Typhoid-causing bacteria from Asia are reportedly spreading across the globe, and they bring a threat to the public since they are also becoming increasingly resistant to antibiotics.
New research published in The Lancet has shed light on how Salmonella enterica serovar Typhi or S. Typhi appeared to have spread internationally in the last three decades.
Scientists found that the strains from South Asia have become resistant to 2 major antibiotics — quinolones and macrolides, sparking fear in the regions where they are spreading.
Typhoid fever has the highest incidence in South Asia. Worldwide, about 11 million cases and around 100,000 deaths get reported annually, making the disease a major public health concern.
In recent years, the strains from Asia have made their way to other parts of the world through international and intercontinental transfers. As such, experts are urging the implementation of prevention measures in anticipation of the disease.
“The speed at which highly resistant strains of S Typhi have emerged and spread in recent years is a real cause for concern, and highlights the need to urgently expand prevention measures, particularly in countries at greatest risk,” said lead author Dr. Jason Andrews, per Contagion.
The researchers conducted the largest genome analysis of S. Typhi and found that the resistant strains from South Asia have spread to other countries nearly 200 times since 1990.
The antibiotic-resistant strains were prevalent in South Asia, Southeast Asia and Southern Africa. They were also reported in the U.S., U.K. and Canada.
People with typhoid fever develop several signs and symptoms aside from fever that can be as high as 103-104 degrees Fahrenheit. They include weakness, stomach pain, diarrhea or constipation, headache, loss of appetite, and cough, according to the Centers for Disease Control and Prevention (CDC).
S. Typhi infections are commonly mild and self-limiting. However, since the disease is highly contagious and can be fatal if left untreated, the CDC recommends seeing a doctor immediately after manifesting the symptoms.
Although the researchers did a great job at genome sequencing and analyzing sample isolates from more than 70 countries, they acknowledged that their study did not include sequences from other regions, including sub-Saharan Africa and Oceania, where the condition is endemic.
News-Medical.Net said there is a need to expand genomic surveillance of the strains to derive a more comprehensive report that would help tackle the emergence, expansion and spread of the antibiotic-resistant bacteria.