PAHO issues first scientific guide

[BUENOS AIRES, SciDev.Net] The Pan American Health Organization (PAHO) has published its first evidence-based guide to the treatment of tungiasis, a neglected tropical disease that affects millions of people in Latin America, the Caribbean and Sub-Saharan Africa.

Tungiasis is caused by the sand flea Tunga penetrans — also known by names including jigger or chigoe — a parasite that burrows into the skin causing intense inflammation, pain, burning and itching, particularly on the feet.

According to PAHO, children and older adults are the most affected by the disease, which can lead to chronic complications, debilitating deformities, and social stigma in the most severe cases.

“Available studies allow us to characterise it as a disease … primarily associated with communities living in poverty and marginalisation in tropical and subtropical areas,” Ana Luciañez, PAHO’s regional advisor on neglected infectious diseases, told SciDev.Net.

Dos and don’ts

The new guidelines recommend using low-viscosity dimethicone — a silicone compound that kills fleas when applied to the lesion — which is easy to apply and less expensive than surgical removal. If this medication is unavailable, they recommend ivermectin.

The agency advises against parasite removal “without adequate antiseptic measures or trained personnel”. Removal is a widespread practice in endemic countries, using various sharp objects, including needles, scissors, or hairpins.

The new guide also discourages the use of potassium permanganate, which can cause burns and dark or purplish pigmentation and hydrogen peroxide, which has not been shown to be beneficial and can cause skin irritation, burns, or blisters.

“It constitutes the first global document based on scientific evidence for the treatment of tungiasis, making it a contribution not only to the Americas but also to the international community,” said Luciañez.

Neglected disease

PAHO includes tungiasis in the group of neglected tropical diseases, characterised by limited research, low investment, a lack of international protocols, and little interest from the pharmaceutical industry.

The disease is still not included in most national public health plans.

Manuel Calvopiña, a tropical medicine specialist and one of the experts on the PAHO Guidelines Development Group, told SciDev.Net: “Although its incidence has decreased over the last 20 years, some people are left incapacitated.

“The goal is to raise awareness among patients, healthcare workers, and authorities so they can develop health policies.”

Calvopiña says that in countries where dimethicone is not available, the next best option is surgical removal, then ivermectin.

PAHO recommends combining “clinical, community, and environmental measures” to tackle the disease. But it says a lack of epidemiological data and economic constraints often prevent countries from responding effectively.

The WHO has previously recommended increasing the use of soap in daily foot washing and sealing or spraying floors with insecticide as preventive measures against tungiasis. It also recommends coconut oil repellents, which it says prevent fleas from penetrating the skin.

Underreporting

In Latin America and the Caribbean, tungiasis infections are concentrated in ten countries. More than 70 per cent of cases reported between 2010 and 2022 were in Brazil, the majority in Amazonian villages.

Colombia also detected serious cases among indigenous populations in the Amazon, while infections were reported in Ecuador, Guatemala, French Guiana, Haiti, Mexico, Bolivia, and Argentina.

According to PAHO, 450 million people live in at-risk areas. However, not all infected people go to hospitals, so the disease often goes underreported, specialists warn.

“It’s a disease that carries a stigma, so people don’t go to health centres and treat it at home,” Calvopiña explained.

“They extract the parasite manually with a needle without any antiseptic, which can cause infections and tetanus. There have even been deaths from this.”

Lack of access to healthcare is a major factor in why this is a forgotten disease, he added.

Dermatologist Cynthia Rossi agrees that tungiasis is a serious problem in Latin America.

“It causes inflammation, burning, pain, and discomfort,” she told SciDev.Net.

“I’ve had patients who couldn’t walk due to the number of lesions,” said the specialist, a member of the Argentine Society of Dermatology, who treated tungiasis cases at the Melchor Posse Hospital in Argentina.

She emphasised that sand fleas should only be removed under aseptic conditions, warning that failure to do so can be a “gateway for other germs and cause bacterial superinfection”.

For Calvopiña, educating health staff, government officials, and communities is critical along with promotion of health policies to support the purchase and availability of dimethicone.

This article was produced by SciDev.Net ‘s Latin America and Caribbean desk.