INTRODUCTION:
Rickettsial diseases are a group of communicable diseases caused by bacteria of Rickettsiaceae family. Most of them are transmitted to the man by arthropod vectors. In many geographical areas due to difficulty in clinical diagnosis and lack of laboratory methods, they are under-diagnosed and contribute substantially to the acute febrile burden and preventive illness in the community. 1-2
Scrub typhus is one of the most widespread rickettsial diseases. The zones that harbor its vector are often made up of secondary ‘scrub’ growth, which grows after clearance of primary forest. However, endemic areas can also as diverse as seashore, rice fields and semi-deserts. The word “typhus” is derived from the Greek word “typhus”, which means “fever with stupor”. Hence the disease is named as ‘scrub typhus’.3 Scrub typhus was first described from Japan in 1899. It is a militarily important disease as it affected thousands of soldiers during the World War-II. Currently the scrub typhus is endemic in Northern Japan, South East Asia, the Western Pacific Islands, Eastern Australia, China, Maritime areas and several parts of South –Central Russia, India and Shri- Lanka. Globally more than 1 million people are affected annually. Since 1930s scrub typhus has been reported from Kumaon region and soldiers in Assam during the world war-II in India. The outbreaks have been also reported from the Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Bihar, West Bengal, Meghalaya, Rajasthan, Maharashtra, Karnataka, Tamil Nadu and Kerala. Scrub typhus is one of the re-emerging infectious disease in India.1,4
Epidemiological Determinants:
a) Agent:
The causative agent of Scrub typhus is Orientia (formerly Rickettsia) tsutsugamushi. It is transmitted to the human beings by bite of infected mite called chiggers (larval stage). Chigger mites act as the primary reservoirs for Orientia tsutsugamushi and the disease is also known as tsutsugamushi disease. ‘Tsutsuga’ means ‘small and dangerous’ and ‘mushi’ means ‘insect or mite’.3 Chigger mites are infected in nature by feeding on the body fluid of small mammals and rodents. They autonomously maintain the infection in their all life stages by-
Transovarial Transmission:
When the adults pass the infection on to their eggs
Transtadial Transmission:
When the infection passes from the egg to the larva or adult.
b) Host:
human beings (people in occupational activities e.g. agriculturist, horticulturist, labourer working in fields, orchard and other recreational activities), animals, rodents
c) Environment:
rainy season, cooler season in southern India, areas such as forest clearings, riverbanks, and grassy regions, seashore, rice fields and semi-deserts.
Life cycle of the mite:
The mite is very small (0.2 – 0.4mm) in size and can be seen with the help of a microscope or magnifying glass. There are four-stages in the lifecycle of the mite: egg, larva, nymph and adult. Only the larval stage (chigger) can transmit the disease to humans and other vertebrates. Both nymph and adult life stages do not feed on vertebrate animals and are free-living in the soil. 3,4
Mode of Transmission:
The scrub typhus is transmitted by the bite of chiggers as shown the transmission cycle. The disease is not directly transmitted from person to person.1
The incubation period:
The incubation period of scrub typhus is about 5-20 days (mean, 10-12 days) after the initial bite.4
Pathogenesis:
Human beings are accidental hosts of Scrub typhus when they encroaches the zone of infected mites. Once the chiggers have grasped a host, they prefer to feed on thin, tender or wrinkled skin and where the clothing is tight. Then the chiggers insert their mouthparts down into the skin pores or hair follicles and inject a liquid that dissolves the tissue around the feeding site. This liquefied tissue is sucked up by the chigger. The Orientia tsutsugamushi that are found in the chigger’s salivary glands, are injected into the host during feeding. After feeding, the engorged chigger drop off its host, burrow into the ground and transform into the nymph stage.2 The bacterium Orientia tsutsugamushi is an obligate intracellular gram-negative bacterium that grows slowly in the cytoplasm of infected cell.4 They can bypass white blood cells. The bacterium divides within the phagocytes and escape from the cell back into the circulation. They proliferate on the endothelium of small blood vessels releasing the cytokines which causes endothelial damage resulting in fluid leakage, platelet aggregation, polymorphs and monocyte proliferation, leading to focal occlusive end-angiitis causing micro infarcts. Further it affects skin, skeletal muscles, kidneys, brain, lungs and cardiac muscles. This can also cause venous thrombosis and peripheral gangrene. 2
