June 4, 2018

 

No treatment yet for blackhead disease in poultry

 

 

The US Food and Drug Administration (FDA) has issued a warning against a poultry disease that has no approved treatments yet in the United States.

 

The FDA said blackhead disease (histomoniasis) is an important poultry disease that affects turkeys and chickens, among others. The disease is caused by Histomonas meleagridis, a protozoan that is transmitted to the bird by the parasite Heterakis gallinarum, a type of nematode, or roundworm.

 

Healthy birds become infected with H. meleagridis when they eat food, invertebrates (such as earthworms), or bird droppings that are contaminated with the protozoa. Because chickens commonly have the roundworm H. gallinarum in their intestines, they often are the source of the protozoal infection for other birds.

 

According to the FDA, birds with blackhead disease are usually listless and have drooping wings, unkempt feathers and yellow droppings. Young birds become sick quickly and usually die within a few days after clinical signs appear. The disease develops more slowly in older birds and they often become emaciated and may eventually die.

 

The FDA said turkeys are highly susceptible to blackhead disease, adding that mortality in an infected turkey flock can reach up to 70%-100%. The US turkey industry reported at least 50 outbreaks of the disease each year since 2009.

 

Less severe in chickens

 

In chickens, blackhead disease is less severe but can lead to poor health and reduced egg production.

 

Prior to 2015, Histostat (nitarsone) was the only FDA-approved drug to prevent blackhead disease in poultry. In 2015, the drug manufacturer voluntarily stopped marketing Histostat and requested withdrawal of the drug's approval due to concerns about inorganic arsenic levels in treated birds.

 

At present, there are no animal drugs approved to prevent, treat, or control blackhead disease in the US, the FDA said.

 

The FDA is encouraging academic institutions, the poultry industry and animal drug companies to invest in promising therapies, such as drugs or vaccines, to treat, control or prevent the disease.

 

It is also encouraging these groups to work with FDA to ensure their research efforts align with the requirements for drug approval or to work with the US Department of Agriculture for vaccine development. "This collaboration will hopefully lead to much-needed safe and effective approved therapies against blackhead disease getting to the marketplace efficiently and quickly", FDA said.