Range NS, Malenganisho W, Temu MM
… +5 more, Changalucha J, Magnussen P, Krarup H, Andersen AB, Friis H
Ann Trop Med Parasitol
· 2010 Jan · PMID 20149295
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To estimate the weight deficit and body composition of cases of pulmonary TB (PTB), and assess the roles of HIV and the acute-phase response, a cross-sectional study was carried out in Tanzania. Weight, body mass index (...To estimate the weight deficit and body composition of cases of pulmonary TB (PTB), and assess the roles of HIV and the acute-phase response, a cross-sectional study was carried out in Tanzania. Weight, body mass index (BMI), arm muscle area (AMA), arm fat area (AFA) and the serum concentration of the acute-phase protein alpha(1)-antichymotrypsin (serum ACT) were evaluated for each of 532 cases of PTB and 150 'non-TB' controls. On average, the female cases of PTB not only weighed 7.8 kg less but also had BMI that were 3.1-kg/m(2) lower, AMA that were 14.8-cm(2) lower, and AFA that were 7.6-cm(2) lower than those seen in the female subjects without TB. Similarly, on average, the male cases of PTB weighed 7.1 kg less and had BMI that were 2.5-kg/m(2) lower, AMA that were 18.8-cm(2) lower and AFA that were 1.6-cm(2) lower than those seen in the male subjects without TB. Although HIV infection was associated with a 1.7-kg lower weight and a 0.6-kg/m(2) lower BMI (with deficits in both AMA and AFA) among males, it was not associated with any such deficits among the female subjects. Elevated serum ACT was found to be a negative predictor of BMI, AMA and AFA, partially explaining the effects of the PTB but not those of the HIV. There is need for a better understanding of the determinants and effects of loss of fat and lean body mass in HIV-positive tuberculosis.
Liao CW, Sukati H, D'Lamini P
… +16 more, Chou CM, Liu YH, Huang YC, Chung MH, Mtsetfwa JS, Jonato J, Chiu WT, Chang PW, Du WY, Chan HC, Chu TB, Cheng HC, Su WW, Tu CC, Cheng CY, Fan CK
Ann Trop Med Parasitol
· 2010 Jan · PMID 20149294
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As there appeared to be no data available on Toxocara canis infection in the children of Swaziland, a serological survey of T. canis infection was recently conducted among 92 children aged 3-12 years from rural slums in...As there appeared to be no data available on Toxocara canis infection in the children of Swaziland, a serological survey of T. canis infection was recently conducted among 92 children aged 3-12 years from rural slums in the low- and middle-veld. A child was considered seropositive if, in western blots based on the excretory-secretory antigens of larval T. canis, his or her serum gave a positive result when diluted 1 : 64. Forty-one (44.6%) of the children were found seropositive. There were no statistically significant differences in seroprevalence between the 49 boys and 43 girls investigated (46.9% v. 41.8%) or between the eight subjects aged 12 years and the 47 aged < or = 5 years (62.5% v. 38.3%); the corresponding odds ratios were 0.81 (95% confidence interval=0.36-1.86; P=0.62) and 2.69 (95% confidence interval=0.57-12.62; P=0.20), respectively. The 66 subjects from the middleveld were, however, significantly more likely to be seropositive than the 26 subjects from the lowveld (54.5% v. 19.2%; odds ratio=5.04, with a 95% confidence interval of 1.70-14.98; P<0.01). It seems likely that T. canis infection is common among the children who live in slums in Swaziland, particularly in the country's middleveld, probably as the result of poor hygiene and poor sanitation.
Ai L, Dong SJ, Zhang WY
… +7 more, Elsheikha HM, Mahmmod YS, Lin RQ, Yuan ZG, Shi YL, Huang WY, Zhu XQ
Ann Trop Med Parasitol
· 2010 Jan · PMID 20149293
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Among the helminths infecting ruminants in China are three taxa belonging to the genus Fasciola: F. hepatica, F. gigantica and the so-called 'intermediate form' that appears to lie between these two species. Based on the...Among the helminths infecting ruminants in China are three taxa belonging to the genus Fasciola: F. hepatica, F. gigantica and the so-called 'intermediate form' that appears to lie between these two species. Based on the sequences of the second internal-transcribed spacers (ITS-2) within the parasites' nuclear ribosomal DNA (rDNA), a pair of primers (DSJf/DSJ3) specific for F. hepatica and a pair (DSJf/DSJ4) specific for F. gigantica were designed and used to develop PCR-based assays. These assays allowed the identification and differentiation of F. hepatica, F. gigantica and the 'intermediate' Fasciola, with no amplicons produced from heterologous DNA samples. The results of sequencing confirmed the species-specific identity of the amplified products. The assays showed good sensitivity, giving positive results with as little as 0.11 ng of F. hepatica DNA and 0.35 ng of F. gigantica DNA. This meant that the DNA from a single Fasciola egg or a single infected snail was sufficient for identification of the Fasciola taxon. The developed PCR assays could provide useful tools for the detection, identification and epidemiological investigation of Fasciola infection in humans, other mammals and snails.