Clinical features:
Scrub typhus is presented with a broad range of clinical features. Firstly, there is the development of a papule at the site of inoculation. Later it ulcerates and eventually heals leaving a black eschar (blackened scab). The general symptoms are sudden fever (>40ºC [104ºF]) with relative bradycardia, severe headache, myalgia, apathy, generalized lymphadenopathy, a dry cough and photophobia. Approximately after one week, a spotted and then maculopapular rash appears first on the trunk and then on the extremities and blenches within a few days. The symptoms generally disappear after 2 weeks even in untreated cases. Interstitial pneumonia (30 to 65% of cases), myocarditis and meningoencephalitis are common complications. In severe cases with pneumonia and myocarditis, the mortality rate may reach 30%.5 The other complications are Acute Respiratory Distress Syndrome (ARDS), acute hepatic failure, acute renal failure, and Disseminated Intravascular Coagulation (DIC) and GI bleeding.3
Lab Diagnosis:
Serological tests:
· Weil- Felix test:
Cheapest, easily available, easy to perform and results are available overnight (50% positive cases during the 2nd week)
· Complement-fixation Test:
To detect specific antibody or specific antigen in a patient’s serum.
· Indirect Immunofluorescence Antibody (IFA):
Indirect Immunofluorescence Antibody (IFA) is the gold standard. Indirect immunoperoxidase (IIP) is a modification of the standard IFA method.
· Qualitative enzyme-linked immunosorbent assay (ELISA):
To detect the immunoglobulin M (IgM) antibodies to O. tsutsugamushi in serum.
Culture:
The O. tsutsugamushi can be grown in tissue culture or mice from the blood of scrub typhus patients.
Polymerase Chain Reaction (PCR):
It is possible from skin rash biopsies, lymph node biopsies or Ethylene Di-amine Tetra Acetic acid (EDTA) blood.
Other tests:
· Blood counts:
To detect leukocytosis and thrombocytopenia.
· Liver Function Tests:
Elevated transaminases (75–95% cases), hypoalbuminemia (50% cases), hyperbilirubinemia (common in all cases).
· Renal Function Tests:
Elevated creatinine level (in severe cases).
· Chest X-ray:
To reveal pleural effusion, pneumonitis or bilateral infiltrates.
· Ultrasound abdomen:
To reveal spleen or liver enlargement. 3
Treatment:
As per DHR-ICMR guidelines for diagnosis and management of rickettsial diseases in India (2015), the scrub typhus can be managed at different levels of health care facility as –
When rickettsial disease is suspected, without waiting for laboratory confirmation, antibiotics should be started.
1. At primary level health care facility:
The health care providers should:
a) Recognize disease severity:
In the patients with complications, Doxycycline should be started before referral.
b) Refer to secondary or tertiary level health care facility in patients with complications like ARDS, meningo-encephalitis, acute renal failure and multi-organ dysfunction. Along with recommended management of community acquired pneumonia, start Doxycycline when the scrub typhus is considered likely.
c) In case of fever for 5 days or more where dengue, malaria and typhoid have been ruled out; following drugs should be administered when scrub typhus is considered likely –
For Adults:
a) Doxycycline -200 mg/day in two divided doses ×7 days ( for patients ˃45 kg ).
Advise the patients to swallow capsules with plenty of fluid during meals while sitting or standing Or
b) Azithromycin-500 mg in a single oral dose × 5 days.
For Children:
a) Doxycycline -4.5 mg/kg of body weight/day in two divided doses (for children < 45 kg) Or
b) Azithromycin-10mg/kg body weight in a single dose × 5 days.
