Browsing by Author "Shirima, Gabriel"

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African Swine Fever Virus (ASFV): Biology, Genomics and Genotypes Circulating in Sub-Saharan Africa
(MDPI, 2021-11-15) Njau, Emma; Machuka, Eunice; Cleaveland, Sarah; Shirima, Gabriel; Kusiluka, Lughano; Okoth, Edward; Pelle, Roger
African swine fever (ASF) is a highly infectious and fatal haemorrhagic disease of pigs that is caused by a complex DNA virus of the genus Asfivirus and Asfarviridae African suids family. The disease is among the most devastating pig diseases worldwide including Africa. Although the disease was first reported in the 19th century, it has continued to spread in Africa and other parts of the world. Globally, the rising demand for pork and concomitant increase in transboundary movements of pigs and pork products is likely to increase the risk of transmission and spread of ASF and pose a major challenge to the pig industry. Different genotypes of the ASF virus (ASFV) with varying virulence have been associated with different outbreaks in several countries in sub-Saharan Africa (SSA) and worldwide, and understanding genotype circulation will be important for ASF prevention and control strategies. ASFV genotypes unique to Africa have also been reported in SSA. This review briefly recounts the biology, genomics and genotyping of ASFV and provides an account of the different genotypes circulating in SSA. The review also highlights prevention, control and progress on vaccine development and identifies gaps in knowledge of ASFV genotype circulation in SSA that need to be addressed.
Antimicrobial resistant coliforms across four poultry production systems in Arusha and Moshi, Tanzania
(Pan African Medical Journal, 2022-01-11) Maganga, Ruth; Sindiyo, Emmanuel; Musyoki, Victor; Shirima, Gabriel; Maina, Brian; Mmbaga, Blandina
Introduction: resistance to antimicrobials poses a threat to human and animal health. This study aimed to determine the prevalence of resistant coliforms in poultry cloacal samples collected from different poultry systems in Arusha and Moshi districts, Tanzania. Methods: ten administrative wards were randomly chosen in Moshi and Arusha urban districts, with a random selection of one representative farm in each ward per production system (extensive, semi-intensive, intensive, and broiler systems). Per farm, 10 chickens were sampled using cloacal swabs. Samples were tested for the presence of coliforms using MacConkey agar without or with tetracycline, ciprofloxacin, ceftazidime, and Imipenem. R software was used for data analysis. Results: of the 80 farms targeted, samples were collected from 79 farms representing a total of 746 samples, of which 648 (86.8%) had coliforms corresponding to 74 of the 79 sampled farms. There was no significant difference in the overall prevalence of coliforms between Moshi (86%) and Arusha districts (87%) (p=0.81). The overall proportions of resistant coliforms in Arusha and Moshi varied depending on each antimicrobial type. The prevalence of coliforms resistant to tetracycline (95%) across all farm types in both districts was higher compared to ciprofloxacin (72%), imipenem (71%), and ceftazidime (84%) (p<0.0001). The median counts of coliform resistance (in log cfu) ranged from 4 to 10, with no significant distinctions between antimicrobial types. Conclusion: there is a widespread presence of antimicrobial resistant coliforms in poultry production systems. High tetracycline resistance was observed across all farm types in both districts.
Assessment of Knowledge, Attitude and Practices (KAP) on Hantavirus Infections at Community Level in Mbeya Region, Tanzania
(Longdom Publishing., 2018-10-26) Sudi, Lwitiho; Mangu, Chacha; Ntinginya, Elias; Shirima, Gabriel; Tarimo, Mokiti
Background: Hantaviruses are zoonotic RNA viral pathogens of public health concern in Tanzania and worldwide. These viruses circulate in both human and reservoir host in Tanzania, however, there is a gap in the assessment of knowledge, Attitude, and practices (KAP) which contributes to the transmission of the virus from Reservoir host to human being. This study aimed to assess the level of community knowledge, attitude, and practices that lead to the transmission of the virus from the reservoir host to a human being. Methods: Cross-sectional questionnaire survey was conducted in the four districts of Mbeya region between June 2018 to July 2018, where questionnaire data were obtained from 438 participants. Descriptive statistics and Chi-square (X2 ) test were used to explain the response of the participants. Results: (22/66) 33.3% and (22/372) 5.91% of both Health care workers and other members of the community, respectively had a knowledge about Hantavirus infections. (219/438) 50% of all participants have rodent breeding sites in their houses. However, (409/438) 93.4% of all participants did not wear masks when cleaning those breeding sites and this increases the risk for the transmission of Hantavirus infections. Discussion: Low level of knowledge for Hantavirus infections observed in the community increases the uncertainty of patient management as well as endangers the community health due to an increase of practices which increases the chance of pathogen transmission to a human being from the reservoir host. Conclusion: Updating the community about Hantavirus infection is more important as far as public health is concerned.