Samie A, Barrett LJ, Bessong PO
… +4 more, Ramalivhana JN, Mavhandu LG, Njayou M, Guerrant RL
Ann Trop Med Parasitol
· 2010 Jan · PMID 20149292
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In a recent study in northern South Africa, the seroprevalence of Entamoeba histolytica infection among 257 HIV-positive and 117 HIV-negative individuals was determined, using an ELISA for the detection of antibodies rea...In a recent study in northern South Africa, the seroprevalence of Entamoeba histolytica infection among 257 HIV-positive and 117 HIV-negative individuals was determined, using an ELISA for the detection of antibodies reacting with the parasite's galactose/-acetyl-D-galactosamine(Gal/GalNAc)-inhibitable adherence lectin. Overall, 34.0% of the 374 participants (36.1% of the females and 28.1% of the males) were found seropositive for E. histolytica. Although all age-groups were affected by the amoebic pathogen, the subjects aged 50-59 years had the highest seroprevalence (69.2%). The seroprevalence of E. histolytica was also significantly higher among the HIV-positive subjects than among the HIV-negative (42.8% v. 14.5%; chi(2)=28.65; P<0.0001). Among the HIV-positive subjects, those with fewer than 200 CD4+ cells/microl were relatively more likely to be seropositive for E. histolytica (60.3% v. 43.8%; chi(2)=4.016; P=0.045). This is the first report indicating a positive association between E. histolytica infection and HIV in South Africa. Further studies, for example to determine the occurrence of diarrhoea or liver abscess in the study area, in relation to seropositivity for E. histolytica and/or HIV, are now needed.
Bhunia GS, Kumar V, Kumar AJ
… +2 more, Das P, Kesari S
Ann Trop Med Parasitol
· 2010 Jan · PMID 20149291
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Human visceral leishmaniasis (VL) or kala-azar remains a major cause of mortality, particularly in the developing world. The disease is common in the internal regions of north-eastern India, which have a tropical or sub-...Human visceral leishmaniasis (VL) or kala-azar remains a major cause of mortality, particularly in the developing world. The disease is common in the internal regions of north-eastern India, which have a tropical or sub-tropical climate. In a recent study on VL in this region, the relationship between the incidence of VL and certain physio-environmental factors was explored, using a combination of a geographical information system (GIS), satellite imagery and data collected 'on the ground'. Some eco-environmental parameters were then used to map and describe the spatial heterogeneity seen in the transmission of the parasite (Leishmania donovani) that causes VL in India, and to identify those habitats, on the Gangetic plain, where the sandfly vectors might thrive. It was found that the presence of waterbodies, woodland and urban, built-up areas, soil of the fluvisol type, air temperatures of 25.0-27.5 degrees C, relative humidities of 66%-75%, and an annual rainfall of 100-<160 cm were all positively associated with the incidence of VL. A VL map was created and stratified into areas of 'risk' and 'non-risk' for the disease, based on calculations of risk indices.
Ann Trop Med Parasitol
· 2010 Jan · PMID 20149290
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The influence of the genetic diversity of Plasmodium falciparum infection on the clinical presentation of human malaria was investigated in rural Bolifamba, Cameroon. Parasite DNA was obtained from the blood of 208 child...The influence of the genetic diversity of Plasmodium falciparum infection on the clinical presentation of human malaria was investigated in rural Bolifamba, Cameroon. Parasite DNA was obtained from the blood of 208 children (aged 1-15 years) with malarial infection. The prevalences of anaemia and symptomatic and asymptomatic malaria among these children were 57.7%, 51.4% and 48.6%, respectively. The frequencies of parasites carrying each of the block-2 allelic variants (MAD20, K1 and RO33) of merozoite surface protein 1 (MSP1) were compared among the symptomatic and asymptomatic cases of malaria, the anaemic and non-anaemic subjects, and in various age groupings. Although all three allelic variants were found in Bolifamba, 32.7% of the children investigated were co-infected with parasites carrying the RO33 and K1 variants. There was a significant difference in the prevalence of each MSP1 allelic variant both between age-groups and between the various categories of anaemia considered (P<0.0001 for each), with the highest number of alleles occurring in the children with severe anaemia. The combination of RO33/K1 co-infection and anaemia was detected in most (57.7%) of the children aged 3-<6 years. The RO33/K1 co-infection was also strongly associated with both fever and high levels of parasitaemia (P<0.0001 for each). Although the children of Bolifamba are exposed to all three allelic variants of MSP1, which occur either singly or in varying combinations in the infected children, RO33/K1 co-infections are particularly associated with fever and this association appears independent of age and parasite density. The preliminary data presented here should facilitate the design of future research towards the development and testing of malaria candidate vaccines in the study area.
