Can we learn more about human cancer from dogs?

Can we learn more about human cancer from dogs?

Can we learn more about human cancer from dogs?

The study of cancer through comparative oncology (the study of cancers in both humans and animals), in recent times, has provided invaluable insights on how the pet-dog is not only man’s companion but also plays an integral role in improving human health and well-being. More importantly, reiterating the added value of One Health (which is a collaborative and multidisciplinary approach to solving societal challenges) by acting or having the potential to act as sentinels (early warning systems) and models for studying, early diagnosis and treatment of human cancer.

Cancer is a devastating diagnosis and may have touched us at some point in our lives, either directly as a patient, or as a relative, friend, workmate or owner to a pet (Figure-1) that develops cancer. Worldwide, it continues to torment man and dog alike, with the global burden increasing in both species.

Figure 1: Lung cancer in a dog

Figure 1: Lung cancer in a dog

 In Kenya, cancer ranks as the number three cause of mortality in humans, after infectious diseases and cardiovascular diseases, with the number of cancer cases projected to nearly double by 2030. This has and will continue to escalate the ‘double burden’ of disease, with an accompanying dual effect of not only straining existing health-care systems but also causing loss of income to already poor families and posing cumulative economic losses. The challenge of addressing cancer in Kenya has been attributed to several technical, economic, infrastructural and social factors.

 The dog is of special interest compared to other laboratory and domestic animals in studying human cancer, because: it naturally and increasingly develops spontaneous cancer similar to humans, which could be as a result of the increasing ‘human-dog bond’ which increases their exposure to similar risk factors and environmental carcinogens (things that cause/initiate cancer). Moreover, the dog is phylogenetically closely related to man this is supported by the fact that, approximately all the 19000 genes identified in the dog match to a similar gene in the human genome. Astonishingly the clinical signs of cancer in dogs also have a close resemblance to those of humans (see Figure-2).

Figure 2: Clinical signs of cancer

Figure 2: Clinical signs of cancer

 Several studies have documented that pet-dogs respond to a number of environmental carcinogens, similar to the way humans do. For instance, the association between industrial activity and consequent bladder cancer has been established, with the dog having a shorter latent period of bladder cancer (10 years), as compared to man (20 years). Thus, humans and dogs do develop similar cancers when exposed to similar risk factors or carcinogens, and by inference, monitoring the health of pet-dogs will aid early identification and correlation between exposure to environmental contaminants and cancer in humans.

Published work in Nairobi (http://dx.doi.org/10.14202/IJOH.2016.42-57) shows that the common cancers in both male humans and dogs are those of the Prostate, the Respiratory tract, Lymphoma and Liver, while in females they are those of the Breast, Mouth, Liver and Lymphoma (see Figure-3 elaborating on lymphosarcoma). With the breeds commonly affected with cancer being those of the German Shepherd, cross breeds and Rottweilers, this could also be attributed to the high population ownership of those breeds as well.

Figure 3: Brief description of lymphosarcoma

Figure 3: Brief description of lymphosarcoma

 

 The high cases of prostate cancer in both male humans and dogs could probably be related to testosterone levels, with a lower occurrence in male dogs compared to humans probably due to dog castration/neutering. The high cases of mammary gland cancers in both dogs and humans, could be explained by the fact that a high proportion of females in both groups are entire (not spayed). Both humans and dogs have high cases of liver cancers which can be explained by the fact that both feed on common diets, specifically maize meal which is prone to aflatoxin contamination.

Clinically most cancers would appear as masses (see figure 4) and clinicians are inclined to surgically remove the mass and this is why the surgical method of treatment is a common therapeutic intervention in both humans and dogs to control or eliminate local cancer in an attempt to improve the quality of the patient’s life; while the medical approach is mainly used on palliative basis. Chemotherapy is also used in some cases (or in combination with surgery) mainly to ease pain and provide the highest quality of life in both humans and pet dogs.

Figure 4: Tumour of the mouth in dog


Figure 4: Tumour of the mouth in dog

 The co-sharing of some of the cancers by both humans and dogs fortifies that it may be possible to use dogs as models and sentinels in studying human cancers. This, therefore, reiterates the fact that developing joint animal-human cancer registries and integrated cancer surveillance systems may possibly lead to accelerated detection of the risks of cancer, especially in developing countries where cancer incidences have recently been shown to be spiking. This calls for more comparative research in this area in order to empower with information for giving collaborative policy guidelines in cancer prevention and control in both humans as well as animals. Since cancer prevention is one of the primary objectives in the government of Kenya, we (physicians and veterinarians-and their sub-groupings) have a responsibility to advise people and pet owners on the benefit of simple lifestyle changes as a means of reducing the risk of cancer in Kenya and other developing countries as well.

