Our Planet

Coronavirus: Greatest impact on BAME communities

The current COVID-19 pandemic has had devastating effects globally, resulting in 327,738 deaths around the world. This death toll continues to rise, there have been 100,284 new confirmed cases and 4,482 deaths globally in the last 48 hours^[1]. Patterns have emerged that the virus is having a disproportionate effect on individuals from Black, Asian and minority ethnic (BAME) groups.

Individuals from different backgrounds differ with regard to their; behaviours, comorbidities, immune profile and their risk of infection. For example, research has found that south Asians have higher rates of diabetes, hypertension and cardiovascular disease compared to non-BAME individuals^[2]. Chronic conditions such as; diabetes, asthma, hypertension, kidney disease and obesity are also more common in African Americans compared to white individuals^[3]. For some BAME individuals it is proposed that this can be attributed to their lower socioeconomic status and their cultural intergenerational cohabitation².

In the UK, 18% of the black population currently work in care, leisure and other essential work. In the US, less than 20% of the black community have jobs which allow them to work from home, compared to 31% for white workers⁴. Therefore, this limited ability to social distance due to their key worker status and their lack of flexibility with regard to working from home may explain why the effects of COVID-19 are having a greater impact on the BAME community.

Effects on BAME groups

Research into COVID-19 fatalities in UK healthcare workers, doctors and nurses were significantly higher for individuals belonging to BAME groups. BAME deaths accounted for 94% of doctors, 71% of nurses and 63% of healthcare workers³(figure 1).

Figure 1. COVID-19 fatalities among healthcare professional in the UK.

The UK’s institute for fiscal studies (IFS) found that the likelihood of dying from COVID-19 differed significantly within the BAME community. Black Africans were 3.5 times more likely, individuals from Pakistani descent were 2.7 times more likely and Black Caribbean’s were 1.7 times more likely to die from coronavirus compared to the white population³.

Between 1^stMarch and 5pm on 21^stApril 2020, a total of 16,272 deaths were observed in NHS England hospitals. There were 492 deaths among Indians and 460 deaths among Caribbean’s, these were the largest deaths in minority ethnic groups⁵. According to the 2011 UK census the white British population make up 81.9% of the UK’s total populations⁶, therefore for this study calculated a standardised mortality rate (SMR) by ethnic group which used the entire population as a reference. Despite a lack of ethnicity data for 9.4% of the deaths, it was concluded that white British and Irish populations had a reduced risk compared to African, Caribbean, Indian, Pakistani and Bangladeshi populations which had an increased risk. There was no recorded increase nor decrease for; Chinese, mixed white and African and mixed white and Caribbean populations (figure 2).

Figure 2. COVID-19 standardised mortality rate (SMR) for different ethnic groups, adjusted by age and region⁵.

COVID-19 and Vitamin D

It has been suggested that a vitamin D deficiency is associated with susceptibility to coronavirus, as it has been proposed that vitamin D plays an important role in modulating the production of interleukins as its absences leads to disease progression⁷. A negative correlation has been found between vitamin D levels and the number of COVID-19 cases⁸. Vitamin D levels are severely low in the ageing population which could be a possible explanation for why the coronavirus has a greater impact on the older generation. However, it was found that 100% of ICU COVID patients were vitamin D deficient and were all aged under 75 years old⁹. Therefore, vitamin D deficiency may be the more influential factor in susceptibility to coronavirus as opposed to age as first thought.

Vitamin D is a secosteroid that has immunomodulatory, anti-inflammatory, antibiotic and antioxidant properties¹⁰. Vitamin D is found in; fatty fish (salmon, mackerel and tuna), red meat, cheese, orange juice, soy milk and egg yolk¹¹.Vitamin D is critical for the active uptake of calcium from the gut, suppression of cancerous cells, hormone regulation and skeletal health. The two routes to obtaining Vitamin D is through; diet and through exposure to UVB sunlight which is important for the synthesis of vitamin D₃(figure 3).

Figure 3. Synthesis and use of Vitamin D₃within the body.

Calcitriol has been found to exhibit protective effects against acute lung trauma by regulating the expression of members of the renin-angiotensin system such as ACE2 in lung tissue¹⁰. Therefore, Calcitriol may play an important role in the body’s immune response to COVID-19.

Melanin

Skin pigmentation influences the effectiveness of vitamin D₃synthesis in the skin. Melanin pigments are found in the epidermal layer of the skin¹², they absorb UVB photons and compete with provitamin D₅(7-dehydrocholesterol) which reduces the skins ability to absorb vitamin D₃from sunlight. Melanated skin requires 6 times the ultraviolet radiation dose to increase levels of vitamin D in the blood compared to those with white skin¹³. Individuals within the BAME group often have melanated skin which will increase their likelihood of becoming vitamin D deficient and possibly increasing susceptibility to COVID-19.

Increase your Vitamin D?

More research needs to be conducted to confirm the link between vitamin D and COVID-19 severity. Despite this, you should all consider increasing your vitamin D intake in your diet, particularly because we’ve all been told to stay at home which will reduce our exposure to natural light. If you choose to take vitamin D supplements be sure to follow the recommended intake on the package as overconsumption can cause hypervitaminosis D, this is when vitamin D levels become toxic due to the increase in normal plasma concentration for calcium (hypercalcaemia). Hypercalcaemia can then depress neuromuscular activity which can then cause cardiac arrhythmias.

If you prefer not to take supplements, try spending more time in your garden or if you don’t have a garden perhaps the park but remember to social distance. The plus side of this is that you cannot overdose on vitamin D from sunlight as our bodies have a negative feedback system, which means as soon as optimal levels are reached the excess will be degraded.

^[1]Who.int. 2020. Coronavirus Disease (COVID-19) – Situation Report 123. [online] Available at: <https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200522-covid-19-sitrep-123.pdf?sfvrsn=5ad1bc3_4> [Accessed 23 May 2020].