For Pregnant women:
Azithromycin can be administered to pregnant women, as doxycycline is contraindicated.
Azithromycin- 500 mg in a single dose × 5 days.
2. at secondary and tertiary level health care facility:
a) Uncomplicated cases:
Start the treatment as specified in above cases.
b) In complicated cases:
Start the treatment as following-
i) Intravenous Doxycycline:
100mg twice daily in 100 ml of Normal Saline to be infused over ½ an hour initially followed by oral therapy × 7-15 days. Or
ii) Intravenous Azithromycin:
500mg IV in 250 ml Normal Saline to be infused over 1 hour O.D. × 1-2 days followed by oral therapy × 5 days. Or
iii) Intravenous Chloramphenicol:
50-100 mg/kg/day 6 hourly to be infused over 1 hour initially followed by oral therapy × 7-15 days.
iv) Management of complications should be done as per institutional protocols. Doxycycline and/or Chloramphenicol resistant strains are sensitive to Azithromycin.6
Prophylactic Treatment:
Prophylaxis is recommended under special circumstances in certain areas where the disease is endemic. For prophylaxis, a single oral dose of Chloramphenicol or tetracycline is given once in every 5 days for a total of 35 days, with 5-day non-treatment intervals. It produces active immunity to scrub typhus.4
Prevention and Control of Scrub Typhus:
Personal Protective Measures:
· Avoid scrub typhus endemic or mite infested areas.
· Wear protective clothing and high shoes.
· Impregnate clothes and blankets with mitecidal chemicals (permethrin and benzyl benzoate)
· Application of mite repellants (diethyltoluamide).
· Avoid sleeping in outdoors.
· Avoid lying or sitting on bare ground or grass.
· Use a ground sheet or cover.
· After working outdoors, take a thorough bath with soap and water.
Environmental Sanitation:
· Destroy and treat the vegetation with residual insecticides.
· Control of rodent’s population by trapping, poisoning and use of natural predators.
· Eliminate mites by application of chlorinated hydrocarbons (lindane, dieldrin and chlordane) to the ground and vegetation.
Vaccine:
Currently there is no effective vaccine available for the prevention of scrub typhus due to antigenic variation in the Orientia tsutsugamushi strains. 1,3
Nursing Management:
There is an ample scope for the nurses working in community and hospital setting for the prevention and management of patient with scrub typhus. While working in community settings, nurses can search for an eschar in hidden areas of body among the suspected patients, but scar may not seen in all the patients. Nurses can refer all the scrub typhus suspected patients to health center and start Doxycycline as per physician order. They can collect the blood sample and sent to laboratory for appropriate tests for Scrub typhus. They can closely monitor the patient for the signs of complications and multi organ failure and refer to secondary or tertiary centre. Doxycycline stock should be monitored on daily basis at peripheral health centers. Nurses can create awareness in general public by health education campaigns, role plays and distribution of pamphlets, leaflets etc. in endemic areas in pre-monsoon period (June-July) every year.6, 7
The patient with scrub typhus need a well organized nursing care. For the treatment, If a patient is prescribed Tab. Doxycyline (a tetracycline group antibiotic), it should be given with plenty of water during or after meals.. Monitor the patient for side-effect of the drug as the Tetracyclines group drugs may cause teeth discoloration, enamel hypoplasia, and skeletal growth retardation in children. Thus, they should not be used in children below 8 years of age and in pregnancy.5 In case of fever, administer anti-pyretic as prescribed. Tepid sponging can be done to bring down the temperature to an acceptable level. The patient should be nursed in a well-ventilated room. A calm and quiet environment will ensure adequate rest and sleep. Maintain personal hygiene by daily bath with soap and water. Provide clean cotton clothes. Back care should be given to prevent pressure sores. Bed linen should be kept clean, wrinkleless and dry.
