Typhoidal Salmonella Trends in Thailand

Abstract

Abstract.Typhoid and paratyphoid fever remain endemic diseases in Thailand with wide variation in subnational incidence trends. We examined these trends alongside contextual factors to study potential interactions and guide control strategies for this disease. Culture-confirmed typhoid and paratyphoid fever data from 2003 to 2014 were collected from the Ministry of Public Health website. Contextual factor data were collected from various sources including World Health Organization/United Nations Children’s Fund Joint Monitoring Program, United Education Statistical World Bank database, World Bank, Development Research group, and global child mortality estimates published in the Lancet. Typhoid fever exhibited a declining trend with peak incidence reported in 2003 at 8.6 cases per 100,000 persons per year. Incidence dropped to three cases per 100,000 persons in 2014. The trend in paratyphoid fever remained stable with the peak incidence of 0.77 cases per 100,000 persons observed in 2009. Subnational variations of typhoid were seen throughout the study period with the highest incidence observed in the northwestern region of Thailand. Increases in female literacy, and access to improved water and sanitation were observed with decreases in poverty head count ratio and diarrheal mortality rate per 1,000 live births. Case fatality remained consistently low at 0.4% or less in all years with reported deaths. At the national level, typhoid fever incidence has shown a notable decline; however, incidence appears to have plateaued since 2007 with access to improved water supply and sanitation above 80%. Eliminating this disease will require strong disease prevention measures in conjunction with effective treatment interventions.

Typhoid in Laos: An 18-Year Perspective

“…This province borders neighboring provinces in Vietnam and Thailand, where low typhoid incidence has also been reported. 3,4 In Vietnam, most patients present in the Mekong Delta area in the far south, and in Thailand, most cases are seen in the northwest. 3,4,24 The highest number of typhoid cases in Vientiane capital came from a rural district (Sangthong), which is the furthest district from the city center.…”

“…3,4 In Vietnam, most patients present in the Mekong Delta area in the far south, and in Thailand, most cases are seen in the northwest. 3,4,24 The highest number of typhoid cases in Vientiane capital came from a rural district (Sangthong), which is the furthest district from the city center. The high number of S. Typhi cases in rural populations has also been seen in other studies in the region, with the highest burden of typhoid fever in infants seen in rural communities in Cambodia.…”

“…Salmonella enterica serovar Typhi antibiotic resistance in Thailand also remains uncommon. 3,4 Of the 59 Lao MDR isolates, the majority of them (93.2%) were isolated between 2000 and 2004 with only four isolates cultured since 2004; the majority came from a single, probably clonal, outbreak in Oudomxay Province. The majority (96%) of ceftriaxone intermediate and resistant isolates were also obtained between 2000 and 2004.…”

“…1,2 Salmonella enterica serovar Typhi is an important cause of community-acquired bacteremia in South and Southeast Asia. Thailand reported a decrease in cases from 8.6 cases/100,000 people in 2003 to 3/100,000 people in 2014, 3 and Vietnam has reported a continued decline from an estimated incidence of 14.7/100,000 people in 2003. 4 Immunization programs were started in Thailand in the 1970s and Vietnam in the 1990s, which may have led to these decreases in case burden.…”

“…4 Immunization programs were started in Thailand in the 1970s and Vietnam in the 1990s, which may have led to these decreases in case burden. 3,4 The role that water, sanitation, and hygiene initiatives and economic growth have also had in this decline is difficult to judge, although they have probably played a major role. The WHO has long recommended immunization for people living in endemic areas and has recently advised the use of a new prequalified typhoid conjugate vaccine.…”