Epidemological investigations of rift valley fever in livestock in three ecological zones of Malawi.

ThesisDue to uncertainty on the status of Rift Valley fever (RVF) in Malawi, limited knowledge about its epidemiology, and debates on whether it is a real or perceived threat for the livestock and human population in the country, a study was formulated to investigate the epidemiology of RVF. The study was carried out between January, 2020 and July, 2020 in 8 districts of Malawi, namely Chitipa (CP), Karonga (KA), Salima (SA), Mangochi (MH), Chiradzulu (CZ), Thyolo (TO), Chikwawa (CK) and Nsanje (NE). These districts were purposively selected from three ecological zones (EZ). Across-section survey using semi-structured questionnaire (n=400), was conducted to capture knowledge, attitude and management practices (KAP) information towards RVF. Average KAP score was calculated from total scores for knowledge, attitude and practices and assessed. In addition, 1,523 whole blood samples of cattle, goat and sheep were collected and 361 livestock farmers participated in questionnaire administration to capture information on potential risk factors. Indirect competition ELISA (cELISA) and IgM Antibody Capture Enzyme-Linked Immunoassay (MAC-ELISA) were used to detect presence of Rift Valley fever virus (RVFV) antibodies in serum. Questionnaire survey and the sero-positivity data, were analyzed for quantitative results using descriptive statistics. Bivariate analysis for association was conducted using Pearson chi-square and univariate linear regression, followed by multivariate analysis using stepwise binary logistic regression to determine the predictors of knowledge and risk factors for RVFV sero-positivity. Further, molecular techniques were used to isolate and identify RVFV genome from serum that tested positive to IgM ELISA test. Participants had overall poor knowledge (score= 17.94%), negative attitude (score= 9.40%), and poor management practices (score= 41.23%) towards RVF. Only 8.25% participants had sufficient knowledge on RVF. The crude seroprevalence was 17.14%, (95% CI= 15.33-19.11) at individual livestock level. The seroprevalence across the ecological zones (EZ) were 20.34%, 11.78% and 14.55% for EZ1, EZ2 and EZ3, respectively, while seroprevalence for species were 21.35%, 7.72% and 25.68% for cattle, goat and sheep, respectively. The overall herd seroprevalence was 33.24%, (95% CI= 28.18-38.11). Sheep herd registered seroprevalence of 100% (95% CI= 73.23– 1.00) higher than cattle and goat (p=0.019), consisted of 64.29% for IgG seroprevalence and 35.71% for IgM seroprevalence herds. Further, the herd seroprevalence for EZ2 was comparatively higher at 36.36%, (95% CI= 28.6-44.55) than EZ1 34.12%, (95% CI= 24.40-45.88) and EZ3 29.32%, (95% CI= 21.92–37.95), at (p=0.047). Risk factors for RVFV seropositivity at individual livestock was sex of livestock and risk factors at herd level were areas receiving rainfall amount of <1,000mm and mixed species herds. The study demonstrated the presence of RVFV through detection of RVFV genome from three samples of livestock. Results of this study provided epidemiological information of RVF in livestock in Malawi and the available gaps in control and prevention of the disease. Therefore, the study recommends community sensitization on RVF and investigation of RVFV seroprevalence in humans working in the risky areas for better clarification of impact of predisposing factors and risky management practices observed in the study area. Further, recommends study on molecular epidemiology of RVFV in livestock, humans and mosquitoes to effectively describe the RVFV in circulation

Prescribing Patterns of Antibiotics According to the WHO AWaRe Classification during the COVID-19 Pandemic at a Teaching Hospital in Lusaka, Zambia: Implications for Strengthening of Antimicrobial Stewardship Programmes

