NRU :: Browsing by Author "Kirunda, Halid"

Browsing by Author "Kirunda, Halid"

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Disparate thermostability profiles and HN gene domains of field isolates of Newcastle disease virus from live bird markets and waterfowl in Uganda
(Virology Journal, 2016) Omony, John B.; Wanyana, Agnes; Mugimba, Kizito K.; Kirunda, Halid; Nakavuma, Jessica L.; Otim-Onapa, Maxwell; Byarugaba, Denis K.
Uganda poultry production is still faced with frequent outbreaks of Newcastle disease (ND) in the backyard free-range systems despite the accessibility of cross protective vaccines. Live bird markets and waterfowl has long been reported as a major source of disease spread as well as potential sources of avirulent strains that may mutate to virulent strains. ND-virus has been reported enzootic in Ugandan poultry but limited studies have been conducted to ascertain thermostability phenotypes of the Ugandan ND-virus strains and to understand how these relate to vaccine strains. Methods: This study evaluated thermostability of 168 ND-virus field isolates recovered from live bird markets and waterfowls in Uganda compared to two live commercial vaccine strains (I2 and LaSota) by standard thermostability procedures and Hemagglutinin-Neuraminidase (HN) gene domains. The known pathotypes with thermostability profiles were compared at HN amino acid sequences. Results: Field isolates displayed disparate heat stability and HN gene domains. Thermolabile isolates were inactivated within 15 min, while the most thermostable isolates were inactivated in 120 min. Four thermostable isolates had more than 2 log2 heamaglutinin (HA) titers during heat treatment and the infectivity of 9.8 geometric mean of log10 EID50 % in embryonated eggs. One isolate from this study exhibited a comparable thermostability and stable infectivity titers after serial passages, to that of reference commercial vaccine was recommended for immunogenicity and protection studies. Conclusion: The occurrence of ND-virus strains in waterfowl and live bird markets with disparate thermostability and varying HN gene domains indicate circulation of different thermostable and thermolabile ND-virus pathotypes in the country.
Geographic distribution of non-clinical Theileria parva infection among indigenous cattle populations in contrasting agro-ecological zones of Uganda: implications for control strategies
(Parasites & vectors, 2014) Kabi, Fredrick; Masembe, Charles; Muwanika, Vincent B.; Kirunda, Halid; Negrini, Riccardo
Non-clinical Theileria parva infection among indigenous cattle occurs upon recovery from primary disease during the first year of life. Continuous exposure to infection through contaminated tick infestations with absence of clinical disease gives rise to endemic stability. Endemic stable populations may become sources of infection if contaminated tick vectors are shared with susceptible exotic cattle. This study aimed at establishing a nationwide distribution of non-clinical T. parva infection among indigenous cattle populations to inform novel control strategies. Methods: The occurrence of non-clinical T. parva infection among apparently healthy 925 indigenous cattle from 209 herds spread out in 10 agro-ecological zones (AEZs) was determined using a nested PCR assay. The influence of AEZ, breed, sex, age and farmers’ ranking of ECF importance were interrogated for influence of non-clinical parasite occurrence. Results: The overall prevalence of non-clinical T. parva infection was 30% (278/925). A gradual increase of non-clinical T. parva infection was observed ranging from 17% (95% CI: 0.03 – 0.23) to 43% (95% CI: 0.3 – 0.55) in the North Eastern Savannah Grasslands (NESG) to the Western Highland Ranges (WHR) respectively. A similarly associated 18% (95% CI: 0.07 – 0.28) and 35% (95% CI: 0.3 – 0.39) non-clinical parasite prevalence was observed among the East African shorthorn Zebu (EASZ) and Ankole cattle respectively. Average herd level non-clinical T. parva prevalence was 28%, ranging from zero to 100%. The likelihood of non-clinical T. parva infection was 35.5% greater in the western highlands compared to the northeastern semi-arid AEZs. Conclusions: Non-clinical T. parva occurs countrywide, structured along patterns of AEZ and breed gradients. These findings may guide policy formulation, deployment of integrated control strategies and local cattle improvement programs.
High pathogenicity and low genetic evolution of avian paramyxovirus type I (Newcastle disease virus) isolated from live bird markets in Uganda
(Virology Journal, 2014) Byarugaba, Denis K.; Mugimba, Kizito K.; Omony, John B.; Okitwi, Martin; Wanyana, Agnes; Otim, Maxwell O.; Kirunda, Halid; Nakavuma, Jessica L.; Teillaud, Angélique; Paul, Mathilde C.; Ducatez, Mariette F.