Ann Trop Med Parasitol
· 2010 Jan · PMID 20149289
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Although human toxocariasis ranks among the most common zoonotic infections worldwide, it remains relatively unknown to the public. The causal agents are the nematode parasites Toxocara canis and T. cati, whose definitiv...Although human toxocariasis ranks among the most common zoonotic infections worldwide, it remains relatively unknown to the public. The causal agents are the nematode parasites Toxocara canis and T. cati, whose definitive hosts are dogs and cats, respectively. When embryonated eggs are accidentally ingested by humans, larvae hatch in the small intestine, penetrate the intestinal wall and migrate, via the bloodstream, to the liver, lungs, muscles, eye and central nervous system. Although most human infections are asymptomatic, two well-defined clinical syndromes are classically recognised: visceral larva migrans (a systemic disease caused by larval migration through major organs) and ocular larva migrans (a disease limited to the eyes and optic nerves). Two less-severe syndromes have recently been described, one mainly in children (covert toxocariasis) and the other mainly in adults (common toxocariasis). Here, the current laboratory diagnosis, epidemiology and main clinical features of both the systemic and ocular forms of human toxocariasis are reviewed. New developments in serological diagnosis are described, the available seroprevalence data are analysed, and the results of relevant clinical studies that have been published over the last decade are explored, to provide an updated overview of this neglected but highly prevalent human infection.
Liao CW, Lee YL, Sukati H
… +15 more, D'lamini P, Huang YC, Chiu CJ, Liu YH, Chou CM, Chiu WT, Du WY, Hung CC, Chan HC, Chu B, Cheng HC, Su J, Tu CC, Cheng CY, Fan CK
Ann Trop Med Parasitol
· 2009 Dec · PMID 20030998
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Ann Trop Med Parasitol
· 2009 Dec · PMID 20030996
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In the U.S.A., human monocytotropic ehrlichiosis (HME) caused by Ehrlichia chaffeensis is an emerging tick-transmitted zoonosis. In Cameroon, where E. canis, E. chaffeensis and E. ewingii have recently been detected in d...In the U.S.A., human monocytotropic ehrlichiosis (HME) caused by Ehrlichia chaffeensis is an emerging tick-transmitted zoonosis. In Cameroon, where E. canis, E. chaffeensis and E. ewingii have recently been detected in dogs and/or ticks (Rhipicephalus sanguineus), the potential exists for human infections. Patients from the coastal region of Cameroon who had acute fevers of unknown aetiology were therefore checked for ehrlichial infection, using a real-time PCR that amplifies part of a genus-specific gene (dsb) that codes for a disulphide-bond formation protein. Ehrlichial blood was detected in the peripheral blood from 12 (10%) of the 118 patients investigated by PCR. When the 12 amplicons from the positive cases were sequenced, they were found to be identical to each other and to the corresponding dsb sequence of an Arkansas strain of E. chaffeensis. The 12 patients who were PCR-positive for E. chaffeensis suffered from fever (100%), headache (67%), myalgia (42%), arthralgia (58%), pulmonary involvement (17%) and/or a diffuse rash (17%).
