovative technology in undergraduate and post-graduate training and professional development, the importance of regional and international collaboration and the accreditation and recognition of veterinary training.

Rare primary extrahepatic intra-abdominal hydatid cysts

Hydatid disease is an endemic parasitic disease prevalent in sheep-rearing countries. Although liver and lung are the commonly involved organs, hydatid disease can occur in any organ or tissue. In this case series, we share our experience of some rare primary extrahepatic intra-abdominal hydatid cysts.

Utility of a Protein Fraction with Cathepsin L-Like Activity Purified from Cysticercus Fluid of Taenia solium in the Diagnosis of Human Cysticercosis

Neurocysticercosis, an endemic parasitic disease in most developing countries, is caused by Taenia solium and compromises the human central nervous system. Cathepsin L-like proteases are secreted by several parasites including T. solium and constitute important antigens for immunodiagnostics. A protein fraction with cathepsin L-like activity was purified from the cysticercus fluid by size exclusion and ion exchange chromatography. Cathepsin L-like activity was measured fluorometrically by detecting the hydrolysis of the fluorogenic substrate Z-Phe-Arg-AMC. The purified protein fraction included antigens of 53 and 25 kD that were tested in a Western immunoblot and in an enzyme-linked immunosorbent assay (ELISA) for detection of human cysticercosis. The sensitivity of the Western immunoblot was 96% for patients infected with multiple cysts and 78% for patients with a single cyst. Specificity was 98%. The sensitivity of the ELISA was 98% in patients with multiple cysts and 84% in patients with a single cyst. Specificity was 92.7%.

Diagnostic value of rectal temperature of African cattle of variable coat colour infected with trypanosomes and tick-borne infections

Diagnosis of major endemic bovine parasitic diseases in sub-Saharan Africa such as trypanosomosis, theileriosis, anaplasmosis, babesiosis and cowdriosis is increasingly relying on clinical diagnosis due to deterioration of veterinary services and laboratory facilities. Pyrexia is a common clinical feature of aforementioned diseases whose detection relies on measurement of rectal temperature. The research undertaken in this study was aimed at assessing the effects of diurnal changes and variable coat colour of indigenous Nkedi Zebu cattle on the diagnostic value of rectal temperature under tropical conditions. The results revealed that variation in rectal temperature was significantly influenced by time of day it was taken and by the coat colour of the Nkedi Zebu cattle ( P < 0.001). Rectal temperature experienced diurnal changes: steadily rising to reach a peak at 17.00 h before declining. The mean rectal temperature of unhealthy cattle was significantly higher ( P < 0.05) than that of the healthy ones only between 13.00 and 17.00 h of the day. During which period the proportion of unhealthy cattle having a rectal temperature of 39.4 °C or higher was significantly higher than that of healthy ones ( P < 0.001). Regarding the variable coat colour of indigenous breeds, rectal temperature among cattle of different coat colours was significantly different ( P < 0.05). In conclusion it is important to consider diurnal changes in rectal temperature and differences due to variable coat colour of indigenous African breeds when measuring rectal temperature for assessing pyrexia, during clinical diagnosis of bovine trypanosomosis and tick-borne diseases that are endemic in many countries in sub-Saharan Africa.

Pulmonary Vascular Disease in the Developing World

The prevalence, cause, and pathobiology of pulmonary vascular disease in the developing world are not known, but estimates put the prevalence at 20 to 25 million. A major contributor is infectious disease. The present review examines the association between infectious disease and other causes in the developing world and pulmonary vascular disease and the need for further research in this area. Schistosomiasis (Bilharzias)1 is the third-leading endemic parasitic disease in the world, following malaria and amebiasis. More than 300 million individuals are infected, and another 600 million are at risk of infection.2 The disease ranks higher in prevalence than HIV/AIDS. It is endemic in eastern South America, the Caribbean Islands, east Asia, and some parts of China and the Middle East, with sub-Saharan Africa being the most endemic area. It is a major public health problem that is closely correlated with socioeconomic conditions. Modern endeavors to develop and construct water schemes to meet local power and agricultural needs have increased the prevalence in many parts of the world.2,3 Few countries have eradicated the disease or undertaken successful and sustainable control programs despite the collaborative efforts of local governments, the World Health Organization, the World Bank, the United Nations, and philanthropic organizations. Schistosomiasis is caused by flatworms. There are many species of Schistosoma . S mansoni infects >120 million people in Africa and Brazil. The final target of this species is the intestinal and hepatic circulatory system. S hematobium is endemic in Africa, the Middle East, and east Asia. It targets the genitourinary circulatory system. S japonicum , which is endemic in China and southeast Asia, affects the intestinal and hepatic circulatory system. ### The Life Cycle of Schistosomiasis The worms live in the perivisceral veins of the intestine, liver, and genitourinary systems. Their eggs find their way into the urine and feces of …

Primary retroperitoneal hydatid cyst: A case report

Retroperitoneal echinococcal cyst is a rare manifestation of hydatid disease. Hydatid disease is an endemic parasitic disease of the Mediterranean countries [1]. Although the liver and lungs are the most commonly involved organs, the disease may be found in any part of the body. We present here an experience of treating a patient with retroperitoneal hydatid presenting as al tumor. Keywords : echinococcosis, retroperitoneal hydatid cyst, India. Nigerian Journal of Parasitology Vol. 29 (1) 2008 pp. 29-31

Malária não complicada por Plasmodium vivax e P. falciparum no Brasil: evidências sobre fármacos isolados e associações medicamentosas empregados em esquemas terapêuticos recomendados pelo protocolo terapêutico oficial

Malaria is the most important endemic parasitic disease in the world. Conditions are favorable for transmission of the disease in 60% of Brazil's territory. Over 500,000 cases per year are recorded in the country. However, the geographic distribution is uneven, which may explain differences in the efficacy and effectiveness of antimalarial drugs. We conducted an extensive literature review of antimalarial treatment in Brazil from 1980 to 2005 in order to identify evidence that might have been available for the 2001 Edition of the Malaria Treatment Manual, the official Ministry of Health guidelines. Only a few studies, of low methodological quality, were identified by the search. None of the studies would have been capable of generating evidence-based guidelines according to the current classification of levels of pharmacological and clinical evidence. Studies published after 2001 drew on more evidence and are expected to provide the basis for the next edition of the manual, due in 2007. References in the 2001 Edition were outdated, possibly perceived as traditional references in the field, but lacking in specificity for region, population, and/or type of malaria.

