Lumpy Skin Disease: Does It Spread To Humans? Is It Safe To Consume Milk?

According to official figures, the aggregate number of cattle deaths caused by lumpy skin disease has reached 97,435 as of 23 September, nearly double the 49,682 deaths recorded three weeks ago.

According to the Ministry of Fisheries, Animal Husbandry and Dairying, the lumpy skin disease has affected over 20 lakh animals in 251 districts across 15 states [1]. In April, the first infection was reported in Gujarat's Kutch region, where over 75,000 cattle have died since July. Rajasthan has experienced the most severe losses, with 14 lakh cattle dying.

What Is Lumpy Skin Disease?

Lumpy skin disease (LSD) is an infectious disease in cattle caused by a virus belonging to the family Poxviridae, also known as the Neethling virus. It is a virus that affects cattle. In addition, blood-feeding insects, such as certain species of flies and mosquitoes, as well as ticks, transmit the disease [2].

There are several African countries where the disease is present. In 2012, the disease spread from the Middle East to south-east Europe, affecting EU Member States (Greece and Bulgaria) and several other countries in the Balkans. There is now a vaccination program to arrest the spreading of the disease.

Lumpy skin disease virus shares similarities with sheep and goat pox. It is not a zoonotic virus; therefore, it cannot be transmitted to humans.

What Causes The Lumpy Skin Disease?

Blood-feeding insects, such as certain species of flies and mosquitoes, as well as ticks, transmit lumpy skin disease [3]. The lumpy skin disease is caused by the capripox virus and affects only cattle and not humans. It is spread by flies, mosquitoes, lice and wasps and is responsible for causing nodules to appear on the skin.

What Are The Symptoms Of Lumpy Skin Disease?

The symptoms of lumpy skin disease in cattle include high fever, reduced milk output, skin nodules, loss of appetite, increased nasal discharge, and watery eyes [4].

How Does Lumpy Skin Disease Spread?

Infected animals may shed the virus through oral and nasal secretions, which may contaminate common feeding and watering troughs, according to the United Nations Food and Agriculture Organization (FAO).

The disease can spread through direct contact with the vectors or contaminated fodder and water. Studies have also shown that it can be transmitted through animal semen during artificial insemination [5].

An animal infected with LSD causes the lymph nodes to enlarge, causing the lumps on the skin to appear, thereby gaining its name. Cutaneous nodules appear on the head, neck, arms, thighs, udders, genitalia, and perineum of infected cattle. The nodules may later grow into ulcers and ultimately develop scabs.

Several sources estimate that the incubation period between infection and symptoms is about 28 days, according to the FAO, and 4 to 14 days, according to other sources [6].

Does Lumpy Skin Disease Spread To Humans?

The lumpy skin disease is not transmitted to humans, nor has it affected milk or meat, according to the Maharashtra Animal Husbandry Commissioner Sachindra Pratap Singh. According to the Commissioner, the virus is not zoonotic and cannot be transmitted from one individual to another through milk or meat consumption [7].

2019 Study Detects Lumpy Skin Disease In Humans

However, one study, titled Comparative studies on lumpy skin disease virus in humans, published in the Medical and Clinical Archives Egypt, suggests that the lumpy virus is capable of infecting humans directly without the need for insect vectors; most probably by inhalation and certainly by direct contact with infected materials, infected persons [man to man], as well as a laboratory-acquired infection [8].

In addition to causing skin nodules, LSDVh (a lumpy skin disease in humans) can also be fatal when it affects the internal organs or occurs as a generalized infection.

This work, published in 2019, has discovered the LSDVh for the first time in history. However, it should be noted that the co-infection of herpes virus with the LSDVh has been observed. So, it is possible that the herpes virus triggered the onset of the disease.

Is It Safe To Consume Milk Amidst Lumpy Skin Disease Outbreak?

According to studies, there has been no confirmation of the presence of viable and infectious LSDV virus in milk derived from an infected animal. However, FAO notes that most milk collected in Asia is processed after collection by pasteurizing, boiling or drying it to produce milk powder, which ensures that the virus has been destroyed or inactivated.

According to My Mohanty, Joint Director at the Indian Veterinary Research Institute (IVRI), milk from cattle infected with Lumpy Skin Disease is safe to consume since it is not a zoonotic disease [9][10].

"It is safe to consume milk from the infected cattle. There is no problem in the quality of milk even if you have it after boiling or without boiling," Mr Mohanty said.