Browsing by Author "Misinzo, Gerald"

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Aedes aegypti abundance, larval indices and risk for dengue virus transmission In Kinondoni district, Tanzania
(BMC, 2022) Ngingo, Baraka L; Mboera, Leonard E. G; Chengula, Augustino; Machelle, Ines; Makange, Mariam R; Msolla, Michael; Mwanyika, Gaspary O; Rugarabamu, Sima; Misinzo, Gerald
Background: Tanzania has experienced periodic dengue outbreaks with increased incidence since 2010. However, there is limited information on vector dynamics and transmission risk in most parts of the country. This study was conducted to determine Aedes mosquito abundance, larval indices and dengue virus infection rate as risk indicators for DENV transmission in Kinondoni district, Dar es Salaam, Tanzania. Methods: A cross-sectional study was conducted in three wards of Kinondoni district in Tanzania between Decem- ber 2019 and January 2020. In each ward, three streets were randomly selected for adult and immature mosquito sampling. The adult mosquitoes were collected using Mosquito Magnet traps, while mosquito larvae and pupae were inspected in water-holding containers in the selected household compounds. The detection of dengue virus (DENV) in female Aedes mosquitoes was done using a one-step reverse transcription–polymerase chain reaction (RT–PCR) method. Results: Of the 1416 adult female mosquitoes collected, Ae. aegypti accounted for 16.8% (n = 238). A total of 333 water-holding containers were inspected and 201 (60.4%) had at least an Aedes larvae or pupae. Water-holding containers supporting the breeding of Aedes larvae and pupae included discarded car tires, flowerpots and small and large plastic containers. The overall House Index, Container Index and Breteau Index were 55.1%, 60.4% and 114.2, respectively. None of the 763 female Aedes mosquitoes tested by RT–PCR was found to be infected with DENV. Conclusion: The presence and abundance Ae. aegypti mosquitoes and the large proportion of water-holding con- tainers infested with the mosquito larvae and pupae put residents of Kinondoni district at high risk of DENV trans- mission. Our findings emphasize the need for continuous mosquito vector surveillance and control to prevent the possibility of future DENV outbreaks in Tanzania.
Batrachochytrium dendrobatidis detected in Kihansi spray toads at a captive breeding facility (Kihansi, Tanzania)
(Inter Research [Commercial Publisher], 2014-09-30) Makange, Mariam; Kulaya, Neema; Biseko, Emiliana; Kalenga, Parson; Mutagwaba, Severinus; Misinzo, Gerald
The chytrid fungus Batrachochytrium dendrobatidis (Bd) is the aetiological agent of amphibian chytridiomycosis, a disease associated with global amphibian population declines. In November 2012, mass mortalities of Kihansi spray toads Nectophrynoides asperginis were observed at the Kihansi captive breeding facility, located in the Udzungwa Mountains, Tanzania. Mortalities increased rapidly, and dead toads showed typical clinical signs of chytridiomycosis, including reddening of the skin that was especially evident on the toe pads. Treatment of toads with itraconazole rapidly reduced mortalities. Dead toads (n = 49) were collected and used to per- form Bd-specific polymerase chain reaction and subsequent nucleotide sequencing. All toads col- lected at the facility were positive for Bd. The obtained Bd 5.8S rRNA gene and flanking internal transcribed spacer regions (ITS1 and ITS2) were not 100% identical to any other Bd sequences in GenBank, but closely resembled isolates from Ecuador, Japan, USA, Brazil, Korea, and South Africa. To our knowledge, this is the first study reporting molecular characteristics of Bd isolated from the Udzungwa Mountains. Strict biosecurity measures at the breeding facility and in Kihansi spray wetlands where toads have been reintroduced have been implemented. Further studies on Bd epidemiology in the Udzungwa Mountains are recommended in order to understand its origin, prevalence, and molecular characteristics in wild amphibian populations. This will be important for conservation of several endemic amphibian species in the Udzungwa Mountains, which are part of the Eastern Arc Mountains, a global biodiversity hotspot.
