Which infectious disease outbreak/epidemic will emerge this year? There may not be an immediate answer to this question, but based on past experience and weaknesses, we can estimate the potential infectious disease outbreak.
Nepal has a history of facing some kind of outbreak every year, especially during the monsoon season. Natural disasters such as floods and landslides seem to have added to this problem. While waterborne epidemics were more common a decade ago, insect-borne diseases have been gaining momentum in the last few years. However, this does not mean that the risk of waterborne infections has been completely controlled. With the onset of the monsoon in Nepal, the risk of seasonal epidemics is also increasing. An analysis of possible epidemics is being made here based on past experiences.
Dengue
A few days ago, while I was sitting with my colleagues, mosquitoes were moving around. Although the monsoon has not yet arrived, the activity of mosquitoes is somewhat unusual, but it is definitely a matter of concern. Remember, when dengue suddenly spread in Dharan in 2019, the monsoon had not yet entered Nepal. That is, at that time, the abnormal increase in mosquitoes due to unseasonal rains and the dengue finally reaching Kathmandu through one district after another, Kathmanduites had to face the big challenge of dengue for the first time. If we look at the official statistics, dengue has been seen for about 12 months in the past few years.
In the case of a large and long epidemic, dengue starts spreading from the onset of the monsoon, and when it takes the form of an outbreak in a certain place, dengue appears ‘post monsoon’, that is, after Dashain-Tihar. In 2022, dengue caused a devastating epidemic in Kathmandu. This was the largest epidemic seen in a three-year interval after 2019.
If we look at the statistics of Nepal, dengue has taken the form of an outbreak/epidemic in an interval of two to three years. With each epidemic, the infectiousness, aggressiveness, and complexity of the virus also seem to be increasing. Therefore, the strong possibility that dengue could cause a new epidemic wave in Kathmandu at any time cannot be ruled out. And, it cannot be said that it will not be even more extensive than in the past. However, unfortunately, we still do not seem to be taking dengue prevention measures seriously or making sufficient efforts to control it.
Scrub Typhus
This disease is caused by a bacteria called ‘Orienta tsusugamusi’. It is an insect-borne disease caused by the bite of a chigger mite. It gained special attention in Nepal after some children died of scrub typhus in 2015. Although some say that this disease spread/appeared due to the 2072 BS earthquake, studies have shown that this bacteria was already seen in Nepal two decades ago.
However, scrub typhus was not included in routine testing until the Dharan incident, so its status seems to have been unknown before 2015. Hospital statistics show that scrub typhus is more active every year in Nepal, especially during the monsoon season. Some people are seen to die due to delay in treatment or even during treatment.
Especially when going to the countryside or to the forest (to cut grass) or recently, the increasing trend of hiking in the city has also increased the risk of scrub typhus. For some reason, when people come into contact with tall or large bushes or grasslands, chigger mites attach to them and bite them, increasing the likelihood of scrub typhus disease. Even now, many people ignore fever, and scrub typhus seems to have taken a complicated situation. There is a need to promote information about scrub typhus more effectively.
Cholera
Two decades ago, cholera patients seemed to be regular in Kathmandu. Not only regular, but the hospital would be full with the onset of monsoon. The author has the experience of 40/50 people coming to the hospital within an hour. Currently, that terrible situation is not there, but cholera has not been confined to history in Nepal either. Cholera is still seen as regular in Kathmandu.
A few years ago, some patients died in Nawalparasi due to cholera. Even in severe cases of cholera, the chances of death can be reduced by getting immediate treatment. However, if cholera of a complex nature is seen in geographically remote and remote places, there is a possibility of death.
Because it is difficult to bring patients to well-equipped hospitals from such places in time. For example, 111 people died due to cholera in Jajarkot during April-July 2009. It also seems that cholera has recurred many times in Jajarkot. That is, we do not seem to have learned a lesson from this incident or it does not seem to be serious. Currently, there is a difference in the way or source of cholera spread. Cholera is mainly spread through water and contaminated food. Recently, people have started to be somewhat careful about water and food.
