Prevalence of Zoonotic Parasites in Stray Dogs in Rural Communities Tanzania

The aim of this study was to identify and establish the baseline information on the prevalence of zoonotic parasites in stray dogs in Tanzania. A cross sectional study was conducted in Katavi, Arusha and Rukwa Regions in Tanzania. Intestinal parasites were analyzed from faecal samples collected from 364 dogs using modified sedimentation technique. Sixty-six percentage (66%) of the faecal samples were positive for gastrointestinal parasites while 7% had mixed infections, 27% were negative for the parasites. Higher proportions of the faecal samples were positive for gastrointestinal parasites in Arusha and Rukwa compared to Katavi (p < 0.0001). The prevalence of Ancylostoma caninum (49%) was higher compared to that of other parasites (p < 0.0001). Prevalence of A. lumbricoides was significantly higher compared to that of E. granulosus and S. stercoralis (p = 0.0046). There was a positive association between parasite positivity rates and collecting dog’s faecal samples near domestic animals (p < 0.00001). Parasite diversity was higher in stray dogs from Katavi and Arusha (p > 0.05). There was no association between parasite diversity and parasite positivity rates. Strategies to control the number of stray dogs should be established to minimize the potential health risks to humans, animal populations and environmental health.Keywords: Zoonotic parasites; Stray dogs, Prevalence; Tanzani

Placental Insulin-Like Growth Factor-1 Receptor, Protein Kinase B and Mammalian Target of Rapamycin are Downregulated in HIV-1 Positive Women on Antiretroviral Drugs

HIV-1 and ARV drugs uptake during pregnancy may change placental phenotype during pregnancy affecting fetal growth. We investigated the influence of maternal HIV-1 and ARV drugs on expression of placental genes important for fetus growth. A total 51 HIV-1 positives and 46 HIV-1 negative pregnant women were studied. Placental gene expression changes of insulin-like growth factor receptor 1 (IGF-1) R, mammalian target of rapamycin (mTOR), protein kinase B (AKT-1), sodium-coupled neutral amino acid transporters (Slc38a1, Slca38a2, Slc38a4), inhibin A, adrenomedullin and 11 beta-Hydroxysteroid dehydrogenase type (HSD)-2 were assessed by RT-qPCR. There was a significant decrease in mRNA expression of placental IGF-1R, mTOR, and AKT-1 in HIV-1 positive placentas compared to controls (p < 0.0001). There was also significant upregulation of an antiangiogenic molecule, inhibin A and downregulation of angiogenic molecule adrenomedullin in HIV-1 positive placenta (all p < 0.0001). However, the mRNA expression of placental Slc38a1 and Slca38a2 was higher in both HIV-1 positive and negative women delivering LBW babies compared to controls (p < 0.0001). The placental mRNA expression of 11 β-HSD-2 increased by 17 folds in HIV-1 negative and by 3.8 folds in HIV-1 positive women delivering LBW babies. IGF-1-P13-AKT-1-mTOR signaling pathway is dysregulated in placenta of HIV-1 positive women on ARV drugs. Higher mRNA expression levels of inhibin A and lower levels of adrenomedullin occur in placenta of HIV-1 positive women delivering LBW babies. ARV drugs and HIV-1 may be involved in the disruption of vascular tone of the placenta and therefore placental perfusion. Keywords: Pregnant women, HIV-1, ARV drugs, Placental IGF-1-AKT-1-mTOR signaling, inhibin A, adrenomedullin, amino acid transporters

Malaria-associated changes in fetal syncytiotrophoblast function

Ph.D. University of Hawaii at Manoa 2013.Includes bibliographical references.The fetus is entirely dependent on syncytiotrophoblasts (ST) that line the intervillous space (IVS) of the placenta as ST play a critical role in fetal development. During placental malaria (PM), Plasmodium falciparum infected erythrocytes (IE) bind to ST causing inflammation; leading to low birth weight babies due to fetal growth restriction (FGR) and preterm delivery (PTD). We hypothesize that the microenvironment that prevails during PM alters ST functions that are important for fetus growth. We conducted genome-wide expression studies of fetal cells from PM-infected placentas to investigate whether changes occur in fetal cells during to PM. We then developed a protocol and established an in vitro system to investigate if the changes identified in vivo were occurring in ST. The BeWo cell line with characteristics of ST was co-cultured with CS2 IE, schizogonic products, cytokines and chemokines prepared in vitro by co-culturing THP-1IE. Our microarray data showed that insulin like growth factor 1(IGF-1), insulin, mammalian target of ramphamycin (mTOR), vascular endothelia growth factor (VEGF), transforming growth factor 1 (TGFβ1), epidermal growth factor (EGF) and prostaglandin synthesis and regulation signaling pathways were significantly (p≤ 0.05) dysregulated in fetal cells from chronically PM-infected placentas. Several genes (leptin, system A amino acid transporters and placental 11beta-hydroxysteroud dehydorogenase-2-gene) known to be important in fetal growth) were also downregulated. In vitro results demonstrated that optimal response of BeWo cell line to CS2 IE occurred when BeWo were treated with 10μM forskolin for 72 hrs and cultured with 10 IE: 1 BeWo for 48 hrs. Using the same protocol, we showed inflammatory cytokines and chemokines, but not IE or IE with schizogonic products, significantly altered genes linked with vasculogenesis, blood vessel formation and negative regulation of vasoconstriction. Interestingly, cytokines and chemokines significantly dysregulated growth pathways similar to those that were altered in chronically infected placentas, including IGF1, insulin, mTOR. TGFβ1, EGF, platelet derived growth factor and prostaglandin synthesis. We concluded that perturbation of ST functions by the cytokines and chemokines secreted by maternal cells upon exposure to IE explains the biological mechanisms that lead to increased risk of FGR during chronic PM

