Health

Are we losing the war on dengue, chikungunya and mystery fever?

Be it heavy breeding, unplanned construction or possible virus mutation, the dengue and chikungunya cases have spiraled out of control this year. Emergence of mystery fever makes the situation worse

 
By Kundan Pandey, Deepanwita Gita Niyogi, Aakriti Shrivastava, Subhojit Goswami
Last Updated: Wednesday 14 September 2016 | 06:07:59 AM

Dengue spreads its tentacles

More than 28,000 cases of dengue have been reported in the country, and it is not even October. This vector-borne disease has reached alarming proportions in Kerala, Telangana, Uttar Pradesh and West Bengal. With 24 deaths reported so far, West Bengal is the worst-affected state. Last year, the death toll was 14. Already, 5,600 cases have been reported. The number of cases will increase in the coming six weeks before the incidence of the disease is expected to fall. Casualties have been higher in areas where stagnant water is a perennial problem. The civic agencies are being blamed for the alarmingly high number of dengue deaths this year.

Uttar Pradesh, which has seen a three-fold jump in dengue cases as compared to last year, suffers from the same problem: stagnant water, especially at construction sites. As many as 2,173 cases have been reported till September 12 as against 731 in the corresponding period in 2015. Three people have died. About 24 districts are currently under its grip. According to official data, 179 cases were reported in the past 24 hours.

Delhi ill-equipped

At least 1,158 cases of dengue have been reported in the national capital with nearly 390 of them being recorded in the first 10 days of September. This is the time when this vector-borne disease begins to peak. In October, the city recorded a staggering 7,283 cases in October alone. With October still couple of weeks away, the national capital is expected to see a major rise in dengue cases. At least nine deaths due to dengue have been reported so far.

The magnitude of the problem is realised when you know that government hospitals in the city are running out of beds. Serious questions have been raised about whether health infrastructure of Delhi can cope with the crisis since it has less than three beds per 1,000 people, far less than five per 1,000 recommended by the WHO.

Moreover, the flu outbreak has hit the capital’s primary labour force. Work on roads and bridges are delayed by weeks as migrant workers leave the city. Disease outbreak has also depleted sanitation work force in East Delhi.

Kerala shows the way

Down south, 5,286 cases were reported in Kerala till August, as against 4,114 in 2015. However, thanks to early detection of the disease, the death toll has been contained. Nine people have died as against 29 last year. Health officials have managed the dengue outbreak effectively so far by setting up blood transfusion facilities in every districts and talukas. Getting platelets has become lot easier for patients.

Hyderabad and Bhubaneswar struggle

Hyderabad has reported seven deaths till August this year against just two in 2015. In the same month, it recorded 135 cases, almost double the cases (73) it witnessed last year.

Dengue fever scare gripped Bhubaneswar after seven persons from the Salia Sahi slum here tested positive for the disease in the last week of August. It is only after the cases surfaced that the administration stepped up measures to prevent and curb incidents of dengue.

Under-reporting of dengue cases

The figures released by corporations and government agencies are not reflective of the crisis because there has been massive under-reporting of cases. In absence of a robust infrastructure in government health facilities, a good number of patients don’t visit government hospitals and resort to private practitioners close to their places of residence. Those cases often don’t get recorded in official data.

Chikungunya cases on the rise

Chikungunya cases are mounting in the country’s capital, crossing the 1000-cases mark. For the first time, chikungunya has led to three deaths in New Delhi.

The first of these was reported on Monday, September 13, when a 65-year-old man succumbed to the mosquito-borne infection at a private hospital. Details of the other two are yet to be known.

A total of 1,057 chikungunya cases were recorded this year till September 10. Of these, 497 cases were recorded in the past week alone.

A surge in cases was also seen in other parts of NCR including Ghaziabad and Noida. As per the district health department, 82 chikungunya cases have been reported in Ghaziabad.

While the municipal corporations in Delhi claim to check breeding regularly, the spread of chikungunya continues. So far this year, the civic bodies have sprayed over 15 lakh houses and conducted over two crore home visits to check for mosquito breeding, as per a media report.

Till August 31, 12,255 cases of chikungunya have been reported in India, as per the National Vector Borne Diseases Control Programme. Of these, nearly 73 per cent or 8,941 have been in Karnataka. Other southern states of Andhra Pradesh and Telangana registered 492 and 404 cases respectively. Maharashtra reported 839 cases in the period. In East India, West Bengal reported 389 cases and Tripura and Meghalaya witnessed 86 and 32 cases respectively, as of August 31. The numbers can be expected to rise in September, if the trends in other states resemble the capital, where almost half of the total cases were reported in one week.

