Pakistan is witnessing an increasing surge of Dengue fever these days especially in Lahore city, the capital of Punjab province. As we continue to live amid a Covid pandemic, the risk has compounded with the infections caused by the Dengue virus and coronavirus since many symptoms of dengue and Covid-19 overlap, which can make treatment difficult and outcome gloomy. The covid-19 pandemic is not yet over, as of 19 October 2021, there are more than 25000 active Covid cases in Pakistan while in total 12,65,650 confirmed positive cases, 28,300 deaths and 12,11,710 recovered cases since the beginning of this outbreak in Pakistan. From a clinical and diagnostic perspective, it is very difficult to differentiate between dengue fever and Covid-19 since both diseases share similar laboratory and clinical characteristics.
Corona Virus: Coronavirus disease 2019 (COVID-19) is a respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has now spread to almost all countries around the world, resulting in a global pandemic. SARS-CoV-2 is primarily transmitted from person-to-person through droplets while coughing and sneezing, from symptomatic and pre-symptomatic patients and probably from asymptomatic individuals as well. Some established symptoms are fever, dry cough aches and pains with tiredness, sore throat with headache, diarrhoea, difficulty breathing or shortness of breath.
Dengue: Dengue fever is an important infectious disease in Pakistan with increasingly frequent epidemics in recent past years. It is also called bone-breaking fever, dengue is a viral infectious disease caused by any of the four related dengue viruses which are called its serotypes – DEN-1, DEN-2, DEN-3, and DEN-4. The common symptoms of dengue disease include high-grade fever with severe headache, muscle and joint pain coupled with nausea and vomiting.
As it is very difficult to differentiate between both diseases, healthcare providers in areas where dengue is endemic or who are treating patients with recent travel history to these areas, need to consider dengue and COVID-19 in the differential diagnosis of acute febrile illnesses. Most people with dengue and COVID-19 have mild illness and can recover at home; symptoms usually last a few days, and people tend to feel better after a week. However, both dengue and COVID-19 can cause severe illness that can result in death. The clinical management for people who develop a severe illness with either of these two diseases is quite different, often requiring hospital-based care. Anyone of any age can develop a severe illness with dengue or COVID-19. Both infections are more likely to cause complications in adults with underlying chronic conditions, such as diabetes and heart disease.
Clinicians and lab experts should perform appropriate tests (for dengue; for COVID-19) and follow the patient closely for warning signs. Dengue Virus warning signs include persistent vomiting, mucosal bleeding, difficulty breathing, lethargy/restlessness, postural hypotension, liver enlargement and progressive increase in hematocrit. Warning signs of COVID-19 include difficulty breathing, persistent pain or pressure in the chest, new confusion, inability to wake or stay awake, bluish lips or face. Complications for both infections can develop before test results come back so clinical management should be guided by clinical presentation.
If we talk about the transmission pattern of both viruses then Dengue virus is mainly transmitted to people through the bites of infected Aedes species mosquitoes (primarily Ae. aegypti or Ae. albopictus species) While COVID-19, is mainly transmitted from person to person through respiratory droplets that are spread when an infected person coughs, sneezes, or talks. The incubation period for the dengue virus ranges between 3-10 days, typically 5-7 days while the incubation period for the COVID-19 virus is thought to extend to 14 days, with a median of 4-5 days from exposure to symptoms onset. The clinical manifestations of both dengue and COVID-19 can range from mild to critical. In the mild to moderate phase, both have a fever, headache, myalgia, Nausea, vomiting, rash, fatigue etc. Covid would also have a loss of taste and smell, running nose, congestion and in some cases diarrhoea. Critical phases of both diseases are different from each other which help clinicians to focus on disease and its medication. In Dengue fever abdominal pain, persistent vomiting, clinical fluid accumulation, mucosal bleeding, lethargy, restlessness, and liver enlargement are important. In these cases, complete blood count is very important as it tells about possible depletion in white blood cells and platelets. This rapid clinical deterioration may occur within 48 hours after defervescence (3–7 days after fever onset).
Severe dengue disease is defined by dengue with symptoms like Plasma leakage leading to shock, Fluid accumulation with respiratory distress, severe bleeding with thrombocytopenia, Severe organ impairment such as liver disease with elevated transaminases, or meningoencephalitis with impaired consciousness. The critical phase of Covid-19 disease include those patients who developed severe disease like the medium time to dyspnea ranged from 5 to 8 days, the median time to acute respiratory distress syndrome (ARDS) ranged from 8 to 12 days, and the median time to ICU admission ranged from 10 to 12 days. Very severe illnesses can include dyspnea, hypoxia, respiratory failure, shock and multi-organ system dysfunction.
Risk factors for both diseases are a little bit different. Risk factors for severe dengue include age (infant), Second dengue infection; In most dengue-endemic countries, children and young adults are at the highest risk for a second infection, patients with chronic medical conditions, including diabetes, asthma, or heart disease. While the risks factors for severe illness with COVID-19 include: Age >65, Underlying conditions like cardiovascular disease, diabetes, chronic respiratory disease, hypertension, prior stroke, liver disease, obesity, chronic lung disease, chronic kidney disease undergoing dialysis, or immunocompromised (e.g., poorly controlled HIV, undergoing cancer treatment, using corticosteroids, smoking).
Measures to avoid these Public Health crises
Undoubtedly, the co-infection and co-occurrence of dengue and COVID-19 epidemic in the country have created a great burden on the medical and public health programs, Pakistan is a developing country with resource-limited settings and both diseases have raised serious concern as the healthcare infrastructure is already under tremendous pressure due to the COVID-19 pandemic. Also, it is a challenge for diagnostic staff to come out with correct laboratory diagnoses of shared clinical symptoms shown by infected individuals. The main pillars to control both devastating diseases are preventive measures such as vector control, protective measures and proper surveillance.
In such a situation, the need of the hour is gold-standard diagnostic tests that could precisely distinguish between dengue and Covid-19 diseases. In the case of Dengue disease, NS-1 ELISA and Dengue PCR are vital diagnostic markers to rule out dengue disease while in the case of covid disease, molecular-based RNA detection of SARS-COV-2 virus is subsequently important. To avoid rising numbers of dengue cases in Lahore when the COVID-19 is also at its peak, it is necessary that the hospitals develop sufficient infrastructure to treat patients with co-infection. It is also important that patients must be diagnosed with all the infections since clinical diagnosis is not easy due to overlapping symptoms.
At the same time, it is important that people follow COVID-appropriate behaviour as well as the general guideline dengue prevention including, but not limited to preventing the accumulation of freshwater, wearing clothes covering arms and legs, using mosquito nets and repellents, and screening on windows and doors, and cover water containers tightly or use a chemical larvicide to prevent the breeding of mosquitoes.