Circulation of dengue serotype 1 viruses during the 2019 outbreak in Dar es Salaam, Tanzania
(Informa UK Limited, trading as Taylor & Francis Group., 2021) Mwanyika, Gaspary O.; Mboera, Leonard E. G.; Rugarabamu, Sima; Makange, Mariam; Sindato, Calvin; Lutwama, Julius J.; Paweska, Janusz T.; Misinzo, Gerald
Dengue is an important mosquito-borne viral disease in humans in tropical and subtropical countries. In 2019, a total of 6917 dengue cases were reported in Tanzania based on serological analysis. The aim of this study was to confirm the presence of dengue virus (DENV) and conduct its genetic characterization. A total of 191 serum samples were collected from the outpatients seeking care from health facilities in Kinondoni and Ilala districts between March and May 2019. All the samples were initially tested for the presence of non-structural protein 1 and anti-DENV immunoglobulin G (IgG) and IgM using a commercial OnSite Duo Dengue Ag-IgG/IgM rapid test. Of the 191 sera, 110 (57.6%) were DENV seropositive. The presence of DENV ribonucleic acid was confirmed in 18.2% of the seropositive sera by reverse transcription polymerase chain reaction (RT-PCR). The RT-PCR products were cleaned and partial sequences of DENV poly protein gene determined using dideoxynucleotide cycle sequencing followed by phylogenetic analysis. We present the occurrence of DENV serotype 1 (DENV-1) during the 2019 outbreak in Tanzania. The DENV-1 strains reported in the present study are highly identical and cluster with Asian DENV-1 strains indicating the possibility of intercontinental spread of DENV through globalization. We advocate for the need for molecular surveillance of dengue viruses during outbreaks to provide rapid evidence of the disease to guide public health interventions.
Climate change influences potential distribution of infected aedes aegypti co-occurrence with dengue epidemics risk areas in Tanzania
(PLOS, 2016) Mweya, Clement N; Kimera, Sharadhuli I; Stanley, Grades; Misinzo, Gerald; Mboera, Leonard E. G
Dengue is the second most important vector-borne disease of humans globally after malaria. Incidence of dengue infections has dramatically increased recently, potentially due to changing climate. Climate projections models predict increases in average annual tem- perature, precipitation and extreme events in the future. The objective of this study was to assess the effect of changing climate on distribution of dengue vectors in relation to epi- demic risk areas in Tanzania.
Crossing the line: seroprevalence and risk factors for transboundary animal diseases along the Tanzania-Zambia border
(Veterinary Epidemiology and Economics, a section of the journal Frontiers in Veterinary Science, 2022) Lysholm, Sara; Lindahl, Johanna F.; Munyeme, Musso; Misinzo, Gerald; Mathew, Coletha; Alvåsen, Karin; Dautu, George; Linde, Siri; Mitternacht, Lydia; Olovsson, Emelie; Wilén, Elsa; Berg, Mikael; Wensman, Jonas J.
Transboundary pathogens pose a threat to livelihood security in countries such as Zambia and Tanzania. This study aimed to investigate the seroprevalence of peste des petits ruminants virus (PPRV), foot and mouth disease virus (FMDV), sheep and goat pox virus (SGPV), Rift Valley fever virus (RVFV) and Brucella spp. in sheep and goats along the Tanzania-Zambia border. Another aim was to assess the association between certain predictor variables and seroprevalence, focusing on trade and proximity to an international border, to a town and to the Tanzania-Zambia highway. During September-October 2018, 486 serum samples from small ruminants in Zambia and 491 in Tanzania were collected and analyzed using enzyme-linked immunosorbent assays (ELISA). A questionnaire focused on management strategies was administered to each household. The animal-level seroprevalence in Zambia was 0.21% [95% confidence interval (CI) (0.01–1.14) for PPRV, 1.03% (95% CI 0.33–2.39) for FMDV, 0% (95% CI 0–0.76) for SGPV, 2.26% (95% CI 1.14–4.01) for RVFV and 1.65% (95% CI 0.71–3.22) for Brucella spp.]. In Tanzania, animal-level seroprevalence was 2.85% (95% CI 1.57–4.74) for PPRV, 16.9% (95% CI 13.7–20.5) for FMDV, 0.20% (95% CI 0.01–1.13) for SGPV, 3.26% (95% CI 1.87–5.24) for RVFV and 20.0% (95% CI 14.5–26.5) for Brucella spp. For PPRV (OR 6.83, 95% CI 1.37–34.0, p = 0.019) and FMDV (OR 5.68, 95% CI 1.58–20.3, p = 0.008), herds situated more than 30 km from an international border were more likely to be seropositive, while being located 10–30 km (OR 4.43, 95% CI 1.22–16.1 p = 0.024) from a border was identified as a risk factor for Brucella spp. For FMDV (OR 79.2, 95% CI 4.52–1388.9, p = 0.003), being situated within 30 km from a town was associated with seropositivity. Furthermore, contact with wild ruminants (OR 18.2, 95% CI 1.36–244), and the presence of sheep in the household (OR 5.20, 95% CI 1.00–26.9, p = 0.049), was associated with seropositivity for PPRV, and FMDV. No significant associations between trade or distance to the Tan-Zam highway and seroprevalence were found. We recommend that the impact of trade and proximity to borders, towns and roads should be further evaluated in larger studies, ideally incorporating aspects such as temporal trade fluctuations.