Administer analgesics as prescribed to relieve severe headache and lymphadenopathy pain. The calamine lotion should be applied on the rashes to sooth the skin. No dressing is required on the eschar as it will heal by itself. Use honey to soothe the throat for coughs. Increase fluid intake in the form of fruit juices, milk, vegetable soups etc. Atleast 2-3 litres fluid per day should be given orally. Oral hygiene should be maintained. Lips should be kept moist by lubricating with an ointment. Easily digestible, palatable, liquid or soft high calorie diet should be provided to affected person. Monitor the patient for the complications (pneumonia, myocarditis and meningoencephalitis).
In severe cases with dyspnea and cyanosis oxygen is administered. If the patient develops the pneumonia, administer antibiotics as prescribed. Turn the patient side to side to prevent consolidation. If needed, administer plasma or whole blood or intravenous fluids as ordered. Maintain input and output chart. I.V. fluids should be administered cautiously due to the risk of fluid overload which may lead to pulmonary edema. Administer Vitamin-K as prescribed to check the hemorrhage. Avoid infrequent vein puncture due to risk of venous thrombosis. Monitor the vital signs accurately. Trachycardia and rapid respirations are indicative of heart or lung complications. The patient may have long convalescent period. 8
CONCLUSION:
Scrub typhus is a re-emerging infectious disease of India that often creates threat for the nation’s health care infrastructure and resources. Difficulty in clinical diagnosis as the early sign and symptoms of the disease mimic like other viral illnesses, lack of laboratory methods and under-diagnosis of the disease is still a challenging situation among health care providers. Nurse’s valuable collaboration and co-ordination with other member of the health care team will help to meet the need of demanding situation.
REFERENCES:
1. Park. K. Parks text book of Preventive and Social Medicine. 23rd edition: M/s Banarsidas Bhanot: 2015.p. 299-300
2. Mahajan SK. Scrub Typhus. Journal of the Association of Physicians of India. [Internet].2005 Nov [cited 2016 Dec 11]; 53: 954-958. Available from: http:// www. japi.org/november2005/R-954.pdf
3. Ramasubramanian V, Senthur Nambi P. Scrub Typhus [Internet] [cited 2016 Dec 11]; 19-22. Available from: http://www.apiindia.org/medicine_update_2013/chap06.pdf
4. WHO. Frequently Asked Questions Scrub Typhus. [Internet] 2013 [cited 2016 Dec 11]. Available from: http://www.searo.who.int/entity/ emerging diseases /CDS_faq_ Scrub_Typhus.pdf.
5. National Centre for Disease Control. DGHS. GOI. CD Alert. Scrub Typhus & Other Rickettsioses. [Internet] 2009 [cited 2016 Dec 11]. Available from: http://www.ncdc.gov. in/ writereaddata/ linkimages/May%20June-20098604739980.pdf
6. DHR-ICMR. Diagnosis and management of rickettsial diseases in india. [Internet] 2015 [cited 2016 Dec 11]. Available from:http://www.icmr.nic.in/guide/DHR ICMR%20 Guidelines%20on%20Ricketesial%20Diseases.pdf
7. Director Health Services. Himachal Pradesh. Guidelines for the Management of Scrub Typhus [Internet] [cited 2016 Dec 11]. Available from: http://www.himachal.nic.in/WriteReadData/l892s/19_l892s/ 1442477 304.pdf
8. Worden I. Scrub Typhus Fever. Nursing of scrub typhus patients in a combat zone. The American Journal of Nursing [Internet].1944 Oct [cited 2016 Dec 11]; 44(10): 942-944. Available from: http://journals.lww.com/ajnonline /Citation/1944/10000/Scrub _ Typhus_Fever__Nursing_of_scrub_typhus.13.aspx
Received on 11.01.2017 Modified on 18.01.2017
Accepted on 30.01.2017 © A&V Publications all right reserved
Int. J. Adv. Nur. Management. 2017; 5(2):172-176.
DOI: 10.5958/2454-2652.2017.00037.3