Female and male-controlled livestock holdings impact pastoralist food security and women's dietary diversity.

BACKGROUND: Food insecurity is a global problem that requires a One Health approach. As many households in low- and middle-income nations rely on crops and livestock that they produce to meet their household's needs, food security and nutrition are closely linked to the health of animals and the environment. Resources controlled by women are more often allocated to uses that benefit the entire household, such as food, health, and educating children, than men's resources. However, studies of gender control of resources among pastoralist societies are scant. We examined the effect of female and male control of livestock resources on food security and women's dietary diversity among households from one agro-pastoralist and two pastoralist tribes in Iringa Region in south-central Tanzania. METHODS: We conducted surveys with 196 households, which included questions on food availability and food consumption among women, livestock holdings, gender control of livestock and livestock product income, and household demographics, as well as open-ended questions on the use of income. Food availability and food consumption responses were used to construct food security and women's dietary diversity indexes, respectively. We conducted mixed effects logistic regression to analyze how household food security and dietary diversity were associated with livestock and other household variables. We also examined qualitative responses for use of income controlled by women and how the household obtained income when needed. RESULTS: Female-controlled livestock generally supported better household nutrition outcomes. Greater chicken holdings increased the probability of being food secure in pastoralist households but decreased it in agro-pastoralist households, while increasing the probability of having medium-high dietary diversity among all tribes. Male-controlled livestock holdings were not related to food security status. Women used income to supplement food supplies and livestock they controlled as a primary response to unanticipated household needs. CONCLUSIONS: Our results show that female-control of livestock is significantly related to household food security and dietary diversity in pastoralists and agro-pastoralists in rural Tanzania. Importantly, the relationship between food security and dietary diversity differs among tribes for both male and female-controlled livestock, which suggests that blanket policies regarding management of livestock holdings may have unintended consequences. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s42522-020-00032-5.

The evolutionary history of ACE2 usage within the coronavirus subgenus Sarbecovirus.

Severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1) and SARS-CoV-2 are not phylogenetically closely related; however, both use the angiotensin-converting enzyme 2 (ACE2) receptor in humans for cell entry. This is not a universal sarbecovirus trait; for example, many known sarbecoviruses related to SARS-CoV-1 have two deletions in the receptor binding domain of the spike protein that render them incapable of using human ACE2. Here, we report three sequences of a novel sarbecovirus from Rwanda and Uganda that are phylogenetically intermediate to SARS-CoV-1 and SARS-CoV-2 and demonstrate via in vitro studies that they are also unable to utilize human ACE2. Furthermore, we show that the observed pattern of ACE2 usage among sarbecoviruses is best explained by recombination not of SARS-CoV-2, but of SARS-CoV-1 and its relatives. We show that the lineage that includes SARS-CoV-2 is most likely the ancestral ACE2-using lineage, and that recombination with at least one virus from this group conferred ACE2 usage to the lineage including SARS-CoV-1 at some time in the past. We argue that alternative scenarios such as convergent evolution are much less parsimonious; we show that biogeography and patterns of host tropism support the plausibility of a recombination scenario, and we propose a competitive release hypothesis to explain how this recombination event could have occurred and why it is evolutionarily advantageous. The findings provide important insights into the natural history of ACE2 usage for both SARS-CoV-1 and SARS-CoV-2 and a greater understanding of the evolutionary mechanisms that shape zoonotic potential of coronaviruses. This study also underscores the need for increased surveillance for sarbecoviruses in southwestern China, where most ACE2-using viruses have been found to date, as well as other regions such as Africa, where these viruses have only recently been discovered.

Viral emergence in marine mammals in the North Pacific may be linked to Arctic sea ice reduction.