Brucella Species Circulating in Smallholder Dairy Cattle in Tanzania
(MDPI, 2024-09-21) Mengele, Isaac; Akoko, James; Shirima, Gabriel; Bwatota, Shedrack; Motto, Shabani; Hernandez-Castro, Luis; Komwihangilo, Daniel; Lyatuu, Eliamoni; de Clare Bronsvoort, Barend; Cook, Elizabeth
Brucellosis is a zoonosis caused by bacteria of the genus Brucella, which results in economic losses relating to livestock and threatens public health. A cross-sectional study was conducted to determine the molecular prevalence of Brucella species in smallholder dairy cattle in six regions of Tanzania from July 2019 to October 2020. Dairy cattle (n = 2048) were sampled from 1371 farms. DNA extracted from blood and vaginal swabs was tested for Brucella using qPCR targeting the IS711 gene and positives were tested for the alkB marker for B. abortus and BMEI1172 marker for B. melitensis. The molecular prevalence was 3.5% (95% CI: 2.8–4.4) with the highest prevalence 8.1% (95% CI: 4.6–13.0) in Njombe region. B. melitensis was the predominant species detected (66.2%). Further studies are recommended to understand the source of B. melitensis and its implications for veterinary public health. Livestock keepers should be informed of the risks and biosecurity practices to reduce the introduction and control of Brucella. Cattle and small ruminant vaccination programs could be implemented to control brucellosis in high-risk populations in the country.
Brucellosis infection dynamics in cattle and the impacts on production and reproduction in pastoral settings of Tanzania
(Academic Journals, 2022-03) Shirima, Gabriel
Brucellosis is endemic in pastoral settings of Tanzania with significant socio-economic implications. However, comprehensive studies to establish its impacts had not been elucidated. A longitudinal study was conducted in order to elucidate the dynamics and its impact on production and reproduction. Initially, 464 animals were enrolled with baseline seroprevalence in each herd. Animals were bled every three months to determine the incidence rate, impacts and trends in sero-status. In addition, individual animal reproductive information was collected. Milk yield was measured indirectly by estimating the calves’ growth rate. Data were analysed using Epi Info 7.0 software where descriptive analyses were used to establish proportions, associations and relationships. Wilcoxon test was used to establish the growth rate differences. Forty-seven new c-ELISA seropositive animals were identified over the period of three months representing an incidence rate of 0.811 cases per animal-year at risk. Households with a high seroprevalence during baseline screening were observed to have high infection rate in the subsequent visit. There was no statistical association between new seropositive cases and seasons (P>0.05). Furthermore, positive to negative seroconversion was observed. Of the 94 females that were expected to parturate, 15% aborted with 29% of these being seropositive. Retained placenta was observed in 4.3% of the domestic ruminants. Of the 79 calves that were screened, 21.5% were seropositive with majority born from seropositive dams. Calves born from seropositive dams were 27 times more likely to be seropositive. Growth rate was not different (p>0.05) between calves suckling from seropositive and seronegative dams. Key words: Brucellosis impacts, incidence rate, seropositivity.
Brucellosis testing patterns at health facilities in Arusha region, northern Tanzania
(Plos one, 2022-03-23) Yapi, Richard; Lukambagire, AbdulHamid; Shirima, Gabriel; Shayo, Damas; Mathew, Coletha; Kasanga, Christopher; Mmbaga, Blandina; Kazwala, Rudovick; Halliday, Jo
Background Brucellosis is listed as one of six priority zoonoses in Tanzania’s One Health strategic plan which highlights gaps in data needed for the surveillance and estimation of human brucellosis burdens. This study collected data on current testing practices and test results for human brucellosis in Arusha region, northern Tanzania. Methods Retrospective data were extracted from records at 24 health facilities in Arusha region for the period January 2012 to May 2018. Data were captured on: the test reagents used for brucellosis, procurement and testing protocols, the monthly number of patients tested for brucellosis and the monthly number testing positive. Generalised linear mixed models were used to evaluate relationships between health facility characteristics and the probability that brucellosis testing was conducted in a given month, and the proportion of individuals testing positive. Results Four febrile Brucella agglutination tests were used widely. The probability of testing for brucellosis in a given month was significantly associated with an interaction between year of testing and facility ownership. Test probability increased over time with more pronounced increases in privately owned as compared to government facilities. The proportion of individuals testing positive for brucellosis was significantly associated with facility type and district, with individuals tested in hospitals in Meru, Monduli and Ngorongoro districts more likely to test positive. Conclusions Febrile Brucella agglutination tests, known for their poor performance, were the mainstay of brucellosis testing at health facilities in northern Tanzania. The study indicates that historical data on human brucellosis in Arusha and other regions are likely to provide an inaccurate measure of true disease burden due to poor performance of the tests used and variation in testing practices. Measures to address these identified shortcomings could greatly improve quality of testing and surveillance data on brucellosis and ultimately inform prevention and control of this priority disease.
