As per WHO release on typhoid at end of 2018, Pakistan Health Authorities have reported an ongoing outbreak of extensively drug resistant (XDR) typhoid fever that began in the Hyderabad district of Sindh province in November 2016. An increasing trend of typhoid fever cases caused by antimicrobial resistant (AMR) strains of Salmonella enterica serovar Typhi (or S. Typhi) poses a notable public health concern. The disease has ever since spread despite efforts on part of the health authorities.
Factors of spread
Main factor contributing to the spread of this deadly disease are:
1. False Negative Test Reports
Lab tests (Widal as well as Typhidot) being used to diagnose typhoid, have up to 30% false negative results. False negative means the patient is actually having typhoid fever but his/her lab test is negative. This situation leads to delayed or no timely treatment at all. Health authorities are therefore emphasizing on mandatory use of Blood Culture test in cases of suspected typhoid fever.
2. Asymptomatic Carriers
People after successful treatment for typhoid fever, may not have any symptoms but still passing S.typhi bacteria in their feces causing spread of the disease to others for many months to years.
3. Lack of Herd Immunity
As observed in many other bacterial diseases, an attack of typhoid fever also does not provide long lasting immunity from a future episode of the same illness. Moreover in Pakistan very low percentage of population gets typhoid vaccines.
4. Diagnostic Dilemma in COVID-19
Shared features of COVID 19 and typhoid fever have further complicated the diagnosis and management of typhoid during ongoing global COVID19 pandemic. There is growing evidence of higher ratio of false positive Typhidot tests in patients having COVID19.
How to save ourselves?
- Frequent hand wash
- Avoid hoteling whenever possible
- Whole family to get Typhoid vaccine
Who are at high risk?
The typhoid vaccination is highly recommended under the following conditions:
1. For protection of persons in direct contact with patients and carriers.
2. For persons exposed by reason of their occupation (medical and Paramedical staff etc.)
3. In institutions where the appropriate hygienic conditions are not met.
4. People living is areas which have high rate of Typhoid ( Pakistan is already having an epidemic of typhoid , which means whole of Paksitani population is at risk for getting it.)
How effective is Typhoid vaccine?
WHO recommends the introduction of typhoid conjugate vaccine (TCV) for infants and children over six months of age in typhoid-endemic countries. TCV provides long-lasting protection, requires fewer doses and is suitable for children under two years of age. These advantages allow delivery through routine infant immunization programs for better protection of young children.
One single 0.5 mL dose of Typbar-TCV, injected intramuscularly, offers protection for at least 3 years to adults, children, and infants over 6 months of age.
Dr Salman Ahmad Bajwa
MBBS, RMP, FCPS (Peads)