10 Human Health and Diseases - part 05 - Filariasis,Typhoid, Pneumonia

 

10 Human Health and Diseases - part 05 - Filariasis,Typhoid, Pneumonia

Filariasis/ Elephantiasis :

• Caused by thread like worms nematodes. 
• These nematode parasites are transported from person to person via mosquito bite. 
• Filariasis can be divided into 3 subtypes as 

1. Lymphatic Filariasis, 
2. Subcutaneous Filariasis (e.g. Loa loa, Mansonella spp.) and
3. Serous (abdominal)cavity Filariasis (e.g. Mansonella spp.).

• Lymphatic Filariasis (Elephantiasis) is caused by the worms - Wuchereria bancrofti, Brugia malayi, Brugia timori.

Signs and symptoms :-

• Edema with thickening of skin and underlying tissue. 
• Wuchereria bancrofti affects the legs, arms, breasts, scrotum, etc.
• In lymphatic filariasis, worms infect lymphatic system and causes enlargement of lymph vessels and nodes. This is elephantiasis i.e. limbs are swollen like legs of elephant.
• Lymphedema i.e. accumulation of lymh fluid in tissue causing swelling.
• Hydrocele i.e. testis are enlarged due to accumulation of lymphatic fluid in testis.
  

Mode of transmission : 

• Wuchereria bancrofti is transmitted to human body by female Culex mosquito.
• The larvae escape mosquito body and arrive on the human skin. 
• They penetrate the skin, undergo two moultings before they become adults and settle in the lymphatic system. 
• Incubation period can be as long as 8-16 months.

Diagnosis and Treatment : 

• Use of diethyl -carbamazine citrate twice a day for three weeks and thereafter for five days every six month is effective against filarial worms.

Prevention and Control : 

• Avoid mosquito bite by using mosquito nets and insect repellents.
• Eradication of mosquitoes is essential for control of filariasis.

Typhoid :

• Is an acute infection of intestine.
• Caused by Salmonella typhi. 
• It is Gram -ve bacteria found in intestinal lumen of infected preson. 
• Pathogenicity is due to “O”- antigen, a lipopolysaccharide (LPS), present on surface coat. 
• Flagella contains “H”- antigen.

Signs and Symptoms :

• Prolonged fever as high as 104⁰F.
• General nausea, fatigue, headache.
• Abdominal pain, constipation or diarrhoea
• Rose-coloured rash on skin.
• White coat on tongue, cough.
• Anorexia (loss of apetite).
• If not treated- breathlessness, irregular heartbeats, haemorrhage.

Mode of transmission :

• It is a food and water borne disease.
• Insects like housefly and cockroaches feeding on fecal matter, may transfer the bacteria to food material.
• Poor hygiene habits and poor sanitation conditions are responsible for the spread of typhoid.

Diagnosis and Treatment :- 

• Widal test is used for diagnosis of typhoid. 
• Treatment of typhoid involves surgical removal of gall bladder in severe cases. 
• Antibiotics like Chloromycetin is helpful treatment.
• For prevention of typhoid WHO recommendes two vaccines as oral (Ty21a vaccine) and injectable (Typhoid polysaccharide vaccine) sold as- typhim vi and typherix.

Pneumonia :

• Is an inflammatory condition of lungs or alveoli of lungs. 
• Caused by a variety of pathogens which may be viruses like - 

1. Influenza virus
2. Adenovirus,
3. Para influenza and 
4. Respiratory Syncytial Virus (RSV) or 
5. Bacteria like Streptococcus pneumoniae or fungal pathogens 

• e.g. Pneumocystis jirovecii and Pneumocystis carinii. 
• Pneumonia can also be caused by chemical burns or physical injury to lungs.

Signs and Symptoms :-

• Cough produces yellow or greenish sputum or phlegm.
• High fever.
• Shortness of breath (Dyspnea).
• Chest pain during deep breath or coughing.
• Loss of appetite, fatigue, headaches, vomiting, joint pains a nd muscle aches.

Mode of transmission : 

• Pneumonia mostly spreads by direct person to person contact.
• It can also spread via droplets released by infected person or even by using shared clothes and utensils.

Diagnosis and Treatment :- 

• Course of treatment depends upon pathogen leading to the disease. 
• For bacterial pneumonia, antibiotics like Benzyl penicillin, Ampicillin and Chloramphenicol are effective.

Prevention and Control :-

• Vaccination is important prevention in both children and adults. 
• Vaccines against Haemophilus influenzae and Streptococcus pneumoniae in first year of life, help greatly to reduce the chances of causing Pneumonia.