Ann Trop Med Parasitol
· 2009 Dec · PMID 20030995
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The epidemiological status of human leptospirosis in Tanzania has not been well defined because of a general lack of awareness of the disease and difficulties in its diagnosis. A cross-sectional seroprevalence study, usi...The epidemiological status of human leptospirosis in Tanzania has not been well defined because of a general lack of awareness of the disease and difficulties in its diagnosis. A cross-sectional seroprevalence study, using the microscopic agglutination test with a threshold titre of 1 : 160, was therefore conducted, among various occupational groups from Tanga city, in November 2005. Of the 199 subjects investigated, 30 (15.1%) were found to have antibodies that reacted with antigens from at least one of the six Leptospira interrogans serovars used in the agglutination test. Of the seropositive samples, 36.6% were positive for serovar Icterohaemorrhagiae, 30.0% for Bataviae, 20.0% for Hardjo, 6.6% for Tarrassovi, 3.3% for Ballum and 3.3% for Pomona. Amongst the occupational groups examined, livestock farmers, veterinary/meat inspectors and abattoir workers appeared to be most at risk, with seroprevalences of 19.4%, 18.1% and 17.1%, respectively. Subjects who reported that they milked cows were significantly more likely to be found seropositive for Leptospira infection than the other subjects (odds ratio=3.44; P<0.001). These findings indicate that a significant proportion of the population of Tanga city is being exposed to pathogenic Leptospira. Public-health interventions against leptospirosis will need to target not only the occupational groups considered to be at high risk of infection but also the general population at large.
Craig SB, Graham GC, Burns MA
… +4 more, Dohnt MF, Jansen CC, Smythe LD, McKay DB
Ann Trop Med Parasitol
· 2009 Dec · PMID 20030994
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Magnesium imbalance in leptospirosis has, for the most part, been neglected by the medical and leptospirosis communities. In a recent, retrospective study, serum concentrations of magnesium were followed in 15 patients w...Magnesium imbalance in leptospirosis has, for the most part, been neglected by the medical and leptospirosis communities. In a recent, retrospective study, serum concentrations of magnesium were followed in 15 patients with severe leptospirosis. The results revealed that 14 of the 15 patients developed hypomagnesaemia at some time during the first 10 days of their illness. In severely ill patients, such magnesium deficiency can worsen clinical outcome. Magnesium concentrations may affect a number of organ systems and mental status. Since altered mental status in leptospirosis is a poor prognostic indicator, it is suggested that serum concentrations of magnesium be monitored closely in patients with leptospirosis. Any hypomagnesaemia can then be treated promptly, in an effort to reduce the morbidity and mortality attributable to the disease.
Jimenez JC, Fontaine J, Grzych JM
… +2 more, Capron M, Dei-Cas E
Ann Trop Med Parasitol
· 2009 Dec · PMID 20030993
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The mechanisms involved in the induction of the immune response in humans or experimental hosts infected with Giardia intestinalis are not well understood. The results of previous studies indicate that the parasite induc...The mechanisms involved in the induction of the immune response in humans or experimental hosts infected with Giardia intestinalis are not well understood. The results of previous studies indicate that the parasite induces a mixed Th1/Th2 response and that, in experimentally infected mice, the parasite's excreted/secreted (E/S) proteins contain cysteine proteases that are recognised by the murine immune system. In the present study, the possible effects of the E/S proteases of G. intestinalis on the host's humoral and cellular immune responses were investigated in BALB/c mice immunized with the parasite's E/S proteins. High titres of specific IgG(1), IgG(2a) and IgE antibodies were detected after immunization with native E/S proteins. Spleen cells stimulated with such proteins in vitro showed a significant antigen-specific proliferative response accompanied by the production of high concentrations of interleukin-4 (IL-4), interleukin-5 (IL-5) and interleukin-10 (IL-10) but little secretion of interferon-gamma (IFN-gamma). When, before use, the proteases in the E/S proteins were inhibited, by heat treatment or the addition of E-64, they elicited much lower titres of specific IgG(1) and IgE in mice while, in splenocytes in vitro, they triggered much lower production of IL-4, IL-5 and IL-10 and reduced antigen-specific proliferation. Since E-64 only inhibits cysteine proteases, these results indicate that the excreted/secreted cysteine proteases of G. intestinalis may be involved in the induction and regulation of a specific immune response in the infected host.
