Tuesday, April 23, 2013

Aye papi!



Fibropapillomatosis: Global Disease Plaguing Endangered Sea Turtles

Fibropapillomatosis (FP) is a “complex and disfiguring disease that effects mainly green turtles; but has been found in other species (e.g. loggerheads, Kemp’s ridleys, and Olive ridley). This disease causes “benign, cauliflower-like tumors found on the soft tissue of sea turtle”. They can inhibit a turtle’s eating and swimming as well as vision. The tumors can also in severe cases grow internally, causing a variety of health problems for the turtles; while some of the internal tumors have been found to have low-grade malignancy.  According to EcoHealth alliance, incidence of FP have been increasing over the past 20 years.

The exact origin of the disease is unknown, but has been associated with two herpes viruses (i.e. papillomavirus and retrovirus).  FP has been shown to have a strong correlation to pollution in warmer parts of the ocean (e.g. algae blooms, fertilizer runoff, pet waste). 

According to Kawachi, 2012, anthropogenic land-based sources of pollution such as elevated nutrient inputs appear to negatively impact marine hervibores by stimulating a nutrient storage metabolism of bloom species of marine plants.

Eco Health Alliance has stated that there is a slight chance that if turtles can last long enough with these tumors, they may begin to shrink. Ongoing research is in progress to determine why this regression takes place. “The epidemiology of FP can also serve as an effective tool to monitor ecosystem health in local warm-water, near-shore marine habitats” (EcoHealth Alliance, 2006).  

If you are interested in learning more about this subject, Kawachi did an in depth study on the topic and is listed in the references below.  

 

References:

Eco health Alliance. 2006. http://www.ecohealthalliance.org/news/55fibropapillomatosis_global_disease_plaguing_endangered_sea_turtles

 
Kawachi, M., 2012. TESTING LINKS AMONG EUTROPHICATION, BLOOM ALGAE, AND GREEN TURTLE FIBROPAPILLOMATOSIS. Online. Available through Proquest. http://search.proquest.com/docview/1267130377
 

Monday, April 8, 2013

Flu the coop.



New strain of bird flu jumps to humans


H7N9, one serotype of the influenza A H7 virus, has jumped from animals to humans in China.We have posted on avian influenza in the past, but with recent activity in China, thought it was important to relay this health warning. 
The following Q&A section is taken directly from the World Health Organization website.

Frequently Asked Questions on human infection with influenza A(H7N9) virus, China
Update as of 5 April 2013

Note that this document supersedes the previous version. Updates will be posted as new information becomes available.

1. What is the influenza A(H7N9) virus?
Influenza A H7 viruses are a group of influenza viruses that normally circulate among birds. The influenza A(H7N9) virus is one subgroup among the larger group of H7 viruses. Although some H7 viruses (H7N2, H7N3 and H7N7) have occasionally been found to infect humans, no human infections with H7N9 viruses have been reported until recent reports from China.

2. What are the main symptoms of human infection with influenza A(H7N9) virus?
Thus far, most patients with this infection have had severe pneumonia. Symptoms include fever, cough and shortness of breath. However, information is still limited about the full spectrum of disease that infection with influenza A(H7N9) virus might cause.

3. How many human cases of influenza A(H7N9) virus have been reported in China to date?
New cases that are reported are now being compiled and posted daily. The most current information on cases can be found in Disease Outbreak News.

4. Why is this virus infecting humans now?
We do not know the answer to this question yet, because we do not know the source of exposure for these human infections. However, analysis of the genes of these viruses suggests that although they have evolved from avian (bird) viruses, they show signs of adaption to growth in mammalian species. These adaptations include an ability to bind to mammalian cells, and to grow at temperatures close to the normal body temperature of mammals (which is lower than that of birds).

5. What is known about previous human infections with H7 influenza viruses globally?
From 1996 to 2012, human infections with H7 influenza viruses (H7N2, H7N3, and H7N7) were reported in the Netherlands, Italy, Canada, United States of America, Mexico and the United Kingdom. Most of these infections occurred in association with poultry outbreaks. The infections mainly resulted in conjunctivitis and mild upper respiratory symptoms, with the exception of one death, which occurred in the Netherlands. Until now, no human infections with H7 influenza viruses have been reported in China.