The total number of chikungunya cases in India has been rising since 2012. The figure reached over 27,000 cases in 2015.

Chikungunya is a viral disease transmitted to humans by mosquitoes. It causes fever and severe joint pain. Other symptoms include muscle pain, headache, nausea, fatigue and rash. The disease spreads from the bite of an infected female Aedes aegypti mosquito. The spread of chikungunya can be curbed by checking open breeding grounds of mosquitoes.

Mystery Fever

Officials of Delhi's Hindu Rao Hospital say the number of undiagnosed fever cases has increased manifold since July (Photo: Vikas Choudhary)Outbreaks of viral fever occur with seasonal regularity during the monsoon in India. For the past few years, dengue and chikungunya viruses have been the predominant pathogens. But this year, the country is in the grip of a strange fever. Its symptoms are similar to chikungunya and dengue but tests on patients show negative results for these mosquito-borne viral diseases. Reena, a resident of Bhogal in south Delhi, is one such patient. She ran high temperature for 10 days and suffered from severe pain in the joints, rashes and swollen face—symptoms associated with chikungunya. But the tests showed negative results. Similar was the case of Prachi Nautiyal, a resident of Noida, Uttar Pradesh. In August, Prachi suffered from high fever, body ache, joint pain and skin rashes but tests for dengue and chikungunya showed negative results. 


The phenomenon is not limited to Delhi. Vivek Billampelly, former president of General Practitioners Association, Pune, says the city too has had a high number of viral fever cases. Samarjit Naskar, critical care expert at Belle Vue Hospital, Kolkata, also says that there is a huge number of patients with undiagnosed viral fever this year.

Difficulty in diagnosis also increases the treatment cost for patients because they have to undergo several tests. Ajay Nagar of Rajbeer Colony, Delhi, had to spend R10,000 on treatment and identification of the viral strain her mother was suffering from. But the tests remained inconclusive.

Experts clueless

Doctors have no clue about what could be leading to this fever. Officials from hospitals in Delhi estimate that around 30 per cent of all fever cases are undiagnosed.

S Chatterjee, internal medicine expert at Indraprastha Apollo Hospital, Delhi, says that apart from dengue and chikungunya there are two other kinds of fever cases this year—one caused by normal respiratory infections and another which shows symptoms of chikungunya but does not get confirmed in tests. Naskar is of the opinion that the virus could have changed its genetic pattern. R S Taneja, head of internal medicine department at Ram Manohar Lohia Hospital, Delhi, too believes that the virus could have mutated. Billampelly says that since symptoms are similar to chikungunya, the virus could be its variant.

But there has been very little research on mutations in chikungunya and dengue, says P Jambulingam, director of Vector Control Research Centre, Puducherry. For example, a mutation in chikungunya was last identified in 2007. This mutated virus had caused a high number of cases that year, he says. However, Soumya Swaminathan, director of Indian Council of Medical Research, says that so far, the institute has not found evidence of the viruses being new or mutated versions of older dengue or chikungunya strains. The National Institute of Virology, Pune, the key body on viral research in the country, did not respond to phone calls and emails on the state of research on the unidentified viral strains.

Usual suspects

Dengue and chikungunya continue to plague several states. Chatterjee says that the number of fever cases has increased at least five times since July. A pathologist from Bansal Hospital in New Friends Colony, Delhi, says that almost 150 cases come for diagnosis daily.

The hospitals are incapable of dealing with the rising number of patients. Apollo Hospital and Sir Ganga Ram Hospital have allotted more beds for fever patients. Safdarjung Hospital is using its psychiatry ward to accommodate the rising numbers. Till August 31, a total of 27,879 cases of dengue and 12,255 cases of chikungunya were reported in the country, according to data released by the Union Ministry of Health and Family Welfare. In Delhi, the figure stood at 487 for dengue and 432 for chikungunya. Other states in the grip of chikunguya are Karnataka, Andhra Pradesh, Telangana and Maharashtra, while states with high number of dengue cases are Bihar, Haryana, Andhra Pradesh, West Bengal, Karnataka and Kerala.

Environmental factors could be behind the spurt in cases, says A C Dhariwal, Director of National Vector Borne Disease Control Programme. He warns that the numbers could rise because September and October are suitable for mosquito breeding. P K Das, former director of Vector Control Research Centre, Puducherry, points out that the problem would continue till we do not take steps to reduce the breeding points of the vector.

