Ministry of Health warns: Scrub typhus appears year-round in Vietnam

Recently, scrub typhus has occurred in Yen Bai province, concentrated in Van Chan, Tram Tau, Mu Cang Chai districts, and Nghia Lo town; from April to September this year, there were nearly 80 scrub typhus patients, mainly ethnic people living in the highlands.

On October 13, information from the Department of Preventive Medicine under the Ministry of Health said that scrub typhus occurs in Vietnam all year round but mainly during the rainy season from April to October, peaking in June-July. The disease is usually sporadic but can break out into an epidemic when many people who are not immune enter the right epidemic area.

The disease occurs mainly in rural mountainous areas accounting for more than 80%, rare in urban areas. All ages can get the disease but mainly in working age, distributed according to the nature of occupation such as forestry, agriculture, military.

The patient was bitten by a tick.

Scrub typhus is a disease caused by the agent Orientia tsutsugamushi, which has a natural epidemic, and is transmitted randomly to humans when bitten by mite larvae. The disease is mainly prevalent in Asia and the Western Pacific. The pathogen Orientia tsutsugamushi (also known as R.orientalis, or R.tsutsugamushi), is 1.2-3mm long, 0.5-0.8mm wide, spherical or cocci, often arranged in purple-red clusters, and has a membrane under an electron microscope. R.orientalis has two natural reservoirs: mites and rodents - small animals.

Sick people are not able to transmit the disease to others. Mites and larvae prefer to live in cool, moist soil in caves, along river banks, shady places with bushes and low trees with nuts waiting for small animals - rodents to come and gnaw. People can be bitten in conditions such as working in epidemic areas; clearing fields for farming; soldiers on picnics; sitting, lying down, resting on grass...

According to the Department of Preventive Medicine, the incubation period for tick fever is on average 8-12 days. Initially, at the site where the mite larvae bite, there is a pea-sized blister that is painless, so patients often do not pay attention. During the full-blown period, the patient may have a high, continuous fever that lasts 15-20 days, or even up to 27 days if not treated; sometimes shivering for the first 1-2 days accompanied by fever, severe headache, and muscle aches.

The characteristic ulcer (typical of scrub typhus) is usually in soft, moist skin areas such as the genitals, subscapular region, anus, groin, armpits, neck; sometimes in unexpected locations in the ear, navel, eyelids (easily mistaken for styes). The characteristic of the ulcer is that it is painless, not itchy and appears in 65-80% of cases.

The initial blister gradually develops into a cloudy fluid on a red papule, after 4-5 days it ruptures into a blister with a light or dark brown scab depending on the soft or hard skin and the age of the ulcer.

After a while, the scabs fall off to reveal shallow, pale pink, non-pustular, non-exuding ulcers with red or dark edges depending on whether the disease is developing or has receded; after the fever subsides, the ulcers gradually heal. Severe patients often experience symptoms such as muffled heart sounds, low blood pressure, slow pulse compared to temperature, nosebleeds, bronchitis, atypical pneumonia, etc.

The Ministry of Health recommends that, to prevent tick fever, people avoid sitting, lying down, drying clothes or placing backpacks on the grass, near bushes or tree roots. When going to clear fields, go on field trips or scout in the forest, wear shoes and socks, and tie up the pants; it is best to soak clothes in mite killer or use mite repellent creams.

People can kill mites in the environment by spraying diazinon and fenthion on moist soil, grass and bushes less than 20cm high around the house, especially in shady places...; clearing bushes around the house.

According to Vietnam+