Dromedary camels are a putative source for human infections with Middle East respiratory syndrome coronavirus. We showed that camels sampled in different regions in Kenya during 1992-2013 have ...antibodies against this virus. High densities of camel populations correlated with increased seropositivity and might be a factor in predicting long-term virus maintenance.
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DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The four human coronaviruses (HCoVs) are globally endemic respiratory pathogens. The Middle East respiratory syndrome (MERS) coronavirus (CoV) is an emerging CoV with a known zoonotic source in ...dromedary camels. Little is known about the origins of endemic HCoVs. Studying these viruses’ evolutionary history could provide important insight into CoV emergence. In tests of MERS-CoV–infected dromedaries, we found viruses related to an HCoV, known as HCoV-229E, in 5.6% of 1,033 animals. Human- and dromedary-derived viruses are each monophyletic, suggesting ecological isolation. One gene of dromedary viruses exists in two versions in camels, full length and deleted, whereas only the deleted version exists in humans. The deletion increased in size over a succession starting from camelid viruses via old human viruses to contemporary human viruses. Live isolates of dromedary 229E viruses were obtained and studied to assess human infection risks. The viruses used the human entry receptor aminopeptidase N and replicated in human hepatoma cells, suggesting a principal ability to cause human infections. However, inefficient replication in several mucosa-derived cell lines and airway epithelial cultures suggested lack of adaptation to the human host. Dromedary viruses were as sensitive to the human type I interferon response as HCoV-229E. Antibodies in human sera neutralized dromedary-derived viruses, suggesting population immunity against dromedary viruses. Although no current epidemic risk seems to emanate from these viruses, evolutionary inference suggests that the endemic human virus HCoV-229E may constitute a descendant of camelid-associated viruses. HCoV-229E evolution provides a scenario for MERS-CoV emergence.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
A new hepatitis E virus (HEV-7) was recently found in dromedaries and 1 human from the United Arab Emirates. We screened 2,438 dromedary samples from Pakistan, the United Arab Emirates, and 4 African ...countries. HEV-7 is long established, diversified and geographically widespread. Dromedaries may constitute a neglected source of zoonotic HEV infections.
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DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Outbreaks of a Haemorrhagic Septicaemia (HS) like disease causing large mortalities in camels (Camelus dromedarius) in Asia and in Africa have been reported since 1890. Yet the aetiology of this ...condition remains elusive. This study is the first to apply state of the art molecular methods to shed light on the nasopharyngeal carrier state of Pasteurellaceae in camels. The study focused on HS causing Pasteurella multocida capsular types B and E. Other Pasteurellaceae, implicated in common respiratory infections of animals, were also investigated.
In 2007 and 2008, 388 nasopharyngeal swabs were collected at 12 locations in North Kenya from 246 clinically healthy camels in 81 herds that had been affected by HS-like disease. Swabs were used to cultivate bacteria on blood agar and to extract DNA for subsequent PCR analysis targeting P. multocida and Mannheimia-specific gene sequences.
Forty-five samples were positive for P. multocida genes kmt and psl and for the P. multocida Haemorrhagic Septicaemia (HS) specific sequences KTSP61/KTT72 but lacked HS-associated capsular type B and E genes capB and capE. This indicates circulation of HS strains in camels that lack established capsular types. Sequence analysis of the partial 16S rRNA gene identified 17 nasal swab isolates as 99% identical with Mannheimia granulomatis, demonstrating a hitherto unrecognised active carrier state for M. granulomatis or a closely related Mannheimia sp. in camels.