Moreover, there is now evidence that vectors which earlier bred only in clean water have developed capability to breed in saline water as well. Unless the government takes steps to augment research and health infrastructure, the signs are ominous.

Viruses mutate, emerge, re-emerge
 
In 2015, World Health Organization (WHO) published a list of top emerging pathogens likely to cause severe outbreaks in the near future. Other than chikungunya, the list of pathogens includes Zika, Crimean-Congo haemoerrhagic fever, filovirus diseases such as Ebola, coronaviruses like MERS Co-V and SARS, Lassa Fever, Nipah and Rift Valley Fever.

In recent years, there is evidence that mutations have become more common. In the case of Ebola, the virus that caused the 2014 outbreak was different from those that caused outbreaks earlier. It had accumulated more than 395 mutations between 2014 and 2016, when the researchers collected the last samples. In 2003, researchers identified eight mutations in dengue virus type 4. Chikungunya, which was largely confined to developing countries in Africa and Asia before 2004, reached developed nations, like France, due to a single amino acid change in the envelope glycoprotein.

All you need to know about dengue

Dengue is known to spread after monsoon, but in the last couple of years, cases of the vector-borne disease have been recorded in summer as well (Photo via Creative Commons)

What is Dengue?

According to the World Health Organization, Dengue is a vector-borne disease transmitted by the bite of an infected female Aedes Aegypti mosquito. The mosquito becomes infected when it feeds on the blood of a person infected with the virus. After about one week, the mosquito can then transmit the virus while biting a healthy person.

How many strains of dengue are there?

There are 4 serotypes of the virus that causes dengue. These are known as DEN-1, DEN-2, DEN-3, DEN-4. Infection with one strain will provide life-time protection only against that particular strain. However, it is still possible to become infected by other strains and develop into severe dengue.

Can it spread from person to person?

Dengue cannot be spread directly from person to person. However, a person infected and suffering from dengue fever can infect other mosquitoes. Humans are known to carry the infection from one country to another or from one area to another during the stage when the virus circulates and reproduces in the blood system.

Where does dengue happen?

Most cases occur in tropical areas of the world, including the Indian subcontinent, Southeast Asia, Southern China, Taiwan, the Pacific Islands, the Caribbean, Mexico, Africa, Central and South America.

What are the symptoms of dengue?

Dengue causes flu-like symptoms and lasts for 2-7 days. Dengue fever usually occurs after an incubation period of 4-10 days after the bite of the infected mosquito. High Fever (40°C/ 104°F) is usually accompanied by at least two of the following symptoms: headaches, pain behind eyes, nausea, vomiting, swollen glands, joint, bone or muscle pains and rash.

What happens in severe dengue?

Severe abdominal pain, persistent vomiting, bleeding gums, vomiting blood, rapid breathing, fatigue/ restlessness.

What is the treatment for dengue?

There is no vaccine or specific medication for dengue fever. Patients should seek medical advice, rest and drink plenty of fluids. Paracetamol can be taken to bring down fever and reduce joint pains. However, aspirin or ibuprofen should not be taken since they can increase the risk of bleeding.

Patients who are already infected with the dengue virus can transmit the infection via Aedes mosquitoes after the first symptoms appear. As a precautionary approach, patients can adopt measures to reduce transmission by sleeping under a treated net especially during the period of illness with fever.

Chikungunya: know your enemy

What is chikungunya?

Chikungunya is a viral disease transmitted to humans by infected mosquitoes. It causes fever and severe joint pain. Other symptoms include muscle pain, headache, nausea, fatigue and rash. The disease is caused by an RNA virus that belongs to the alphavirus genus of the family Togaviridae.

As per the World Health Organization (WHO), chikungunya shares some clinical signs with dengue, and can be misdiagnosed in areas where dengue is common.

How is chikungunya contracted?

Chikungunya is transmitted through mosquito bites. Though the virus does not spread directly from one person to another, a female mosquito that bites an infected person can spread the disease to other human beings. Most commonly, the mosquitoes species Aedes aegypti and Aedes albopictus, transmit the virus. These mosquitoes can be found biting throughout daylight hours, though there may be peaks of activity in the early morning and late afternoon.

Chikungunya has been identified in over 60 countries in Asia, Africa, Europe and the Americas.

What is the treatment for chikungunya?

There is no specific antiviral drug treatment for chikungunya. Treatment is directed at relieving the symptoms, including the joint pain using anti-pyretics, optimal analgesics and fluids. There is no vaccine available for chikungunya.