Climate change-driven alterations in Arctic environments can influence habitat availability, species distributions and interactions, and the breeding, foraging, and health of marine mammals. Phocine distemper virus (PDV), which has caused extensive mortality in Atlantic seals, was confirmed in sea otters in the North Pacific Ocean in 2004, raising the question of whether reductions in sea ice could increase contact between Arctic and sub-Arctic marine mammals and lead to viral transmission across the Arctic Ocean. Using data on PDV exposure and infection and animal movement in sympatric seal, sea lion, and sea otter species sampled in the North Pacific Ocean from 2001-2016, we investigated the timing of PDV introduction, risk factors associated with PDV emergence, and patterns of transmission following introduction. We identified widespread exposure to and infection with PDV across the North Pacific Ocean beginning in 2003 with a second peak of PDV exposure and infection in 2009; viral transmission across sympatric marine mammal species; and association of PDV exposure and infection with reductions in Arctic sea ice extent. Peaks of PDV exposure and infection following 2003 may reflect additional viral introductions among the diverse marine mammals in the North Pacific Ocean linked to change in Arctic sea ice extent.

Further Evidence for Bats as the Evolutionary Source of Middle East Respiratory Syndrome Coronavirus.

The evolutionary origins of Middle East respiratory syndrome (MERS) coronavirus (MERS-CoV) are unknown. Current evidence suggests that insectivorous bats are likely to be the original source, as several 2c CoVs have been described from various species in the family Vespertilionidae Here, we describe a MERS-like CoV identified from a Pipistrellus cf. hesperidus bat sampled in Uganda (strain PREDICT/PDF-2180), further supporting the hypothesis that bats are the evolutionary source of MERS-CoV. Phylogenetic analysis showed that PREDICT/PDF-2180 is closely related to MERS-CoV across much of its genome, consistent with a common ancestry; however, the spike protein was highly divergent (46% amino acid identity), suggesting that the two viruses may have different receptor binding properties. Indeed, several amino acid substitutions were identified in key binding residues that were predicted to block PREDICT/PDF-2180 from attaching to the MERS-CoV DPP4 receptor. To experimentally test this hypothesis, an infectious MERS-CoV clone expressing the PREDICT/PDF-2180 spike protein was generated. Recombinant viruses derived from the clone were replication competent but unable to spread and establish new infections in Vero cells or primary human airway epithelial cells. Our findings suggest that PREDICT/PDF-2180 is unlikely to pose a zoonotic threat. Recombination in the S1 subunit of the spike gene was identified as the primary mechanism driving variation in the spike phenotype and was likely one of the critical steps in the evolution and emergence of MERS-CoV in humans.IMPORTANCE Global surveillance efforts for undiscovered viruses are an important component of pandemic prevention initiatives. These surveys can be useful for finding novel viruses and for gaining insights into the ecological and evolutionary factors driving viral diversity; however, finding a viral sequence is not sufficient to determine whether it can infect people (i.e., poses a zoonotic threat). Here, we investigated the specific zoonotic risk of a MERS-like coronavirus (PREDICT/PDF-2180) identified in a bat from Uganda and showed that, despite being closely related to MERS-CoV, it is unlikely to pose a threat to humans. We suggest that this approach constitutes an appropriate strategy for beginning to determine the zoonotic potential of wildlife viruses. By showing that PREDICT/PDF-2180 does not infect cells that express the functional receptor for MERS-CoV, we further show that recombination was likely to be the critical step that allowed MERS to emerge in humans.

Stakeholders in One Health.

The stakeholders in One Health include the ultimate beneficiaries (i.e. animals, people and the environment) and the organisations that work to protect them (i.e. research institutes, government ministries, international organisations and professional bodies). However, identifying these stakeholders who will contribute to One Health activities and develop solutions to complex health problems can be difficult, as these problems often affect all sectors of society. In addition, evolving concepts about health and its dependence on environmental resilience necessitate the inclusion of ministries, organisations and disciplines that may not have been traditionally considered to be related to health. The multilateral organisations with greatest responsibilities in the global health arena have recognised that the best way to protect health security and promote overall global well-being is to work together across disciplinary and jurisdictional boundaries. Permanent regional networks and ad hoc networks created to tackle specific issues (both of which require donor investment) are also facilitating improved disease surveillance and collaborative approaches to synchronised interventions across country borders. These networks necessarily involve the key ministries for One Health, those of health, agriculture/livestock, and natural resources/environment. Ministries play a critical role in the formulation and implementation of policies for the promotion of health and disease control. They contribute to all stages of the One Heath process, as do universities, which engage by generating knowledge and capacity through teaching, research and extension services. Similarly, non-governmental organisations have a key role in stewardship; resource mobilisation; generation of knowledge; capacity development; intervention design; and implementation. Finally, communities, including rural and indigenous peoples, particularly those that are in close proximity to natural areas, are at the heart of the One Health concept.