The findings of this study provide evidence for the presence of acapsular P. multocida or of hitherto unknown capsular types of P. multocida in camels, closely related to P. multocida strains causing HS in bovines. Further isolations and molecular studies of camelid P. multocida from healthy carriers and from HS-like disease in camels are necessary to provide conclusive answers. This paper is the first report on the isolation of M. granulomatis or a closely related new Mannheimia species from camelids.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Productive global agriculture is under a convergence of pressures, and particularly climate change and population growth. The impact is especially stark in East Africa where crop production is mostly ...rain-fed and population growth rates are among the highest in the world. Our objective for this study was to understand how climate change and population growth have impacted the size of agropastoral areas across Kenya over 40 years. Climate-suitable areas for all primary crops decreased 28% over the study period. Climate-suitable areas for primary crops increased 3% in highly productive counties, decreased 25% in moderately productive counties, and decreased 62% in low productive counties. Climate-suitable areas over the study period decreased 13% for ranching areas, 21% for dairying areas, 24% for mixed crop and ranching areas, and 28% for mixed crop and dairying areas, while climate-suitable areas for pastoralism increased 12%. Population across Kenya more than tripled over the study period, while population relative to climate-suitable areas for crops increased nearly fourfold, and population relative to climate-suitable areas for pastoralism nearly tripled. Population relative to available climate-suitable areas for crops more than doubled in highly productive counties, increased more than four-fold in moderately productive counties, and was nearly 15 times higher in low productive counties. Examining the cumulative effects of climate change and population growth on agricultural sectors across Kenya can help to develop policies and strategies to reach the UN Sustainable Development Goals.
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NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
Ruminant production systems in the arid and semi-arid regions of Sub-Saharan Africa confront severe challenges due to recurring droughts and the intensifying effects of climate change (CC). These ...systems grapple with numerous stress factors, including poor animal nutrition, water scarcity, gastrointestinal (GIT) parasite burdens, and heat stress, which contribute to below optimal animal productivity and a high environmental footprint. Addressing these issues urgently, by creating livestock systems resilient to CC that also promote better animal health, enhanced productivity, and reduced environmental impact, is paramount to safeguarding the livelihoods of the rural population. This 50-day study aimed to evaluate the effects of improved feeding and nutritional management in sheep, focusing on GIT parasite infections, feed intake and digestibility, liveweight (LW) gain, and enteric methane (CH 4 ) emissions. We investigated the legume forage tree, Calliandra ( Calliandra calothyrsus ), as a high-quality feed source because of its rich crude protein content and its potential as a remedy for gastrointestinal tract (GIT) parasite infections, attributed to its high condensed tannin (CT) content. Twenty-eight Dorper lambs underwent random allocation across four treatments, each consisting of seven lambs. These treatments combined either a trickle infection or no infection with Haemonchus contortus with a supplementation (40% of diet on a dry matter basis or lack thereof) of the basal diet (Rhodes grass hay) with dried Calliandra leaflets. The treatments were: UnHay (uninfected, fed on hay-only), InHay (infected, fed on hay-only), InHay+Cal (infected, fed on hay plus Calliandra), and InHay+Cal+PEG infected, fed on hay, Calliandra, and polyethylene glycol (PEG). The latter was to evaluate the potential effects of Calliandra’s condensed tannins. The results show that lambs in the InHay+Cal treatment exhibited a higher packed cell volume (PCV) and lower faecal egg counts (FEC) compared to the InHay group. No effects of infection on the other measured variables were observed in unsupplemented lambs. Calliandra supplementation increased total feed dry matter intake (DMI) by 20% (61.8 vs. 51.7 g DM/kg LW0.75) (InHay+Cal vs. InHay) and enhanced LW gain (7.2 g/d) in the InHay+Cal group, whereas the unsupplemented infected group (InHay) experienced LW loss (-26.6 g/d). Calliandra supplementation to infected lambs reduced daily CH 4 emission by 15% (13.9 vs. 16.2 g/d) and CH 4 yield (g/kg DMI) by 30% (18.7 vs. 26.5 g/kg DMI), compared to emissions from unsupplemented infected lambs. Nonetheless, Calliandra supplementation decreased the digestibility of crude protein and fibre and raised the faecal nitrogen (N) output to N intake (FN/NI) ratio. The effects of PEG supplementation on CT activity remained inconclusive. The study concludes that a 40% replacement of a protein-deficient basal diet with Calliandra may be excessive. However, the findings underscore the considerable advantages of integrating Calliandra into farming systems. Such nature-based solution control GIT parasite infections and their lifecycle, bolster the nutritional value of a deficient basal diet, improve animal productivity cost-effectively, and mitigate enteric methane emissions both in absolute terms and intensity.
