Publications by authors named "Saasa Ngonda"
Article Synopsis
- * Our findings identified new or previously unclassified viruses, including murine adenovirus 4 and two new species from the paramyxovirus and picornavirus families.
- * The study highlights rodents as significant carriers for potential zoonotic viruses, which could pose risks to human health in the future.
Wastewater-based surveillance has emerged as an important method for monitoring the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). This study investigated the presence of SARS-CoV-2 in wastewater in Zambia. We conducted a longitudinal study in the Copperbelt and Eastern provinces of Zambia from October 2023 to December 2023 during which 155 wastewater samples were collected.
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- Enteric infections from viral pathogens like rotavirus and adenovirus are a significant public health issue, prompting the need for effective surveillance systems in wastewater to identify risk areas.
- In Zambia, researchers tested wastewater samples using different methods to concentrate viruses, resulting in a high detection rate (90% for HAdV and 70% for RVA) through molecular techniques.
- The study concluded that certain concentration methods, particularly skimmed milk flocculation and bag-mediated filtration, could be beneficial for ongoing surveillance in resource-limited settings, highlighting the importance of monitoring these pathogens in the community.
Article Synopsis
- Poultry production is crucial for many rural Zambian households, but it's threatened by infectious diseases, especially Newcastle disease virus (NDV).
- The study sequenced six NDV isolates from poultry in live bird markets and wild waterfowl, discovering that the poultry isolates belonged to virulent strains, while those from wild birds were avirulent and likely introduced from Eurasia.
- This research highlights ongoing NDV circulation in Zambia's live bird markets and emphasizes the need for ongoing surveillance to monitor NDV evolution and potential outbreaks.
Article Synopsis
- Rotavirus significantly contributes to diarrhea in young children and animals globally, prompting a study on porcine rotavirus in Zambia's pig farms.
- The research analyzed 148 stool samples, finding a 22.9% prevalence rate for rotavirus, and further genetic testing revealed strains with similarities to both porcine and human rotavirus.
- The findings suggest potential gene reassortment and interspecies transmission between pigs and humans, advocating for a "One Health" approach to better monitor and control rotavirus in both populations.
Objectives: To determine the prevalence of COVID-19 postmortem setting in Lusaka, Zambia.
Design: A systematic, postmortem prevalence study.
Setting: A busy, inner-city morgue in Lusaka.
The epidemiology of Rift Valley fever (RVF) is poorly understood in Malawi. Here, a cross-sectional study was conducted (March-June 2020) to investigate the seroprevalence and potential risk factors of RVF virus (RVFV) in cattle, goats, and sheep in three ecological zones of Malawi. A total of 1523 serum samples were tested for anti-RVFV IgG and IgM antibodies by ELISA.
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- A lot of money has been spent on studying the COVID-19 virus in Africa, leading to over 100,000 virus samples being analyzed to understand the spread of the disease.
- *More countries in Africa are now able to do these studies themselves, which helps them get results faster and keep a close watch on the virus.
- *To keep fighting COVID and other diseases, more funding and support for testing and research in Africa is really important for the future.
During a COVID-19 outbreak in a prison in Zambia from December 14 to 19, 2021, a case-control study was done to measure vaccine effectiveness (VE) against infection and symptomatic infection, when the Omicron variant was the dominant circulating variant. Among 382 participants, 74.1% were fully vaccinated, and the median time since full vaccination was 54 days.
View Article and Find Full Text PDFRift Valley fever (RVF) is a mosquito-borne viral zoonosis whose cases go unreported in endemic areas without active surveillance. Information on the knowledge, attitude, and practice of RVF among livestock farmers remains speculative in Malawi. A cross-section survey using a semi-structured questionnaire ( = 400) was conducted in eight districts of Malawi to capture information on knowledge, attitude, and management practices (KAP) regarding RVF.
View Article and Find Full Text PDFTick-borne diseases (TBDs), including emerging and re-emerging zoonoses, are of public health importance worldwide; however, TBDs tend to be overlooked, especially in countries with fewer resources, such as Zambia and Angola. Here, we investigated , , and Apicomplexan pathogens in 59 and 96 adult ticks collected from dogs and cattle, respectively, in Shangombo, a town at the Zambia-Angola border. We detected and in 15.
View Article and Find Full Text PDFWe conducted a systematic review and meta-analysis to investigate the prevalence and current knowledge of influenza A virus (IAV) and influenza D virus (IDV) in non-human mammalian hosts in Africa. PubMed, Google Scholar, Wiley Online Library and World Organisation for Animal Health (OIE-WAHIS) were searched for studies on IAV and IDV from 2000 to 2020. Pooled prevalence and seroprevalences were estimated using the quality effects meta-analysis model.
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- The SARS-CoV-2 pandemic in Africa has varied significantly across countries, and its overall impact remains unclear.
- An analysis of 8,746 genomes from 33 African countries indicated that most outbreaks originated from Europe before international travel restrictions took effect.
- As the pandemic continued, increased movement and local transmission led to the emergence of several variants within Africa, emphasizing the need for a strong pandemic response on the continent to prevent becoming a source of new variants.
Article Synopsis
- The study investigated the prevalence of Cryptosporidium infections in 490 children under five years old in Zambia, finding a 10% overall infection rate, particularly peaking during the late rainy season in March.