^[2]Pareek, M., Bangash, M., Pareek, N., Pan, D., Sze, S., Minhas, J., Hanif, W. and Khunti, K., 2020. Ethnicity and COVID-19: an urgent public health research priority. The Lancet, 395(10234), pp.1421-1422.

^[3]Kirby, T., 2020. Evidence mounts on the disproportionate effect of COVID-19 on ethnic minorities. The Lancet Respiratory Medicine.

⁴Liverpool, L., 2020. Why are ethnic minorities worse affected?. New Scientist, 246(3279), p.11.

⁵Aldridge, R., Lewer, D., Katikireddi, S., Mathur, R., Pathak, N., Burns, R., Fragaszy, E., Johnson, A., Devakumar, D., Abubakar, I. and Hayward, A., 2020. Black, Asian and Minority Ethnic groups in England are at increased risk of death from COVID-19: indirect standardisation of NHS mortality data. Wellcome Open Research, 5, p.88.

⁶Ethnicity-facts-figures.service.gov.uk. 2018. Regional Ethnic Diversity. [online] Available at: <https://www.ethnicity-facts-figures.service.gov.uk/uk-population-by-ethnicity/national-and-regional-populations/regional-ethnic-diversity/latest> [Accessed 23 May 2020].

⁷Silberstein, M., 2020. Vitamin D: A simpler alternative to tocilizumab for trial in COVID-19?. Medical Hypotheses, 140, p.109767.

⁸Ilie, P., Stefanescu, S. and Smith, L., 2020. The role of vitamin D in the prevention of coronavirus disease 2019 infection and mortality. Aging Clinical and Experimental Research.

⁹Lau, F., Majumder, R., Torabi, R., Saeg, F., Hoffman, R., Cirillo, J. and Greiffenstein, P., 2020. Vitamin D insufficiency is prevalent in severe COVID-19. [online] Available at: <https://www.medrxiv.org/content/10.1101/2020.04.24.20075838v1> [Accessed 23 May 2020].

¹⁰Ebadi, M. and Montano-Loza, A., 2020. Perspective: improving vitamin D status in the management of COVID-19. European Journal of Clinical Nutrition.

¹¹Lee, J., Hecke, O. and Roberts, N., 2020. Vitamin D: A Rapid Review Of The Evidence For Treatment Or Prevention In COVID-19 – CEBM. [online] CEBM. Available at: <https://www.cebm.net/covid-19/vitamin-d-a-rapid-review-of-the-evidence-for-treatment-or-prevention-in-covid-19/> [Accessed 23 May 2020].

¹²Nair, R. and Maseeh, A., 2012. Vitamin D: The “sunshine” vitamin. Journal of Pharmacology and Pharmacotherapeutics, 3(2), pp.118-126.

¹³Brenner, M. and Hearing, V., 2007. The Protective Role of Melanin Against UV Damage in Human Skin†. Photochemistry and Photobiology, 84(3), pp.539-549.

Chytridiomycosis: An Amphibian Crisis

To mark the end of April and the end of Frog month, today’s post is dedicated to a very special member of the amphibian family… Frogs!

Amphibians

Amphibians are a group of small vertebrates which belong to the taxonomic class, Amphibia. The main orders of amphibians are; Anura (Frogs and Toads), Urodeles (Newts), Caudates (Salamanders) and Gymnophiones (Caecilians). There are approximately 8,000 living amphibian species that have been discovered, however this is believed to only be a small portion of the world’s actual amphibian population^[1]. Amphibians are very sensitive to environmental change and they are predominantly found in the tropics and on every continent except for Antarctica.

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Figure 1. The amphibian tree of life^[2]

Amphibian Characteristics

Amphibians share numerous characteristics, such as; small body size, permeable skin, a lack of external scales, oviparity (expulsion of undeveloped eggs) which is dependent on water and they have the ability to respire through simple lungs, gills, skin and buccopharyngeal membranes^[3].

Despite the similarities, the three amphibian groups are easy to distinguish from one another (figure 2). Salamanders are often mistaken for lizards due to their long tails, slender bodies, similar sized hind and forelimbs, medium length trunks and their four or five digits on the forelimbs and hindlimbs respectively. Compared to Frogs which have a recognisable short stout trunk, protruding eyes, long hind limbs, elongated pelvic girdle, lack of tail in adults and four or five digits on the forelimbs and hindlimbs respectively.

Due to Caecilians being further away on the evolutionary tree their physical differences are more noticeable in comparison to Frogs and Salamanders. Caecilians have a worm like appearance, ringed markings on the body, long trunks, a lack of limbs and a cloacae at caudal end of the body².

Figure 2. Physical appearances of Salamanders, Frogs and Caecilians.

Amphibian Threats

Like most taxonomic groups, amphibians too face a range of pressures which threaten their survival and has resulted in a 42% decline in amphibian populations¹.

Figure 3. Pie chart representing the proportion of species impacted by the top 10 amphibian threats. Created using the data from the IUCN and EDGE of existence¹.

A species that has seen an alarming 90% population decline is the Mountain Chicken Frog^[4].

Mountain Chicken (Leptodactylus fallax)

The mountain chicken or as it is also known, the Giant Ditch Frog is a frog that belongs to the Leptodactylidaefamily and the Leptodactylus genus. Locals renamed this frog the mountain chicken as its flesh is said to taste of chicken. The frogs vary in colour but are mostly chestnut brown with a yellow underneath, they have a large body, large head and muscular legs.

Historically the species were present in Guadeloupe, Martinique, Saint Kitts and Nevis, Dominica and Montserrat, however they are currently only found in two locations; Dominica and Montserrat. In Dominica the species is restricted to an area of approximately 40km²and an even smaller area in Montserrat (less than 1km²). The species was last assessed in 2017 and was categorised as critically endangered on the IUCN red list due to their low population of 132 mature individuals and decreased range^[5].

