Tag: Malaria

Tropical Diseases in Africa – Malaria

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by Shravya Murali – Art in Tanzania internship

As a significant health problem in several tropical regions of the world, malaria costs almost 435,000 lives annually. A substantial fraction of these deaths occurs in Africa. The proportion of cases and deaths In Tanzania alone constitutes to 3% of those globally. Over the past few years, the number of malaria cases have been on the rise, with a staggering increase by 3.5 million from 2016 to 2017 as reported by the WHO.

How does malaria spread?

Malaria in humans is caused by four kinds of parasites from the Plasmodium genus – Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, and Plasmodium malariae. A fifth species Plasmodium knowlesi, is a zoonotic species infecting animals. Of the five species, P.falciparum results in the most severe form of malaria and is responsible for the majority of malaria-related deaths, especially among children below the age of five.

Malaria is transmitted to humans through the bite of a female Anopheles mosquito that is infected by one of the malaria-causing parasites. The Anopheles mosquito can also spread the parasite from a human to another human when it feeds on an infected human’s blood meal, and later goes to bite another human.

Human-to-human transmission can also occur through blood transfusion, organ transplant, or sharing needles containing contaminated blood as the malaria parasite can be found on red blood cells. Malaria can also be transmitted from a pregnant mother to her child before or during delivery, which is also known as congenital malaria.

However, malaria is not contagious and cannot be transmitted through casual contact (i.e., by sitting next to someone infected) or sexual contact.

What are the effects of the disease?

Those infected with malaria often experience flu like illnesses and fever. Symptoms often include headache, fatigue, chills, muscle soreness, nausea, vomiting, and diarrhoea. As malaria can cause a loss of red blood cells it may lead to anemia, and jaundice, which is the yellow colouring of skin and eyes. If left untreated malaria becomes life-threatening as it can cause kidney failure, mental confusion, seizures, coma, and death. Usually, these symptoms occur about 10 days after a malaria infection.

Malaria caused by P.vivax and P.ovale may occur again and the parasites may reside in the liver for up to around four years after an individual has been bitten by an Anopheles mosquito. These dormant parasites may become active later and invade the individual’s red blood cells, causing another malarial infection.

How is malaria treated?

If a patient is suspected to be infected with malaria, a drop of his/her blood is often observed under a microscope to detect the malaria parasite. Treatments for malaria vary based on the severity of malaria, clinical status of the patient, the Plasmodium species causing the infection, and prior use of anti-malarial drugs.

In Mainland Tanzania, artemether lumefantrine, a drug that can be orally consumed, is used for uncomplicated malaria. In Zanzibar, however, artesunate and amodiaquine are used. For severe malaria, artesunate and quinine are injected in patients in both Mainland Tanzania and Zanzibar. Quinine is another drug that is only used when other drugs are ineffective, as quinine is known to have more side effects than the others. However, quinine is used to treat malaria in the first trimester of pregnancy as it is not known to have significant effects on the child at therapeutic doses.

What could be done to prevent the disease?

To prevent malaria, one could consume anti-malarial drugs (i.e., atovaquone, chloroquine, doxycycline). While it is possible to provide infants and children some of these drugs, not all drugs are suitable for children and doses are based on the weight of the child.

Apart from anti-malarial drugs, one should also prevent mosquito bites (specifically at night), which could be done by sleeping under insecticide-treated bed nets, wearing fully covered / long-sleeved clothing at night, and carrying an insect repellent.

With the increase in the number of malaria cases over the years, it is crucial that members of the public and healthcare professionals cooperate in fight against the disease. While the research for vaccination against malaria is ongoing, it is also essential for everyone to play a part by taking precautions to avoid malaria.

References:

1. Carfagno, J. (2018, July 16). Noninvasive Malaria Test Wins Royal Academy of Engineering’s Africa Prize. Docwire News. https://www.docwirenews.com/docwire-pick/future-of-medicine-picks/noninvasive-malaria-test-wins-royal-academy-of-engineerings-africa-prize/. 

2. Centers for Disease Control and Prevention. (2021, January 26). CDC – Malaria – About Malaria – FAQs. Centers for Disease Control and Prevention. https://www.cdc.gov/malaria/about/faqs.html.

3. Mutabazi, T. (2021, June 6). Assessment of the accuracy of malaria microscopy in private

health facilities in Entebbe Municipality, Uganda: a cross-sectional study. Malaria Journal. https://malariajournal.biomedcentral.com/articles/10.1186/s12936-021-03787-y

4. Ryan, S. J. (2020, May 1). Shifting transmission risk for malaria in Africa with climate

change: a framework for planning and intervention. Malaria Journal. https://malariajournal.biomedcentral.com/articles/10.1186/s12936-020-03224-6

5. Tanzania. Severe Malaria Observatory. (2007, January 17). https://www.severemalaria.org/countries/tanzania.

6. Thomas, D. L. (2020, March 13). Triple therapies effective and safe in malaria. News. https://www.news-medical.net/news/20200312/Triple-therapies-effective-and-safe-in-malaria.aspx. 

