George Omondi Oluoch

Dr. George Omondi Oluoch

orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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28 October 2022 in Toxicon: X
Verified
Journal Article
Open access
JSJonathan Steinhorst
Jonathan Steinhorst
FTFrank-Leonel Tianyi
Frank-Leonel Tianyi
AHAbdulrazaq Garba Habib
Abdulrazaq Garba Habib
GOGeorge Omondi Oluoch
George Omondi Oluoch
DLDavid G. Lalloo
David G. Lalloo
YSYmkje Stienstra
Ymkje Stienstra
Snakebite envenoming is an acute medical emergency which affects hundreds of thousands of people worldwide, primarily in remote rural areas of low-and middle income countries in the Global South. A considerable proportion of snakebite patients turn to traditional healers (THs) for help, driven by a number of push and pull factors. These include socio-cultural factors, geographical proximity, and the absence or inaccessibility of overstretched and often costly allopathic healthcare services. Although traditional healers and allopathic healthcare staff share a common focus -the recovery and well-being of their patients- both systems operate largely in parallel to each other with collaborations being an exception rather than the rule. This is to the detriment of snakebite patients, who frequently find themselves being caught-up in the dualism between the two separate systems. Given the right circumstances, snakebite patients could benefit from elements of care from both modalities. Here, we have reviewed the role of THs in snakebite care and explored how their integration into the formal healthcare system could improve the implementation and outcome of care. The effective recruitment of THs to aid in disease control and treatment efforts in diseases other than snakebite underscores the potential benefits of this strategy. Carefully devised proof of concept studies are needed to test our hypothesis that collaborations between the formal healthcare sector and THs are feasible and improve outcomes in snakebite care.

22 March 2022 in Toxins
Verified
Journal Article
Open access
PDF file
JAJaffer Ali Alsolaiss
Jaffer Ali Alsolaiss
CEChloe A. Evans
Chloe A. Evans
GOGeorge Omondi Oluoch
George Omondi Oluoch
NCNicholas Casewell
Nicholas Casewell
RHRobert Harrison
Robert Harrison
Snake envenoming causes rapid systemic and local effects that often result in fatal or long-term disability outcomes. It seems likely that acute phase and inflammatory responses contribute to these haemorrhagic, coagulopathic, neurotoxic, nephrotoxic and local tissue destructive pathologies. However, the contributory role of acute phase/inflammatory responses to envenoming is under-researched and poorly understood—particularly for envenoming by sub-Saharan African venomous snakes. To provide data to help guide future studies of human patients, and to explore the rationale for adjunct anti-inflammatory medication, here we used an in vivo murine model to systematically assess acute phase and inflammatory responses of mice to ten African snake venoms. In addition to investigating snake species-specific effects of venom on the cardiovascular system and other key organs and tissues, we examined the response to intravascular envenoming by acute phase reactants, including serum amyloid A, P-selectin and haptoglobin, and several cytokines. Venoms of the spitting (Naja nigricollis) and forest (N. melanoleuca) cobras resulted in higher acute phase and inflammatory responses than venoms from the other cobras, mambas and vipers tested. Naja nigricollis venom also stimulated a 100-fold increase in systemic interleukin 6. Thin blood films from venom-treated mice revealed species-specific changes in red blood cell morphology, indicative of membrane abnormalities and functional damage, lymphopenia and neutrophil leukocytosis. Our ex vivo assays with healthy human blood treated with these venoms identified that N. nigricollis venom induced marked levels of haemolysis and platelet aggregation. We conclude that African snake venoms stimulate very diverse responses in this mouse model of acute systemic envenoming, and that venoms of the African cobras N. nigricollis and N. melanoleuca, in particular, cause marked inflammatory and non-specific acute phase responses. We also report that several African snake venoms cause haemolytic changes. These findings emphasise the importance of understanding acute responses to envenoming, and that further research in this area may facilitate new diagnostic and treatment approaches, which in turn may lead to better clinical outcomes for snakebite patients.

