Crawling insects such as cockroaches, spiders, flies, ants and rodents are common in our homes. Apart from running on tables and cupboards, most of them are capable of transmitting diseases. Sometimes, their presence triggers allergies for people within the house.

Although such vermin can be wiped out using pesticides and insecticides, improper application can even be more harmful.

According to Dr Daniel Gahungu, a general practitioner at Polyclinic de I’Ectoile in Kigali, chemicals used to kill vermin can affect ones health if not applied with caution.

"Some of them are very toxic when inhaled thus when spraying, one should ensure that open body parts such as ears, eyes, and mouth are protected to prevent such risks,” he says.

In this case, wearing overalls is essential especially if the entire house is subjected to fumigation. Gahungu says such precaution prevents contact between the body and chemicals which may cause allergies.

"As a must, both cloths and foodstuff in the house should be well covered during the time of fumigation. This is because the clothes absorb some chemicals and after spraying could trigger nausea, vomiting, coughing sneezing, running nose and headaches. In food, such chemicals are likely to result into lung damage, reproductive problems, and cancer,” he explains.

Other experts suggest that since most chemicals are mostly applied on the ground, individuals should ensure that children in the house especially those under the age of five, are kept away.

"Most children under the age of five like crawling meaning that they are likely to encounter the chemicals on the ground. Some of them eat whatever they find, so it is better that fumigation is done when they are away”.

He adds that if possible, individuals should ensure that only affected areas are sprayed instead of applying to places where it is not necessary.

"If possible, the affected areas should be sprayed rather than the entire house, this is because people react differently to some chemicals, and they can end up hospitalised,” he adds.

However, Francis Kazungu, a general practitioner in Kigali, advises that since these chemicals come with precautions, individuals should read and follow them carefully.

"As a must, after use, the cans should be disposed as recommended. The person carrying out the fumigation should be able to understand all written instructions on the products to avoid overuse or related hazardous effects that may come along with misuse,” he explains.

Control breeding sites

Dr Kazungu further points out that while fumigating live vermin, good hygienic practices should be maintained to control breeding of insects such as houseflies.

"Pests thrive in dirty places…. leftovers of foods should be properly kept. Cockroaches lay eggs in crevices and these should be fixed at least every month to disrupt breeding cycles. Regular vacuum cleaning of the house can prevent their spread,” remarks Kazungu.

Rachna Pande, a specialist in internal medicine at Butaro cancer center, explains that after waiting for two to three hours shortly after fumigation, the entire house should be scrubbed using detergents such as vinegar and soap to remove the residues.

"Unclean dishes should not be kept overnight, particularly with food particles sticking; kitchen dustbins should be emptied every day, drains should not be clogged. After fumigation all surfaces should be cleaned,” she explains.

Much as most people neglect vermin, Dr Pande warns that chemicals used during fumigation could have immediate and long term effects on the person. These include redness and discharge from eyes, troubled breathing, blurred vision, stomach cramps, diarrhea and vomiting among others.

"Besides, higher doses can be fatal, and long term health hazards include neurotoxicity, kidney failure, brain damage, arthritis and cancers. It is important to consider the option of natural pesticides,” explains Dr Pande.