Rise of scrub typhus: Urgent action required

Of late Nepal is seeing a steep rise in scrub typhus cases, with the disease spreading to half of the country. There is a need to pay attention to the sudden rise in the cases of this bacterial disease that can be fatal if not treated on time

“Got a fever?” “It could be a typhoid fever.” This is a very common conversation among us. When an individual develops a fever, a doctor usually starts empirical treatment with anti-microbial agents against a typhoid fever. Nevertheless, in recent years, statistics show that scrub typhus cases have been significantly rising compared to typhoid in febrile patients in Nepal.

At present, dozens of febrile patients from different hospitals are being sent to Sukraraj Tropical & Infectious Disease Hospital (STIDH) to identify the causes. Of them, on an average, at least half a dozen febrile patients (sometimes even over dozens) are being diagnosed with scrub typhus on a daily basis, indicating that sooner or later scrub typhus is going to take over typhoid fever—or it could even become the most common causes of febrile illnesses in Nepal.

Scrub typhus first attracted nationwide attention back in 2015 due to its association with unexplained and sudden deaths among febrile children despite treatment by experts. At least 108 scrub typhus cases were reported from 16 districts—of them eight cases were fatal. In 2016, scrub typhus cases were reported from 47 districts and deaths doubled to 14. More than half of the cases were reported among people below 30 years of age.

In general, fatality rate can be as high as 30 per cent. In India, overall mortality varies from 7 per cent to 30 per cent—only next to malaria among infectious diseases. To date, there has been no reliable and accurate data on deaths to scrub typhus complications in Nepal. It can be, however, assumed that patients with scrub typhus complications such as pneumonia, acute respiratory distress syndrome, meningitis, cardiac problem and gastroenteritis may have been visiting different speciality hospitals in Kathmandu and may not be receiving appropriate antibiotic therapy.

In some of the cases, people with acute gastroenteritis were earlier treated accordingly. But when there was no response to treatment, it was found to be a scrub typhus infection.

Similarly, meningitis, an unusual complication of scrub typhus, has also dramatically increased among patients.

Last year, nearly 20 per cent of people infected with scrub typhus treated at STIDH were found to have developed acute encephalitis syndrome (AES). Cases of meningitis/ encephalitis due to scrub typhus are also increasing.

Researchers showed that AES is still found in Nepal despite the introduction of Japanese encephalitis vaccine.

There is still a lack of confirmatory laboratory tests in remote rural areas of Nepal. As a result, almost all health care providers usually prescribe antibiotics for typhoid fever.

They usually suspect typhoid fever based on Widal test, a popular laboratory test which is affordable and readily and easily available compared to other tests. However, a false positive of Widal test is quite common and usually represents past infection, especially in the regions where typhoid fever is common.

Despite this limitation, what usually happens is that nearly all patients who develop fever almost always first get treatment for typhoid fever and so they receive various—but inappropriate—antibiotics before they arrive at central hospitals for further evaluation. Consequently, most of them experience complications, which can be life-threatening.

Hence, in the absence of confirmatory lab tests, to avoid possible complications or deaths health care providers must have knowledge about clinical manifestations of scrub typhus, its seasonal patterns, updated geographical distribution and use of short course accurate antibiotics.

A severe headache, high-grade fever (up to 104 degrees Fahrenheit), sweating, red eyes, lymphadenopathy, rash, painless and a black eschar at the site of insect bite and breathing difficulty are the main signs and symptoms of scrub typhus.

In Nepal, cases of scrub typhus are seen between July and September. According to a retrospective study done by Nepal Health Research Council, scrub typhus has already spread over half the areas of the country.

If its signs and symptoms, seasonal patterns, and current geographical distributions are known, then it is wise to use of antibiotics for a short period of time (at least for two days), meaning if the fever gradually or rapidly subsides 24 to 48 hours after the treatment with antibiotic doxycycline, it is possibly a scrub typhus infection.

This can be helpful in reducing or preventing scrub typhus related complications or deaths, especially in remote rural areas where a confirmatory test is not available.

In a nutshell, scrub typhus is becoming the most common cause of febrile illnesses in Nepal. Many patients with scrub typhus are being admitted to the ICU in recent years, although it is an easily curable infectious disease. But prompt treatment is the must.

It is always to know scrub typhus symptoms. If you have a fever, severe headache, red eyes, a hard crust or scab on the skin (eschar), sweating and breathing difficulty, then it could be scrub typhus.

Pun is chief of Clinical Research Unit at Sukraraj Tropical & Infectious Disease Hospital, Kathmandu