Tuberculosis infection in wildlife from the Ruaha ecosystem Tanzania: implications for wildlife, domestic animals, and human health.

Mycobacterium bovis, a pathogen of conservation, livestock, and public health concern, was detected in eight species of wildlife inhabiting protected areas bordering endemic livestock grazing lands. We tested tissues from 179 opportunistically sampled hunter-killed, depredation, road-killed, and live-captured wild animals, representing 30 species, in and adjacent to Ruaha National Park in south-central Tanzania. Tissue culture and PCR were used to detect 12 (8.1%) M. bovis-infected animals and 15 (10.1%) animals infected with non-tuberculosis complex mycobacteria. Kirk's dik-dik, vervet monkey, and yellow baboon were confirmed infected for the first time. The M. bovis spoligotype isolated from infected wildlife was identical to local livestock, providing evidence for livestock-wildlife pathogen transmission. Thus we advocate an ecosystem-based approach for bovine tuberculosis management that improves critical ecological functions in protected areas and grazing lands, reduces focal population density build-up along the edges of protected areas, and minimizes ecological stressors that increase animals' susceptibility to bovine tuberculosis.

Novel symptomatology and changing epidemiology of domoic acid toxicosis in California sea lions (Zalophus californianus): an increasing risk to marine mammal health.

Harmful algal blooms are increasing worldwide, including those of Pseudo-nitzschia spp. producing domoic acid off the California coast. This neurotoxin was first shown to cause mortality of marine mammals in 1998. A decade of monitoring California sea lion (Zalophus californianus) health since then has indicated that changes in the symptomatology and epidemiology of domoic acid toxicosis in this species are associated with the increase in toxigenic blooms. Two separate clinical syndromes now exist: acute domoic acid toxicosis as has been previously documented, and a second novel neurological syndrome characterized by epilepsy described here associated with chronic consequences of previous sub-lethal exposure to the toxin. This study indicates that domoic acid causes chronic damage to California sea lions and that these health effects are increasing.

Tissue distribution of phocine herpesvirus-1 (PhHV-1) in infected harbour seals (Phoca vitulina) from the central Californian coast and a comparison of diagnostic methods.

The polymerase chain reaction (PCR) was used to determine the tissue distribution of phocine herpesvirus-1 (PhHV-1) DNA in 20 stranded Pacific harbour seals (17 pups and three seals older than one year) that died during rehabilitation. The aim was to begin to define stages of infection and to investigate the relation between the presence of PhHV-1 in tissues, histological lesions and serology. PhHV-1 DNA was detected in a wide range of tissues from 10/17 pups and 3/3 subadults or adults. Different clinical patterns emerged from the examination of ante- and post-mortem samples. These patterns probably represented pups with active PhHV-1 infection, pups recovering from infection, and older harbour seals with chronic, reactivated infection. As PhHV-1 DNA was detected in tissues in the absence of typical histological lesions in seven seals and in the absence of PhHV-1 specific antibodies in four seals, it is clear that both histological examination and serology underestimate the presence of infection. These results showed that infection can occur in the absence of obvious disease and that seroconversion may be associated with clinical recovery.

Patterns of mortality in southern sea otters (Enhydra lutris nereis) from 1998-2001.

Detailed postmortem examination of southern sea otters (Enhydra lutris nereis) found along the California (USA) coast has provided an exceptional opportunity to understand factors influencing survival in this threatened marine mammal species. In order to evaluate recent trends in causes of mortality, the demographic and geographic distribution of causes of death in freshly deceased beachcast sea otters necropsied from 1998-2001 were evaluated. Protozoal encephalitis, acanthocephalan-related disease, shark attack, and cardiac disease were identified as common causes of death in sea otters examined. While infection with acanthocephalan parasites was more likely to cause death in juvenile otters, Toxoplasma gondii encephalitis, shark attack, and cardiac disease were more common in prime-aged adult otters. Cardiac disease is a newly recognized cause of mortality in sea otters and T. gondii encephalitis was significantly associated with this condition. Otters with fatal shark bites were over three times more likely to have pre-existing T. gondii encephalitis suggesting that shark attack, which is a long-recognized source of mortality in otters, may be coupled with a recently recognized disease in otters. Spatial clusters of cause-specific mortality were detected for T. gondii encephalitis (in Estero Bay), acanthocephalan peritonitis (in southern Monterey Bay), and shark attack (from Santa Cruz to Point Año Nuevo). Diseases caused by parasites, bacteria, or fungi and diseases without a specified etiology were the primary cause of death in 63.8% of otters examined. Parasitic disease alone caused death in 38.1% of otters examined. This pattern of mortality, observed predominantly in juvenile and prime-aged adult southern sea otters, has negative implications for the overall health and recovery of this population.