Culturing circular ssDNA viruses for the production of vaccines Inventors
(2007-11-27) Meerts, Peter; Nauwynck, Hans; Misinzo, Gerald
The present invention relates to the use of interferon in the in vitro cultivation of animal circular ssDNA virus such as Porcine Circovirus 2 or human TT virus in an animal cell line. Increased titres of animal circular ssDNA virus are obtained by addition of interferons or agents which ensure the production of endogenous interferons by said cell line.
Dengue virus infection and associated risk factors in Africa: a systematic review and meta-analysis
(MDPI, 2021) Mwanyika, Gaspary O.; Mboera, Leonard E. G.; Rugarabamu, Sima; Ngingo, Baraka; Sindato, Calvin; Lutwama, Julius J.; Paweska, Janusz T.; Misinzo, Gerald
Dengue contributes a significant burden on global public health and economies. In Africa, the burden of dengue virus (DENV) infection is not well described. This review was undertaken to determine the prevalence of dengue and associated risk factors. A literature search was done on PubMed/MEDLINE, Scopus, Embase, and Google Scholar databases to identify articles published be- tween 1960 and 2020. Meta-analysis was performed using a random-effect model at a 95% confidence interval, followed by subgroup meta-analysis to determine the overall prevalence. Between 1960 and 2020, 45 outbreaks were identified, of which 17 and 16 occurred in East and West Africa, respectively. Dengue virus serotype 1 (DENV-1) and DENV-2 were the dominant serotypes contributing to 60% of the epidemics. Of 2211 cases reported between 2009 and 2020; 1954 (88.4%) were reported during outbreaks. Overall, the prevalence of dengue was 29% (95% CI: 20–39%) and 3% (95% CI: 1–5%) during the outbreak and non-outbreak periods, respectively. Old age (6/21 studies), lack of mosquito control (6/21), urban residence (4/21), climate change (3/21), and recent history of travel (3/21) were the leading risk factors. This review reports a high burden of dengue and increased risk of severe disease in Africa. Our findings provide useful information for clinical practice and health policy decisions to implement effective interventions.
Diagnosis and genotyping of African swine fever viruses from 2015 outbreaks in Zambia
(AOSIS Publishing, 2016-04-29) Thoromo, Jonas; Simulundu, Edgar; Chambaro, Herman M; Mataa, Liywalii; Lubaba, Caesar H; Pandey, Girja S; Takada, Ayato; Misinzo, Gerald; Mweene, Aaron S
In early 2015, a highly fatal haemorrhagic disease of domestic pigs resembling African swine fever (ASF) occurred in North Western, Copperbelt, and Lusaka provinces of Zambia. Molecular diagnosis by polymerase chain reaction targeting specific amplification of p72 (B646L) gene of ASF virus (ASFV) was conducted. Fourteen out of 16 domestic pigs from the affected provinces were found to be positive for ASFV. Phylogenetic analyses based on part of the p72 and the complete p54 (E183L) genes revealed that all the ASFVs detected belonged to genotypes I and Id, respectively. Additionally, epidemiological data suggest that the same ASFV spread from Lusaka to other provinces possibly through uncontrolled and/or illegal pig movements. Although the origin of the ASFV that caused outbreaks in domestic pigs in Zambia could not be ascertained, it appears likely that the virus may have emerged from within the country or region, probably from a sylvatic cycle. It is recommended that surveillance of ASF, strict biosecurity, and quarantine measures be imposed in order to prevent further spread and emergence of new ASF outbreaks in Zambia.
