Salmonella enterica Serovar Paratyphi A and S. enterica Serovar Typhi Cause Indistinguishable Clinical Syndromes in Kathmandu, Nepal

Abstract

The importance of S. Paratyphi A has been underestimated. Infection is common, the agent causes disease as severe as that caused by S. Typhi and is highly likely to be drug resistant. Drug resistance and lack of effective vaccination suggest that S. Paratyphi A infection may become a major world health problem.

Antimicrobial resistance trend of Salmonella typhi and paratyphi from 2011-2013: A descriptive study from tertiary care hospital of Nepal

“…In recent years, studies have shown increase in incidence of SPA infection 4,5 . However, ST and SPA were found to cause indistinguishable clinical syndrome 6 …”

Mix-infection of S. Typhi and ParaTyphi A in Typhoid Fever and Chronic Typhoid Carriers: A Nested PCR Based Study in North India

“…Interestingly, a multicentric study conducted in Asian countries i.e. China, Pakistan, India, Vietnam, Indonesia [1] along with many other isolated reports from India [2][3][4][5][6][7] and Nepal [8][9] have revealed that S. ParaTyphi A might be contributing as much as 50% of all the enteric fever cases. Therefore, S. ParaTyphi A has recently been projected as an emerging pathogen.…”

“…The possibility of co-infection has already been suggested by the population based serological study from Nigeria [4] and nucleic acid based detection in blood from Pakistan in acute enteric fever cases [11]. Moreover, S. ParaTyphi A causes indistinguishable clinical features [8] and may be associated with more complications [12][13]. It is now established that in biological specimens, amplification of specific DNA sequences by nested PCR is better tool than single round PCR.…”

Vi polysaccharide–protein conjugate vaccine for the prevention of typhoid fever in children: hope or hype?

“…A retrospective study in New Delhi revealed an increase in the proportion of Salmonella paratyphi from 6.5% in 1994 to 44.9% in 1998 [25]. Also, the assumption that paratyphoid fever is less severe than typhoid fever has been proven untrue in areas with high incidence of enteric fevers [26]. The fact that there are no licensed vaccines against paratyphoid fever is of concern and merits address from vaccine developers.…”