Irrational and inappropriate prescribing of antibiotics is a major problem that can lead to the development of antimicrobial resistance (AMR). In Zambia, there is insufficient information on the prescribing patterns of antibiotics according to the World Health Organization (WHO) AWaRe classification. Therefore, this study assessed the prescribing patterns of antibiotics using the AWaRe classification during the COVID-19 pandemic at the University Teaching Hospital in Lusaka, Zambia. A cross-sectional study was conducted using 384 patient medical files at the University Teaching Hospital in Lusaka, Zambia, from August 2022 to September 2022. All antibiotics were classified according to the WHO “AWaRe” tool and assessed for appropriateness using the 2020 Zambian Standard Treatment Guidelines. Of the 384 patient medical files reviewed, antibiotics were prescribed 443 times. The most prescribed antibiotics were ceftriaxone (26.6%), metronidazole (22.6%), amoxicillin (10.4%), amoxicillin/clavulanic acid (5.6%), and azithromycin (5%). The prescribing of 42.1% of “Watch” group antibiotics was greater than the recommended threshold by the WHO. Most antibiotics were prescribed for respiratory infections (26.3%) and gastrointestinal tract infections (16.4%). The most prescribed antibiotic was ceftriaxone, a Watch antibiotic. This is a worrisome observation and calls for strengthened antimicrobial stewardship and implementation of the AWaRe framework in prescribing antibiotics

Potency of conventional comparative intradermal bovine tuberculosis test and its efficiency over interferon gamma test in mixed herd goats

Masters ThesisDiagnosis of bovine tuberculosis (BTB) in asymptomatic goats is a big challenge towards control of the disease in mixed herds. This is because not all of the available diagnostic methods in cattle are easily applicable and capable of detecting the disease in goats. In this study, two BTB diagnostic tests commonly used in cattle were employed to diagnose BTB in goats. The study established the potency and effiency of conventional comparative intraderma test (CIT) over interferon (IFN)-γ test. Goats (n= 71) and 10 cattle used in this study, were from mixed herds randomly selected from urban and periurban of Morogoro municipality. Blood sample for IFN-γ test was collected from each animal, which was immediately followed by intradermal injection of Bovine Purified Protein Derivative (PPD-Bovine) and Avian Purified Protein Derivative (PPD-Avian) 12 cm apart after proper shaving of middle third of the neck on right side. The blood samples were collected from jugular vein and investigated at the Sokoine University of Agriculture (SUA) laboratory. After 72 hours, CIT results were obtained by re-measure of the same skin fold. Results showed that CIT isolated 5 reactors while IFN-γ isolated 9 reactors from the sample size. Comparative intradermal test results proved to have no significant better potency and efficiency over the IFN-γ test (P<0.05; 95% confidence interval). Results from both tests were confirmed with pathological lesions observed in two sacrified goats. It is concluded that CIT has no peculiar potency and efficiency in diagnosis of BTB in asymptomatic goats. Therefore, IFN-γ test could be a sound option in diagnosis of BTB in carrier asymptomatic goats in a mixed herds and thus aid in a long run, the control of the disease.Southren Africa Development Community –Transboundary Animal Diseases (SADC-TADs

Potency of conventional comparative intradermal bovine tuberculosis test and its efficiency over interferon gamma test in mixed herd goats

Masters ThesisDiagnosis of bovine tuberculosis (BTB) in asymptomatic goats is a big challenge towards control of the disease in mixed herds. This is because not all of the available diagnostic methods in cattle are easily applicable and capable of detecting the disease in goats. In this study, two BTB diagnostic tests commonly used in cattle were employed to diagnose BTB in goats. The study established the potency and effiency of conventional comparative intraderma test (CIT) over interferon (IFN)-γ test. Goats (n= 71) and 10 cattle used in this study, were from mixed herds randomly selected from urban and periurban of Morogoro municipality. Blood sample for IFN-γ test was collected from each animal, which was immediately followed by intradermal injection of Bovine Purified Protein Derivative (PPD-Bovine) and Avian Purified Protein Derivative (PPD-Avian) 12 cm apart after proper shaving of middle third of the neck on right side. The blood samples were collected from jugular vein and investigated at the Sokoine University of Agriculture (SUA) laboratory. After 72 hours, CIT results were obtained by re-measure of the same skin fold. Results showed that CIT isolated 5 reactors while IFN-γ isolated 9 reactors from the sample size. Comparative intradermal test results proved to have no significant better potency and efficiency over the IFN-γ test (P<0.05; 95% confidence interval). Results from both tests were confirmed with pathological lesions observed in two sacrified goats. It is concluded that CIT has no peculiar potency and efficiency in diagnosis of BTB in asymptomatic goats. Therefore, IFN-γ test could be a sound option in diagnosis of BTB in carrier asymptomatic goats in a mixed herds and thus aid in a long run, the control of the disease.Southren Africa Development Community –Transboundary Animal Diseases (SADC-TADs