Newcastle disease is still a serious disease of poultry especially in backyard free-range production systems despite the availability of cross protective vaccines. Healthy-looking poultry from live bird markets have been suspected as a major source of disease spread although limited studies have been conducted to ascertain the presence of the virulent strains in the markets and to understand how they are related to outbreak strains. Methods: This study evaluated the occurrence of Newcastle disease virus in samples collected from poultry in live bird markets across Uganda. The isolates were pathoyped using standard methods (mean death time (MDT), intracelebral pathogenicity index (ICPI), and sequencing of the fusion protein cleavage site motif) and also phylogenetically analysed after sequencing of the full fusion and hemagglutin-neuraminidase genes. The isolates were classified into genotypes and subgenotypes based on the full fusion protein gene classification system and compared with other strains in the region and world-wide. Results: Virulent avian paramyxovirus type I (APMV-1) (Newcastle disease virus) was isolated in healthy-looking poultry in live bird markets. The viruses belonged to a new subgenotype, Vd, in genotype V, and clustered together with Tanzania and Kenya strains. They harbored low genetic diversity. Conclusion: The occurrence of virulent AMPV-1 strains in live bird markets may serve as sources of Newcastle disease outbreaks in non-commercial farms
Inspiring Anti-Tick Vaccine Research, Development and Deployment in Tropical Africa for the Control of Cattle Ticks: Review and Insights
(Vaccines, 2022) Kasaija, Paul D.; Kirunda, Halid; Nanteza, Ann; Kabi, Fredrick; Mugerwa, Swidiq; Fuente, José de la
Ticks are worldwide ectoparasites to humans and animals, and are associated with numerous health and economic effects. Threatening over 80% of the global cattle population, tick and tick-borne diseases (TTBDs) particularly constrain livestock production in the East, Central and Southern Africa. This, therefore, makes their control critical to the sustainability of the animal industry in the region. Since ticks are developing resistance against acaricides, anti-tick vaccines (ATVs) have been proposed as an environmentally friendly control alternative. Whereas they have been used in Latin America and Australia to reduce tick populations, pathogenic infections and number of acaricide treatments, commercially registered ATVs have not been adopted in tropical Africa for tick control. This is majorly due to their limited protection against economically important tick species of Africa and lack of research. Recent advances in various omics technologies and reverse vaccinology have enabled the identification of many candidate anti-tick antigens (ATAs), and are likely to usher in the next generation of vaccines, for which Africa should prepare to embrace. Herein, we highlight some scientific principles and approaches that have been used to identify ATAs, outline characteristics of a desirable ATA for vaccine design and propose the need for African governments to investment in ATV research to develop vaccines relevant to local tick species (personalized vaccines). We have also discussed the prospect of incorporating anti-tick vaccines into the integrated TTBDs control strategies in the sub-Saharan Africa, citing the case of Uganda.
Monitoring the Subolesin Vaccine Field Trial for Safer Control of Cattle Ticks Amidst Increasing Acaricide Resistance in Uganda
(Vaccines, 2022) Kabi, Fredrick; Dhikusooka, Moses; Matovu, Moses; Mugerwa, Swidiq; Kasaija, Paul; Emudong, Patrick; Kirunda, Halid; Contreras, Marinela; Gortazar, Christian; De la Fuente, Jose
A collaboration program was established between the group of Health and Biotechnology (SaBio) of the IREC Institute of Game and Wildlife Research (CSIC-UCLM-JCCM, Spain) and the National Agricultural Research Organization of Uganda (NARO) for the development of vaccines for the control of cattle ticks in Uganda. Controlled pen trials identified a tick protective antigen, Rhipicephalus appendiculatus Subolesin, and a cross-species-effective vaccine formulation. As the next step, a controlled vaccine field trial has been approved by Ugandan state regulatory authorities, the Uganda National Council for Science and Technology (UNCST) and the National Drug Authority (NDA), to evaluate the efficacy and effectiveness of the vaccine formulation for the control of cattle tick infestations under field conditions. The results of this trial may lead to the approval of the vaccine for application in Uganda to improve cattle health and production while reducing the use of acaricides.
Poor biosecurity in live bird markets in Uganda: A potential risk for highly pathogenic avian influenza disease outbreak in poultry and spread to humans
(Avian Diseases, 2014) Kirunda, Halid; Kibuuka, Hannah; Byaruhanga, Achilles; Mworozi, Edison; Bwogi, Josephine; Lukwago, Luswa,; Millard, Millard; Wabwire-Mangen, Fred; Byarugaba, Denis K.
