Gonorrhoea is caused by Neisseria gonorrhoeae. Chancroid, is caused by Haemophilus ducreyi. Syphilis is caused by Treponema pallidum. Giardiasis and trichomoniasis are protozoan diseases.

• Meningoencephalitis is the Inflammation of the brain and surrounding tissues, usually caused by infection.
• Signs of meningoencephalitis include unusual behavior, personality changes, and thinking problems and Symptoms may include headache, fever, pain in neck movement, light sensitivity, and seizure.
• Causative organisms include protozoans, viral and bacterial pathogens.
  
• The protozoal pathogen responsible for Meningoencephalitis is Trypanosoma.
• Hence Meningoencephalitis is caused by Trypanosoma.
• So, the correct answer is 'Trypanosoma'.

• African trypanosomiasis, also known as sleeping sickness is caused by a protozoan parasite called Trypanosoma brucei.
• Trypanosomiasis is spread by spread by the bite of an infected tsetse fly and is most common in rural areas.
  
• Hence Trypanosoma/Trypanosomiasis is spread by Tse-tse fly.
• So, the correct answer is 'Tse-tse fly'.

Any disease that can be transferred from infected person to healthy is called as communicable disease such as malaria because malaria is caused by Plasmodium and transferred from infected to healthy by the help of vector i.e., mosquitoes. Whereas cancer (caused by abnormal cell growth), Heart attack (caused by abnormal metabolism) and diabetes (caused by abnormal secretion of hormone) are the non-communicable disease

Sleeping sickness is curable if treatment is given quickly, however, if left untreated the disease is fatal. Once in the second stage of the disease, when the parasite has crossed the blood-brain barrier, treatment becomes much more aggressive with more toxic drugs needed to kill the parasite. So, the correct option is "C" (Cerebrospinal fluid).

Protozoan diseases are caused by the organisms belonging to the Kingdom Protista, called Protozoa.

Entamoeba histolytica is an endoparasile lives in the large intestine of man. It lives in tissues of caecum and colon of large intestine. The pathogenic form cause amoebiasis and hepatic amoebiasis. Thus, the correct answer is option A.

Sleeping sickness is caused by two germs (protozoa), Trypanosoma brucei rhodesiense and Trypanosomoa brucei gambiense. The more severe form of the illness is caused by T. brucei rhodesiense. Tsetse flies carry the infection. Thus, the correct answer is option A.

Entamoeba histolytica is a microscopic endoparasite of man and is commonly found in the lumen of the upper part of the large intestine, that is the colon. In chronic cases, they get into blood circulation and migrate to the spleen, liver, lungs, gonads, and brain, where they produce secondary complications.

Entamoeba histolytica complete its life cycle in two stage on one host only infective stage and colon invasive trophozoite stage.  In infective stage, infection occurs by the ingestion of tetranucleated cyst through the contaminated food and water. So, the correct answer is option B.

• Filariasis is a parasitic disease caused by an infection with roundworms such as Wuchereria bancrofti.
  
• Amoebiasis, also known as amoebic dysentery, is an infection caused by Entamoeba. The housefly transmits pathogens via touch or from bodily fluids, including from their saliva, faeces, vomit, and urine. Housefly act as a vector for amoebic dysentery, typhoid, cholera, Trachoma, tapeworm, roundworm, leprosy, mycoses etc.
  
• Malaria is a mosquito-borne infectious disease that affects humans and other animals. The vector for malaria is female Anopheles mosquito.
  
• Ascariasis is a disease caused by the parasitic roundworm Ascaris lumbricoides. The source of infection is from objects which have been contaminated with faecal matter containing eggs.
  

Normal RBCs are disc-shaped and can move easily through the blood vessels. RBCs contain haemoglobin, which carries oxygen from lungs to rest of the body. Sickle cells contain abnormal haemoglobin called sickle haemoglobin or haemoglobin S. This causes the RBCs to develop sickle or crescent shape. These cells are stiff and sticky and tend to block the blood flow in the blood vessels, which can cause pain and organ damage and also increased the risk for infection. So, the correct answer is option C.

Phlebotomus is a genus of sand flies. They are primarily responsible for the transmission of leishmaniasis, an important parasitic disease. The most common forms are cutaneous leishmaniasis which causes skin sores and visceral leishmaniasis which affects several internal organs.
Therefore, the correct answer is option A.

Kala azar is also known as 'black fever' and is considered to be the most severe form of leishmaniasis. It is caused by the protozoans of Leishmania genus. 

The occurrence of more than one form of an individual  in a single species within an interbreeding population is known as polymorphism. Trypanosoma shows this feature with three main forms, all of which have a small kinetoplast and a conspicuous undulating membrane. Hence, option B is correct.