A study was conducted with Red Maasai and Dorper lambs to evaluate the effects of infection with the gastrointestinal nematode (GIN)
Haemonchus contortus
on feed intake, liveweight gain (LWG), feed ...energy and nitrogen partitioning, and enteric methane (CH
4
) emissions. Six- to seven-month-old Red Maasai (n=12) and Dorper (n=12) lambs were randomly allocated to three treatments (n=8, four lambs per breed) in a 2×3 factorial cross-over study over two periods (P1 and P2) of 36 days each. The treatments consisted of three combinations of GIN infection and feeding level: Infected + ad libitum feeding (I-adlib), uninfected + ad libitum feeding (Un-adlib), and uninfected + restricted feeding (Un-restd), across the two breeds. Lambs in the I-adlib group were trickle-infected daily with 1,000 L3 stage larvae of
H. contortus
for four consecutive days (Days 1–4), whereas lambs in the other experimental treatments were kept GIN free. The feed intake was measured daily. Liveweight (LW), faecal egg counts (FEC), and packed cell volume (PCV) were measured on Day 1 and weekly thereafter. On Days 29–33 total faecal and urine outputs were determined in metabolic crates. The lambs were then housed in respiration chambers for three consecutive days (Days 34–36). There was a washout period of 21 days before P2 started. Uninfected lambs (Un-adlib and Un-restd) had undetectable FEC throughout the study. On Day 36, FEC did not differ between the breeds (P>0.05). Infected lambs (I-adlib) had lower PCV than uninfected (Un-adlib and Un-restd) lambs on day 36. Neither breed nor infection influenced feed and nutrient intake, but as expected, restricted-fed lambs had a lower intake (
P
<0.05). The LWG of Un-adlib lambs was significantly higher than that of I-adlib and Un-restd lambs (
P
<0.05), whereas there was no breed difference (P>0.05). Neither breed nor infection affected feed digestibility, nitrogen retention or energy metabolisability (P>0.05). However, feed restriction decreased feed intake, LWG and N retention, whereas feed digestibility and energy metabolisability were unaffected. Neither daily CH
4
emissions nor yield (per unit of feed intake) were affected by experimental infection, but Un-restd lambs had lower CH
4
emissions per day. Red Maasai lambs had consistently lower daily CH
4
emissions and yields than Dorper (
P
<0.01). This study confirmed the relative resistance of indigenous sheep (Red Maasai) to
H. contortus
infection, but the increased CH
4
emission and yield due to GIN observed in other studies was not confirmed. Further investigations are needed to test whether in environments with multiple stress factors, local or indigenous breeds or their crossbreeds with exotic breeds may be better equipped to sustain production and simultaneously have a reduced carbon footprint than purebred exotic breeds.