22 July 2022 in Preprints.org
Verified
Preprint
Open access
PDF file
HTHeshborne Sheltone Tindih
Heshborne Sheltone Tindih
IOIsaiah Obara
Isaiah Obara
MAMarcello Alessandro
Marcello Alessandro
MAMercy Matindi Akinyi
Mercy Matindi Akinyi
JNJohn Nyambega
John Nyambega
GOGeorge Omondi Oluoch
George Omondi Oluoch
The severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), etiological agent of the novel coronavirus disease 2019 (COVID-19), has spread since December 2019, resulting in massive health and economic crisis worldwide. While efforts to stop the pandemic are crucial, collecting epidemiological data to help manage current and future pandemics will be important. In addition to humans, serological and molecular based studies have demonstrated SARS CoV-2 exposure in several wild, domestic and farmed animals. For examples Shriner and the team showed serologically an exposure of 40% to the white deer living in close proximity to urban centers. Additional reports have also emerged of susceptibility of animal’s species like cats, ferrets, raccoon dogs, cynomolgus macaques, rhesus macaques, white-tailed deer, rabbits, Egyptian fruit bats, and Syrian hamsters to SARS-CoV-2 infection.. It’s worth emphasizing that these reports are based on experimental data mostly derived from Europe, USA, South America and parts of Asia. In limited instances natural infections of SARS-CoV-2 have been reported in pet dogs, cats, tigers, lions, snow leopards, pumas, gorillas at zoos and farmed mink and ferrets. The presence of the virus in animal species and an understanding of whether these are natural or recent human to animal transmissions is important. It’s possible that such transmission could passage the virus or subject the virus to a different immunological pressure thereby helping with the development of viral variants in addition to being a host for future reservoirs of the virus. In Kenya SARS-CoV-2 was first detected on March 12th 2020 from imported human cases of persons who had travelled from the United States. This was followed by detection of imported cases majorly from China, Sweden and United Kingdom. Later infections were confirmed in Nairobi and Mombasa suggesting further cases of disease importations through the major ports of entry. However, no comparable data on animal exposure have hitherto been generated in Kenya. To address this key concern, we focused on three objectives; 1) development of a robust antibody ELISA based on crude SARS-CoV-2 lysate. 2) SARS-CoV-2 serology of domestic animals in Kenya. 3) Corroboration of the crude lysate based seroprevalence data and a commercial ELISA kit based on the Spike receptor binding domain (RBD) antigen. Our sample set included camel sera (both pre- & post outbreak sera), as well as sera from cats and dogs collected at the peak of the pandemic. Our results using the ELISA based on crude SARS-CoV-2 lysate indicated SARS-CoV-2 antibodies in camels (71%, N=145), cats 11% (N=16) and dogs (81%, N=36) with varying titer levels. These findings were comparable to those obtained using the commercial ELISA kit based on the spike RBD antigens. In summary, the data warrants two key conclusions: (i) we have demonstrated that the crude lysate ELISA allows for SARS-CoV-2 antibody detection, and given its potential to offer robust detection could be applied for initial mass screening (ii) although the current study cannot disentangle the relative contributions of antigenic cross-reactivity, pre-pandemic exposure to SARS-CoV-2 or human-animal transmission, it nonetheless demonstrates for the first time the prevalence of SARS-CoV-2 like antibodies in domestic and wild animals in Kenya. Our findings set the scene for further research into the prevalence of SARS-CoV-2 in domestic and wild animals to understand their potential epidemiological implications.