6. Is the influenza A(H7N9) virus different from influenza A(H1N1) and A(H5N1) viruses?
Yes. All three viruses are influenza A viruses but they are distinct from each other. H7N9 and H5N1 are considered animal influenza viruses that sometimes infect people. H1N1 viruses can be divided into those that normally infect people and those that normally infect animals.

7. How did people become infected with the influenza A(H7N9) virus?
Some of the confirmed cases had contact with animals or with an animal environment. The virus has been found in a pigeon in a market in Shanghai. It is not yet known how persons became infected. The possibility of animal-to-human transmission is being investigated, as is the possibility of person-to-person transmission.

8. How can infection with influenza A(H7N9) virus be prevented?
Although both the source of infection and the mode of transmission are uncertain, it is prudent to follow basic hygienic practices to prevent infection. They include hand and respiratory hygiene and food safety measures.

Hand hygiene:
• Wash your hands before, during, and after you prepare food; before you eat; after you use the toilet; after handling animals or animal waste; when your hands are dirty; and when providing care when someone in your home is sick. Hand hygiene will also prevent the transmission of infections to yourself (from touching contaminated surfaces) and in hospitals to patients, health care workers and others.
• Wash your hands with soap and running water when visibly dirty; if not visibly dirty, wash your hands with soap and water or use an alcohol-based hand cleanser.
Respiratory hygiene:
• Cover your mouth and nose with a medical mask, tissue, or a sleeve or flexed elbow when coughing or sneezing; throw the used tissue into a closed bin immediately after use; perform hand hygiene after contact with respiratory secretions.

9. Is it safe to eat meat, i.e. poultry and pork products?
Influenza viruses are not transmitted through consuming well-cooked food. Because influenza viruses are inactivated by normal temperatures used for cooking (so that food reaches 70°C in all parts— "piping" hot — no "pink" parts), it is safe to eat properly prepared and cooked meat, including from poultry and game birds.

Diseased animals and animals that have died of diseases should not be eaten.
In areas experiencing outbreaks, meat products can be safely consumed provided that these items are properly cooked and properly handled during food preparation. The consumption of raw meat and uncooked blood-based dishes is a high-risk practice and should be discouraged.

10. Is it safe to visit live markets and farms in areas where human cases have been recorded?
When visiting live markets, avoid direct contact with live animals and surfaces in contact with animals. If you live on a farm and raise animals for food, such as pigs and poultry, be sure to keep children away from sick and dead animals; keep animal species separated as much as possible; and report immediately to local authorities any cases of sick and dead animals. Sick or dead animals should not be butchered and prepared for food.

11. Is there a vaccine for the influenza A(H7N9) virus?
No vaccine for the prevention of influenza A(H7N9) infections is currently available. However, viruses have already been isolated and characterized from the initial cases. The first step in development of a vaccine is the selection of candidate viruses that could go into a vaccine. WHO, in collaboration with partners, will continue to characterize available influenza A(H7N9) viruses to identify the best candidate viruses. These candidate vaccine viruses can then be used for the manufacture of vaccine if this step becomes necessary.

12. Does treatment exist for influenza A(H7N9) infection?
Laboratory testing conducted in China has shown that the influenza A(H7N9) viruses are sensitive to the anti-influenza drugs known as neuraminidase inhibitors (oseltamivir and zanamivir). When these drugs are given early in the course of illness, they have been found to be effective against seasonal influenza virus and influenza A(H5N1) virus infection. However, at this time, there is no experience with the use of these drugs for the treatment of H7N9 infection.

13. Is the general population at risk from the influenza A(H7N9) virus?
We do not yet know enough about these infections to determine whether there is a significant risk of community spread. This possibility is the subject of epidemiological investigations that are now taking place.

14. Are health care workers at risk from the influenza A(H7N9) influenza virus?
Health care workers often come into contact with patients with infectious diseases. Therefore, WHO recommends that appropriate infection prevention and control measures be consistently applied in health care settings, and that the health status of health care workers be closely monitored. Together with standard precautions, health care workers caring for those suspected or confirmed to have influenza A(H7N9) infection should use additional precautions (http://www.who.int/csr/resources/publications/swineflu/WHO_CDS_EPR_2007_6/en/index.html).