Human African trypanosomiasis, also known as sleeping sickness, is a vector-borne parasitic disease. It is caused by infection with protozoan parasites belonging to the genus Trypanosoma. They are transmitted to humans by tsetse fly (Glossina genus) bites which have acquired their infection from human beings or from animals harbouring the human pathogenic parasites.

Tetanus (lockjaw) is an infectious disease caused by the bacteria Clostridium tetani. Measles is a highly contagious infection caused by the measles virus. Filariasis a parasitic disease caused by an infection with roundworms of the Filarioidea type. African trypanosomiasis or sleeping sickness is a parasitic disease of humans and other animals. It is caused by protozoa of the species Trypanosoma brucei.

African trypanosomiasis or sleeping sickness is a parasitic disease of humans and other animals. It is caused by protozoa of the species Trypanosoma brucei. It is usually transmitted by the bite of an infected tsetse fly and are most common in rural areas.

African trypanosomiasis also known as sleeping sickness, is a vector-borne parasitic disease caused by protozoan parasites belonging to the genus Trypanosoma. The small, single-celled organisms called trypanosomes are transmitted through the bites of tsetse flies. Tsetse flies include all the species in the genus Glossina.

Malaria is caused by Protozoa belonging to genus plasmodium.

Entamoeba histolytica is a parasitic protozoan that is responsible for causing amoebic dysentery. The disease is transmitted by food and water which is contaminated by fecal matter of the infected person. The symptoms include stomach pain, diarrhea, etc. 

Giardia is an infection of i small intestine. causes diarrhoea.

African sleeping sickness is a disease which is caused by a parasite which is a protozoa known as Trypanosoma brucei. There are certain flies which get infected by this protozoan. When the infected fly bites the human, there is transmission of the diseases. The fly is native to Africa and hence, the disease is known as African sleeping sickness. 

Trypanosomiasis is a term which describes various diseases which affect men and cattle. While Trypanosoma gambiense is the milder form, Trypanosoma rhodesiense is one which afflicts more. This deadly parasitic infection is commonly called as sleeping sickness, is transmitted in man by the bite of the infected Tsetse fly of genus Glossina and family Glossinidae that inhabits the mid continental Africa between Sahara and Kalahari deserts.

Kala azar is a parasitic disease next to malaria but along with sleeping sickness this is one of the dangerously neglected diseases of the tropical belt. This disease which is endemic in more than 60 countries attacks the immune system making it nearly fatal.  his disease is transmitted to human beings by the bites of infected phlebotomine sandflies which is the vector for  the leishmania parasite. so, the correct answer is option A.

Sleeping sickness is transmitted by Tse-tse fly. Leprosy is an ailment of the skin and housefly can spread the causative agent. Dysentery can be spread by housefly when they sit on infected materials like stool and contaminate water as well as food. Typhoid is caused by bacteria, housefly can spread it when infected sputum and clothes are infested with houseflies and contaminate food and water. So, the correct answer is option D.

Gambian fever or Gambian sleeping sickness is caused by a protozoan Trypanosoma gambiense and is transmitted by Glossina palpalis (tse-tse fly).

Vector host is an agent that transmits the pathogens of infectious disease from one living organism to another and may be a person, animal or microorganism. While the Anopheles mosquito is the vector for malarial parasites, sandfly is a vector for leishmaniasis, tsetse fly are vectors of trypanosomes that causes trypanosomiasis or sleeping sickness. Houseflies on the other hand are vector for nearly 100 pathogens that causes, typhoid, cholera, salmonellosis, tuberculosis, anthrax etc., eer flies which belong to the genus Chrysops are vectors for pathogens that causes diseases such as anthrax, tularemia and loa loa filariasis.

• Amoebiasis or amoebic dysentery is an infection caused by any of the amoebae of the Entamoeba group( For example, Entamoeba histolytica).
• Symptoms may include abdominal pain, diarrhea, or bloody diarrhea.
  
• In the feces of a person suffering from Amoebiasis Small white stone-like Charcot-Leydon crystals are found. They are indicative of a disease involving eosinophilic inflammation or proliferation.
• So, the correct answer is 'Amoebiasis',

Trichomonas vaginalis is an anaerobic protozoan parasite. It causes trichomoniasis. It is a sexually transmitted infection. Symptoms include inflammation, itching and soreness around vaginal area, changes in vaginal discharge like profuse, yellowish to greenish, frothy discharge and pain during passing urine. While Treponema and Neisseria are bacteria Herpes simplex is a virus. Thus, the correct answer is option D.