However, there are reports that coliforms are regularly found in some bottled or jarred drinking water available in the market. That is, this can be taken as an indication that water mixed with feces is reaching every household. The risk of cholera has increased since such water is not purified and drunk. Similarly, in the past, flies have also started appearing everywhere. Flies are also a means of spreading cholera.
In the past, information was regularly circulated that the disease was spread by flies, but today such propaganda has decreased. Similarly, the lack of regular and effective monitoring of commercial water has increased the risk of cholera and this has increased the possibility of outbreaks/epidemics.
Japanese Encephalitis
After a long gap, Japanese encephalitis increased abnormally in Nepal last year, due to which at least 14 people died. This was double the number of people infected with this virus last year. More than 60 people were infected with this virus. This shows that Japanese encephalitis is re-emerging in a ‘step ladder’ manner. So, the question ‘Is there a possibility of infection and mortality this year too?’ has arisen seriously. The answer to this question will be determined to some extent by the reasons for the increasing number of infections each year and the state of preparedness to prevent the spread. The duration of the effectiveness of the vaccines used against this virus or whether the vaccines have been sustained or not will also be important.
The number of Japanese encephalitis patients seen last year can also indicate that the mosquitoes that spread Japanese encephalitis are active during the monsoon. Therefore, this year is unlikely to be different from the previous year.
Respiratory infections
Every year, a wave of respiratory infections, especially flu viruses, appears in the middle of the monsoon. Based on past experience, it seems that the flu virus sometimes takes the form of a pandemic. Before COVID-19, the flu virus named ‘H1N1PDM09’ was declared a pandemic. In 1918, the flu virus known as ‘Spanish Flu’ killed an estimated 50 million people.
Although it is customary to consider it as a ‘viral’ or common cold in Nepal, it seems to complicate the health of senior citizens, chronically ill people, and children. The available vaccines against flu are largely helpful in preventing complications from the infection.
Wearing a mask when going outside or in public places during the active period of the flu and washing your hands thoroughly with soap and water after coming home will also be helpful in preventing the infection to a large extent. Such information will be more effective if it is continuously provided through various media and taught to students in schools.
Unknown or imported infectious diseases
In Nepal, a small number of infectious diseases or infections are still routinely included in routine testing. That is why most patients are not diagnosed due to fever. Thousands of Nepalese go abroad for employment every week. From there, the risk of previously unseen infections entering Nepal is high. Viruses such as COVID-19, African malaria, and Chandipura virus are some of the diseases that have recently entered Nepal. Infectious diseases such as Zika virus, Nipah virus, Cassinur Forest disease (monkey fever), and MERS coronavirus are emerging in neighboring countries like India and the Middle East, which should also be considered a risk for Nepal.
Due to the limitations of regular testing, it is not possible to confirm whether these infections have entered Nepal or not. Even if they have not entered now, there is no basis to believe that they will not enter in the coming days. Since these diseases are also airborne or insect-borne infections, there is a risk of spreading during the monsoon season.
Therefore, it would be appropriate to arrange additional testing for infections that are not detected by the currently available regular tests. Because these infectious diseases that are yet to be confirmed cannot be said to become an outbreak or epidemic tomorrow. A strong example of this is the dengue virus, which was confirmed in one person in 2004, which has recently emerged as the biggest challenge for Nepal.
Finally, the habit of panicking after an infection takes the form of an epidemic and forgetting about it after it is over is still evident. COVID-19 and the dengue epidemic of 2022 can be taken as vivid examples of this. Planning should be done before the monsoon based on past experiences and available resources and the implementation aspect of the plan should be implemented as soon as the monsoon begins. The possibility that the above-mentioned infectious diseases may appear as an outbreak/epidemic in the coming days (during the monsoon) cannot be ruled out.
Infectious disease specialist Dr. Sher Bahadur Pun is the coordinator of the Clinical Research Unit at Shukraraj Tropical and Infectious Diseases Hospital.
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