Drivers, risk Factors and dynamics of African Swine Fever outbreaks, southern highlands, Tanzania
(Multidisciplinary Digital Publishing Institute, 2020-02-25) Fasina, Folorunso O.; Kissinga, Henry; Mlowe, Fredy; Mshang’a, Samora; Matogo, Benedict; Mrema, Abnery; Mhagama, Adam; Makungu, Selemani; Mtui-Malamsha, Niwael; Sallu, Raphael; Misinzo, Gerald; Magidanga, Bishop; Kivaria, Fredrick; Bebay, Charles; Nong’ona, Solomon; Kafeero, Fred; Nonga, Hezron
African swine fever remains an important pig disease globally in view of its rapid spread, economic impacts and food implications, with no option of vaccination or treatment. The Southern Highlands zone of Tanzania, an important pig-producing hub in East Africa, is endemic with African swine fever (ASF). From approximately the year 2010, the recurrence of outbreaks has been observed and it has now become a predictable pattern. We conducted exploratory participatory epidemiology and participatory disease surveillance in the Southern Highlands to understand the pig sector and the drivers and facilitators of infections, risk factors and dynamics of ASF in this important pig-producing area. Pigs continue to play a major role in rural livelihoods in the Southern Highlands and pork is a major animal protein source. Outbreaks of diseases, particularly ASF, have continued to militate against the scaling up of pig operations in the Southern Highlands. Intra- and inter-district and trans-border transnational outbreaks of ASF, the most common disease in the Southern Highlands, continue to occur. Trade and marketing systems, management systems, and lack of biosecurity, as well as anthropogenic (human) issues, animals and fomites, were identified as risk factors and facilitators of ASF infection. Changes in human behavior and communication in trade and marketing systems in the value chain, biosecurity and pig management practices are warranted. Relevant training must be implemented alongside the launch of the national ASF control strategy for Tanzania, which already established a roadmap for combating ASF in Tanzania. The high-risk points (slaughter slabs, border areas, and farms with poor biosecurity) and high-risk period (November–March) along the pig value chain must be targeted as critical control points for interventions in order to reduce the burden of infection.
Epidemiological investigation into the introduction and factors for spread of Peste des Petits Ruminants, southern Tanzania:
(AOSIS, 2012-01) Muse, Epaphras A; Karimuribo, Esron D; Misinzo, Gerald; Mellau, Lesakit SB; Msoffe, Peter LM; Gitao, George C; Swai, Emmanuel S
A study was carried out to confirm and identify sources and elucidate factors associated with the introduction of Peste des Petits Ruminants (PPR) in southern Tanzania. This study was conducted in Tandahimba and Newala districts of Mtwara region following suspected outbreak of PPR in the area. Qualitative data were collected using semi-structured questionnaires and in-depth interviews of key informants who included goat and sheep owners with suspected cases of PPR and animal health service providers as well as local administrative authority. Additionally, 216 serum samples and 28 swabs were collected for serological and virological laboratory disease confirmation. The results show that PPR was first introduced in Likuna village of Newala district in February 2009 through newly purchased goats from the Pugu livestock market located about 700 km in the outskirts of Dar es Salaam city …
Exposure to salinity and light spectra regulates glucosinolates, phenolics, and antioxidant capacity of brassica carinata L. microgreens
(MDPI, 2021-07-26) Maina, Sylvia; Ryu, Da Hye; Cho, Jwa Yeong; Jung, Da Seul; Park, Jai-Eok; Nho, Chu Won; Bakari, Gaymary; Misinzo, Gerald; Jung, Je Hyeong; Yang, Seung-Hoon; Kim, Ho-Youn
