A study found that the economic and health burden of the human hookworm infection is far greater than other diseases that receive more attention and funding. The study published Thursday in the journal PLOS Neglected Tropical Diseases found the loss of productivity and years of living with disability due to the infection results in a significant economic and health burden.

Researchers from the John Hopkins Bloomberg School of Public Health in Baltimore and the Baylor College of Medicine in Houston developed a computational simulation model that can calculate the estimated economic and health burdens of the hookworm infection.

Researchers used data on the prevalence of the hookworm and the intensity of the infection to come up with an estimate for the number of years lived with disability. They also included data on the Gross National Income per capita and the minimum wage to accurately calculate the loss of productivity.

“At first glance, it may be easy to underestimate the impact of hookworm since it does not tend to result in death,” Sarah Bartsch from the John Hopkins Bloomberg School of Public Health, said in a statement.

“However, the blood loss and potential disturbances to growth and cognition caused by hookworm impairs peoples' ability to contribute to society and these productivity losses add up over time,” she added.

According to the U.S. Centers for Disease Control and Prevention, an estimated 576 to740 million people are infected with hookworm worldwide. The infection was once widespread in the U.S. but positive changes to living conditions have reduced the number of infections significantly.

Most people show no symptoms when infected. However, people infected for the first time may show gastrointestinal symptoms. Those infected could also suffer from blood loss resulting in anemia and protein loss. Infection can also result in lethargy, affect physical and cognitive development, and cause adverse pregnancy outcomes.

The researchers found that hookworm infection can cost between $7.5 billion and $138.9 billion in productivity losses every year worldwide. China alone could experience productivity losses of up to $6.7 billion. Nigeria, which has the highest number of cases in Africa, could lose up to $283 million.

However, the authors warn that the figures are likely to be conservative and could end up costing more than diseases like dengue which receive more attention and investments.

“Knowing the economic burden of hookworm is important,” Bruce Y. Lee, senior author of the study from the Johns Hopkins Bloomberg School of Public Health, said. “Policy makers, funders, and companies often use costs and financial measures to determine where to invest and allocate their resources and efforts.”

The authors believe that these investments are capable of not just helping those infected with the parasite but also support the economic growth of the regions whose productivity is affected.