19 February 2026 in Toxins
Verified
Journal Article
Open access
PDF file
VMValentine Musabyimana
Valentine Musabyimana
JKJohn Kagira
John Kagira
Jacob LubuyaJacob Lubuya
Jacob Lubuya
CNCaroline Wangari Ngugi
Caroline Wangari Ngugi
BMBrian M. Musau
Brian M. Musau
GOGeorge Omondi Oluoch
George Omondi Oluoch
Antivenom administration is currently the only therapy for snakebite envenoming. However, in sub-Saharan Africa, inadequate quality control systems have led to deficits in the availability, accessibility, efficacy and safety of regionally available antivenoms, which, in turn, hinder snakebite treatment and management in the region. To address this impediment to snakebite treatment in Kenya, this study aimed to assess the preclinical neutralising potencies of four different antivenoms previously or currently available in Kenya (SAIMR polyvalent, AFRIVEN, PANAF-PremiumTM and InoserpTM) against key snakes of medical importance in the region, towards establishing a national antivenom quality control laboratory. Venoms were extracted from the Kenyan “big five” medically important snake species: Naja ashei, Naja pallida, Naja nigricollis, Dendroaspis polylepis and Bitis arietans, and their lethal potencies were determined using a murine median lethal dose (LD50) assay. In vitro immunological assays (ELISAs and immunoblotting) and an established preclinical murine in vivo neutralisation assay (median effective dose [ED50]) were used to assess the immunoglobulin-binding and venom-neutralising efficacies of the test antivenoms. In vitro assays revealed high venom-binding titres of SAIMR polyvalent, AFRIVEN and PANAF-PremiumTM, and reactivity to a wide range of venom proteins across the different snake venoms. Contrastingly, InoserpTM antivenom had low binding titres and poor reactivity to the snake venom proteins. These findings were aligned with the in vivo results, where SAIMR polyvalent, AFRIVEN and PANAF-PremiumTM showed potent venom-neutralising efficacies against all the tested snake venoms, while InoserpTM had low potency and failed to neutralise the lethal effects of N. ashei, N. pallida and D. polylepis venoms at the manufacture-claimed doses. Based on these robust preclinical results, we conclude that SAIMR polyvalent, AFRIVEN and PANAF-PremiumTM antivenoms offer considerable potential for the treatment of envenoming by diverse medically important snakes in Kenya. The observed deficiencies with the InoserpTM product highlight the importance of (i) robust, independent preclinical antivenom efficacy testing and (ii) the value of establishing a quality control laboratory to inform local regulatory and procurement decision making.

22 February 2026 in Methods and Protocols
Verified
Journal Article
Open access
PDF file
WOWathuto Ogopotse
Wathuto Ogopotse
VMValentine Musabyimana
Valentine Musabyimana
PKPamela M. Khasandi
Pamela M. Khasandi
DKDennis Kotti
Dennis Kotti
MNMaina Ngotho
Maina Ngotho
GOGeorge Omondi Oluoch
George Omondi Oluoch
Caprylic acid (CA) fractionation of serum is a simple and cost-effective method of producing high-quality immunoglobulins. While standardised procedures exist for CA purification of IgG for various animals, no published protocol exists for baboon IgG. This study aimed to optimise an efficient protocol for purifying IgG from baboon serum using CA through a stepwise one-factor-at-a-time (OFAT) approach. The effects of serum pH, CA concentration, stirring time and intensity, dialysis buffer, and lyophilisation were evaluated based on the protein content, with SDS-PAGE profiles and albumin–globulin ratios distinguishing IgG from residual albumin. Serum at pH 5.0 with 7% CA (v/v) produced the highest yield, minimising albumin while maximising IgG content. Lower pH (4.0–4.5) and CA (5–6%) reduced protein content, while a higher pH (5.5–6.0) and CA (8–15%) increased protein, but with elevated albumin and contaminants. Stirring serum vigorously at 1200 rpm for 60 min provided effective precipitation of non-IgG proteins. Lower intensities and shorter times resulted in higher albumin and residual proteins, while excessive stirring caused protein denaturation. Dialysis buffer composition had little impact, while lyophilisation significantly enhanced IgG concentration. The optimal protocol involved serum at pH 5.0, 7% CA (v/v), vigorous stirring (1200 rpm) for 60 min, and dialysis against sodium phosphate buffer (pH 7.4) followed by lyophilisation. The resulting IgG enrichment and purity were comparable to commercial-grade products. This study thus established optimal conditions for the purification of baboon IgG with CA, which could be used to support research in this animal model of immunology.