The effect of salt treatment on Brassica carinata (BC) microgreens grown under different light wavelengths on glucosinolates (GLs) and phenolic compounds were evaluated. Quantifiable GLs were identified using ultra-high performance-quadrupole time of flight mass spectrometry. Extracts’ ability to activate antioxidant enzymes (superoxide dismutase (SOD) and catalase (CAT)) was evaluated on human colorectal carcinoma cells (HCT116). Furthermore, BC compounds’ ability to activate expression of nuclear transcription factor-erythroid 2 related factor (Nrf2) and heme- oxygenase-1 (HO-1) proteins was examined using specific antibodies on HCT116 cells. Sinigrin (SIN) was the abundant GLs of the six compounds identified and its content together with total aliphatic GLs increased in saline conditions. Fluorescent (FL) and blue plus red (B1R1) lights were identified as stable cultivation conditions for microgreens, promoting biomass and glucobrassicin contents, whereas other identified individual and total indole GLs behaved differently in saline and non-saline environments. Blue light-emitting diodes and FL light in saline treatments mostly enhanced SIN, phenolics and antioxidant activities. The increased SOD and CAT activities render the BC microgreens suitable for lowering oxidative stress. Additionally, activation of Nrf2, and HO-1 protein expression by the GLs rich extracts, demonstrate their potential to treat and prevent oxidative stress and inflammatory disorders. Therefore, effective salt treatments and light exposure to BC microgreens present an opportunity for targeted regulation of growth and accumulation of bioactive metabolites.
Filter paper is a simple and cost-effective transport medium for serological diagnosis of Peste des petits ruminants
(Elsevie, 2019-01) Torsson, Emeli; Abubakar, Muhammad; Alvåsen, Karin; Manzoor, Shumaila; Roos, Nils; Zahur, Aamer; Misinzo, Gerald; Berg, Mikael; Wensman, Jonas
Peste des petits ruminants (PPR) is a highly contagious disease caused by peste-des-petits-ruminants virus. Following the successful eradication of the related rinderpest virus, a program to control and eradicate PPR was launched by the FAO and OIE. PPR is today present in many tropical countries where maintaining the cold chain for sample transportation is one of the major barriers for timely processing. Transport of samples on filter paper is a simple and cost-effective method, however validation and optimization is required to fully adapt this approach. The objective of this study was to evaluate and validate the use of filter paper in serological diagnosis of PPR. Blood samples (serum and filter paper) were collected from sheep and goats in both Tanzania and Pakistan and analysed using a PPRV-specific cELISA. The positive proportion was 10.7% in Tanzania and 80% in Pakistan when performing the analysis on serum. These results were then considered as reference and compared to the results from the filter papers analysed by the same cELISA. According to the statistical analysis the cut-off for a positive results for samples stored on filter paper was adjusted from <50 % competition percentage to <84% in Tanzania and to <69% in Pakistan. These results demonstrate that filter papers are an acceptable and cost-effective transport method of whole blood samples for later use in serological analysis.
Forty-two years of responding to ebola virus outbreaks in Sub-Saharan Africa: a review
(BMJ Global Health, 2020-01) Rugarabamu, Sima; Mboera, Leonard; Rweyemamu, Mark; Mwanyika, Gaspary; Lutwama, Julius; Paweska, Janusz; Misinzo, Gerald
Ebola virus disease (EVD) is one of the deadliest haemorrhagic fevers affecting humans and non- human primates. Thirty-four outbreaks have been reported in Africa since it was first recognised in 1976. This review analysed 42 years of EVD outbreaks and identified various challenges and opportunities for its control and prevention in Sub-Saharan Africa.
Genetic diversity and risk factors for the transmission of antimicrobial resistance across human, animals and environmental compartments in East Africa: a review
(Springer Nature, 2020-08-06) Katale, Bugwesa Z.; Misinzo, Gerald; Mshana, Stephen E.; Chiyangi, Harriet; Campino, Susana; Clark, Taane G.; Good, Liam; Rweyemamu, Mark M.; Matee, Mecky I.