Live bird markets (LBMs) are essential for marketing of poultry, but can be a hub for the rapid spread of diseases including avian influenza (AI). We assessed the status of biosecurity in 108 LBMs in 37 districts of Uganda. In all LBMs, carcasses were disposed of in the open and birds were introduced in the markets without initial quarantine. A high proportion of markets lacked a dedicated site for unloading of birds (86.1%) and a programme for disinfection (99.1%), had dirty feed/water troughs (93.5%), were accessed by stray animals (97.2%), and had sick and healthy birds (96.3%) or different bird species (86.1%) sold together. Differences in practices occurred among geographical regions and market location. Birds were more likely to be slaughtered in the open in urban compared to rural LBMs (OR=14.6, 95% CI: 1.50 - 142), while selling of un-caged birds was less likely in central compared to western region (OR=0.2, 95% CI: 0.04 - 0.17). Different poultry species confined in the same cage were more likely to be sold in urban (OR=22, 95% CI: 1.14 - 435) compared to rural markets. We conclude that LBMs in Uganda are a potential risk for spread of AI to poultry and humans.
Prevalence of influenza A viruses in livestock and free-living waterfowl in Uganda
(BMC Veterinary Research, 2014) Kirunda, Halid; Erima, Bernard; Tumushabe, Agnes; Kiconco, Jocelyn; Tugume, Titus; Mulei, Sophia; Mimbe, Derrick; Mworozi, Edison; Bwogi, Josephine; Luswa, Lukwago; Kibuuka, Hannah; Millard, Monica; Byaruhanga, Achilles; Ducatez, Mariette F.; Krauss, Scott; Webby, Richard J.; Webster, Robert G.; Wurapa, Kofi; Byarugaba, Denis K.; Wabwire-Mangen, Fred
Avian influenza viruses may cause severe disease in a variety of domestic animal species worldwide, with high mortality in chickens and turkeys. To reduce the information gap about prevalence of these viruses in animals in Uganda, this study was undertaken. Results: Influenza A virus prevalence by RT-PCR was 1.1% (45/4,052) while sero prevalence by ELISA was 0.8% (24/2,970). Virus prevalence was highest in domestic ducks (2.7%, 17/629) and turkeys (2.6%, 2/76), followed by free-living waterfowl (1.3%, 12/929) and swine (1.4%, 7/511). A lower proportion of chicken samples (0.4%, 7/1,865) tested positive. No influenza A virus was isolated. A seasonal prevalence of these viruses in waterfowl was 0.7% (4/561) for the dry and 2.2% (8/368) for the wet season. In poultry, prevalence was 0.2% (2/863) for the dry and 1.4% (24/1,713) for the wet season, while that of swine was 0.0% (0/159) and 2.0% (7/352) in the two seasons, respectively. Of the 45 RT-PCR positive samples, 13 (28.9%) of them were H5 but none was H7. The 19 swine sera positive for influenza antibodies by ELISA were positive for H1 antibodies by HAI assay, but the subtype(s) of ELISA positive poultry sera could not be determined. Antibodies in the poultry sera could have been those against subtypes not included in the HAI test panel. Conclusions: The study has demonstrated occurrence of influenza A viruses in animals in Uganda. The results suggest that increase in volumes of migratory waterfowl in the country could be associated with increased prevalence of these viruses in free-living waterfowl and poultry.
Risk factors for human anthrax outbreak in Kiruhura District, Southwestern Uganda: a population-based case control study
(PAMJ - One Health, 2021) Migisha, Richard; Mbatidde, Irene; Agaba, David C.; Turyakira, Eleanor; Tumwine, Gabriel; Byaruhanga, Aggrey; Siya, Aggrey; Ruzaaza, Gad N.; Kirunda, Halid
Introduction: in 2018, Uganda experienced recurrent outbreaks of anthrax in both humans and livestock. We aimed to determine risk factors for human anthrax outbreak among residents of Kazo County, Kiruhura District, south-western Uganda. Methods: we conducted an unmatched case control study during March-April 2019. We defined a case as having had anthrax infection reported to be diagnosed by a healthcare worker in a resident of Kazo County between May 1st, 2018 and June 1st, 2018. A control was a resident in the nearest neighboring household who had not been diagnosed with anthrax between May 1st and June 1st and who had no symptoms suggestive of anthrax in May 2018. We obtained participants' sociodemographic, clinical and exposure characteristics using a structured questionnaire. We performed logistic regression to identify risk factors for human anthrax. Results: we recruited 101 participants (28 cases and 73 controls) with median age of 34 (IQR; 26-47) years; most (61.4%) were female. The overall attack rate was 1.9%, while the most common clinical manifestations were ulcers (96.4%) and fever (96.4%). The risk factors for contracting human anthrax were: slaughtering of anthrax infected animals (aOR=5.74; 95%CI: 1.39-23.8), consuming of anthrax infected meat (aOR=6.4; 95%CI: 1.53- 6.7) and being male (aOR=12.8; 95%CI: 3.31-49.1).

Browsing by Author "Kirunda, Halid"

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