In the aftermath of World War II, United States Army physician Dr. Thomas Mackie, in his research Tropical Disease Problems Among Veterans of World War II, says 1,672 soldiers who served in Leyte during the war got infected with schistosomiasis.
He said results of a survey of the incidence of Schistosomiasis japonica among personnel in a station hospital in the Philippines showed that "a number of soldiers previously on the island of Leyte and hospitalized for varied vague complaints were, in fact, instances of infection by this fluke."
"Of the 107 individuals examined, 34 were found to be infected. All of these were on active duty and had few if any symptoms at the time of examination," the study said.
Schistosomiasis is identified by the World Health Organization as one of the 17 Neglected Tropical Diseases along with dengue, rabies, leprosy and lymphatic filariasis, among others. The 17 diseases were chosen because of their adverse impact, relative obscurity, and the availability of tools to combat them.
NTDs are called "neglected" because they generally afflict the world's poor and historically have not received as much attention as other diseases. NTDs tend to thrive in developing regions of the world, where water quality, sanitation, and access to health care are substandard.
Schistosomiasis is endemic in 189 municipalities and 15 cities in 28 provinces in the Philippines with approximately 12 million people at risk and 2.5 million individuals directly exposed to the disease. A certain area is considered endemic to the parasite if it has the presence of the host snail and infected individuals.
In Eastern Visayas, the parasite is endemic in four of its six provinces — Leyte, Samar, Northern Samar, and Eastern Samar — affecting 63 towns and cities and covering 897 barangays.
Agnes Cuayzon, program manager of the Schistosomiasis Control and Elimination Program at the Department of Health regional office in Eastern Visayas, says the 897 barangays in the region make up 55 percent of the 1,609 barangays in the country where schistosomiasis is endemic.
The DoH conducts a survey every five years to determine the prevalence of infection in endemic areas. In 2017, the prevalence rate of schistosomiasis in the country was pegged at 4.68 percent. In Eastern Visayas, however, the prevalence rate stands at 7.5 percent – 8.3 percent in Leyte, 8.6 percent in Northern Samar, 5.3 percent in Samar, and 4.1percent in Eastern Samar.
Cuayzon explains that the prevalence rate is the percentage of individuals who were found positive for infection from among randomly chosen individuals that were subjected to a Kato-Katz or stool examination in an identified endemic area.
In the categorization of endemicity, Cuayzon said 5 percent and above is considered as high. "There is a high prevalence of schistosomiasis in Eastern Visayas," she said.
The prevalence rate is expected to shoot up when another survey is conducted next year due to the failure of many residents in endemic areas to take the prescribed medicine in 2020 and 2021 due to restrictions imposed in connection with the Covid-19 spread.
It was almost noon and the scorching heat of the sun is already taking a toll on Manny Lantajo, a 48 years old rice farmer in Sta. Fe, Leyte, forcing him to take a break from plowing the over one-hectare rice land of his father.
Later he brings his carabao to a shaded area to rest and cool down on a nearby stream like what other farmers do. The stream runs to a small river believed to be infested with schistosomiasis-hosting snails.
"Who among the farmers here never had schisto?" he asks. "It is already a fact that if you are a farmer, you will have schisto. We have learned to live with it. As long as you take the medicine you will not die."
(To be continued)