Background: The emergence and spread of antimicrobial resistance (AMR) present a challenge to disease control in East Africa. Resistance to beta-lactams, which are by far the most used antibiotics worldwide and include the penicillins, cephalosporins, monobactams and carbapenems, is reducing options for effective control of both Gram-positive and Gram-negative bacteria. The World Health Organization, Food and Agricultural Organization and the World Organization for Animal Health have all advocated surveillance of AMR using an integrated One Health approach. Regional consortia also have strengthened collaboration to address the AMR problem through surveillance, training and research in a holistic and multisectoral approach. This review paper contains collective information on risk factors for transmission, clinical relevance and diversity of resistance genes relating to extended-spectrum beta-lactamase-producing (ESBL) and carbapenemase producing Enterobacteriaceae, and Methicillin-resistant Staphylococcus aureus (MRSA) across the human, animal and environmental compartments in East Africa. Main body: The review of the AMR literature (years 2001 to 2019) was performed using search engines such as PubMed, Scopus, Science Direct, Google and Web of Science. The search terms included ‘antimicrobial resistance and human-animal-environment’, ‘antimicrobial resistance, risk factors, genetic diversity, and human animal-environment’ combined with respective countries of East Africa. In general, the risk factors identified were associated with the transmission of AMR. The marked genetic diversity due to multiple sequence types among drug-resistant bacteria and their replicon plasmid types sourced from the animal, human and environment were reported. The main ESBL, MRSA and carbapenem related genes/plasmids were the bla CTX-Ms (45.7%), SCCmec type (27.3%) and IMP types (23.8%), respectively. Conclusion: The high diversity of the AMR genes suggests there may be multiple sources of resistance bacteria, or the possible exchange of strains or a flow of genes amongst different strains due to transfer by mobile genetic elements. Therefore, there should be harmonized One Health guidelines for the use of antibiotics, as well as regulations governing their importation and sale. Moreover, the trend of ESBLs, MRSA and carbapenem resistant (CAR) carriage rates is dynamic and are on rise over time period, posing a public health concern in East Africa. Collaborative surveillance of AMR in partnership with regional and external institutions using an integrated One Health approach is required for expert knowledge and technology transfer to facilitate information sharing for informed decision-making.
Genetic diversity of newcastle disease virus involved in the 2021 outbreaks in backyard poultry farms in Tanzania
(MDPI, 2023) Amoia, Charlie F.; Hakizimana, Jean N; Chengula, Augustino A; Rohaim, Mohammed A; Munir, Muhammad; Weger-Lucarelli, James; Misinzo, Gerald
Newcastle disease virus is a significant avian pathogen with the potential to decimate poultry populations all over the world and cause enormous economic losses. Distinct NDV genotypes are currently causing outbreaks worldwide. Due to the high genetic diversity of NDV, virulent strains that may result in a lack of vaccine protection are more likely to emerge and ultimately cause larger epidemics with massive economic losses. Thus, a more comprehensive understanding of the circulating NDV genotypes is critical to reduce Newcastle disease (ND) burden. In this study, NDV strains were isolated and characterized from backyard poultry farms from Tanzania, East Africa in 2021. Reverse-transcription polymerase chain reaction (RT-PCR) based on fusion (F) gene amplification was conducted on 79 cloacal or tracheal swabs collected from chickens during a suspected ND outbreak. Our results revealed that 50 samples out 79 (50/79; 63.3%) were NDV- positive. Sequencing and phylogenetic analyses of the selected NDV isolates showed that 39 isolates belonged to subgenotype VII.2 and only one isolate belonged to subgenotype XIII.1.1. Nucleotide sequences of the NDV F genes from Tanzania were closely related to recent NDV isolates circulating in southern Africa, suggesting that subgenotype VII.2 is the predominant subgenotype throughout Tanzania and southern Africa. Our data confirm the circulation of two NDV subgenotypes in Tanzania, providing important information to design genotype-matched vaccines and to aid ND surveillance. Furthermore, these results highlight the possibility of the spread and emergence of new NDV subgenotypes with the potential of causing future ND epizootics.
Historical environmental change in africa drives divergence and admixture of aedes aegypti mosquitoes:aprecursor to successful worldwide colonization?
