Three or more liquid or watery stools in a 24-hour period are considered as diarrhea. Diarrhea may also be bloody, called dysentery. An episode of diarrhea lasting for less than 14 days is defined as acute diarrhea. Persistent diarrhea is defined as an episode of diarrhea that begins acutely and lasts for at least 14 days.
Intestinal infection is the most common cause of acute diarrhea worldwide. The etiologic pathogen may be virus, bacteria, protozoa, or helminth (Table 1). In spite of the numerous diarrhea-causing organisms, recent studies have shown that the majority of cases in virtually all setting are caused by five organisms: rotavirus, E. coli,Shigella, C. jejuni, and C. parvum. Salmonella and V. cholerae are also important causes of acute diarrhea in some developing countries.
Dengue is the most common mosquito-borne viral disease of humans that in recent years has become a major international public health. Globally, 2.5 billion people live in areas where dengue viruses can be transmitted. The geographical spread of both the mosquito vectors and the viruses has led to the global resurgence of epidemic dengue fever (DF) and emergence of dengue hemorrhagic fever ( DHF ) in the past 25 years with the development of hyperendemicity in many urban centers of the tropics.
DHF was first recognized in the 1950s during the dengue epidemics in the Philippines and Thailand. By 1970 nine countries had experienced epidemic DHF and now, the number has increased more than fourfold and continues to rise. DHF has become a leading cause of hospitalization and death among children in several countries.
Japanese encephalitis (JE) is an inflammatory disease in the central nervous system including cerebrum, cerebellum, and spinal cord caused by viral infection transmitted by Culex mosquitoes. JE is an important disease in East, Southeast, and South Asia, which lead to serious complication and high mortality rate. Complete cure is shown in only one third of the patients. However the ratio of symptomatic infection with neurological manifestation and asymptomatic infection is 1:25 to 1000. There is no any effective treatment however prevention of JE is possible by avoiding visits to epidemic season, avoiding mosquito bites, and receiving vaccine.
Gnathostomiasis is a food-born parasite zoonosis causes by a round worm in the genus Gnathostoma e.g. G.spinigirum, G.hispidum. It can cause both cutaneous and visceral symptoms in humans.
The adult worms live in gastric wall of tigers, dogs and cats that are definitive hosts. The female worms pass eggs in the hosts’ feces. In water, eggs become first stage larvae. After being ingested by cyclops that are the first intermediate hosts, they develop into second-stage larvae. When the second intermediate hosts (fish, birds, frogs, and snakes) ingest cyclops, the second stage larvae will develop into third stage larvae which are infective stage for humans and other definitive host. If dogs or cats, the definitive host, eat them, third stage larvae will develop into adult worms in the stomach wall. Humans are accidental host and the larvae will never develop into adult worms.
Kawasaki disease (KD) is an acute, febrile systemic vasculitis of childhood. It is the leading cause of acquired heart disease in children worldwide. KD was first reported by Tomisaku Kawasaki in 1967 (1). This self-limiting disease causes a 20-25% probability of acquiring coronary artery abnormalities in untreated patients. (2, 3)
Malaria, one of the most life-threatening diseases in the world, is estimated to cause 300-660 million clinical cases with the global distribution of malaria transmission risk up to 50% higher than those reported by the World Health Organization (WHO) (1). By the best estimation derived from a variety of epidemiological approaches, there was a malaria-attributable mortality of 881,000 (610,000–1,212,000) deaths worldwide in 2006, of which 90% were in the African Region, and 4% in each of the South-East Asia and Eastern Mediterranean regions. The risk of death from malaria is considerably higher in Africa than other parts of the world. An estimated 85% of deaths occur in children under 5 years, but the proportion is much higher in the African (88%) and Eastern Mediterranean regions (76%) than in other regions (16–40%). For epidemiology of malaria in Thailand, even though the number of malaria cases was steadily reduced from the year 2000, as shown in Figure 1 according to the Thailand country report (2), the number of admission cases still persist. The intensive malaria control programme in Thailand during the past five decades has resulted in considerable reduction in malaria incidence. Confirmed cases declined from 81,692 in 2000 to 30,006 cases in 2014. P. falciparum proportions were around 40% of the confirmed cases. All reported cases are examined microscopically or by RDT. Malaria epidemics occurred periodically in high risk areas, especially along the international borders of Thailand and Myanmar and Thailand and Cambodia. This is according to the active control program of the Ministry of Public Health, Thailand by the Global Funds to flight AIDS Tuberculosis and Malaria (GFATM) in the year 2002-2003.
Rotavirus is a leading cause of viral gastroenteritis among infants and young children aged between 6 months and 2 years. It is also an important cause of severe dehydrating diarrhea and electrolyte disturbances1. The global mortality rate for rotavirus is high, estimated at 450,000-600,000 deaths per year2. Epidemiologic data show that rotavirus remains the most common cause of severe diarrhea in developed countries. Therefore, vaccination serves as a primary prevention strategy to reduce rotavirus burden in order to diminish severe disease, death and use of public health resources