Main Threats to the Mountain Chicken:

Habitat Loss	Logging and wood harvesting Land cleared for housing Tourism and recreational areasVolcanic activity on Montserrat
Overexploitation	National dish of Dominica (annual harvest of 8,000-36,000 individuals in 2002)⁵Replaced as the national dish in 2016 to reduce demand
Invasive Species	Mammal predationRats, Cats, Dogs, Pigs, Goats, Cows, Donkeys, the Common Possum (Dominica) and the Small Indian Mongoose Amphibians Increased competition from the Cane toad
Emerging Infectious Diseases	Chytridiomycosis Caused by the Batrachochytrium dendrobatidis (Bd) fungus

Chytridiomycosis

Batrachochytrium dendrobatidis (Bd) is a fungal pathogen which causes a skin disease called Chytridiomycosis and has devastating impacts on the functioning of an amphibian’s permeable skin. Bd was first discovered in 1999, it then emerged in Dominica in 2002 and in Montserrat in 2009. The international spread of this fungus is thought to be facilitated by the commercial trading of live amphibians^[6].The fungus is capable of colonising a large number of hosts and is known to infect at least 520 amphibian species^[7].

Most chytrid fungi are present in moist soils and fresh water which makes the mountain chicken susceptible as they lay their eggs in fresh water and moist soils. The African clawed frog (Xenapus laevis) and the North American Bullfrog (Lithobates catesbeianus) are widely traded and are both known carriers of Bd as they act as reservoir hosts, therefore when introduced to new environments they are able to pass the infection on to susceptible native species by sharing their habitat.

Researchers Fight a Devastating Amphibian Infection Using Heat ...

Figure 4. Ventral portion of a mountain chicken being swapped for chytrid tests^[8].

Infection sites are commonly identified on the ventral portion of the body in addition to the feet and digits (figure 4). The skin of amphibians is well vascularised which enables them to use it as their main respiratory organ. Chytrid zoospores infect the epithelial cells in the skin which causes damage and impacts of on homeostasis, respiration and the excretion of toxins. The optimum temperature for Bd is 23^oC which explains why it has depleted mountain chicken populations in the Caribbean.

Clinical signs:

Lethargy and poor swimming abilities which reduces foraging capacities
Muscle tremors
Excessive skin sloughing
Skin redness (erythema)
Skin discoloration
Affects the keratinised epidermal cells of adult amphibians and pre-keratinised mouth parts of larvae
Death due to electrolyte depletion and osmotic imbalance

Conservation efforts

Durrell Wildlife Conservation Trust, Zoological Society of London (ZSL), Chester Zoo, Norden’s Ark, Paignton Zoo and the governments of Montserrat and the Commonwealth of Dominica collaborated to form the Mountain Chicken Recovery Programme (MCRP). This is a 20-year recovery programme which aims to have a healthy population of mountain chickens as a flagship species for the islands natural and cultural heritage by 2034. There are also several biosecure populations at ZSL, Chester Zoo, Durrell Wildlife Conservation Trust and Norden’s Ark devoted to captive breeding^[9].

In 2009-2010, fifty individuals were translocated from Montserrat to zoological collections for captive breeding as the population was beginning to decline. The remaining in-situ individuals had an anti-fungal treatment trialled on them which was successful but ultimately not feasible in the long-term^[10].

Get involved with Conservation!

Become a member of the IUCN SSC Amphibian specialist group! – https://www.iucn-amphibians.org/getinvolved/become-an-asg-member/

Check out some of the amazing work ZSL’s EDGE of Existence programme are doing! – https://www.edgeofexistence.org/projects/

Donate if you can!

https://donate.zsl.org/support-zsl-london-whipsnade-zoos/?_ga=2.262517580.1778846652.1588263467-1430555776.1446463390

^[1]EDGE of Existence. 2020. EDGE Amphibians | EDGE Of Existence. [online] Available at: <https://www.edgeofexistence.org/amphibians/> [Accessed 30 April 2020].

^[2]Wake, D. and Koo, M., 2018. Amphibians. 28th ed. Berkley: Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA.

^[3]1974. Amphibians: Guidelines For The Breeding, Care, And Management Of Laboratory Animals.Washington: National Academies Press.

^[4]Zoological Society of London (ZSL). 2020. Mountain Chicken Frog Conservation. [online] Available at: <https://www.zsl.org/conservation/regions/americas/mountain-chicken-frog-conservation> [Accessed 30 April 2020].

⁵SSC), 2020. IUCN Red List Of Threatened Species: Mountain Chicken. [online] IUCN Red List of Threatened Species. Available at: <https://www.iucnredlist.org/species/57125/3055585> [Accessed 30 April 2020].

⁶Kolby, J. and Daszak, P., 2016. The Emerging Amphibian Fungal Disease, Chytridiomycosis: A Key Example of the Global Phenomenon of Wildlife Emerging Infectious Diseases. Microbiology Spectrum, 4(3).

⁷Van Rooij, P., Martel, A., Haesebrouck, F. and Pasmans, F., 2015. Amphibian chytridiomycosis: a review with focus on fungus-host interactions. Veterinary Research, 46(1).

⁸Parker, J., 2020. Researchers Fight A Devastating Amphibian Infection Using Heat. [online] The Scientist Magazine®. Available at: <https://www.the-scientist.com/notebook/researchers-fight-a-devastating-amphibian-infection-using-heat-66905> [Accessed 30 April 2020].

⁹Adams, S., Morton, M., Terry, A., Young, R., Dawson, J., Martin, L., Sulton, M., Cunningham, A., Garcia, G., Goetz, M., Lopez, J., Tapley, B., Burton, M. and Gray, G., 2014. Long-Term Recovery Strategy for the Critically Endangered mountain chicken 2014-2034.