Current Epidemiological Assessment of Plasmodium falciparum and Helminth Co-Infections in Children after a Decade of Implementation of Control Programs in Morogoro Region, Tanzania

A school based cross-sectional study was conducted from July to November 2018 to assess the burden of asymptomatic Plasmodium falciparum, Schistosoma and soil transmitted helminth (STH) infections in Mvomero. A total of 374 children (age range = 5–16 years, mean age = 11.3 years) were recruited from five primary schools. Prevalence of asymptomatic P. falciparum infections were 29.9%, S. haematobium 49.7%, hookworm 20.3%, Ascaris lumbricoides 12.6%, Taenia saginata 0.5% and S. mansoni 0.3%. Malaria parasite density increased with increasing children age (r = 0.99). Only 6.5% (12/186) of S. haematobium infected children were presented with heavy infections, whereas all STH-positive children harboured light infections. The overall P. falciparum-helminths co-infection rate was 11%. Schistosoma haematobium and hookworm infections positively influenced P. falciparum parasitaemia (R2 = 0.55 and 0.73, respectively). Being between 11 and 13 years of age, father being a farmer, poor housing, not sleeping under insecticide treated net, working in rice and sugarcane fields were the major factors associated with asymptomatic P. falciparum-helminth co-infections (all p < 0.05). Prevalence of both asymptomatic P. falciparum infections and P. falciparum-helminths-co-infections has decreased by over 40%. However prevalence of S. haematobium and hookworm infections is alarmingly high, calling for community based-integrative control measures incorporating strategies to combat both P. falciparum and helminths infection reservoirs in Mvomero. Keywords Asymptomatic Plasmodium falciparum; malaria; Soil transmitted helminths; Schistosoma haematobium; Mvomero; Tanzani

The impact of Anopheles gambiae egg storage for mass rearing and production success

Abstract Background Mass rearing requires a large colony from which male individuals can be harvested for sterilization and release. Attention is needed when monitoring life parameters of the reared population, knowing that any variations within the target population would lead to mismatching between two populations. The aim of this study was to assess the impact of Anopheles gambiae sensu stricto (s.s.) egg storage on hatchability and life history traits. For each parameter, comparison was made between freshly laid and stored eggs in three densities (40, 80, 120 eggs). Methods Anopheles gambiae s.s. freshly laid eggs were collected from the Tropical Pesticide Research Institute (TPRI) insectary. Eggs to be stored were kept at − 20 °C for 10 min and then transferred to refrigerators at 4 °C for intervals of 5, 10, 15, 20, and 25 days. After respective storage days, the eggs were transferred from refrigerators to ambient temperature of (25 ± 2) °C for 24 h and then placed in incubators for 24 h. Thereafter eggs were hatched. The egg hatchability, emerged larvae development, larvae survival and emerged adult sex ratios were monitored. Results This study found that hatching rates decreased with increase in storage time. The difference was significant in eggs stored for 10 and 15 days (P  0.05). Anopheles larvae development (L1 to pupae) was not significantly affected by storage time across all hatching densities. The study also found that larvae survival decreased with increase in egg storage time. However, there was no significant difference between larvae from freshly hatched eggs and those from eggs at 5 and 10 storage days (P > 0.05) but not for eggs stored for 15 days. Furthermore, there was a decrease in emerged adult males and increase in females relative to increased time of egg storage. The difference was significant (P < 0.05) at 15 storage days but not for eggs stored for 5 and 10 days (in triplicate densities). Conclusion From this study it was concluded that storing An. gambiae eggs at 4 °C and 48 ± 2% relative humidity (RH) for 5 days is the optimal condition and time that did not affect egg hatching rates, larval development and survivorship and emerged adult mosquito sex ratio

Seroprevalence of circulating taeniid antigens in pigs and associated risk factors in Kongwa district, Tanzania