Molecular identification and genetic characterization of tick-borne pathogens in sheep and goats at two farms in the central and southern regions of Malawi

Tick-borne diseases (TBDs) caused by pathogens belonging to the genera Anaplasma, Ehrlichia, Babesia and Theileria in small ruminants are widespread in the tropical and sub-tropical countries. The epidemiology of tick borne pathogens (TBPs) in small ruminants is less understood compared to those infecting cattle in general. This study was carried out to investigate and characterize TBPs in sheep and goats using molecular tools. A total of 107 blood samples from sheep (n = 8) and goats (n = 99) were collected from animals that were apparently healthy from two farms in the central and the southern regions of Malawi. The V4 hypervariable region of the 18S ribosomal RNA gene (rDNA) and the V1 hypervariable region of the 16S rDNA polymerase chain reaction (PCR) assays were used for detection of tick-borne piroplasms and Anaplasmataceae, respectively. Almost the full-length 18S rDNA and the heat shock protein (groEL) gene sequences were used for genetic characterization of the piroplasms and Anaplasmataceae, respectively. The results showed that 76.6 % of the examined animals (n = 107) were positive for at least one TBP. The overall co-infection with at least two TBPs was observed in fortyeight animals (45 %). The detected TBPs were Anaplasma ovis (65 %), Ehrlichia ruminantium (4%), Ehrlichia canis (2%), Babesia strain closely related to Babesia gibsoni (1%), Theileria ovis (52 %), Theileria mutans (3%), Theileria separata (2%), Anaplasma sp. (1%) and Theileria sp. strain MSD-like (17 %). To the authors knowledge this is the first molecular study of TBPs in sheep and goats in Malawi. These results have therefore provided a significant milestone in the knowledge of occurrence of TBPs in sheep and goats in Malawi, which is prerequisite to proper diagnosis and control

Determination of the Prevalence and Antimicrobial Resistance of <i>Enterococcus faecalis</i> and <i>Enterococcus faecium</i> Associated with Poultry in Four Districts in Zambia

The presence of antimicrobial-resistant Enterococci in poultry is a growing public health concern worldwide due to its potential for transmission to humans. The aim of this study was to determine the prevalence and patterns of antimicrobial resistance and to detect drug-resistant genes in Enterococcus faecalis and E. faecium in poultry from four districts in Zambia. Identification of Enterococci was conducted using phenotypic methods. Antimicrobial resistance was determined using the disc diffusion method and antimicrobial resistance genes were detected using polymerase chain reaction and gene-specific primers. The overall prevalence of Enterococci was 31.1% (153/492, 95% CI: 27.1–35.4). Enterococcus faecalis had a significantly higher prevalence at 37.9% (58/153, 95% CI: 30.3–46.1) compared with E. faecium, which had a prevalence of 10.5% (16/153, 95% CI: 6.3–16.7). Most of the E. faecalis and E. faecium isolates were resistant to tetracycline (66/74, 89.2%) and ampicillin and erythromycin (51/74, 68.9%). The majority of isolates were susceptible to vancomycin (72/74, 97.3%). The results show that poultry are a potential source of multidrug-resistant E. faecalis and E. faecium strains, which can be transmitted to humans. Resistance genes in the Enterococcus species can also be transmitted to pathogenic bacteria if they colonize the same poultry, thus threatening the safety of poultry production, leading to significant public health concerns

Antibiotic Resistance Patterns of Listeria Species Isolated from Broiler Abattoirs in Lusaka, Zambia

L. monocytogenes is a public health threat linked to fast foods such as broiler chickens. This study aimed to verify the occurrence of Listeria species in chickens from abattoirs and evaluate their antimicrobial resistance. In total, 150 broiler carcass swabs distributed as cloacal (n = 60), exterior surface (n = 60), and environmental (n = 30) were collected. Listeria species were characterized using biochemical tests and PCR. We conducted antibiotic resistance tests using the disc diffusion and Etest (Biomerieux, Durham, NC, USA) methods. Overall isolation of Listeria species was 15% (23/150) 95% CI (10.16&ndash;22.33), 2% (3/150) 95% CI (0.52&ndash;6.19) and 13% (20/150) 95% CI (8.53&ndash;20.08) came from environmental swabs and carcass swabs, respectively. Proportions of positive Listeria isolates were L. monocytogenes 74% (17/23), L. welshimeri 22% (5/23), and L. innocua 4% (1/23). Listeria species from the exterior carcass swabs was 61% (14/23), cloacal swabs 26% (6/23), and environmental swabs 3% (3/23). L. monocytogenes had the greatest resistance percentage to the following antibiotics: clindamycin (61%, 10/23), tetracycline 30% (7/23), and erythromycin 13%, (3/23). Isolation of L. monocytogenes in relatively high numbers, including the antimicrobial profiles, suggests a potential risk of the pathogen remaining viable in the food continuum and a public health risk to would-be consumers