¹⁰Hudson, M., Young, R., Lopez, J., Martin, L., Fenton, C., McCrea, R., Griffiths, R., Adams, S., Gray, G., Garcia, G. and Cunningham, A., 2016. In-situ itraconazole treatment improves survival rate during an amphibian chytridiomycosis epidemic. Biological Conservation, 195, pp.37-45.

Chocolate: A guilty pleasure or hidden health benefit?

We’ve all just had Easter weekend, I am sure for many of you that consisted of; resting, spending time with your family and eating ridiculous amounts of Easter eggs! So, I thought I would focus today’s post on the history of chocolate and its potential benefits.

The custom of having Easter eggs at Easter is associated with pagan traditions, it is believed to be an ancient symbol of new life and is used to celebrate the beginning of spring^[1]. On average 80 million Easter eggs are sold in the UK each year, with children receiving on average 8.8 eggs each^[2]!

Origin of chocolate

Theobroma cacao is a tropical hardwood tree which is also known as the cacao tree or cocoa tree. Theobroma cacao trees belong to the Malvaceae family and are classified under the Theobroma genus^[3]. These trees are found in west Africa, central Africa and in the tropical forests of South America^[4], as the plants thrive well in relatively high temperatures and humidity^[5]. They produce a fruit called a pod which turns yellow, red or purple wen ripe and each pod contains 20-60 reddish brown cocoa beans surrounded by a sugary pulp⁴(figure 1).

The Cacao Tree, Cacao Fruits & Cacao Beans - Aduna

Figure 1. Ripened pods on the Theobroma cacao tree^[6]

The tree is cultivated for its beans which are primarily used for the production of chocolate and cocoa butter^[7]. The Latin meaning of the word Theobroma means ‘food of the gods’ and the word chocolate is derived from the Aztec word ‘xocolatl’ meaning bitter water⁴. Historically, the Maya people in South America are thought to have been the first to have cultivated the cacao plant, however it is now largely cultivated due to the increased demand^[8]. The Mayans traditionally used the chocolate to produce a cocoa drink with hot water, cinnamon and pepper. The International Cocoa Organization (ICCO) recorded that 4,739,000 tonnes of cocoa beans were produced between 2016-2017, these beans were predominantly from Africa⁵.

Types of chocolate

The production method of chocolate produces different types of chocolate which have slightly different ingredients and characteristics. There are four types of chocolate⁵;

Dark chocolate – It contains both cocoa bean solids (make up to 80% of the total weight) and cocoa butter, it also has a slightly bitter aftertaste.

Gianduja chocolate –It combines hazelnuts, cocoa and sugar.

Milk chocolate –Itcontains; cocoa butter, sugar, milk powder, lecithin and cocoa solids (approx. 20-25% of the total weight). It also has a sweet taste.

White chocolate– It contains; cocoa butter, milk, sugar and no cocoa solids.

Baking 101: When to use different kinds of chocolate – SheKnows

Health benefits

The health benefits of chocolate stem from epicatechin which is a flavanol found in cacao^[9]. The manufacturing process of dark chocolate is able to retain epicatechin compared to milk, gianduja and white chocolate where significant amounts are lost, therefore making dark chocolate the best for your health. The important components found in chocolate consist of; flavonoids (antioxidants), cocoa butter, caffeine, theophylline and theobromine.

Cardiovascular benefits

Cocoa has been found to have positive effects on blood pressure, insulin resistance and vascular function. Low-density lipoprotein (LDL) cholesterol is found in a lot of food and has a negative impact on the body as it gets deposited on the endothelial lining of arterial walls, forming a plague which blocks the arteries causing diseases such as atherosclerosis. Cocoa has been found to have antioxidant effects such as delaying the oxidation of LDL cholesterol which reduces the risk of atherosclerosis and other heart diseases whilst improving blood pressure and platelet function^[10].

Polyphenols are micronutrients that are found in abundance in dark chocolate, they activate endothelial nitric oxide synthase which increases nitric oxide production. Nitric oxide causes vasodilation and as a result lowers blood pressure^[11]. It has also been found that cocoa plays a role in treating cerebral conditions such as a stroke as it is associated with increased cerebral blood flow^[12].

Immune System benefits

The positive effects of cocoa flavonoids on the immune system (related to several allergic mechanisms) are known, such as reducing the release of mediators, restoring the balance of T-helper 1 and T-helper 2 cells, and down-regulation of IgE production (the antibodies released in an allergic reaction)⁵.

Methylxanthines such as; caffeine, theophylline and theobromine are known to enhance the action of cAMP (cyclic adenosine monophosphate) which is a second messenger involved in intracellular signal induction and generating an immune response⁸. Through cAMP generating an immune response the body is able to defend itself against foreign bodies. Cocoa has also been found to protect nerves from injury and inflammation and through the antioxidant properties acts to protect skin from oxidative damage caused by exposure to UV radiation^[13].

Dangerous?

Despite the health benefits of cocoa on human health it has adverse effects of the health of other species such as dogs. In dog’s theobromine and caffeine have toxic effects on the nervous, cardiovascular and respiratory systems of canines. While us as humans are quickly able to digest and excrete methylxanthines, the absorption process in dogs is approximately six times longer^[14].

If a dog consumes large amounts of chocolate the symptoms displayed will commonly include; vomiting, haematemesis (vomiting up blood) and polydipsia (excessive drinking). These symptoms generally appear within two hours of ingestion it is possible they may take longer to appear due to the slow metabolism of theobromine. However, if your pet is exhibiting any of these symptoms please contact a veterinary professional for advice immediately.

Guilty pleasure or health benefit?