15. What investigations have begun?
Local and national health authorities are taking the following measures, among others:
• Enhanced surveillance for pneumonia cases of unknown origin to ensure early detection and laboratory confirmation of new cases;
• Epidemiological investigation, including assessment of suspected cases and contacts of known cases;
• Close collaboration with animal health authorities to determine the source of the infection.

16. Does this influenza virus pose a pandemic threat?
Any animal influenza virus that develops the ability to infect people is a theoretical risk to cause a pandemic. However, whether the influenza A(H7N9) virus could actually cause a pandemic is unknown. Other animal influenza viruses that have been found to occasionally infect people have not gone on to cause a pandemic.

17. Is it safe to travel to China?
The number of cases identified in China is very low. WHO does not advise the application of any travel measures with respect to visitors to China nor to persons leaving China.

18. Are Chinese products safe?
There is no evidence to link the current cases with any Chinese products. WHO advises against any restrictions to trade at this time.

Other resources for information about avian influenza:

references:

Monday, April 1, 2013

If you only Gnu



Species focus: Wildebeest and disease concerns

















Description:

The wildebeest , belonging to the family Bovidae has two species, (Connochaetes gnou – black wildebeest; Connochaetes taurinus – blue wildebeest); both native to Africa. The black wildebeest is known as the white tail gnu, and the blue, the brindled gnu. It is the most abundant large game species in Africa. They are even toed, horned ungulates.

Physiology:

Blue: Bigger of the two species; standing 150cm tall and weighing 180kg. The horns of the blue wildebeest protrude to the side then curve downward and up. They tend to be grey in color. The blue utilize a wide variety of habitat [woodland and grassland]. The blue gnu migrate over very long distances in the winter. The wildebeest is best known for this annual migration and will be discussed below.

Black: stands 120cm tall; their horns curve forward, then downwards and back up at tips. They have brown colored fur. The black gnu reside exclusively in open grassland and do not migrate.

This link provides a really good overview of the species.

Disease implications and etiology:

As many as one million wildebeest make a 1,800 mile migration each year.  All wildebeest are reservoirs for the disease MCF (Malignant Catarrhal fever). They themselves have no clinical signs of infection or disease, however can transfer the disease to other species, especially domestic livestock. With such vast numbers of animals moving in close proximity to cattle in Africa, it is a big concern. In adults, the virus is cell associated, and is rarely transmitted to other animals. With approximately 400,000 wildebeest being born yearly on migration, this is where the disease is spread. Calve shed the cell-free virus until approximately 4 months of age. This is done via lacrimal and nasal secretions, along with feces. “MCF  can be transmitted to cattle and other susceptible species by inhalation in aerosol droplets, ingestion of contaminated feed and water, or possibly transmission by arthropods” (CVMA,2008).

(Next section is an excerpt from the CVMA website) “Malignant catarrhal fever is a gammaherpesvirus that persists as a subclinical infection in carrier species, such as wildebeest and sheep. In certain ruminants, primarily cattle, bison and deer, it is frequently a fatal disease. The two main epidemiologic forms of MCF are named for the reservoir species of the disease. Alcelaphine herspesvirus-1 (AlHV-1) is the African form or wildebeest-associated MCF (WA-MCF) and Ovine herpesvirus-2 (OvHV-2) is the sheep-associated MCF (SA-MCF).   The carrier species are well adapted to the virus and not affected by the disease. Carrier hosts transmit the virus to clinically susceptible animals when in close contact or via fomites.   Clinically and histopathologically, the two forms of the disease are indistinguishable. Poorly adapted hosts, such as cattle, are considered dead-end hosts that do not shed the infectious virus”. 

It is important to note this is not a zoonotic disease, so there is no threat to humans; however it can be economically devastating. 

This link has an in depth look at MCF and is worth reading.

References:

 
CDS, 2010. Tackling wildebeest disease to save cattle.  http://www.ukcds.org.uk/news-Tackling_wildebeest_disease_to_save_cattle-224.html
 
CVMA, 2008. Wildebeest-Associated Malignant Catarrhal Fever.  http://www.cvma.net/doc.asp?id=20386