Ait-Oudhia K, Lami P, Lesceu S
… +4 more, Harrat Z, Hamrioui B, Dedet JP, Pratlong F
Ann Trop Med Parasitol
· 2009 Dec · PMID 20030992
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Between 2005 and 2008, a serological survey for leishmanial infection was conducted among dogs from urban and peri-urban Algiers, with the focus on the new, densely populated areas that were built after the 2003 earthqua...Between 2005 and 2008, a serological survey for leishmanial infection was conducted among dogs from urban and peri-urban Algiers, with the focus on the new, densely populated areas that were built after the 2003 earthquake. Serum samples were collected from 1810 animals and tested for the presence of leishmanial antibodies by IFAT, ELISA and western blotting. The overall seroprevalence recorded was 25.1%. Of the seropositive dogs, 58.8% showed no clinical signs of the disease, 25.8% had a few, minor signs and the remaining 15.4% showed more severe illness. The major clinical signs of infection were weight loss, skin lesions and lymphadenopathy. Although seropositive dogs were found in all of the boroughs (daïras) of Algiers, seroprevalences were highest in the western part of the city (i.e. in the boroughs of Bouzaréah, Chéraga and Zéralda), ranging from 23.0% to 44.5%. Statistical analysis showed a relationship between seropositivity for leishmanial infection and the dog's age and lifestyle (i.e. whether the dog lived outside and/or in areas with dense vegetation). Only two zymodemes were identified amongst the 50 isolates investigated: MON-1 (88%) and MON-281 (12%). The latter zymodeme has not been previously found in Algeria, sandflies or dogs.
Ann Trop Med Parasitol
· 2009 Dec · PMID 20030991
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The lymphocytic phenotypes involved in the pathogenesis of visceral leishmaniasis (VL) in Iraqi children have recently been investigated, in a study based on cluster-of-differentiation (CD) markers. Each case of VL inves...The lymphocytic phenotypes involved in the pathogenesis of visceral leishmaniasis (VL) in Iraqi children have recently been investigated, in a study based on cluster-of-differentiation (CD) markers. Each case of VL investigated was confirmed parasitologically by the observation of amastigotes in a bone-marrow smear. Compared with the values for the healthy children used as controls, a lymphocyte from an untreated VL case was significantly less likely to be CD3+ or CD4+, significantly more likely to be CD8+, and more (but not significantly more) likely to be CD22+. The untreated cases also had significantly lower CD4+/CD8+ ratios than the controls. Among the untreated cases, gender and age had no apparent effect on any of these variables. After 28 days of treatment with sodium stibogluconate, there was a trend towards normalization in the lymphocytic phenotypes of the VL cases, with significant increases in the CD4+/CD8+ ratios and the percentages of lymphocytes that were CD3+ or CD4+, and a significant decrease in the percentages of lymphocytes that were CD22+.
Ann Trop Med Parasitol
· 2009 Dec · PMID 20030990
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Between August 1997 and February 2005, a prospective study of human visceral leishmaniasis (VL) was undertaken in two villages in the Konso district of south-western Ethiopia, to provide epidemiological indices of subcli...Between August 1997 and February 2005, a prospective study of human visceral leishmaniasis (VL) was undertaken in two villages in the Konso district of south-western Ethiopia, to provide epidemiological indices of subclinical infection and active VL. Six cross-sectional surveys at 6-month intervals (ending in August 2000) were complemented by a single survey in February 2005. The prevalences and incidences of leishmanial infection and active VL, which were determined using leishmanin skin tests (LST), direct agglutination tests (DAT) and parasitological diagnosis, varied spatio-temporally and by age and gender. At baseline, when 1339 individuals were investigated, the overall prevalences of LST positivity, DAT positivity and active VL among the 1232 subjects who had not been treated previously were 30.0%, 5.4% and 0.49%, respectively. During the study, <10% of the subjects found DAT-positive at baseline progressed to active VL (with a mean of about nine cases of subclinical infection for every one of active VL). The median age of an incident VL case was 10.5 years. The highest rates of LST conversion occurred among the subjects aged 5-25 years. A subject who became LST-positive during the study was much less likely to develop active VL than the other subjects.
Malecela MN, Mwingira U, Mwakitalu ME
… +3 more, Kabali C, Michael E, Mackenzie CD
Ann Trop Med Parasitol
· 2009 Oct · PMID 19843398
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The Tanzania Lymphatic Filariasis Programme, which was launched in 2000, is, in terms of geographical coverage, among the largest disease-control programmes in Tanzania's history, currently reaching 9.4 million people in...The Tanzania Lymphatic Filariasis Programme, which was launched in 2000, is, in terms of geographical coverage, among the largest disease-control programmes in Tanzania's history, currently reaching 9.4 million people in 34 districts. The issues associated with this programme's implementation are reviewed here, in the context of the various players/stakeholders involved. This article provides an insight of how the programme began and discusses key areas in the programme's design. Mainly, however, it gives some impressions of how the programme is perceived by, and how it affects, village healthworkers, patients and politicians - the people who contribute to the implementation of the programme at various levels.