We are all aware that milk, gianduja and white chocolate have a greater negative impact on our bodies due to the addition of sugar and other ingredients which causes conditions such as; diabetes, obesity and dental decay to name a few^[15]. Compared to dark chocolate which has a growing list of health benefits for us humans! So, if you’re looking for a treat during this quarantine period and are health conscious reach for the dark chocolate (ideally sustainable and Fairtrade), but be sure to keep it out of reach of our furry friends!

How you can help!

You can donate to sustainable cocoa harvesting:

https://www.rainforest-alliance.org/support#region-2

^[1]Gillan, J., 2020. The Ancient Pagan Origins Of Easter. [online] Ancient-origins.net. Available at: <https://www.ancient-origins.net/myths-legends/ancient-pagan-origins-easter-001571> [Accessed 14 April 2020].

^[2]Naylor, D., 2020. 10 Fascinating Easter Facts That You Might Not Have Known. [online] mirror. Available at: <https://www.mirror.co.uk/news/world-news/10-fascinating-easter-facts-you-14384346> [Accessed 13 April 2020].

^[3]Bhattacharjee, R., 2018. Taxonomy And Classification Of Cacao. Burleigh Dodds Science Publishing Limited.

^[4]Rainforest Alliance. 2020. Species Profile: Cacao. [online] Available at: <https://www.rainforest-alliance.org/species/cacao> [Accessed 14 April 2020].

^[5]Montagna, M., Diella, G., Triggiano, F., Caponio, G., Giglio, O., Caggiano, G., Ciaula, A. and Portincasa, P., 2019. Chocolate, “Food of the Gods”: History, Science, and Human Health. International Journal of Environmental Research and Public Health, 16(24), p.4960.

^[6]Aduna. 2020. The Cacao Tree, Cacao Fruits & Cacao Beans – Aduna. [online] Available at: <https://aduna.com/blogs/learn/cacao-tree> [Accessed 15 April 2020].

^[7]Couch, J., Zintel, H. and Fritz, P., 1993. The genome of the tropical tree Theobroma cacao L. Molecular and General Genetics MGG, 237-237(1-2), pp.123-128.

^[8]Verna, R., 2013. The history and science of chocolate. The Malaysian journal of pathology, 35(2), pp.111-121.

^[9]Higginbotham, E. and Taub, P., 2015. Cardiovascular Benefits of Dark Chocolate?. Current Treatment Options in Cardiovascular Medicine, 17(12).

^[10]Corti, R., Flammer, A., Hollenberg, N. and Lüscher, T., 2009. Cocoa and Cardiovascular Health. Circulation, 119(10), pp.1433-1441.

^[11]Mancia, G., de Backer, G. and Dominiczak, A., 2007. 2007 ESH‐ESC Guidelines for the management of arterial hypertension. Blood Pressure, 16(3), pp.135-232.

^[12]Khawaja, O., Petrone, A., Kanjwal, Y., Gaziano, J. and Djoussé, L., 2015. Chocolate Consumption and Risk of Atrial Fibrillation (from the Physicians’ Health Study). The American Journal of Cardiology, 116(4), pp.563-566.

^[13]Katz, D., Doughty, K. and Ali, A., 2011. Cocoa and Chocolate in Human Health and Disease. Antioxidants & Redox Signaling, 15(10), pp.2779-2811.

^[14]Finlay, F. and Guiton, S., 2005. Chocolate poisoning. BMJ, 331(7517), p.633.

^[15]Żukiewicz-Sobczak, W., Wróblewska, P., Adamczuk, P. and Kopczyński, P., 2013. Causes, symptoms and prevention of food allergy. Advances in Dermatology and Allergology, 2, pp.113-116.

Ring-necked Parakeet: Tropical Invasion

Garden wildlife is the term used to encompass the countless species we regularly encounter in our gardens, common examples include; Grey squirrels (Sciurus carolinensis), Hedgehogs (Erinaceus europaeus), Red foxes (Vulpes vulpes), a range of bird species and numerous insects. We often don’t take the time to acknowledge the elaborate ecosystem in which we live and are surround by. For example, I have lived in my house for 11 years now and it wasn’t until this week that I noticed a flock of green birds both perched and flying around the cherry tree in my garden. These birds had a beautifully radiant plumage and were producing loud vocalisations, this aesthetic bird is the Ring-necked Parakeet.

Ring-necked Parakeet (Psittacula krameri)

The Ring-necked Parakeet or the Rose-ringed Parakeet as it is also known, is a large parrot which belongs to the Psittacidae family and the Psittaculagenus^[1]. The species is categorised as ‘least concern’ on the IUCN Redlist assessment which was conducted in 2018 and they have remained in this category since their first assessment 16 years ago. This category was justified due to their increasing population size, lack of threats and their extremely large geographical range, which are all sustainable conditions for a viable population.

Historically, Ring-necked Parakeet populations were found solely in the Asian and African continents. They are an example of an invasive, non-native species as they are now present in at least 35 countries across 5 continents^[2](figure 1), in locations such as; the UK, USA, Bolivia, Spain and Turkey to name a few. Previously they had migrated to Australia but have now been documented as extinct in Australia.

Figure 1. Global distribution of ring-necked parakeets. Map created using the data on the IUCN Redlist¹.

In Britain, the species is found predominantly in the south-east of England, particularly; Surrey, Kent and Sussex^[3]. The species was first known to breed in the wild in 1969 in Kent, south-east Londonand it is now estimated that there are 8,600 breeding pairs in the UK^[4]. Despite being an invasive species, they are protected in the UK under the Wildlife and Countryside Act 1981³.

The Parakeets arrival in Britain is not well understood, and there are many theories around how the species was introduced, for example; the birds escaping from the set of the movie ‘The African Queen’ or Jimi Hendrix releasing them on Carnaby Street in London in the 1960s^[5]. Despite the controversial theories of this exotic birds’ arrival, these birds are known to be involved in international pet trading^[6]. Therefore, it can be presumed that these parakeets were introduced to the UK as pets which may have escaped or had been deliberately released into the wild.