If you work in Veterinary Cancer Registry field, join the Global Initiative for Veterinary Cancer Surveillance https://www.givcs.org/

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Important Infectious Diseases Outbreaks in Kenya between 1947 to 2018

Important Infectious Diseases Outbreaks in Kenya between 1947 to 2018

Important Infectious Diseases Outbreaks in Kenya between 1947 to 2018

Infectious diseaseYear (last outbreak)Cases
Anthrax 201819
Chikungunya201840
Cholera 20185781
Hepatitis B2018
Measles2018
Rabies 2018
Rift Valley fever 2018120
Amoebiasis 201730
Dengue 20171199
Leishmaniasis - visceral2017277
Malaria2017144
Hepatitis E201621
Typhoid and enteric fever 2015317
Rubella 2014646
Poliomyelitis and acute flaccid paralysis201314
Brucellosis 2011*
Escherichia coli diarrhea200918
Shigellosis200919
Schistosomiasis - haematobium 200830
Schistosomiasis - mansoni200877
Meningitis - bacterial2006131
Leptospirosis2004141
O'nyong nyong200415
Q-fever 2000*4
Orf1994*
Yellow fever199355
Plague199044
Salmonellosis 198798
Tuberculosis1987*
Trypanosomiasis - African1984
Botulism19796
Conjunctivitis - viral1974
Enterovirus infection1974
Trichinosis1972*
Relapsing fever1947*
* indicates publication year (not necessarily year of outbreak)

Source: Global Infectious Diseases and Epidemiology Network website available at https://web.gideononline.com/ and accessed on 19th December 2018

Online disease reporting systems: rhetoric or reality?

Online disease reporting systems: rhetoric or reality?

Online disease reporting systems: rhetoric or reality?

Introductory remark

Generally, under the emblem of a One Health approach towards disease surveillance, the media and health professionals (Fig.1) have a critical role when it comes to disease surveillance and reporting.

Fig1. A clinical officer collecting field data from a respondent for surveillance purposes. Photo credit: ZED Group

The media are many times, alluded as “unofficial sources” when it comes to disease reporting while the Director of Veterinary/Medical Services and/or the County Directors of Veterinary/Medical Services are alluded as “official sources.” It is important to argue from a point of evidence and weigh the pros and cons of both and especially reiterating their complementation. I will try to convince you how these three systems complement each other and especially support the importance of having the open access online reporting systems (of which the media plays a huge role).

Categorizing the online disease reporting systems

 The term online disease reporting systems bring to mind initially three groups of disease reporting systems:
  • Open access systems such as ProMED-mail founded in 1994 (ProMED-mail, 1994), HealthMap founded in 2006 (Healthmap, 2006), which capture a wide range of disease outbreaks and others targeting a single disease/pathogen e.g. Global Ranavirus reporting system (GRRS, 2015) (it is important to note that both ProMED-mail and Healthmap, borrow alot of their information from the media as well as the official reporting systems such as WAHIS as well as WHO-DONs)
  • Closed access systems such as those at the level of government ministries using the DHIS2 web application (such as the Health Information System in Kenya (Fig.2) and Lebanon initiated by World Health Organisation (WHO, 2014) and also the Visual Confidentiality Mobility Report system in Los Angeles (Dibya, 2002).
  • Semi-closed systems such as the more recently launched EPICORE system which is trying to provide a platform of “verifying” or discarding the rumours from the media through the use of speciliasts to verify outbreak related information.

Fig2. The user interface of the Kenya Health Information System

Systems like ProMED-mail disseminates its information via email lists, websites and social media. Which is a free subscription service with over 75,000 subscribers in 180 countries. The accuracy and quality of all reports on ProMED-mail may be assured because all reports are screened by experts before posting (Woodall, 2015).

Benefits of online disease reporting systems

Several benefits or “added value” of online disease reporting systems are:

  • Provide early warning of outbreaks of infectious diseases, toxins and environmental contamination affecting humans, animals and food and feed worldwide e.g. Avian Influenza-H7N9 in China (ProMED-mail, 2016)
  • Ability to access the reports by mobile devices e.g. cell phones from locations without health services and therefore connection cost is not borne by the ministry of health e.g. HealthMap android App
  • Ability of the public to monitor and easy to understand visualizations of disease epidemiology such as the HealthMap e.g. Chronic wasting disease in deer in Oneida county-Wisconsin, click to view image-HealthMap-CWD-Wiscosin.png  (HealthMap, 2016)
  • Enhancing accuracy and accelerating the collection of reported information to a central point as compared to the old decentralized systems of using phoned/faxed reports that would result to lateness and full of errors (see SARS outbreak in Beijing (Healthxchange, 2013) which resulted to adoption of online systems) and the Visual CMR system in Los Angeles (Sarkar, 2002).
  • A more recent system (The EPICORE system Fig.3) is trying to provide a pathway of “verifying or discarding the rumours from the media.”