A case-control study on the driving factors of childhood brain volume loss: What pediatricians must explore
(PLOS ONE, 2022-12-30) Sungura, Richard; Shirima, Gabriel; Spitsbergen, John; Mpolya, Emmanuel; Vianney, John-Mary
Background The brain volume loss also known as brain atrophy is increasingly observed among children in the course of performing neuroimaging using CT scan and MRI brains. While severe forms of brain volume loss are frequently associated with neurocognitive changes due to effects on thought processing speed, reasoning and memory of children that eventually alter their general personality, most clinicians embark themselves in managing the neurological manifestations of brain atrophy in childhood and less is known regarding the offending factors responsible for developing pre-senile brain atrophy. It was therefore the goal of this study to explore the factors that drive the occurrence of childhood brain volume under the guidance of brain CT scan quantitative evaluation. Methods This study was a case-control study involving 168 subjects with brain atrophy who were compared with 168 age and gender matched control subjects with normal brains on CT scan under the age of 18 years. All the children with brain CT scan were subjected to an intense review of their birth and medical history including laboratory investigation reports. Results Results showed significant and influential risk factors for brain atrophy in varying trends among children including age between 14-17(OR = 1.1), male gender (OR = 1.9), birth outside facility (OR = 0.99), immaturity (OR = 1.04), malnutrition (OR = 0.97), head trauma (OR = 1.02), maternal alcoholism (OR = 1.0), antiepileptic drugs & convulsive disorders (OR = 1.0), radiation injury (OR = 1.06), space occupying lesions and ICP (OR = 1.01) and birth injury/asphyxia (OR = 1.02). Conclusions Pathological reduction of brain volume in childhood exhibits a steady trend with the increase in pediatric age, with space occupying lesions & intracranial pressure being the most profound causes of brain atrophy.
Combining Multiple Assays Improves Detection and Serotyping of Foot-and-Mouth Disease Virus. A Practical Example with Field Samples from East Africa
(MDPI, 2021-08-10) Foglia, Efrem; Lembo, Tiziana; Kazwala, Rudovick; Ekwem, Divine; Shirima, Gabriel; Grazioli, Santina; Brocchi, Emiliana; Pezzoni, Giulia
Multiple serotypes and topotypes of foot-and-mouth disease virus (FMDV) circulate in endemic areas, posing considerable impacts locally. In addition, introductions into new areas are of great concern. Indeed, in recent years, multiple FMDV outbreaks, caused by topotypes that have escaped from their original areas, have been recorded in various parts of the world. In both cases, rapid and accurate diagnosis, including the identification of the serotype and topotype causing the given outbreaks, plays an important role in the implementation of the most effective and appropriate measures to control the spread of the disease. In the present study, we describe the performance of a range of diagnostic and typing tools for FMDV on a panel of vesicular samples collected in northern Tanzania (East Africa, EA) during 2012–2018. Specifically, we tested these samples with a real-time RT-PCR targeting 3D sequence for pan-FMDV detection; an FMDV monoclonal antibody-based antigen (Ag) detection and serotyping ELISA kit; virus isolation (VI) on LFBKαVβ6 cell line; and a panel of four topotype-specific real-time RT-PCRs, specifically tailored for circulating strains in EA. The 3D real-time RT-PCR showed the highest diagnostic sensitivity, but it lacked typing capacity. Ag-ELISA detected and typed FMDV in 71% of sample homogenates, while VI combined with Ag-ELISA for typing showed an efficiency of 82%. The panel of topotype-specific real-time RT-PCRs identified and typed FMDV in 93% of samples. However, the SAT1 real-time RT-PCR had the highest (20%) failure rate. Briefly, topotype-specific real-time RT-PCRs had the highest serotyping capacity for EA FMDVs, although four assays were required, while the Ag-ELISA, which was less sensitive, was the most user-friendly, hence suitable for any laboratory level. In conclusion, when the four compared tests were used in combination, both the diagnostic and serotyping performances approached 100%.