The aim of this study was to investigate exposure to porcine cysticercosis (PC) and asso-ciated risk factors in the Kongwa District, eastern-central Tanzania. For thefirst time across-sectional investigation of the seroprevalence in pigs using a commercial genusspecific cysticercosis enzyme linked immunosorbent assay (apDia Ag-ELISA) was under-taken in eastern-central Tanzania. Moreover, the identity of suspectedT. soliumcysts frompigs in the study area were confirmed by sequencing parasites’mitochondrialcox1gene.Structured questionnaires and direct observations were used to investigate risk factorsassociated with parasite transmission. A total of 102 pig-keeping households were sur-veyed during the dry season between July and August 2017 and 126 households in therainy season between March and April 2018. Of the 447 examined pigs, 77 (17%, 95% C.I.14%e20%) tested positive in the ELISA. Seroprevalence was higher in pigs examined duringthe rainy (21%, 95% C.I. 16%e26%) than dry (12%, 95% C.I. 7%e17%) season (p¼0.019). Eightcyst-positive-pigs were confirmed to be infected withT. soliumby sequencing. Risk factorsassociated with PC seropositivity included origin of piglets or pigs (OR¼0.27, 95% C.I. 0.13e0.42, p¼0.001), socioeconomic factors and pig production system (OR¼0.22, 95% C.I.0.07e0.37, p¼0.005) and sanitation and hygiene practices (OR¼0.19, 95% C.I. 0.04e0.34,p¼0.014). This study has recorded a highTaeniaspp. seroprevalence in pigs in Kongwasuggesting the presence of people in the community carrying the adult parasite,Taeniasolium. Ourfindings also suggest risk of infection byT. soliumto people in urban centresand cities consuming pigs from rural areas in Kongwa. The high seroprevalence in Kongwacalls for further studies on taeniasis and cysticercosis in the human population in order todetermine suitable control strategies

Soil contamination by Taenia solium egg DNA in rural villages in Kongwa district, Tanzania

The presence ofTaenia solium DNA from eggs in soils around the households in four Tanzanian villages in Kongwa district were analysed in relation to seasonal fluctuations and infection risk implications. A total of 192 pooled soil samples from five sampling points per household were examined by droplet digital Polymerase Chain Reaction (ddPCR) from 96 pig-keeping households both during the dry and rainy seasons. The pooled samples were first processed by a flotation-double sieving technique, followed by screening for worm DNA employing universal primers targeting the mitochondrial cytochrome c oxidase subunit I (cox1) gene of human taeniid species and some other helminths. All DNA positive samples were later confirmed by a specific ddPCR probe assay targeting the mitochondrial cox1 gene of T. solium. A total of 17.2% (n = 33) samples were positive with the universal ddPCR, whereas T. solium DNA was confirmed by the specific ddPCR only in 3.1% (n = 3) of the surveyed households. The detection of T. solium DNA in this study spells out a low risk of exposure to T. solium eggs from contaminated household soil. Based on our results, ddPCR seems to be a promising technology for screening T. solium eggs in soil

Impact of HIV-1 infection on the IGF-1 axis and angiogenic factors in pregnant Cameroonian women receiving antiretroviral therapy.

Although mother-to-child transmission of HIV has dramatically declined, the number of in utero HIV-exposed, uninfected infants is on the increase. HIV-exposed infants are at an increased risk of mortality, morbidity and slower early growth than their non-HIV exposed counterparts. Maternal HIV increases the risk of having preterm deliveries, intrauterine growth restriction and low birth weight babies. However, the mechanism underlying dysregulation of fetal growth in HIV-infected pregnant women is unknown. We sought to determine whether maternal HIV is associated with dysregulation of the insulin-like growth factor (IGF) axis, some angiogenic factors or other related biomarkers that regulate fetal growth. A total of 102 normotensive pregnant women were enrolled in a small cross-sectional study. Amongst these were thirty-one HIV-1 positive women receiving combination antiretroviral therapy (cART) (Mean age: 30.0 ± 5.1 years; % on ART: 83.9%; median plasma viral load: 683 copies/ml; median CD4 count: 350 cells/ul) and 71 HIV uninfected women (mean age: 27.3 ± 5.8) recruited at delivery. A panel of biomarkers including IGF1 and IGF binding proteins (IGFBP1, IGFBP3), angiopoietins (ANG) 1 and 2, matrix metalloproteinases (MMP) 2 and 9, and galectin 13, was measured in plasma collected from the placental intervillous space. The levels of IGF1, IGFBP1, ANG1, ANG2, MMP2, MMP9 and Gal-13 were not affected by maternal HIV, even when adjusted for maternal factors in linear regression models (all p>0.05). It was observed that HIV-infection in pregnancy did not significantly affect key markers of the IGF axis and angiogenic factors. If anything, it did not affect women. These findings highlight the importance of the use of ART during pregnancy, which maintains factors necessary for fetal development closer to those of healthy women. However, decrease in IGF1 levels might be exacerbated in women con-infected with HIV and malaria