Outbreak of drug-resistant typhoid triggers level two alert

Islamabad: An on-going outbreak of extensively drug-resistant (XDR) typhoid fever in Pakistan that has triggered the level two alert can be controlled by sensitizing public and health professionals on following preventive measures religiously and offering vaccination particularly to the population at risk.

The US Centres for Disease Control and Prevention has already issued a travel alert saying anyone heading to Pakistan should take extra care of food and water and get vaccination against typhoid. The CDC said the XDR typhoid strain in Pakistan does not respond to many antibiotics.

Typhoid or Enteric fever is a bacterial infection caused by Salmonella typhi. The faecal oral transmission is the commonest route infecting the healthy ones. Contaminated water and food are the main sources for the spread of the infection.

Associate Professor of Pathology and Consultant Microbiologist at Al-Nafees Medical College Islamabad Dr Humaira Zafar expressed this while talking to ‘The News’ on Sunday.

She said the intestines are primary site of infection. The most common symptoms include continuous high grade fever, generalized weakness, blood stream infection and constipation or diarrhoea. If the infection prolongs either due to partial treatment, drug resistance or any other cause, a patient can land up to chronic phase along with the emergence of complications. The highlighted complications can be enlargement of the spleen, intestinal haemorrhage, perforation of the bowel and meningitis (inflammation of outer layers of brain), she explained.

She added the mortality rate in untreated or drug resistant cases ranges from 12-30 per cent. “Despite the availability of effective antibiotics, about 200,000 people die annually while in successfully treated cases, the survival rate is 99%.”

Typhoid fever is a treatable and curable infection provided accurately treated for proper duration after confirmed diagnosis by culture and sensitivity (blood, stool and bone marrow), she said.

She said currently the biggest challenge is the emergence of drug resistant strain of Salmonella typhi bacteria. The antibiotics from penicillin, quinolones and cephalosporin groups are usually considered amongst the good treatment options but the challenge faced for public health concern was the emergence of resistant pattern to first line treatment (ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole) and the second-line option as well (fluoroquinolones). Due to this situation, ceftriaxone (third generation cephalosporin) is considered as the empirical treatment of choice for typhoid fever patients. However, now there is emergence of a strain that is also resistant to ceftriaxone. Thus giving this bug a label of extensively drug-resistant (XDR) typhoid, said Professor Humaira.

She added the condition severely limits treatment options. The six months statistical data of National Institute of Health in Islamabad confirmed about 2000 cases of (XDR) Salmonella typhi in Pakistan. Emergence of such cases in Pakistan is becoming a global voice and has brought Pakistan in a lime light. The travellers and tourists visiting Pakistan are advised to take additional precautionary measures in order to not acquire infection, she said.

The crisis in Pakistan represents the first known outbreak of an XDR strain and this state of affairs if not controlled may lead some researchers to warn that it could turn the clock 70 years back when surviving the disease was more a matter of luck than treatment, said Dr. Humaira.

This preventable disease can be prevented by preventing fecal contamination in drinking water and food supplies. Since human faeces are the main sources for disease transmission, so awareness regarding practicing hygienic measures like hand washing, waste management, water purification, accurate diagnosis with the help of culture and sensitivity and proper treatment of the typhoid fever can help control the outbreak and reduce the high mortality rate, she said.