Comparative analysis of clinical breakpoints, normalized resistance interpretation and epidemiological cut-offs in interpreting antimicrobial resistance of Escherichia coli isolates originating from poultry in different farm types in Tanzania
(Microbiology Society, 2014-07-14) Maganga, Ruth; Sindiyo, Emmanuel; Musyoki, Victor; Shirima, Gabriel; Mmbaga, Blandina
Introduction. Existing breakpoint guidelines are not optimal for interpreting antimicrobial resistance (AMR) data from animal studies and low-income countries, and therefore their utility for analysing such data is limited. There is a need to integrate diverse data sets, such as those from low-income populations and animals, to improve data interpretation. Gap statement. There is very limited research on the relative merits of clinical breakpoints, epidemiological cut-offs (ECOFFs) and normalized resistance interpretation (NRI) breakpoints in interpreting microbiological data, particularly in animal studies and studies from low-income countries. Aim. The aim of this study was to compare antimicrobial resistance in Escherichia coli isolates using ECOFFs, CLSI and NRI breakpoints. Methodology. A total of 59 non-repetitive poultry isolates were selected for investigation based on lactose fermentation on MacConkey agar and subsequent identification and confirmation as E. coli using chromogenic agar and uidA PCR. Kirby Bauer disc diffusion was used for susceptibility testing. For each antimicrobial agent, inhibition zone diameters were measured, and ECOFFs, CLSI and NRI bespoke breakpoints were used for resistance interpretation. Results. According to the interpretation of all breakpoints except ECOFFs, tetracycline resistance was significantly higher (TET) (67.8 –69.5 %), than those for ciprofloxacin (CIPRO) (18.6 –32.2 %), imipenem (IMI) (3.4 –35 %) and ceftazidime (CEF) (1.7 –45.8 %). Prevalence estimates of AMR using CLSI and NRI bespoke breakpoints did not differ for CEF (1.7 % CB and 1.7 % COWT ), IMI (3.4 % CB and 4.0 % COWT ) and TET (67.8 % CB and 69.5 % COWT ). However, with ECOFFs, AMR estimates for CEF, IMI and CIP were sig- nificantly higher (45.8, 35.6 and 64.4 %, respectively; P<0.05). Across all the three breakpoints, resistance to ciprofloxacin varied significantly (32.2 % CB, 64.4 % ECOFFs and 18.6 % COWT , P<0.05). Conclusion. AMR interpretation is influenced by the breakpoint used, necessitating further standardization, especially for microbiological breakpoints, in order to harmonize outputs. The AMR ECOFF estimates in the present study were significantly higher compared to CLSI and NRI.
Complete genome sequence of Brucella abortus isolated from a human blood culture sample in Tanzania
(American society for microbiology, 2024-01-30) Mbwambo, Gershom; Zwetselaar, Marco; Sonda, Tolbert; Lukambagire, AbdulHamid; Njau, Judith; Wadugu, Boaz; Ignass, Ignass; Amani, Nelson; Hugho, Ephrasia; Rubach, Matthew; Sakasaka, Philoteus; Oisso, Rose; Mkenda, Nestory; Shirima, Gabriel; Ashford, Roland; Haydon, Daniel; Maro, Venance; Kazwala, Rudovick; Kumburu, Happiness; Mmbaga, Blandina; Halliday, Jo E.