Identification

Ring-necked Parakeets have an average body length of 38-42cm and are easily identifiable through characteristics such as their;

Large green body
Curved red beak
Tapered tail
Pointed wings with black exterior

Male parakeets differ slightly in appearance as they possess a pink and black neck ring, which makes them easily distinguishable from the females.

Figure 2. Female parakeet [Photograph taken in Greater London, Smith, O.C.D., April 2020]

Figure 3. Male parakeet with black and pink neck ring [Photograph taken in Greater London, Smith, O.C.D., April 2020]

Behaviour

These Parakeets are a very adaptable species which can inhabit a vast range of environments. Suitable habitats for this species include; Forests, Savanna, Shrublands, Grasslands, Wetlands and Rural gardens. They have also been found at an upper elevation of 2,000m¹.

Ring-necked parakeets are hole-nesters which means they often compete with woodpeckers for available nests. They begin nesting in January which is early compared to some other birds which don’t begin nesting until June. An earlier breeding season is advantageous as this enables the parakeets to have the greatest selection of nesting sites with minimal competition for the holes, by species such as; starlings, woodpeckers and owls³. The average wild parakeet has a life expectancy of 15-20 years and reaches sexual maturity at 3 years old. The mature female produces as clutch of 2-4 eggs, which she incubates for approximately 3 weeks, once the young are 40-50 days old they will leave the nest³.

Parrots are well known for their vocal abilities, Parakeets are no different! These birds are very noisy as they produce a loud high-pitched screech which they use for communication^[7]. They are also able to copy human speech and can be taught specific words or phrases^[8].

Diet

Ring-necked parakeets frequently visit bird tables and garden feeders all year round but will particularly flock to gardens when food availability is scarce during the winter months. Limited resources mean species that share the same ecological niche have to compete, this interspecific competition for available food has had a massive impact on other avian species as they are often unsuccessful competitors against the large parakeet species^[9]. You will most likely observe these birds feeding either early in the morning or late afternoon as midday is reserved for other activities such as preening or loafing³.

In their natural tropical habitat, the species is herbivorous and traditionally consumes; fruit, berries, nuts, grains and seeds. Contrastingly, in the UK the species has been found to be omnivorous as they have been recorded feeding on; fruits, grains, seeds and scraps left by humans which often contain meat.

How can you help nature?

An easy way to relieve competition between bird species is to increase the resources available, therefore positioning a bird feeder in your garden can massively benefit bird populations! This allows species that have previously been out-competed by the parakeet such as; Starlings, Woodpeckers and Owls a chance to feed and increase their populations.

It is amazing if you want to help local bird populations thrive, but it is also important to consider the entire ecosystem. So, if you have some spare time have a look at some ideas below on how you can make your garden a home for wildlife!

Ways to make your garden wildlife friendly:

Add a bird bath
Add a bird feeder
Build nest boxes for birds
Build hedgehog boxes
Add a garden pond
Build insect homes
Build bat boxes

Other suggestions are available here: https://www.rspb.org.uk/get-involved/activities/give-nature-a-home-in-your-garden/?channel=paidsearch&gclid=CjwKCAjwpqv0BRABEiwA-TySwWV_NzxBPzg4qZAgIm8GBBeEPBH4ntbjjf6frSudleiGuI2X3YJKphoCbbYQAvD_BwE

^[1]Iucnredlist.org. 2018. IUCN Red List Of Threatened Species: Rose-Ringed Parakeet. [online] Available at: <https://www.iucnredlist.org/species/22685441/132057695#geographic-range> [Accessed 6 April 2020].

^[2]Ph.D. thesis, Dept of Zoology, Edward Grey Inst. of Field Ornithology, Univ. of Oxford., n.d. Population biology of the introduced rose‐ringed parakeet Psittacula krameri in the UK.

^[3]The RSPB. 2020. Ring Necked Parakeet Facts | Psittacula Krameri – The RSPB. [online] Available at: <https://www.rspb.org.uk/birds-and-wildlife/wildlife-guides/bird-a-z/ring-necked-parakeet/> [Accessed 6 April 2020].

^[4]Musgrove, A., Aebischer, N., Eaton, M., Hearn, R., Newson, S., Noble, D., Parson, M., Risely, K. and Stroud, D., 2003. Population estimates of birds in Great Britain and the United Kingdom. British Birds, (106), pp.64-100.

^[5]Heald, O., Fraticelli, C., Cox, S., Stevens, M., Faulkner, S., Blackburn, T. and Le Comber, S., 2019. Understanding the origins of the ring‐necked parakeet in the UK. Journal of Zoology.

^[6]Cassey, P., Blackburn, T., Russell, G., Jones, K. and Lockwood, J., 2004. Influences on the transport and establishment of exotic bird species: an analysis of the parrots (Psittaciformes) of the world. Global Change Biology, 10(4), pp.417-426.

^[7]Holden, P. and Abbott, G., n.d. RSPB Handbook Of Garden Wildlife.

⁸Wildlifetrusts.org. 2020. Ring-Necked Parakeet | The Wildlife Trusts. [online] Available at: <https://www.wildlifetrusts.org/wildlife-explorer/birds/parakeet/ring-necked-parakeet> [Accessed 6 April 2020].

⁹Le Louarn, M., Couillens, B., Deschamps-Cottin, M. and Clergeau, P., 2016. Interference competition between an invasive parakeet and native bird species at feeding sites. Journal of Ethology, 34(3), pp.291-298.

Locust Plague: Swarming East Africa

Current Situation

A swarm of pests have descended on the crops and pasture lands of countless east African countries, causing catastrophic damage for the farmers. They have most recently been seen in the democratic republic of Congo and have now made their way to Kuwait, Bahrain, Qatar and the coast of Iran. There are three key factors that cause locusts plagues; rainfall which aids egg development, temperature which also contributes to egg development and wind which is utilised for migration^[1].

