Dharan’s case shows large-scale dengue outbreak can occur anytime, anywhere. Government authorities need to remain better prepared to control such outbreak
On May 24, a 29-years old lady visited Sukraraj Tropical and Infectious Disease Hospital (STIDH) for medical and laboratory tests after she was diagnosed of dengue in Dharan. STIDH’s test confirmed dengue. She had developed high fever, nausea, severe joint pain, rash, body ache but there was no history of pain behind the eyes. She said that several others in her town had showed similar symptoms. This was the first observation of beginning of dengue outbreak in Dharan.
In Nepal, dengue outbreak usually occurs after the end of the monsoon season. In March, 2017, however, two patients were found to be infected with dengue in Kathmandu and therefore it was then considered as off-season dengue fever. It is established that aedes mosquito, the primary vector for dengue virus, is main cause of dengue. This indicates that dengue can be found even prior to pre-monsoon season (or anytime), where aedes mosquitoes are present. In Dharan, it can be assumed that aedes mosquitoes are widespread and locals may lack adequate knowledge regarding dengue. Dharan had never faced such an uncontrolled dengue outbreak before.
Now dengue is spreading to nearby cities such as Dhamak and Biratnagar, adding to the challenge of controlling it. Dengue could even spread to other parts of the country. According to the 2011 study, dengue was reported in nine districts until 2006, and expanded to 24 districts during 2010 dengue outbreak. Thus we cannot rule out the possibility Dharan dengue spreading to other parts of the country.
It is apparent that conducting trainings about dengue won’t be adequate to bring dengue under control. For example, media reports say that local people are found reluctant to throw or replace water collected inside their homes, which is one of the main obstacles in interrupting mosquitoes breeding cycles. Inadequate water supply is the problem in Nepali communities and people tend to collect and store water inside their homes.
Similar situation can be seen in densely populated Kathmandu. If a dengue outbreak occurs in Kathmandu, it will be very difficult to control it within a short period of time. If regular water supply is ensured, it could help in preventing dengue outbreak.
A person can be infected with dengue virus after being bitten by an infected female aedes mosquito. Symptoms may appear four to 10 days after the bite. Fever, headache, pain behind the eyes, joint pain, rash, nausea and vomiting fatigue are major symptoms. Some patients, however, do not experience pain behind the eyes. They may experience warning signs such as persistent vomiting, mucosal bleeding (eg gums or nose bleeding), blood in vomiting, severe abdominal pain, fluid accumulation in abdomen or chest, restlessness and liver enlargement. Laboratory test shows rapid decrease in platelet count concurrent with increase with hematocrit level. It is also known as “critical phase” and usually lasts for 24 to 48 hours. In severe dengue, there are signs of plasma leakage (fluid accumulation with respiratory distress and shock) and involvement of vital organs (such as liver, heart and nervous system).
My study has found that that 8.7 percent of the dengue-infected patients developed critical phase, and majority of patients belong to 20 to 44 years of age group. This means physicians need to be vigilant and attentive to young adult patients with dengue fever.
Due to overlapping symptoms among infectious diseases, laboratory confirmation is a must. So far, mainly rapid diagnostic test (RDT) kit has been used in clinical samples to confirm dengue virus. Such kits have been provided free of cost by the government, whenever and wherever outbreaks occur. However, RDT kits are periodically in short supply during outbreaks. It is learnt that presently there is an acute shortage of RDT kits in Dharan and hence people are compelled to pay higher prices for these kits.
Very recently, the government has set new eligibility criteria to test dengue virus among suspected cases. Patients must have fever lasting for three days along with low white blood cell count and platelet count below 100,000 cumm. This criterion could be helpful in identifying true dengue patients avoiding unnecessary use of RDT kits.
The government has failed to take timely action against dengue outbreak. As a result, the outbreak is continuing with high intensity and spreading to other parts of the country. In response to public criticism, the Epidemiology and Disease Control Division (EDCD) has ascribed the current situation to lack of coordination between federal and provincial governments. These governments need to establish effective coordination. We should learn a lesson from this experience and develop strategy to avoid such situation from recurring.
Dengue outbreak in Dharan indicates that large-scale dengue outbreak can occur anytime and anywhere. Thus, concerned government authorities need to remain better prepared to control dengue outbreak, particularly where mosquitoes are widespread. Likewise, there should be proper coordination between federal and provincial governments. They need to realize their roles and responsibilities and act promptly whenever and wherever dengue outbreaks occur.
The author is the Chief of Clinical Research Unit at Sukraraj Tropical and Infectious Disease Hospital, Teku, Kathmandu