Invisible and overlooked: The hidden toll of intestinal worms and bilharzia

Ascaris lumbricoides, which inhabit the human intestine and cause the disease ascariasis.[iStockphoto]

In Luhulu Village, Sabatia Constituency, Vihiga County, three-year-old Shanice Masiza plays cheerfully outside her family’s home, a picture of health that belies the painful ordeal she endured just months ago.

Her mother, Sharon Kaveza, recalls the difficult period when Shanice suffered from soil-transmitted helminths (STH), commonly known as intestinal worms and locally as minyoo.

In late 2025, the young girl’s health suddenly deteriorated. She experienced persistent stomach pain, diarrhoea, nausea, loss of appetite, and a swollen abdomen. “She was always weak, complained of stomach pains, and had lost her appetite. We thought it was a normal illness, but her condition kept worsening,” says Kaveza.

The family initially believed the child had been bewitched and was reluctant to take her to the hospital. One day, Community Health Promoter (CHP) Julia Kadenyi visited the area during her routine household rounds and became concerned about Shanice’s condition.

The family, together with the CHP, sought treatment at Vihiga County Referral Hospital, where doctors diagnosed Shanice with intestinal worms and immediately began treatment.

“After receiving medicine and advice from health workers, she gradually recovered. Today, she is active, eating well, and growing normally,” Kaveza says with relief.

Her husband, James Elegwa, believes poverty played a major role in exposing their daughter to the infection. “My child would sometimes lack food and end up eating fruits that had fallen on the ground,” says Elegwa.

The family also admits that hygiene practices at home were poor, with Shanice rarely washing her hands before eating.

“Many people underestimate worms, but they can seriously affect a child’s health and development. We now ensure our children are dewormed and observe proper hygiene,” Elegwa said.

The couple, who have four children, are among thousands of families across western Kenya benefiting from intensified efforts to eliminate soil-transmitted helminths.

The worms are spread through contaminated food and water, poor hygiene practices, consumption of undercooked food, and contact with contaminated surfaces. Health experts warn that intestinal worm infections can cause stunted growth, anaemia, malnutrition, poor school performance and, in severe cases, death.

Drugs used to treat intestinal worms are administered to children above one year and adults, except pregnant women.

Intestinal worms are among the most common neglected tropical diseases (NTDs) affecting millions of people in western Kenya. Another major NTD is schistosomiasis, commonly known as bilharzia.

For more than 10 years, Meschack Akumari has earned a living making bricks in Ematsuli Village, North East Bunyore, Vihiga County. 

Every morning, he joins dozens of other villagers at clay excavation sites, moulding bricks that are later sold to builders across the region. The work is strenuous and often requires spending long hours in waterlogged areas.

“This is the only job I know. It has enabled me to feed my family and educate my children,” says Akumari. “Many people here depend on brick making because there are very few other employment opportunities.”

Occupation risk

However, the occupation has also exposed workers to the risk of bilharzia, a water-borne disease that remains a public health concern in parts of Vihiga County. North East Bunyore is the only region in the county classified as being at risk of the disease.

The excavation of clay for brick making often leaves behind pits that fill with water during the rainy season. These stagnant pools provide ideal breeding grounds for freshwater snails that carry the bilharzia parasite.

Schistosomiasis is transmitted when urine or faeces from an infected person contaminate freshwater sources.

Several locals have reported experiencing persistent abdominal pain and occasional bleeding while passing urine. The symptoms are often mistaken for a sexually transmitted infection, leading to treatment that offers no relief.

Health officials and Water, Sanitation and Hygiene (WASH) teams have been conducting community sensitisation campaigns to educate residents on the dangers of leaving stagnant water around brick-making sites.

“We have been advised to drain stagnant water and apply paraffin on water surfaces to control snails,” says Akumari. “But paraffin is expensive, and many brick makers cannot afford it regularly.”

Data from the Ministry of Health indicate that millions of Kenyans remain at risk of NTDs, particularly in endemic regions across the Coast, western Kenya, and parts of the Rift Valley.

A 2021 Ministry of Health report showed that more than six million residents of western Kenya were exposed to intestinal worm and bilharzia infections. The report identified Vihiga, Bungoma, Kakamega, and Trans Nzoia counties as high-risk areas.

According to the report, about five million residents are at risk of intestinal worm infections, while approximately 1.5 million face the risk of bilharzia.

For decades, the two diseases have silently affected communities across western Kenya, particularly children, causing anaemia, malnutrition, poor school performance, and reduced productivity. 

Today, however, a combination of government commitment, community participation, and support from development partners is helping turn the tide.

The Ministry of Health is promoting proper toilet use as one of the key interventions to help eradicate intestinal worms in the region. “The use of clean drinking water, well-cooked food, and washing hands and fruits properly before eating can deter these diseases,” says Wendy Nkirote, Programme Manager at the Ministry of Health’s Neglected Tropical Diseases Unit.

To achieve the elimination of NTDs, counties are coordinating initiatives such as mass drug administration, surveillance, surveys, and continuous monitoring. According to World Health Organisation guidelines, control strategies for schistosomiasis and intestinal worms include preventive chemotherapy through mass drug administration using praziquantel for schistosomiasis and albendazole or mebendazole for soil-transmitted helminths. These approaches aim to reduce morbidity, prevent reinfection, and achieve elimination by 2030.

In Vihiga County, health officials say remarkable progress has been recorded through sustained mass drug administration campaigns, health education, and improved sanitation.

“Through regular treatment, community sensitisation, and surveillance, we have managed to interrupt transmission in wards where prevalence was previously low. Our goal is to eliminate these diseases as a public health problem,” says Vihiga County NTD Coordinator Fanuel Khainga.

According to Khainga, continuous monitoring has shown encouraging results, with fewer infections being reported compared to previous years.

The gains are being driven by a strong partnership involving the Ministry of Health, the Ministry of Education, county governments, and organisations such as Amref Health Africa, the African Institute for Health Development (AIHD), The END Fund, AKROS, and the World Health Organisation.

Prevention measures

In 2025, Vihiga County, in collaboration with the Ministry of Health, the Ministry of Education, and Amref Health Africa, launched a five-day countywide mass drug administration campaign under the theme “Eliminate Worms, Nurture Families.”

Director of Public Health Martin Osotsi emphasised the importance of public awareness. “The objective is not just treatment but prevention. Healthy children perform better in school, have improved nutrition, and contribute to healthier communities,” says Osotsi.

Community sensitisation has also emerged as a critical pillar in the elimination strategy.

The fight against NTDs is also extending into schools through innovative awareness campaigns.

Murals promoting hygiene and disease prevention have been painted in schools across western Kenya, while school health clubs and community theatre groups help spread health messages. More than 40 schools in the region have benefited from such initiatives supported by development partners.

However, many schools continue to face inadequate water supplies, leading to poor sanitation and heightened hygiene risks.

To address the challenge, Mwituha Primary School in Vihiga recently benefited from a borehole project funded by development partners. The facility now serves more than 400 learners and members of the surrounding community.

Headteacher Isaac Kisambo says access to clean water has transformed the school environment.

“Since January, when the borehole was completed, we have seen improved attendance and fewer pupils complaining of stomach-related illnesses such as diarrhoea,” says Kisambo.

At Siembe Primary School in Keiyo Ward, Trans Nzoia County, the impact is also visible. Headteacher Edward Eseve says absenteeism linked to worms has declined dramatically.

“Out of eighty learners, about forty used to miss classes because of jiggers and worm infections. Today, those cases have reduced significantly. The children are healthier, and their academic performance has improved,” says Eseve.