Brucella abortus causes infections in humans and livestock. Bacterial isolates are challenging to obtain, and very little is known about the genomic epidemiology of this species in Africa. Here, we report the complete genome sequence of a Brucella abortus isolate cultured from a febrile human in northern Tanzania
Conjugative Plasmids Disseminating CTX-M-15 among Human, Animals and the Environment in Mwanza Tanzania: A Need to Intensify One Health Approach
(MDPI, 2021-07-09) Minja, Caroline; Shirima, Gabriel; Mshana, Stephen
Background: Globally, blaCTX-M-15 beta-lactamases are the most popular extended spectrum beta-lactamase alleles that are widely distributed due its mobilisation by mobile genetic elements in several compartments. We aimed to determine the conjugation frequencies and replicon types associated with plasmids carrying blaCTX-M-15 gene from Extended Spectrum Beta-lactamase producing isolates in order to understand the dissemination of resistance genes in different compartments. Material and methods: A total of 51 archived isolates carrying blaCTX-M-15 beta-lactamases were used as donors in this study. Antibiotic susceptibility tests were performed as previously described for both donors and transconjugants. Conjugation experiment was performed by a modified protocol of the plate mating experiment, and plasmid replicon types were screened among donor and transconjugant isolates by multiplex Polymerase Chain Reaction in a set of three primer panels. Results: The conjugation efficiency of plasmids carrying blaCTX-M-15 was 88.2% (45/51) with conjugation frequencies in the order of 10−1 to 10−9 and a 100% transfer efficiency observed among E. coli of animal origin. Majority of donors (n = 21) and transconjugants (n = 14) plasmids were typed as either Inc FIA or Inc FIB. Resistance to non-beta-lactam antibiotics was transferrable in 34/45 (75.6%) of events. Ciprofloxacin, tetracycline and sulphamethoxazole-trimethoprim resistance was co-transferred in 29/34 (85.3%) such events. Gentamicin resistance was transferred in 17/34 (50%) of events. Conclusions: Majority of plasmids carrying blaCTX-M-15 were conjugatively transferred by IncF plasmids along with non-beta lactam resistance. There is a need for more research on plasmids to understand how plasmids especially multi replicon plasmids interact and the effect of such interaction on conjugation. One Health approach is to be intensified to address antimicrobial resistance which is a public health threat.
Current State of Modern Biotechnological-Based Vaccines for Aquaculture: A Systematic Review.
(Hindawi, 2019-07-29) Mzula, Alexanda; Wambura, Philemon; Mdegela, Robinson; Shirima, Gabriel
This systematic review describes what "the cutting edge vaccines for are". The focus is on types of high tech biotechnological based vaccines, target gene or antigen in developing these vaccines, and challenge model fish species used in vaccines efficacy testing. Vaccines delivery methods, immune response, and their efficacy, adjuvant or carrier systems used, and the overall experimental setup or design of the vaccines under investigation are also described. The search for the original papers published between 2009 and 2018 was conducted in June of 2018, using the PubMed and Google scholar electronic database. Twenty-three (23/4386) studies were included in the final assembly using PRISMA guidelines (Protocol not registered). Recombinant protein vaccines were the highly experimented type of the modern biotechnological based vaccines identified in the selected studies (16/23; 70%). Outer membrane proteins (OMPs) of different -barrels were shown to be a potential antigenic entity for vaccines (57%). Intraperitoneal route with conventional carries or adjuvants was the highly applied delivery system while very few studies used herbal based vaccine adjuvants and nanomaterial as a vaccine carrier. Variation was observed in terms of protection levels in the selected studies. The experimental designs partly contributed to the observed variation. Therefore, recombinant vaccines that use new carrier system technologies and delivered through oral route in feeds would have been of great value for use in the prevention and control of infections in fish. Despite the usefulness as academic tools to identify what is important in pathogenicity of the etiological agent to the host fish, these vaccines are only economically viable in very high-value animals. Therefore, if vaccination is a good option for group, then simple autogenous vaccines based on accurate typing and evidence-based definition of the epidemiological unit for their use would be the most viable approach in terms of both efficacy and economic feasibility especially in low and middle-income countries (LMIC).
Dataset: SNP genotyping of indigenous goats of Uganda based on the Goat_IGGC_65K_v2 illumina chip
(2024-05-23) Nantongo, Ziwena; Birungi, Josephine; Obol Opiyo, Stephen; Shirima, Gabriel; Mugerwa, Swidiq; Mutai, Collins; Kyalo, Martina; Munishi, Linus; Agaba, Morris; Mrode, Raphael
Uganda's indigenous goats are characterised based on ethnic communities that raise them, average mature weight, and hair coat characteristics. Uganda's indigenous goats have been genotyped based on the Goat_IGGC_65K_v2 illumina chip to study their population structure and genetic characteristics. Information generated from this data is vital for the sustainable utilisation, development, and conservation of Uganda's goat genetic resources.
