Follow Us:
Thursday, August 18, 2022

Explained: What are Nairobi flies, which are causing disease in Sikkim?

Nairobi flies, also called Kenyan flies or dragon bugs, are small, beetle-like insects that belong to two species, Paederus eximius and Paederus sabaeus.

Written by Rishika Singh , Edited by Explained Desk | New Delhi |
July 5, 2022 6:52:14 pm
The flies release a powerful toxin called pederin, which causes irritation. (Image: entomart/Wikimedia Commons)

Around 100 students of an engineering college in East Sikkim have reported skin infections after coming in contact with Nairobi flies, officials said on Tuesday (June 5).

The population of Nairobi flies, a species of insect native to East Africa, is growing at a fast pace on campus of the Sikkim Manipal Institute of Technology (SMIT) in Majhitar, officials were quoted as saying. The flies can overwhelm new areas in search of breeding grounds and food supply, Health Department officials said.

The college administration said infected students had been given medication and were recovering. One student who was recently infected had to undergo surgery in his hand.

What are Nairobi flies?

Subscriber Only Stories
Delhi Confidential: Kerala football club stuck in Tashkent, S-G Tushar Me...Premium
Explained: The ‘developed country’ goalPremium
An Expert Explains: Why a stable Kenya is in the interest of Africa &...Premium
With fund & engineers, Taliban help rebuild gurdwara hit by Islamic S...Premium

Nairobi flies, also called Kenyan flies or dragon bugs, are small, beetle-like insects that belong to two species, Paederus eximius and Paederus sabaeus. They are orange and black in colour, and thrive in areas with high rainfall, as has been witnessed in Sikkim in the past few weeks.

Like most insects, the beetles are attracted by bright light.

How are humans affected by them?

Usually, the insects attack pests that consume crops and are beneficial for humans — but at times, they come in contact with humans directly are cause harm. Health officials say these flies do not bite, but if disturbed while sitting on anyone’s skin, they release a potent acidic substance that causes burns.


This substance is called pederin, and can cause irritation if it comes in contact with the skin, leading to lesions or unusual marks or colouring on the skin. The skin begins to heal in a week or two, but some secondary infections can occur, especially if the victim scratches the irritated skin.

Have there been outbreaks of the disease?

Major outbreaks have happened in Kenya and other parts of eastern Africa. In 1998, unusually heavy rain caused a large number of insects to come into the region, reported the Associated Press.

Outside Africa, outbreaks have happened in India, Japan, Israel, and Paraguay in the past.


Newsletter | Click to get the day’s best explainers in your inbox

What is the way to protect oneself against Nairobi flies?

Sleeping under mosquito nets can help. If a fly lands on a person, it should be gently brushed off, and should not be disturbed or touched to reduce the chances of it releasing pederin.

The area where the flies sits should be washed with soap and water. If they are squelched and end up leaving toxic fluids on the skin, care should be taken that unwashed hands do not touch any other part of the body, particularly the eyes.

📣 Join our Telegram channel (The Indian Express) for the latest news and updates

For all the latest Explained News, download Indian Express App.

  • Newsguard
  • The Indian Express website has been rated GREEN for its credibility and trustworthiness by Newsguard, a global service that rates news sources for their journalistic standards.
  • Newsguard
First published on: 05-07-2022 at 06:52:14 pm
0 Comment(s) *
* The moderation of comments is automated and not cleared manually by

Featured Stories