Aspect actuel des bilharzioses

Objectives The article underlines the importance of schistosomiasis in the world. Schistosomiases are endemic parasitic diseases in tropical areas, with several hundred million persons infected throughout the world. Epidemiology These diseases are caused by trematodes of the genus Schistosoma, commonly referred as blood flukes, with five species of human infections and a lot of species of animal infections. The life cycle of schistosomiasis needs appropriate snails in the fresh water. The clinical findings are borne by digestive (abdominal pain, diarrhea) and urinary systems (haematuria) with complications (hepatic fibrosis, hydronephrosis) caused by the eggs which produce a granuloma with chronic inflammatory cells. Diagnosis and treatment Schistosomiasis is diagnosed by identifying characteristic eggs in the feces and in urine sediment. Treatment by praziquantel, administered in a single oral dose, is effective. The treatment of infected persons, the provision of latrines and the reduction of contact with fresh water in endemic areas are the measures of prevention. But it is difficult in such countries with a low socio-economic level, and a need of irrigation for cultivation areas. Prevention As there is a lack of immunization, the education of the people is necessary to control the schistosomiasis.

Severe invalidating pain syndrome associated with benznidazole therapy for Chagas’ disease

Chagas' disease is an endemic parasitic disease and constitutes an important health problem in Latin American countries. The increasing number of immigrants from these countries has resulted in a rise in diagnosis and consequently in the treatment of this disease in developed countries not familiar with this condition. Currently, benznidazole is used for treatment of this condition. However, undesirable effects have been reported with this treatment, and there are few data about continuous long-term use of this drug. We describe a case of invalidating pain syndrome in a 31-year-old Bolivian woman with Chagas' disease while receiving benznidazole therapy. Because of the number of cases with this condition will probably increase because of immigration, a better understanding of the side effects of the treatment of this disease is essential.

Integrated disease mapping in a polyparasitic world

In the past, and still today, people living in the developing world have been, and continue to be, repeatedly exposed to a number of endemic parasitic diseases which impose an intolerable economic, health and social burden on their societies (Stoll, 1947; Sachs and Malaney, 2002). Among the parasitic diseases, malaria due to Plasmodium falciparum inflicts the largest burden (Snow et al., 2005). Concurrently, hundreds of millions of people are plagued by a number of so-called neglected tropical diseases (NTDs). The most significant of these are Chagas disease in South America, human African trypanosomiasis, leishmaniasis, lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminthiasis and trachoma. The scale of the problem is illustrated in Table 1, which summarises current population statistics, including at-risk populations, estimated numbers of people infected, annual morbidity and mortality rates and burden estimates due to malaria and the above-mentioned NTDs. In recent years, there has been an upsurge in public and private spending in global health, with particular efforts aimed at tackling HIV/AIDS, tuberculosis and malaria (Lu et al., 2006). With enhanced funding coming on stream also for the NTDs, new partnerships and global alliances have been formed to tackle a number of NTDs, with preventive chemotherapy playing a key role (Brady et al., 2006; Hotez et al., 2006; WHO, 2006). This funding has coincided with calls to improve the coordination and integration of national control programmes, placing emphasis on simultaneous morbidity control due to NTDs (e.g. schistosomiasis and soil-transmitted helminthiasis) or to eliminate NTDs as a publichealth problem (e.g. lymphatic filariasis) (Brady et al., 2006; Lammie et al., 2006). To help allocate public-health resources, an essential first step is to delineate and understand the spatial distribution of different parasitic diseases (Brooker et al., 2006; Hay and Snow, 2006; Utzinger and de Savigny, 2006).

Influence of malaria on the serum levels of vitamin A, zinc and calcium of children in Douala-Cameroon

Malaria is an endemic parasitic disease that prevails particularly in warm tropical regions of the world. Micronutrient malnutrition such as vitamin A and iron deficiencies which is a public health problem in Cameroon is usually highly prevalent in malaria endemic areas. Characterizing the relationship between micronutrient status (vitamin A, zinc and calcium) and malaria infection among children in Douala town (Cameroon), serum levels of zinc, calcium and vitamin A, were assayed in a total of 116 Cameroonian children (62 controls and 54 malaria patients infected by Plasmodium falciparum) less than six years old by colorimetric and high pressure liquid chromatography (HPLC) techniques respectively showed a significantly lower vitamin A and calcium concentrations (P < 0.01) among malaria patients (0.8 ± 0.4 µmol/l and 81.3 ± 23.7 mg/l) as compared to the controls (1.1 ± 0.6 µmol/l and 96.3 ± 16.7 mg/ml). Vitamin A, calcium and zinc status were lower in 51.85%, 51.85% and 27.27% of malaria patients respectively. Significant correlations (P<0.01) were observed when the following parameters were coupled: Vitamin A/zinc among infected children (r = 0.01), and vitamin A and zinc among uninfected children (r = 0.415). This study suggests that P. falciparum use vitamin A and calcium of its host for its proper metabolism, leading to a decrease in serum levels of these nutrients.