(John Wiley & Sons Ltd., 2016) Bennett, Kelly louise; Shija, Fortunate; Linton, Yvonne-marie; Misinzo, Gerald; Kaddumukasa, Martha; Djouaka, Rousseau; Anyaele, Okorie; Harris, Angela; Irish, Seth; Hlaing, Thaung; P r a k a s h, A n i l; L u t w a m a, J u l i u s; Walton, Catherine
Increasing globalization has promoted the spread of exotic species, including disease vectors. Understanding the evolutionary processes involved in such colonizations is both of intrinsic biological interest and important to predict and mitigate future dis- ease risks. The Aedes aegypti mosquito is a major vector of dengue, chikungunya and Zika, the worldwide spread of which has been facilitated by Ae. aegypti’s adaption to human-modified environments. Understanding the evolutionary processes involved in this invasion requires characterization of the genetic make-up of the source population (s). The application of approximate Bayesian computation (ABC) to sequence data from four nuclear and one mitochondrial marker revealed that African populations of Ae. aegypti best fit a demographic model of lineage diversification, historical admixture and recent population structuring. As ancestral Ae. aegypti were dependent on forests, this population history is consistent with the effects of forest fragmentation and expansion driven by Pleistocene climatic change. Alternatively, or additionally, histori- cal human movement across the continent may have facilitated their recent spread and mixing. ABC analysis and haplotype networks support earlier inferences of a single out-of-Africa colonization event, while a cline of decreasing genetic diversity indicates that Ae. aegypti moved first from Africa to the Americas and then to Asia. ABC analy- sis was unable to verify this colonization route, possibly because the genetic signal of admixture obscures the true colonization pathway. By increasing genetic diversity and forming novel allelic combinations, divergence and historical admixture within Africa could have provided the adaptive potential needed for the successful worldwide spread of Ae. aegypti.
History and current status of peste des petits ruminants virus in Tanzania
(Co-acting Publishing, 2016-10-20) Torsson, Emeli; Kgotlele, Tebogo; Berg, Mikael; Mtui-Malamsha, Niwael; Swai, Emanuel S; Wensman, Jonas Johansson; Misinzo, Gerald
Peste des petits ruminants virus (PPRV) causes the acute, highly contagious disease peste des petits ruminants (PPR) that affects small domestic and wild ruminants. PPR is of importance in the small livestock-keeping industry in Tanzania, especially in rural areas as it is an important source of livelihood. Morbidity and case fatality rate can be as high as 80 100% in naı̈ve herds; however, in endemic areas, morbidity and case fatality range between 10 and 100% where previous immunity, age, and species of infected animal determine severity of outcome. PPR was officially confirmed in domestic animals in the Ngorongoro district of Tanzania in 2008. It is now considered to be endemic in the domestic sheep and goat populations throughout Tanzania, but restricted to one or more areas in the small ruminant wildlife population. In this article, we review the history and the current status of PPR in Tanzania and neighboring countries. To control and eradicate PPR in the region, a joint effort between these countries needs to be undertaken. The effort must also secure genuine engagement from the animal holders to succeed.
Human leptospirosis in tanzania:sequencing and phylogenetic analysis confirm that pathogenic leptospira species circulate among agro-pastoralists living in Katavi-Rukwa ecosystem
(BMC, 2016) Muller, Shabani K; Assenga, Justine A; Matemba, Lucas E; Misinzo, Gerald; Kazwala, Rudovick R
Background: Leptospirosis is a neglected zoonotic disease of worldwide public health importance. The disease affects humans, domestic animals and wildlife. However, leptospirosis is challenging in its diagnosis in humans. Culture technique, which is time consuming, is not recommended for clinical diagnosis. For these reasons, serological and molecular techniques remain the test of choice. The major objective of this study was to explore the genetic characteristic of Leptospira species which are prevalent among agro-pastoralists living in Katavi–Rukwa Ecosystem, Tanzania. Methods: A cross-sectional epidemiological study was carried out in the Katavi-Region South-west, Tanzania between August, 2013 and November, 2014. A total of 267 participants were randomly recruited for the study. Microscopic agglutination test (MAT) was used to detect antibody against six Leptospira antigens including local serogroups