Dataset: SNP genotyping of indigenous goats of Uganda based on the Goat_IGGC_65K_v2 illumina chip
(Zenodo, 2024) Nantongo, Ziwena; Birungi, Josephine; Obol Opiyo, Stephen; Shirima, Gabriel; Mugerwa, Swidiq; Mutai, Collins; Kyalo, Martina; Munishi, Linus; Agaba, Morris; Mrode, Raphael
Uganda's indigenous goats are characterised based on ethnic communities that raise them, average mature weight, and hair coat characteristics. Uganda's indigenous goats have been genotyped based on the Goat_IGGC_65K_v2 illumina chip to study their population structure and genetic characteristics. Information generated from this data is vital for the sustainable utilisation, development, and conservation of Uganda's goat genetic resources. Methods The data was collected from genomic DNA extracted from ear tissue samples of 1032 indigenous goats from different agro-ecological zones of Uganda. The study aimed to characterise the genetic diversity, population structure and signatures of selection of indigenous goats in different agroecological zones of Uganda. Indigenous goats were identified in their known phenotypic/ ethnic classifications of Mubende, Kigezi and Small East African goats in all the 10 agroecologies. Ear tissue samples were collected from each goat using the allflex tissue sampling system that allows for no cross contamination as each sample self locks in a single use tube after it is collected. Genomic DNA was extracted from each sample using the TANBEAD automated DNA extraction system with the 6T2 total tissue DNA extraction kit. DNA samples were genotyped based on the Goat_IGGC_65K_v2 illumina chip. Data processing After genotyping, 59725 SNPs from 1032 genotypes were received in PLINK format. The data was opened in Tassel Version 5.2 and saved as VCF format for further processing. The near complete goat genome (ARS1) was used as reference to align all the SNPs to the right chromosomes and chromosome positions using R (version 4.3.3) software. The final data set was saved as a VCF file for analysis.
Detection of African swine fever virus genotype XV in a sylvatic cycle in Saadani National Park, Tanzania
(Wiley Online Library, 2020-07-22) Njau, Emma; Machuka, Eunice; Githae, Dedan; Okoth, Edward; Cleaveland, Sarah; Shirima, Gabriel; Kusiluka, Lughano; Pelle, Roger
African swine fever (ASF) is a severe haemorrhagic disease of domestic pigs caused by ASF virus (ASFV). ASFV is transmitted by soft ticks (Ornithodoros moubata complex group) and by direct transmission. In Africa, ASF is maintained in transmission cycles of asymptomatic infection involving wild suids, mainly warthogs (Phacochoerus afri canus). ASF outbreaks have been reported in many parts of Tanzania; however, active surveillance has been limited to pig farms in a few geographical locations. There is an information gap on whether and where the sylvatic cycle may occur independently of domestic pigs. To explore the existence of a sylvatic cycle in Saadani National Park in Tanzania, blood and serum samples were collected from 19 warthogs se lected using convenience sampling along vehicle-accessible transects within the na tional park. The ticks were sampled from warthog burrows. Blood samples and ticks were subjected to ASFV molecular diagnosis (PCR) and genotyping, and warthog sera were subjected to serological (indirect ELISA) testing for ASFV antibody detection. All warthog blood samples were PCR-negative, but 16/19 (84%) of the warthog sera were seropositive by ELISA confirming exposure of warthogs to ASFV. Of the ticks sampled, 20/111 (18%) were positive for ASFV by conventional PCR. Sequencing of the p72 virus gene fragments showed that ASF viruses detected in ticks belonged to genotype XV. The results confirm the existence of a sylvatic cycle of ASFV in Saadani National Park, Tanzania, that involves ticks and warthogs independent of domestic pigs. Our findings suggest that genotype XV previously reported in 2008 in Tanzania is likely to be widely distributed and involved in both wild and domestic infection cycles. Whole-genome sequencing and analysis of the ASFV genotype XV circulating in Tanzania is recommended to determine the phylogeny of the viruses.
Detection of carrier state and genetic diversity of Theileria parva in ECF-vaccinated and naturally exposed cattle in Tanzania
(Elsevier B.V., 2019-08) Magulu, Emelesiana Cyprian; Kindoro, Fatuma; Mwega, Elisa; Kimera, Sharadhuli; Shirima, Gabriel; Gwakisa, Paul
Infection and Treatment Method (ITM) has been practiced in Tanzania for over 20 years as a prevention measure against East Coast Fever disease. It is known that ITM, like natural ECF infection, leads to a carrier state, whereby vaccinated cattle become asymptomatic carriers of the parasite. It is expected that ECF vaccination using ITM also leads to generation of combinations of vaccine specific Theileria parva and local strains that circulate in the field what contributes to an unknown level of parasite diversity. Moreover, the long term impact of ITM on carrier state and parasite diversity in cattle are largely unknown. To address this question blood was collected from ECF-vaccinated (n = 239) and unvaccinated (n = 97) cattle from Loiborsoit, Emboreet, Esilalei, Manyara ranch and Mswakini villages in the Maasai steppe of northern Tanzania, as well as Mruazi and Leila farms in Tanga in eastern Tanzania. Screening for T. parva using nested PCR revealed an overall prevalence of T. parva to be 34.5%, with a significant higher prevalence among ECF-vaccinated cattle. Using three VNTR markers (ms2, ms5 and MS7) higher parasite genetic diversity in terms of higher number of alleles and expected heterozygosity was shown in vaccinated than unvaccinated cattle. These parameters were highest in cattle from Manyara ranch. Nevertheless, the principle component analysis (PCoA) showed no distinct clustering patterns as most T. parva alleles clustered together throughout the four quadrants implying parasite homogeneity among the sampled populations. However, some of the parasite alleles closely clustered with Muguga vaccine alleles in two of the quadrants, consistent with closer genetic relatedness between the vaccine strains and the T. parva populations from the Maasai steppe. Likewise analysis of molecular variance (AMOVA) revealed most of the genetic variation (93%) being contained within populations with only 7% being among populations. This study therefore confirms the role of ECF vaccination in enhancing carrier state and T. parva diversity in vaccinated cattle populations. Higher T. parva diversity may play an important role in carrier cattle by way of restricting breakthrough infections from field parasite strains.