Plasmodium is the odd one as it is a digenetic endoparasite with the man as the primary host and female Anopheles mosquito as the vector. While lice, bedbug, and mites all are blood-sucking ectoparasites. Thus the correct answer is option B.

Entamoeba histolytica is an anaerobic parasitic amoebozoan, predominantly infecting humans and other primates causing amoebiasis or dysentery. Symptoms can include fulminating dysentery, bloody diarrhoea, weight loss, fatigue, abdominal pain, irregular bowel. Hence, relapsing fever is not a symptom of Entamoeba histolytica. So, the correct answer is 'Relapsing fever'.

• Sleeping sickness is caused by a parasitic flagellate protozoan called Trypanosoma ambience.
• The disease is transmitted between mammals hist by Tsetse fly
• Fever, severe headaches, irritability, extreme fatigue, swollen lymph nodes, and aching muscles and joints are common symptoms of sleeping sickness.
• Hence The disease caused by Trypanosoma ambience is Sleeping sickness.
  
• So, the correct answer is 'Sleeping sickness'.

Entamoeba histolytica belongs to genus Entamoeba. It frequently exists in the human gastrointestinal tract, infecting the walls of the small intestine. It causes amoeboic dysentery  in  humans.

Trypanosomes are ingested by a Tsetse fly when it feeds on the blood of an infected animal. The trypanosome metacyclics develop further here, invade the local lymph vessels and then move into the bloodstream. The ensuing infection is characterized by successive waves of parasitaemia in the bloodstream, as parasite populations multiply rapidly and die off. The infected animal may die or eliminate the parasites and recover. T. vivax and T. brucei parasites may also invade an animal's connective tissues, and in the final stages of the disease, T. brucei may invade the central nervous system.

Trypanosoma brucei is a species of salivary trypanosome, which causes sleeping sickness in humans and nagana in animals.

Phlebotomus argentipes is a vector of visceral leishmaniasis, an important parasitic disease. The female sand-fly carries the Leishmania donovani protozoa from infected animals after feeding, thus transmitting disease. Phlebotomus is a genus of sand-flies in the Diptera family.
Thus, the correct answer is option (C), 'Leishmania donovani'.

Sickle cell trait provides a survival advantage over people with normal hemoglobin in regions where malaria is endemic. The trait is known to cause significantly fewer deaths due to malaria, especially when Plasmodium falciparum is the causative organism. Sickle trait erythrocytes produce higher levels of the superoxide anion and hydrogen peroxide than do normal erythrocytes, both are toxic to malarial parasites. The sickle cell trait was found to be 50% protective against mild clinical malaria, 75% protective against admission to the hospital for malaria, and almost 90% protective against severe or complicated malaria.
Thus, the correct answer is option (B), 'Sickle ceIl anaemia'.

Kala azar is also called as black fever or dumdum fever or visceral leishmaniasis. It is the most severe form of leishmaniasis. Leishmaniasis is a disease caused by the protozoan parasites of the Leishmania genus, especially Leishmania donovani. So, the correct answer is option C.

'Chagas disease' is also called as American trypanosomiasis. It is a tropical parasitic disease, caused by the protozoan Trypanosoma cruzi. It mostly spreads by insects, knwon as Triatominae or kissing bugs.

Trypanosoma is a genus of kinetoplastids. It is a group of unicellular parasitic flagellate protozoa. As it possesses flagella, it belongs to the class of Mastigophora. 

Sleeping sickness is a vector-borne parasitic disease. It is caused by infection with protozoan parasites belonging to the genus Trypanosoma. They are transmitted to humans by tsetse fly (Glossina genus) bites, which have acquired their infection from human beings or from animals harbouring the human pathogenic parasites. So, the correct answer is option B.

Human African trypanosomiasis is also known as sleeping sickness. It is a vector-borne parasitic disease. It is caused by infection with protozoan parasites belonging to the genus Trypanosoma gambiense. They are transmitted to humans by tsetse fly (Glossina Palpalis) bites, which have acquired their infection from human beings or from animals harboring the human pathogenic parasites. Hence, option B is correct.

Trypanosomiasis is Gambian fever. It is transmitted to man and animals by a blood sucking insect, the tsetse fly. The tsetse flies include all the species in the genus Glossina.
Glossina palpalis is a tsetse fly and is a vector for Gambian fever.
Therefore, the correct answer is option C.

Entamoeba gingivalis is a parasitic protozoan found in the mouth inside the gingival pocket biofilm near the base of the teeth and in periodontal pockets mostly in people with gum disease. Thus the correct answer is option A.

Leucorrhoea, commonly known as whites, refers to a whitish discharge from the female genitals caused by the presence of infection in vaginal tissues.