Locusts are capable of eating their body weight in food every single day and in swarms of billions are able to devour large areas of pasture. This combined with their fast-reproductive rate and short gestation period makes them a major threat to countries reliant on agriculture to power their economy. This current swarm is having a significant impact on the less economically developed countries affected therefore the united nations have appealed for $138m to tackle the crisis^[2]. As these countries enter their rainy seasons (March-April)^[3]they can expect the swarms to increase in size and the effects to worsen, therefore more money will need to be donated to implement adequate control measures to reduce the likelihood of famine and starvation occurring.

Figure 1. Countries currently affect by the locust swarms^[4].

Desert Locust (Schistocerca gregoria)

The desert locust is a swarming short horned grasshopper that belongs to the Acrididae family and are endemic to the African continent and India^[5]. The average life span of a desert locust is three to five months however this is highly dependent on the environmental conditions. The life cycle consists of three stages; egg, nymph and the adult. The adult locust will lay their eggs in the soil, the egg will then take nutrients and moisture from the soil to aid their development before hatching into nymphs. It takes approximately two weeks for the egg to hatch into a nymph, however this stage is influenced by environmental temperature, the species also thrive after periods of heavy rainfall¹.

Desert locusts are able to adapt their behaviour, physiology and morphology to environmental changes and are known to exhibit two very different phenotypes. These two phenotypes are the solitary phase and the gregarious phase, these phases are distinguishable by the nymph’s appearance, behaviour and serotonin levels^[6]. During the solitary phase the solitary nymph matches its colouration to its surroundings and has lower serotonin levels whereas a gregarious nymph has a fixed colour pattern, higher serotonin levels and accumulate in large groups^[7].

Serotonin is a neurotransmitter that is secreted in humans particularly when they exercise and plays a significant role in improving an individual’s mood^[8]. However, in desert locusts it causes a behavioural change which causes a harmless solitary locust to transition into a gregarious locust that will swarm and have devastating effects on nearby crops. Overcrowding of solitary locusts increases the stimulation on the hind legs which increases the levels of serotonin (figure 2). It has also been found that the process can be reversed; transforming a gregarious locust into a solitary locust through the injection of dopamine into the haemocoel⁵.

Figure 2. The behavioural pathway in locusts and the role of serotonin^[9].

Link to Climate Change

It is thought that the swarms of locusts are a direct result of climate change, with increased rainfall, temperatures and cyclones. Within the last 18 months there have been several rare cyclones that have hit eastern Africa which has induced extended periods of unusually wet weather. The wet weather provides optimum breeding conditions for these insects as it makes the soil moist and ideal for them to lay their eggs in. The increased temperatures associated with climate change is thought to potentially shorten the maturation period resulting in more swarming adults being formed in a shorter time frame.

Control measures

Current control measures consist of both aerial and terrestrial spraying of insecticides combined with the continuous tracking of the swarms to identify vulnerable areas. However, resources are scarce and most countries only have limited equipment and trained individuals.

With funding the following techniques should be implemented:

Destroy egg masses
Dig trenches to trap nymphs
Use insecticides on crops and pasture land
Improve soil fertility

These control measures and resources all cost money, which is scarce in the affected countries. If you can help them please donate using any of the links below, no donation is too small!

^[1]Library.wmo.int. 2016. Weather And Desert Locusts. [online] Available at: <https://library.wmo.int/doc_num.php?explnum_id=3213> [Accessed 11 March 2020].

^[2]BBC News. 2020. In Pictures: Locust Swarms In East Africa. [online] Available at: <https://www.bbc.co.uk/news/in-pictures-51618188> [Accessed 11 March 2020].

^[3]Stone, M., 2020. A Plague Of Locusts Has Descended On East Africa. Climate Change May Be To Blame.. [online] National Geographic. Available at: <https://www.nationalgeographic.co.uk/environment-and-conservation/2020/02/plague-of-locusts-has-descended-east-africa-climate-change-may> [Accessed 11 March 2020].

^[4]BBC News. 2020. Locust Swarms Cross Into Hunger-Hit South Sudan. [online] Available at: <https://www.bbc.co.uk/news/world-africa-51547573> [Accessed 11 March 2020].

^[5]Hochkirch, A., Presa, J., Chobanov, D., Kirstin, A., Szovenyi, G., Kleukers, R., Rutschmann, F. and Willemse, L., 2020. IUCN Red List Of Threatened Species: Desert Locust. [online] Iucnredlist.org. Available at: <https://www.iucnredlist.org/species/16084387/74510644> [Accessed 11 March 2020].

^[6]Alessi, A., O’Connor, V., Aonuma, H. and Newland, P., 2014. Dopaminergic modulation of phase reversal in desert locusts. Frontiers in Behavioral Neuroscience, 8.

^[7]Anstey, M., Rogers, S., Ott, S., Burrows, M. and Simpson, S., 2009. Serotonin Mediates Behavioral Gregarization Underlying Swarm Formation in Desert Locusts. Science, 323(5914), pp.627-630.

^[8]Dfarhud, D., Malmir, M. and Khanahmadi, M., 2014. Happiness & Health: The Biological Factors- Systematic Review Article. Iran Journal of Public Health, 43(11), pp.1468-1477.

^[9]Burrows, M., Rogers, S. and Ott, S., 2011. Epigenetic remodelling of brain, body and behaviour during phase change in locusts. Neural Systems & Circuits, 1(1).