Icterohaemorrhagiae, Ballum, Grippotyphosa, Sejroe and reference serogroups Hebdomadis, and Australis. Samples with MAT titers ≥ 1:160 were scored as positive, samples with MAT titers ranging from 1:20 to 1:80 were scored as exposed to Leptospira, and absence of agglutination titers was scored as negative. All MAT positive samples, including the low titre samples were subjected to PCR using the respective 16S rRNA primers for the pathogenic and non-pathogenic species. Results: Out of 267 samples tested, 80 (29.9 %) were positive with MAT. The major circulating leptospiral serogroups were Sejroe (15.7 %,), Icterohaemorrhagiae (8.9 %), Grippotyphosa (4.8 %), Hebdomadis (3.37 %), Australis (1.49 %) and Ballum (1.19 %). By using PCR, 33 (15.7 %) out of 210 samples were pathogenic Leptospira while no saprophytic Leptospira spp. was detected. Partial 16S rRNA gene sequences of Leptospira species which were obtained from this study were submitted to GenBank and acquired accession numbers KP313246 and KP313247. Phylogenetic analysis of the nucleotide sequences revealed that species obtained from Katavi-Rukwa ecosystem clustered in the same group with several published pathogenic Leptospira specifically Leptospira interrogans and Leptospira kirschneri. To the best of the authors’ knowledge , this is the first study from Tanzania to confirm pathogenic Leptospira in human subjects using genomic typing technique. Conclusion: These findings provide ultimate evidence of pathogenic Leptospira species circulating among agro-pastoralists living in Katavi-Rukwa Ecosystem suggesting that active disease surveillance should be undertaken in order to achieve greater protection of the agro-pastoral communities in Tanzania.
Human, animal and plant health benefits of glucosinolates and strategies for enhanced Bioactivity: a systematic review
(MDPI, 2020) Maina, Sylvia; Misinzo, Gerald; Bakari, Gaymary; Kim, Ho-Youn
Glucosinolates (GSs) are common anionic plant secondary metabolites in the order Brassicales. Together with glucosinolate hydrolysis products (GSHPs), they have recently gained much attention due to their biological activities and mechanisms of action. We review herein the health benefits of GSs/GSHPs, approaches to improve the plant contents, their bioavailability and bioactivity. In this review, only literature published between 2010 and March 2020 was retrieved from various scientific databases. Findings indicate that these compounds (natural, pure, synthetic, and derivatives) play an important role in human/animal health (disease therapy and prevention), plant health (defense chemicals, biofumigants/biocides), and food industries (preservatives). Overall, much interest is focused on in vitro studies as anti-cancer and antimicrobial agents. GS/GSHP levels improvement in plants utilizes mostly biotic/abiotic stresses and short periods of phytohormone application. Their availability and bioactivity are directly proportional to their contents at the source, which is affected by methods of food preparation, processing, and extraction. This review concludes that, to a greater extent, there is a need to explore and improve GS-rich sources, which should be emphasized to obtain natural bioactive compounds/active ingredients that can be included among synthetic and commercial products for use in maintaining and promoting health. Furthermore, the development of advanced research on compounds pharmacokinetics, their molecular mode of action, genetics based on biosynthesis, their uses in promoting the health of living organisms is highlighted.
Inhibition of endosome-lysosome system acidification enhances porcine circovirus 2 infection of porcine epithelial cells
(American Society for Microbiology, 2008-02) Misinzo, Gerald; Delputte, Peter L; Nauwynck, Hans J
Recently, Misinzo et al. (G. Misinzo, P. Meerts, M. Bublot, J. Mast, H. M. Weingartl, and H. J. Nauwynck, J. Gen. Virol. 86:2057-2068, 2005) reported that inhibiting endosome-lysosome system acidification reduced porcine circovirus 2 (PCV2) infection of monocytic 3D4/31 cells. The present study examined the effect of inhibiting endosome-lysosome system acidification in epithelial cells, since epithelial cells support PCV2 infection in vivo and are used in culturing PCV2 in vitro. Ammonium chloride (NH4Cl), chloroquine diphosphate (CQ), and monensin were used to inhibit endosome-lysosome system acidification. NH4Cl, CQ, or monensin increased PCV2 (Stoon-1010) infection by 726% ± 110%, 1,212% ± 34%, and 1,100% ± 179%, respectively, in porcine kidney (PK-15) cells; by 128% ± 7%, 158% ± 3%, and 142% ± 11% in swine kidney cells; by 160% ± 28%, 446% ± 50%, and 162% ± 56% in swine testicle (S