- Key risk factors for infection included not boiling water and having recurrent diarrhoea episodes, with children from households neglecting water treatment being 2.5 times more likely to be infected.
- Genotyping of infected samples revealed a predominance of Cryptosporidium hominis, indicating a significant anthroponotic transmission in both urban and rural areas surrounding Lusaka.
Article Synopsis
- Ticks are blood-feeding ectoparasites that host various microorganisms, including both pathogens and beneficial symbionts that aid in their growth and reproduction.
- A study in Zambia screened 175 ticks from six different genera for the presence of a specific type of beneficial symbionts, called CLEs, finding that 45.7% were positive.
- The research indicated a strong evolutionary connection between the ticks and their symbionts, supporting the idea that these CLEs are passed down through generations, but also highlighted the need to explore other potential microorganisms in Zambian ticks.
Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne zoonosis with a high case fatality rate in humans. Although the disease is widely found in Africa, Europe, and Asia, the distribution and genetic diversity of CCHF virus (CCHFV) are poorly understood in African countries. To assess the risks of CCHF in Zambia, where CCHF has never been reported, epidemiologic studies in cattle and ticks were conducted.
View Article and Find Full Text PDFDetection of B.1.351 SARS-CoV-2 Variant Strain - Zambia, December 2020.
MMWR Morb Mortal Wkly Rep
February 2021
Article Synopsis
- COVID-19 cases in Zambia began in March 2020, with a significant rise starting in mid-December, particularly after the identification of the B.1.351 variant strain from South Africa.
- The B.1.351 variant, linked to increased transmissibility, spread quickly from South Africa to other countries, including Zambia, causing a dramatic surge in cases.
- By January 10, 2021, Zambia experienced a 16-fold increase in daily COVID-19 cases, from 44 to 700, coinciding with the presence of the B.1.351 variant in the region.
Article Synopsis
- COVID-19, caused by the SARS-CoV-2 virus, was first discovered in Wuhan, China, in December 2019 and has rapidly spread worldwide.
- Initially, African countries had low COVID-19 cases, but travel links led to the emergence of new cases, like the one identified in Zambia shortly after a traveler returned from France.
- Phylogenomic analysis revealed the strain in Zambia belonged to lineage B.1.1 and emphasized the importance of whole genome sequencing in monitoring the evolution of SARS-CoV-2 across Africa.
In the recent past, sub-Saharan Africa has not escaped the devastating effects of avian influenza virus (AIV) in poultry and wild birds. This systematic review describes the prevalence, spatiotemporal distribution, and virus subtypes detected in domestic and wild birds for the past two decades (2000-2019). We collected data from three electronic databases, PubMed, SpringerLink electronic journals and African Journals Online, using the Preferred Reporting Items for Systematic reviews and Meta-Analyses protocol.
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- * This study analyzed 76 RNA samples from various animals and humans to assess the genetic diversity of rabies, confirming that all strains in the region belong to the Africa 1b lineage and identifying two distinct phylogenetic clusters.
- * The research indicated geographical separation between Zambian and Zimbabwean strains, with evidence of similar virus strains circulating in both wildlife (like jackals) and domestic animals, but no strains from Zimbabwe were found in Zambia.
Rift Valley fever (RVF) is a zoonotic mosquito-borne disease caused by RVF virus (RVFV) that causes abortions and high mortalities in livestock and is also associated with acute and fatal disease in humans. In the Democratic Republic of Congo (DRC), information on the epidemiology of RVF is limited, particularly among cattle reared by smallholder farmers. This cross-sectional study was conducted to investigate the seroprevalence of RVF in cattle raised by smallholder farmers in Kwilu Province of DRC, which has not yet reported an RVF epidemic.
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- A study investigated canine parvovirus (CPV) infections in diarrheic dogs in Zambia, where previous data on the virus was limited.
- The research tested 32 fecal samples and found that 71.9% were positive for CPV, predominantly the CPV-2c strain (91.3%).
- This study is significant as it represents the first genetic characterization of CPV in Zambia, showing a distinct phylogenetic cluster compared to previous findings in other African countries.
Aim: is one of the causes of diarrheal illness in man and animals worldwide and is zoonotic. The study aimed to determine the prevalence and risk factors associated with fecal shedding of oocysts in dogs in Lusaka district of Zambia.
Materials And Methods: A cross-sectional study was conducted in Lusaka district of Zambia during 2015-2016.
The open reading frame of the nucleocapsid protein (NP) of Rift Valley fever virus (RVFV) strain MP12 was cloned and expressed in Vero E6 cells. The recombinant NP (rNP)-expressing cells were used as antigens for an indirect immunofluorescent antibody assay (IFA). The rNP-based IFA and RVFV-infected Vero E6 cell (authentic antigen)-based IFA showed similar IFA profiles with immune rabbit serum, which was prepared by immunization with rNP expressed using a baculovirus vector.
View Article and Find Full Text PDFTick-borne diseases (TBDs), including emerging and re-emerging infectious diseases, are important threats to human and animal health worldwide. Indeed, the number of reported human and animal infectious cases of novel TBD agents has increased in recent decades. However, TBDs tend to be neglected, especially in resource-limited countries that often have limited diagnostic capacity.
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