Coronavirus: An old disease with a new fear

Disease overview

Coronaviruses are a group of viruses that belong to the Coronaviridae family. They are classified based on their surface glycoproteins which form a crown-like appearance on the exterior of the virus, in addition to their chemistry and replication processes¹. There are seven coronaviruses including the novel coronavirus; COVID-19, all of which are zoonotic in nature. Coronaviruses have been reported in avian and mammalian populations, with the main difference being that it is capable of invading various tissues within the body. In the last two decades, three zoonotic coronaviruses have been identified; severe acute respiratory syndrome (SARS), middle east respiratory syndrome (MERS) and swine acute diarrhoea syndrome (SADS)².

Historically, coronaviruses were first discovered in bats as they act as reservoir hosts, they harbour a significantly higher proportion of zoonoses compared to other mammalian species³. The highly diverse cell types and receptors found in bats enable them to host a large variety of viruses. This combined with the bats ability to achieve sustained flight makes them effective vectors for the increased distribution of diseases, as there is increased interspecific interactions⁴.

Transmission

The virus is transmitted via airborne droplets which reside in the nasal mucosa before replicating locally in the ciliated epithelium resulting in tissue damage and inflammation¹. This tissue damage causes the production of nasal secretions containing shed viral particles which can then be spread through contaminated hands. Human-to-human transmission of the novel coronavirus has been described to have an incubation period of 2-10 days, during this time there are no clinical manifestations. Due to the airborne nature of the virus its effective transmission is facilitated by openly coughing without covering the mouth, poor sanitation and the improper sterilisation of surfaces. The virus is known to survive on inanimate surfaces such as; metal, glass or plastic for up to 9 days⁵.

Clinical Manifestations

COVID-19 is an infection of the upper respiratory tract, in common cases the symptoms include; fever, shortness of breath and a prominent cough. However, individuals with a weakened immune system as a result of age or use of immunosuppressant drugs are at a greater risk of developing more severe symptoms. In these severe cases, the infection can cause severe acute respiratory syndrome (SARS), kidney failure, pneumonia and ultimately death. In previously infected individuals’ immunity does not exist, therefore making them susceptible to re-infection.

Current Pandemic

The current COVID-19 outbreak started on 12^thDecember 2019, with the first case being reported from Wuhan, China⁶. It was discovered that the first infected individuals had visited the Huanan Seafood Market⁷in Wuhan, where dead and live animals are exchanged. These markets have been reported to have poor hygiene standards which increases the risk of diseases being transmitted from wildlife to humans. The first infected cases had all visited the markets in recent weeks which suggests the transmission occurred from wildlife to humans. However, as the outbreak progressed individuals who had not visited the markets were becoming infected, thus suggesting that the transmission occurred as a result of human to human interactions. It is believed that China’s food culture of eating live slaughtered animals²and the illegal wildlife trade⁸has contributed to the spread of this pandemic. On 31^stJanuary 2020, the centre for disease control (CDC) declared a state of emergency of international concern.

There are currently 90,870 confirmed COVID-19 cases reported across 72 countries, with 88.4% of these cases being reported in China⁸. There have been 3,112 deaths as result of this novel coronavirus. Within the last 24 hours new cases have been reported in; Andorra, Jordan, Latvia, Morocco, Portugal, Saudi Arabia, Senegal and Tunisia⁹.

Figure 1. Countries, territories or areas with confirmed cases of COVID-19, 03 March 2020⁹.

The incidence of coronaviruses is known to peak in the winter and cause short term epidemics lasting several months¹. Therefore, it is possible that the change in weather will reduce the incidence and prevalence of the viral infections.

Prevention

In an attempt to control the pandemic, it is recommended that the public:

Maintain good personal hygiene standards by regularly washing their hands throughout the day using either; alcohol-based hand gels or soap and water⁹
Avoid touching your eyes, nose and mouth
Keep a 1m distance from individuals who have a cough
Clean surfaces with disinfectants containing 62-71% ethanol, 0.5% hydrogen peroxide or 0.1% sodium hypochlorite as it inactivates the virus and prevents transmission³
Limit travel to affected areas

The government should:

Strengthen wildlife protection legislation (China should maintain their wildlife trading ban).
Increase public knowledge and public awareness⁸.

For more advice visit: https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public

For COVID-19 courses visit: https://openwho.org/channels/covid-19

¹Tyrrell, D. and Myint, S. (1996). Medical Microbiology. 4th ed. [S.l.]: University of Texas Medical Branch at Galveston.

²Fan, Y., Zhao, K., Shi, Z. and Zhou, P. (2019). Bat Coronaviruses in China. Viruses, 11(3), p.210.

³Olival, K., Hosseini, P., Zambrana-Torrelio, C., Ross, N., Bogich, T. and Daszak, P. (2017). Host and viral traits predict zoonotic spillover from mammals. Nature, 546(7660), pp.646-650.

⁴Wong, A., Li, X., Lau, S. and Woo, P. (2019). Global Epidemiology of Bat Coronaviruses. Viruses, 11(2), p.174.

⁵Kampf, G., Todt, D., Pfaender, S. and Steinmann, E. (2020). Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents. Journal of Hospital Infection, 104(3), pp.246-251.

⁶Centers for Disease Control and Prevention. (2020). Coronavirus Disease 2019 (COVID-19). [online] Available at: https://www.cdc.gov/coronavirus/2019-ncov/summary.html [Accessed 3 Mar. 2020].

⁷Sahin, A. (2020). 2019 Novel Coronavirus (COVID-19) Outbreak: A Review of the Current Literature. Eurasian Journal of Medical Investigation.

⁸Bell, D., Roberton, S. and Hunter, P. (2004). Animal origins of SARS coronavirus: possible links with the international trade in small carnivores. Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences, 359(1447), pp.1107-1114.

⁹ Who.int. (2020). Coronavirus disease 2019 (COVID-19) – Situation Report 43. [online] Available at: https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200303-sitrep-43-covid-19.pdf?sfvrsn=2c21c09c_2 [Accessed 3 Mar. 2020].