Effects of petroleum on mink applied as a model for reproductive success in sea otters.

Ranch-reared mink (Mustela vison) were used as a model in an experimental trial to investigate the potential effects of exposure to two petroleum products on sea otters (Enhydra lutris). Mink were exposed either dermally on one occasion 60 days prior to breeding or via low level contamination of their diets daily from 60 days prior to breeding (January 1994) until weaning of kits (June 1994). For dermal exposure, we placed mink in either a slick of Alaskan North Slope crude oil (n = 24) or bunker C fuel oil (n = 24) on sea water or sea water alone (n = 10) for 1 min. For dietary exposure, we fed mink rations containing 500 ppm of either Alaskan North Slope crude oil (n = 24) or bunker C fuel oil (n = 24; control, n = 15). The number of liveborn kits did not differ significantly among mink exposed dermally (5.0 kits/female for crude oil and 6.5 kits/female for bunker C fuel oil) and unexposed controls (5.3 kits/female). However, only 2.3 and 0.7 kits were produced per female for those exposed through the diet to crude oil and bunker C fuel oil, respectively. Females with reduced reproductive success had no clinical signs of toxicosis or behavioral abnormalities. In addition, kits of females exposed through the diet had poor survival to weaning. Once mature, kits born to females exposed to bunker C fuel oil in the diet had significantly reduced reproductive success (3.4 kits/female) although their only exposure to the petroleum products was in utero or during nursing. Therefore, it is possible that sea otter populations consuming contaminated food sources or colonizing previously oiled habitats will have reduced reproductive success.

Exposure to Psoroptes sp. mites is common among bighorn sheep (Ovis canadensis) populations in California.

Sera (n = 806) from 50 populations of bighorn sheep (Ovis canadensis) in California (USA) were evaluated for antibodies to Psoroptes sp. mites using a kinetic enzyme-linked immunosorbent assay (ELISA). Test values for each sample were determined to be either positive or negative at each of two ELISA cutoff values that provided either 100% sensitivity (low cutoff) or 100% specificity (high cutoff), respectively. One hundred sixty-eight (20.8%) sera were seropositive at the low cutoff value, and 87 (10.8%) of these sera also were seropositive at the high cutoff value. Eleven populations were designated as scabies-suspect and 25 populations were designated as scabies-positive because they had at least one seropositive animal at the low and the high cutoff values, respectively. Based on these results, exposure to Psoroptes sp. mites appeared to be widely distributed among bighorn sheep populations from 1980 to 1990 and infested animals may have been present prior to 1980.

Kinetic ELISA for detection of antibodies to Psoroptes sp. (Acari: Psoroptidae) in bighorn sheep (Ovis canadensis).

A kinetic enzyme-linked immunosorbent assay (ELISA) was developed using antigenic extracts prepared from Psoroptes cuniculi mites and sera from 37 Psoroptes sp.-infested and 43 uninfested bighorn sheep (Ovis canadensis). Serial dilutions of these serum samples, representing 3 bighorn sheep subspecies and 9 geographic areas, gave parallel responses when plotted as log dilution versus log kinetic rate. Therefore, all 80 samples were run at a single dilution (1:100) and positive/negative cutoff values were established as the mean kinetic rate of all negative sera plus either 2, 3, or 4 standard deviations. The resulting ELISA was highly reproducible and accurate with sensitivities and specificities of 100% and 97.7%, 94.6% and 97.7%, and 94.6% and 100%, respectively. This immunoassay will be useful for prospective and retrospective studies assessing the distribution and prevalence of Psoroptes sp. infestations in bighorn sheep.