Camels are getting increasingly important for pastoral livestock systems in arid and semi-arid rangelands of East Africa that are adversely affected by climate change. Cattle are more susceptible to ...drought than camels and rely on grass, while camels are primarily browsers. Diet selection can influence the quality of the milk, especially of the milk fat. Little is known about differences in milk fatty acid profile of camels compared to cattle, especially under free-grazing conditions. Camels and two cattle types were compared on Kenyan rangelands in a rainy season and a transition period. Seventy-two lactating animals (12 per animal type per season each) were used. Half of each group received a urea-molasses supplement at night. Intakes of nutrients and phenols were estimated through scan sampling. Milk was collected at the end of each season and analyzed for phenols and fatty acids. Phenol intakes varied between seasons in cattle but not in camels. Different from animal type, season had an effect on milk phenol concentration. Phenol excretion with the milk of cattle correlated with phenol intake. Proportions of mono- and polyunsaturated fatty acids were higher in camel milk than cattle milk. Cattle milk contained more conjugated linoleic acids than camel milk in the rainy season. Proportions of oleic, linoleic, α-linolenic and eicosapentaenoic acid were higher, whereas n-6-to-n-3 fatty acid ratio was lower in camel milk than cattle milk. Camels may have developed control mechanisms limiting adverse effects and transfer of phenols to milk in response to their higher intake of phenol-rich browse. In conclusion, camel milk seems to be more beneficial for human health and nutrition than cattle milk by its characteristic fatty acid profile. This can be another motivation for switching from cattle to camels in arid/semi-arid areas affected by climate change.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
As emerging infectious diseases (EIDs) increase, examining the underlying social and environmental conditions that drive EIDs is urgently needed. Ecological niche modeling (ENM) is increasingly ...employed to predict disease emergence based on the spatial distribution of biotic conditions and interactions, abiotic conditions, and the mobility or dispersal of vector-host species, as well as social factors that modify the host species' spatial distribution. Still, ENM applied to EIDs is relatively new with varying algorithms and data types. We conducted a systematic review (PROSPERO: CRD42021251968) with the research question:
via
We searched five research databases and eight widely recognized One Health journals between 1995 and 2020. We screened 383 articles at the abstract level (included if study involved vector-borne or zoonotic disease and applied ENM) and 237 articles at the full-text level (included if study described ENM features and modeling processes). Our objectives were to: (1) describe the growth and distribution of studies across the types of infectious diseases, scientific fields, and geographic regions; (2) evaluate the likely effectiveness of the studies to represent ecological niches based on the biotic, abiotic, and mobility framework; (3) explain some potential pitfalls of ENM algorithms and techniques; and (4) provide specific recommendation for future studies on the analysis of ecological niches to predict EIDs.
We show that 99% of studies included mobility factors, 90% modeled abiotic factors with more than half in tropical climate zones, 54% modeled biotic conditions and interactions. Of the 121 studies, 7% include only biotic and mobility factors, 45% include only abiotic and mobility factors, and 45% fully integrated the biotic, abiotic, and mobility data. Only 13% of studies included modifying social factors such as land use. A majority of studies (77%) used well-recognized ENM algorithms (MaxEnt and GARP) and model selection procedures. Most studies (90%) reported model validation procedures, but only 7% reported uncertainty analysis.
Our findings bolster ENM to predict EIDs that can help inform the prevention of outbreaks and future epidemics.
https://www.crd.york.ac.uk/prospero/, identifier (CRD42021251968).
Contagious caprine pleuropneumonia (CCPP) is a highly contagious disease caused by Mycoplasma capricolum subsp. capripneumoniae that affects goats in Africa and Asia. Current available methods for ...the diagnosis of Mycoplasma infection, including cultivation, serological assays, and PCR, are time-consuming and require fully equipped stationary laboratories, which make them incompatible with testing in the resource-poor settings that are most relevant to this disease. We report a rapid, specific, and sensitive assay employing isothermal DNA amplification using recombinase polymerase amplification (RPA) for the detection of M. capricolum subsp. capripneumoniae. We developed the assay using a specific target sequence in M. capricolum subsp. capripneumoniae, as found in the genome sequence of the field strain ILRI181 and the type strain F38 and that was further evidenced in 10 field strains from different geographical regions. Detection limits corresponding to 5 × 10(3) and 5 × 10(4) cells/ml were obtained using genomic DNA and bacterial culture from M. capricolum subsp. capripneumoniae strain ILRI181, while no amplification was obtained from 71 related Mycoplasma isolates or from the Acholeplasma or the Pasteurella isolates, demonstrating a high degree of specificity. The assay produces a fluorescent signal within 15 to 20 min and worked well using pleural fluid obtained directly from CCPP-positive animals without prior DNA extraction. We demonstrate that the diagnosis of CCPP can be achieved, with a short sample preparation time and a simple read-out device that can be powered by a car battery, in <45 min in a simulated field setting.
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