Detection of Contagious Caprine Pleuropneumonia and Concurrent Diseases in Outbreaks Presenting with Respiratory Signs in Small Ruminants in Tanzania
(International Journal of TROPICAL DISEASE & Health, 2020-07-06) Chota, Andrew; Shirima, Gabriel; Kusiluka, Lughano
Aims: To establish the prevalence and concurrent diseases in outbreaks presenting with respiratory signs, major associated clinical signs and postmortem lesions and proportions of those diseases in clinically and autopsied small ruminants for a proper diagnosis and control strategies. Study Design: Purposive outbreaks investigation. Place and Duration of Study: Department of Global Health, School of Life Science and Bio-Engineering (LiSBE), Nelson Mandela Institution of Science and Technology (NM-AIST) between September 2016 and December 2018. Methodology: We included investigations of outbreaks of diseases presenting with respiratory signs in small ruminants reported from five agro-ecological zones in Tanzania. Small ruminats with clinical signs or postmortem lesions suggestive of respiratory involvement were subjected to clinical or postmortem examination. Samples from all examined animals were tested in the laboratory using conventional polymerase chain reaction (PCR) to confirm the tentative diagnosis. Results: A total of 205 small ruminats were examined and tested, of these 72.2% and 20.8% were goats and sheep respectively. In goats, 79.1% (117/148) and sheep, 28.1% (16/57) were confirmed to have concurrent infections, and pneumonic pasteurellosis and peste des petits ruminants (PPR) for goats, and PPR for sheep being mostly involved diseases. Contagious caprine pleuropneumonia (CCPP) was detected in 16.1% (n=205) of the animals, and was significantly high in goats (p=0.003, OR=7.3) than sheep. Pneumonic mannheimiosis (prevalence = 9.3%) was less likely to affect goats than sheep (p=0.047, OR=0.38). In goats (n=148), detection of all diseases was significantly (p<0.05) low in clinically examined animals except pneumonic pasteurellosis and PPR, (p =0.056, OR=2.1) and (p=0.096, OR=2.15) respectively, though the difference was not significant. In sheep (n=57), CCPP was significantly (p=0.005, OR=0.17) more likely to be detected in clinically examined animals. Conclusion: In investigations of outbreaks presenting with respiratory signs in small ruminants, it is important to consider concurrent infections in the interventions and control strategies to be deployed, which may include development and use of multivalent vaccines.
Detection of peste des petits ruminants and concurrent secondary diseases in sheep and goats in Ngorongoro district, Tanzania
(Springer, 2018-11-15) Kgotlele, Tebogo; Chota, Andrew; Chubwa, Choby; Nyasebwa, Obed; Lyimo, Beatus; Torsson, Emeli; Karimuribo, Esron; Kasanga, Christopher; Wensman, Jonas; Misinzo, Gerald; Shirima, Gabriel; Kusiluka, Lughano
Small ruminants play an important role in the livelihoods of resource-constrained communities. This study was initiated because of a massive outbreak of a respiratory disease in sheep and goats in Loliondo area in Ngorongoro district of Arusha region in Tanzania in 2016. During flock examination, a total of 240 serum samples and 61 nasal swabs were collected. Antibodies to small ruminant morbillivirus, causative agent of peste des petits ruminants (PPR), were detected from sera using a competitive enzyme-linked immunosorbent assay. A multiplex reverse transcription real-time polymerase chain reaction assay was used to detect four pathogens: small ruminant morbillivirus, Mycoplasma capricolum subspecies capripneumoniae, Pasteurella multocida, and Capripoxvirus from the nasal swabs. Overall seroprevalence of PPR was 74.6%, with all four pathogens detected from nasal swabs. Co-infections of small ruminant morbillivirus and Mycoplasma capricolum subspecies capripneumoniae, small ruminant morbillivirus and Capripoxvirus, small ruminant morbillivirus and Pasteurella multocida, and Mycoplasma capricolum subspecies capripneumoniae and Capripoxvirus were also detected. Presence of PPR and the other diseases in this study provided insight into the severity of the outbreak in sheep and goats in Ngorongoro district. Thus, laboratory confirmation is critical for prompt and appropriate interventions to be made for control of diseases in sheep and goats with similar clinical signs. The findings also call for research into development of combined vaccines targeting common diseases of small ruminants in Tanzania.