Prevalence and Molecular Identification of <i>Schistosoma haematobium</i> among Children in Lusaka and Siavonga Districts, Zambia

Schistosomiasis remains a public health concern in Zambia. Urinary schistosomiasis caused by Schistosoma haematobium is the most widely distributed infection. The aim of the current study was to determine the prevalence and risk factors of urinary schistosomiasis and identify the strain of S. haematobium among children in the Siavonga and Lusaka districts in Zambia. Urine samples were collected from 421 primary school children and S. haematobium eggs were examined under light microscopy. A semi-structured questionnaire was used to obtain information on the socio-demographic characteristics and the potential risk factors for urinary schistosomiasis. DNA of the parasite eggs was extracted from urine samples and the internal transcribed spacer gene was amplified, sequenced and phylogenetically analysed. The overall prevalence of S. haematobium was 9.7% (41/421) (95% CI: 7.16–13.08), male participants made up 6.2% (26/232) (95% CI: 4.15–9.03), having a higher burden of disease than female participants who made up 3.5% (15/421) (95% CI: 2.01–5.94). The age group of 11–15 years had the highest overall prevalence of 8.3% (35/421) (5.94–11.48). Participants that did not go fishing were 0.008 times less likely to be positive for schistosomiasis while participants whose urine was blood-tinged or cloudy on physical examination and those that lived close to water bodies were 9.98 and 11.66 times more likely to test positive for schistosomiasis, respectively. A phylogenetic tree analysis indicated that S. haematobium isolates were closely related to pure S. haematobium from Zimbabwe and hybrids of S. haematobium × S. bovis from Benin, Senegal and Malawi. The current study shows that urinary schistosomiasis is endemic in the study areas and is associated with water contact, and S. haematobium isolated is closely related to hybrids of S. bovis × S. haematobium strain, indicating the zoonotic potential of this parasite

Seroprevalence and Risk Factors of Crimean-Congo Hemorrhagic Fever in Cattle of Smallholder Farmers in Central Malawi

Crimean-Congo hemorrhagic fever virus (CCHFV) is endemic in Africa, Asia, and Eastern Europe where it circulates among animals and ticks causing sporadic outbreaks in humans. Although CCHF is endemic in sub-Saharan Africa, epidemiological information is lacking in many countries, including Malawi. To assess the risk of CCHF in Malawi, we conducted an epidemiological study in cattle reared by smallholder livestock farmers in central Malawi. A cross-sectional study was conducted in April 2020 involving seven districts, four from Kasungu and three from Lilongwe Agriculture Development Divisions. A structured questionnaire was administered to farmers to obtain demographic, animal management, and ecological risk factors data. Sera were collected from randomly selected cattle and screened for CCHF virus (CCHFV) specific antibodies using a commercial ELISA kit. Ticks were collected from cattle and classified morphologically to species level. An overall CCHFV seropositivity rate of 46.9% (n = 416; 95% CI: 42.0&ndash;51.8%) was observed. The seropositivity was significantly associated with the age of cattle (p &lt; 0.001), sex (p &lt; 0.001), presence of ticks in herds (p = 0.01), district (p = 0.025), and type of grazing lands (p = 0.013). Five species of ticks were identified, including Hyalomma truncatum, a known vector of CCHFV. Ticks of the species Hyalomma truncatum were not detected in two districts with the highest seroprevalence for CCHF and vector competency must be further explored in the study area. To our knowledge, this is the first report of serologic evidence of the presence of CCHV among smallholder cattle in central Malawi. This study emphasizes the need for continued monitoring of CCHFV infection among livestock, ticks, and humans for the development of data-based risk mitigation strategies