What preventive measures should be taken during a chikungunya outbreak?

Reducing the open breeding grounds of mosquitoes like artificial water-filled containers, drains, or natural bodies with still water is a key prevention measure against chikungunya and other mosquito-borne diseases. During outbreaks, insecticides may be sprayed to kill flying mosquitoes, applied to surfaces in and around containers where the mosquitoes land and used to treat water in containers to kill the immature larvae.

For protection during outbreaks of chikungunya, clothing which minimises skin exposure to the day-biting vectors is advised. Repellents can also be applied to exposed skin.

How are dengue and chikungunya different?

The diseases are caused by two different viruses: Togaviridae alphavirus for chikungunya and  Flavirideae flavivirus for dengue. Common symptoms between the two diseases can lead to misdiagnosis.

While the acute symptoms of chikungunya resolve within 7-10 days, dengue patients may develop life threatening consequences and require hospitalisation. Once infected by chikungunya, a person develops life-long immunity. Since there are 4 distinct dengue viruses, a person can be infected up to 4 times. Infection with each dengue virus type confers lifetime immunity for that specific virus type.

Climate change and vector-borne diseases go hand in hand

Coastal areas are at increased risk from vector-borne diseases
Credit: Marufish/Flickr

A change of climate over time due to natural or man-made causes is increasingly playing an important role in spreading the extent of vector-borne diseases (VBDs).

According to the World Health Organization, one of the major consequences of climate change is the rise in the number of VBDs, besides heat strokes and skin diseases.

The development of mosquitoes and pathogens in their bodies is affected by climatic conditions, experts says. Ramesh Dhiman of the National Institute of Malaria Research told Down To Earth that temperature is essential for the development of malarial parasites. “Insects are cold-blooded. Temperature affects the development of vectors or pathogens,” he said.

In India, Jharkhand and Chhattisgarh are already suitable places for the transmission of vector borne diseases. But the worrying thing is that in colder areas such as the Himalayan region, projected temperature rise can trigger the breeding of mosquitoes and the rate of transmission. Places like Jammu and Kashmir and Uttarakhand will have to deal with vector-borne diseases, according to Dhiman.

As dengue is the most deadly of all VBDS (others being malaria, filaria, Japanese encephalitis, chikungunya), Dhiman added that preventing water storage and community participation were vital to prevent outbreaks. The major cause of dengue is water storage in all types of containers. As it is not possible for the government alone to ensure that water does not stagnate, the participation of people becomes important here, he said.

The epidemiology of dengue in India has changed over the years in terms of strains, geographical location and severity. Along with temperature rise, rainfall, relative humidity and wind velocity also play an important role in the development of parasites in insects.

According to Asish Ghosh, the director of Centre for Environment & Development, a Kolkata-based non-profit, increasing cases of VBDs can be regarded as the indirect health effects of temperature variations. Temperature rise can lead to floods, especially in the coastal areas and this may, indirectly, lead to an increase in VBDs. Stagnant water serves as breeding grounds for mosquitoes, and thereby, increases the chance of dengue and malaria.

Ghosh said that all tropical diseases, especially malaria, are prevalent in the southern hemisphere. Mosquitoes breed faster due to high temperature and moisture level. Several studies have shown the higher rate of breeding and outbreak of VBDs occur in hot and humid conditions.   

"By 2030-50, India will witness a high level of malarial outbreak and will become the malaria capital of the world," Ghosh added. The mosquito parasite is already present in the country and further temperature rise will make the situation worse.

Ghosh emphasised on adaptation measures, especially in coastal areas, to cope up with the situation. According to him, coastal areas should be equipped with vector-borne disease control programmes. People should be encouraged to use mosquito nets. Water should be purified to prevent contamination. 

In India, VBDs are also prevalent due to poor sanitary conditions, Ghosh said. Water-logging and open defecation make matters worse in the country, the expert added. 

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IEP Resources:

Co-distribution and co-infection of chikungunya and dengue viruses

Comparative evaluation of validity and cost-benefit analysis of rapid diagnostic test (RDT) kits in diagnosis of dengue infection using composite reference criteria: A cross-sectional study from south India

Distribution and prevalence of malaria parasites among long-tailed macaques (Macaca fascicularis) in regional populations across Southeast Asia

Mosquito vectors developing in atypical anthropogenic habitats: Global overview of recent observations, mechanisms and impact on disease transmission

Dengue virus sero-cross-reactivity drives antibody-dependent enhancement of infection with zika virus

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