Determinants of Dogs’ Helminth Treatment-Seeking Behavior among Dog Owners in Rural Northern Tanzania.
(Pre prints.org, 2024-02-20) Kibona, Tito; Buza, Joram; Shirima, Gabriel
Taeniid infections pose a significant threat to both animal and public health, as certain tapeworms within this group can also infect humans, potentially leading to severe health conditions. Therefore, this calls for preventive and control measures, such as regular deworming of dogs. While the efficacy of deworming has been established in developed countries, there is a paucity of reported deworming practices in rural areas of developing countries, such as Tanzania. This study aims to understand determinants for helminth treatment-seeking behaviour towards control of custodial taeniid infections in rural settings in northern Tanzania. A cross-sectional study was undertaken in agropastoral and pastoral areas of northern Tanzania. Comprehensive data from household surveys in selected sub-villages were collected to ascertain dog ownership, dog deworming practices, and the availability of dewormers. Analytical methods were employed to discern how various determinants influenced deworming practices among dog owners in these communities. Awareness of dewormers specifically formulated for dogs emerged as a pivotal factor affecting dog deworming practices. Dog owners who were informed about appropriate dog dewormers were nearly two times more likely to engage in deworming compared to those with limited knowledge (OR = 1.78, 95% CI 1.77 - 4.18, p < 0.001). A majority 32(51.6%, 95% CI: 38.7-64.3) acknowledged accessing dewormers for livestock within their wards. Praziquantel a potent dewormer on cestodes was least known to most dog owners 2(13%, 95% CI: 2.3-41.6). Praziquantel, a potent and common dewormer effective against custodial taeniid infections, remains relatively unknown in rural areas of northern Tanzania. Therefore, more awareness of appropriate deworming agents against taeniids in dogs should be raised in rural dog-keeping communities.
Determinants of Dogs’ Helminth Treatment-Seeking Behavior among Dog Owners in Rural Northern Tanzania: Towards Control of Taenia multiceps, an Emerging Threat to Small Ruminants’ Productivity
(Preprints, 2024-02-20) Kibona, Tito; Buza, Joram; Shirima, Gabriel
Taeniid infections pose a significant threat to both animal and public health, as certain tapeworms within this group can also infect humans, potentially leading to severe health conditions. Therefore, this calls for preventive and control measures, such as regular deworming of dogs. While the efficacy of deworming has been established in developed countries, there is a paucity of reported deworming practices in rural areas of developing countries, such as Tanzania. This study aims to understand determinants for helminth treatment-seeking behavior towards control of cestodial taeniid infections in rural settings in northern Tanzania. A cross-sectional study was undertaken in agropastoral and pastoral areas of northern Tanzania. Comprehensive data from household surveys in selected sub-villages were collected to ascertain dog ownership, dog deworming practices, and the availability of dewormers. Analytical methods were employed to discern how various determinants influenced deworming practices among dog owners in these communities. Awareness of dewormers specifically formulated for dogs emerged as a pivotal factor affecting dog deworming practices. Dog owners who were informed about appropriate dog dewormers were nearly two times more likely to engage in deworming compared to those with limited knowledge (OR = 1.78, 95% CI 1.77 - 4.18, p < 0.001). A majority 32(51.6%, 95% CI: 38.7-64.3) acknowledged accessing dewormers for livestock within their wards. Praziquantel a potent dewormer on cestodes was least known to most dog owners 2(13%, 95% CI: 2.3-41.6). Praziquantel, a potent and common dewormer effective against cestodial taeniid infections, remains relatively unknown in rural areas of northern Tanzania. Therefore, more awareness on appropriate deworming agents against taeniids in dogs should be raised in rural dog-keeping communities