PhD Study Investigates Immune Responses to Carriage of Enteric Pathogens

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Dr Agness Farai Nhidza feels greatly humbled and hopes to continue with her Post-Doctoral studies in molecular immunology and bioinformatics, if the opportunity arises.

Nhidza recently graduated with her PhD in Medical Microbiology in the School of Laboratory Medicine and Medical Sciences under the supervision of Professors Takafira Mduluza and Thajasvarie Naicker.

The biologist, who hails from Zimbabwe, was led to her research topic as a result of challenges related to diarrheal disease outbreaks in the country (Zimbabwe) and sub-Saharan Africa. ‘My PhD study experience was awesome although I encountered financial challenges. The support for reagents and other critical needs for the study was also not enough,’ she said.

Nhidza’s novel study looked at immunological effects of asymptomatic enteric pathogens, in particular, Salmonella typhi, Vibrio cholerae and Entamoeba histolytica in mother-baby pairs in an HIV burdened setting in Harare, Zimbabwe. The study first looked at the prevalence of these asymptomatic disease causing organisms (pathogens) in the study population; followed by looking at the effects of the presence of these pathogens on one’s defense system (immunity) against the pathogens. The immunity was checked through studying cytokines and antibodies released or suppressed as a result (of these pathogens). Cytokines are substances released by the body to fight against disease-causing agents. Similarly, immunoglobulins, also known as antibodies, are released by the body to fight against disease-causing agents.

The findings were that typhoid and cholarae asymptomatic carriers in suburbs which had outbreaks in 2008 and 2012 seem to have cleared the pathogen as Nhidza found 0% prevalence for these pathogens. Asymptomatic carriers are individuals who have disease causing organisms in their bodies but do not necessarily fall sick. Alternatively, they can have very minor symptoms which can clear without treatment.

This study gives preliminary data for development of immunotherapy drugs to benefit pregnant mothers and their neonates in HIV burdened communities with exposure to E. histolytica infections. Immunotherapy drugs are medicines that prevent or treat diseases through boosting the immune system.

Before joining UKZN for her full-time PhD programme, Nhidza was the Head of a laboratory unit and a Quality Manager.

During her tenure, her then employer was accredited to ISO 15189 international standard of quality, under her co-ordination. ‘Professionally, I have good co-ordination and communication skills and pay attention to detail. I have always been an achiever and I am proud of my hard work,’ she said.

Words: Lihle Sosibo 

Photograph: Rajesh Jantilal