An Urgent Threat: The Emerging High-resistant Strains of Typhoid Bacteria are Rising Concerns for India

An Urgent Threat: The Emerging High-resistant Strains of Typhoid Bacteria are Rising Concerns for India

Typhoid fever has been major public health concern since ages and till date, there are nearly 11 million cases and more than 1,00,000 deaths every year due to typhoid. Recently, the emergence of increasingly antimicrobial-resistant strains of S Typhi, has threatened to undermine the effective treatment and control against typhoid, causing a global concern. 

What is Typhoid? 

Typhoid is an acute illness associated with fever caused by the Salmonella enterica serotype Typhi or Salmonella paratyphi bacteria, the later causing a less severe illness. Contaminated food and water or close contact with an infected person are the prime causes for typhoid fever. Other contributory factors include limited access to clean drinking water and poor sanitation.

What are the symptoms of Typhoid infection?

Symptoms of typhoid usually develop 1-2 weeks after the exposure and can vary from mild to severe manifestations. They include high fever, malaise, fatigue, headache, nausea, abdominal pain, constipation or diarrhoea, rose-colored spots on the chest and enlarged spleen and liver. Severe cases of typhoid may lead to serious complications or even death. 

What are the different stages of typhoid fever?

Enteric fever or typhoid is a three-staged manifestation. The first 12-48 hours after exposure is the asymptomatic phase. Though the person does not have any symptoms they can still transmit the infection; at the second stage, the person usually develops GI symptoms; and by the third phase the person develops a high fever and other symptoms. 

How can we define the severity of Typhoid?

Typhoid is a serious enteric fever and without treatment about 30% of typhoid cases can be fatal. Once the bacteria enter the body, they multiply and spread into the bloodstream. As long as a person has typhoid bacteria in their body, though asymptomatic, they act as carriers for the infection; which can last for months, or in some cases, indefinitely. About 4% of people with a typhoid infection become chronic carriersChronic typhoid may cause certain medical complications such as GI bleeding and ulcers, bowel perforation leading to peritonitis, sepsis, lung disorders, meningitis and various neurologic symptoms and may require immediate hospitalization. In chronic cases, typhoid may result in typhoid encephalopathy which has a 55% mortality rate.

Who is at risk?

Typhoid fever is rare in developed nations but is a serious health threat in the developing countries; children being highly susceptible for the contagion. The regions of south Asia and sub-Saharan Africa have reported maximum cases of Typhoid with highest burden countries being Bangladesh, India, Nepal, and Pakistan. Besides, typhoid fever outbreaks can happen in areas with substandard sanitation and hygiene facilities. People who live or work in or travel to places where typhoid infections are common are also at risk.

How can we prevent typhoid?

The preventive measures for typhoid include:

1. Avoiding infection - 

Access to safe water and adequate sanitation, hygiene among food handlers and typhoid vaccination are all effective in preventing typhoid fever.

• Drink boiled, filtered or bottled water.

• Do not have ice in drinks especially when outdoors.

• Avoid using public toilets.

• Be vigilant with street foods and stale eatables.

• Avoid outside fruits and vegetables

• Eat fruits and salad after peeling.

• Get vaccinated

2. Immunization –

There are two vaccines prevalent for defense against typhoid fever:

• an injectable vaccine - for people aged over 2 years

• a live attenuated oral vaccine (capsule) - for people aged over 5 years

These vaccines do not provide long-lasting immunity and is only 50–80% effective, so it is necessary to exercise caution when eating, drinking, and coming into contact with people. 

What medications are recommended for the treatment of Typhoid?

The only effective treatment for typhoid is antibiotics. Most common medicine used is ciprofloxacin (Cipro). Other antibiotics used are chloramphenicol (Chloromycetin), ampicillin (Ampi, Omnipen, Penglobe, and Principen), sulfamethoxazole/trimethoprim (Bactrim). However the recommendation of these medicaments is dependent upon the severity of infection, physical health and other medical concerns of the individual. As resistance to antibiotics has emerged, fluoroquinolones are no longer effective. Thus the current treatment options adopted involve third generation cephalosporins such as ceftriaxone, or azithromycin. 

Why is drug-resistant microbial strains a global concern?

Drug resistance occurs when a pathogen—whether bacteria, virus, or fungus—evolves to withstand the counter drugs. According to W.H.O., drug-resistance ability of disease-causing microbes is a severe health concern because of its potential to render existing medicines ineffective which may result in fatal outcomes. 

New antibiotic-resistant Salmonella enterica serovar Typhi (S. Typhi) is the recent threat-

Typhoid causing pathogen, S. Typhi is a human restricted pathogen that is propagated from an infected person to a healthy individual by contaminated food, polluted water and unhygienic conditions. Typhoid is treatable with antibiotics. 

It has been observed that, S. Typhi has a tendency to rapidly develop resistance towards treatment. This is the reason that over the past 70 years, multiple antibiotic resistance strains of S. Typhi has emerged and spread globally. It has been testified that, at present times, 90% of the typhoid virus strains are resistant to ciprofloxacin while 13% are resistant to ceftriaxone. 

As quinolone-resistant typhoid strains have spread in India, XDR typhoid strains do not respond to five classes of antibiotics, leaving only one oral antibiotic option, azithromycin, or more costly intravenous antibiotics available for treatment. But recently, few instances of azithromycin-resistant typhoid have been reported in India, highlighting the urgent need for more advanced preventative measures.

TCVs can help stop drug-resistant typhoid

Typhoid conjugate vaccines (TCVs) are one of the effective ways to prevent typhoid. According to research studies, TCV is 97% effective against XDR typhoid strains, but are yet to be streamlined. Expanding coverage of typhoid conjugate vaccines (TCVs) will have a crucial role in stopping transmission cycles and ensuring that children are protected.

Conclusion –

While the fight against typhoid is an ancient one, the world is presently facing a confluence of new challenges that has upraised the urgency for improvised prevention and control methodology. Bacteria that cause typhoid fever are becoming more and more resistant to most of the antibiotics thus threatening its effectiveness against treatment. Recently, there have been several incidences of outbreaks of multidrug-resistant typhoid strains, and hence the CDC has recommended the implementation of preventive efforts, such as working to:

• increase vaccination

• improve sanitation and hygiene

• implement better tracking of people with an infection to limit contagion

Source -ThePrint