The EPICORE system interface. Visit the website to apply to be a member (https://epicore.org/#/home)

A case study from Kenya: The Emergency Operation Centre

I would like to reiterate the importance of all the three groups of systems working together in kind of an integration, that is more important than relying on one system. Let me try and clarify using a Kenya context based example as below: The Emergency Operation Centre (EOC) anchored within the Ministry of Health, specifically under the Disease Surveillance and Response Unit is part of Kenya’s Emergency Preparedness and Response programme. The EOC collects data from social media, websites of mainstream media, direct calls and other numerous sources regarding outbreaks and public events of health importance which they use to generate daily reports. Based on these reports they send out alerts to key people for actioning. This is a very good example of a system that has adapted to the technological growth of information for efficient and effective detection and response to outbreaks in Kenya. Of course, in the long run, verified information is important but the question is should we only respond to outbreaks based on the verified information or also on the preliminary information. In my opinion, both have a part to play in an outbreak/emergency scenario using different intervention mechanisms.

Conclusions

In conclusion, the online disease reporting systems have revolutionized surveillance systems and in future social media e.g. Twitter may become an invaluable source of disease outbreaks and it will be imperative to think of a way of advising the public on how to interpret and act on this information. In future, it may also be important for governments to integrate these ‘open access’ systems into their surveillance systems.

Online disease reporting systems provide an early/preliminary working strategy for public safety pending confirmation; for instance, the anthrax outbreak in wildlife in Kenya, if you check on ProMED-mail, the first alert was on 22nd July 2015 sourced from DailyNation (ProMED-mail, 2015a), while the second official report came from OIE on 27 August 2015 (ProMED-mail, 2015b). If the legal action could have been taken on August, 27 you can imagine what would have happened. This certainly informs us that the media and online open access reporting systems do have a role to play in disease surveillance and reporting but above and beyond that, they act as a quick and first line of “defence” termed as “early warning systems” (Madoff, 2004).

Remember to drop your questions, comments and feedback as well.

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Seasonality of Viral Encephalitis and Associated Environmental Risk Factors in Vietnam (2004-2013)

Seasonality of Viral Encephalitis and Associated Environmental Risk Factors in Vietnam (2004-2013)

Seasonality of Viral Encephalitis and Associated Environmental Risk Factors in Vietnam (2004-2013)

The first in a series of papers by Hu Suk exploring the relation between environment and disease supported by CCAFS and (secondarily) by A4NH. This information can help in both disease forecasting and diagnosis.
Read the full paper by clicking here
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The EU report on trends &sources of zoonoses, zoonotic agents and food-borne outbreaks in 2015

The EU report on trends &sources of zoonoses, zoonotic agents and food-borne outbreaks in 2015

The EU report on trends &sources of zoonoses, zoonotic agents and food-borne outbreaks in 2015

“This report of EFSA and the European Centre for Disease Prevention and Control presents the results of the zoonoses monitoring activities carried out in 2015 in 32 European countries (28 Member States (MS) and four non-MS). Campylobacteriosis was the most commonly reported zoonosis and the increasing European Union (EU) trend for confirmed human cases since 2008 continued. In food, the occurrence of Campylobacter remained high in broiler meat. The decreasing EU trend for confirmed human salmonellosis cases since 2008 continued, but the proportion of human Salmonella Enteritidis cases increased. Most MS met their Salmonella reduction targets for poultry. More S. Enteritidis isolates were reported and S. Infantis was confirmed as the most frequent serovar isolated from domestic fowl. In foodstuffs, the EU level Salmonella non-compliance for minced meat and meat preparations from poultry was low. Despite the significant increasing trend since 2008, the number of human listeriosis cases stabilised in 2015. In ready-to-eat foods, Listeria monocytogenes seldom exceeded the EU food safety limit. The decreasing EU trend for confirmed yersiniosis cases since 2008 continued. Positive findings for Yersinia were mainly reported in pig meat and products thereof. The number of confirmed shiga toxin-producing Escherichia coli (STEC) infections in humans was similar to 2014. In food, STEC was most frequently reported in meat from ruminants. A total of 4,362 food-borne outbreaks, including waterborne outbreaks, were reported. Bacteria were the most commonly detected causative agents, followed by bacterial toxins, viruses, other causative agents and parasites. The causative agent remained unknown in 33.5% of all outbreaks. As in previous years, Salmonella in eggs continued to represent the highest risk agent/food combination. The report further summarises trends and sources for tuberculosis due to Mycobacterium bovis, Brucella, Trichinella, Echinococcus, Toxoplasma, rabies, Coxiella burnetii (Q fever), West Nile virus and tularaemia.”

Source: http://ecdc.europa.eu/en/publications/Publications/EU-summary-report-trends-sources-zoonoses-2015.pdf

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Click image to view the report