Tropical Diseases in Africa – Malaria

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By Shravya Murali – Art in Tanzania internship

As a significant health problem in several tropical regions of the world, malaria costs almost 435,000 lives annually. A substantial fraction of these deaths occurs in Africa. The proportion of cases and deaths In Tanzania alone constitutes 3% of those globally. Over the past few years, the number of malaria cases have been on the rise, with a staggering increase by 3.5 million from 2016 to 2017 as reported by the WHO.

How does malaria spread?

Malaria in humans is caused by four kinds of parasites from the Plasmodium genus – Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, and Plasmodium malariae. A fifth species Plasmodium knowlesi, is a zoonotic species infecting animals. Of the five species, Plasmodium falciparum results in the most severe form of malaria and is responsible for the majority of malaria-related deaths, especially among children below the age of five.

Malaria is transmitted to humans through the bite of a female Anopheles mosquito that is infected by one of the malaria-causing parasites. The Anopheles mosquito can also spread the parasite from a human to another human when it feeds on an infected human’s blood meal, and later goes to bite another human.

Human-to-human transmission can also occur through blood transfusion, organ transplant, or sharing needles containing contaminated blood as the malaria parasite can be found on red blood cells. Malaria can also be transmitted from a pregnant mother to her child before or during delivery, which is also known as congenital malaria. However, malaria is not contagious and cannot be transmitted through casual contact (i.e. by sitting next to someone infected) or sexual contact.

What are the effects of the disease?

Those infected with malaria often experience flu like illnesses and fever. Symptoms often include headache, fatigue, chills, muscle soreness, nausea, vomiting, and diarrhea. As malaria can cause a loss of red blood cells it may lead to anemia, and jaundice, which is the yellow coloring of skin and eyes. If left and treated malaria becomes life-threatening as it can cause kidney failure, mental confusion, seizures, coma, and death. Usually these symptoms occur about 10 days after a malaria infection. Malaria caused by P.vivax and P.ovale may occur again and the parasites may reside in the liver for up to around four years after an individual has been bitten by an Anopheles mosquito. These dormant parasites may become active later and invade the individual’s red blood cells, causing another malarial infection.

How is malaria treated?

If a patient is suspected to be infected with malaria, a drop of his/her blood is often observed under a microscope to detect the malaria parasite. Treatments for malaria vary based on the severity of malaria, clinical status of the patient, the Plasmodium species causing the infection, and prior use of anti-malarial drugs.

In Mainland Tanzania, artemether lumefantrine, a drug that can be orally consumed, is used for uncomplicated malaria. In Zanzibar, however, artesunate and amodiaquine are used. For severe malaria, artesunate and quinine are injected in patients in both Mainland and Zanzibar. Quinine is another drug that is only used when other drugs are ineffective, as quinine is known to have more side effects than the others. However, quinine is used to treat malaria in the first trimester of pregnancy as it is not known to have significant effects on the child at therapeutic doses.

What could be done to prevent the disease?

To prevent malaria, one could consume anti-malarial drugs (i.e. atovaquone, chloroquine, doxycycline). While it is possible to provide infants and children some of these drugs, not all drugs are suitable for children and doses are based on the weight of the child.

Apart from anti-malarial drugs, one should also prevent mosquito bites (specifically at night), which could be done by sleeping under insecticide-treated bed nets, wearing fully covered / long-sleeved clothing at night, and carrying an insect repellent.

With the increase in the number of malaria cases over the years, it is crucial that members of the public and healthcare professionals cooperate in fight against the disease. While the research for vaccination against malaria is ongoing, it is also essential for everyone to play a part by taking precautions to avoid malaria.

THE PRESENT STATUS OF MALARIA VACCINE

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By Mazhar Shahen – Art in Tanzania internship

In Tanzania over 90% of the population live in areas where there is risk of malaria. In Africa, Tanzania is the third largest population at risk of malaria. Most of the victims of the disease are children, with around 80,000 death annually caused by malaria. In Tanzania, the Kagera Region on the western shore of Lake Victoria has the highest risk of contracting the disease. The Arusha Region is a lower risk area. However due to climate change and people migration caused an increase in the migration of mosquitoes and caused areas that are malaria free to be exposed to the disease. 

MALARIA

Malaria is a life-threatening disease caused by the transmission through an infected female Anopheles mosquito. The infected mosquito is a carrier of Plasmodium parasite. The parasite is released into the human bloodstream through the mosquito bite. The parasite survives in tropical and subtropical climates. After the parasite enters the human bloodstream it travels to the liver to mature. Maturity of the parasite takes several days, then the parasite goes back to the bloodstream to travel to the red blood cells this time. Once the red blood cells are infected, the parasite starts multiplying withing 2-3 days, causing the infected red blood cells to burst. 

Malaria is an acute febrile disease, which means it shows signs of fever when infected. Symptoms appear in a non-immune person 10-15 days after the infection has occurred. Early symptoms are mild fever, chills, and headache. Since it is mild, it makes the malaria disease harder to detect early on. If not treated the plasmodium parasite can progress to severe illness, usually leading to death.

Severe malaria in children could lead to severe anaemia, respiratory distress, and/or cerebral malaria. Adults are at risk of multi-organ failure. 

In 2019 the World Health Organization (WHO) reported that half of the world’s population is at risk of malaria. With most of the cases and deaths are in the sub-Saharan Africa. This indicates that African community is in need of a malaria vaccine as soon as possible. Malaria control has been better, with the number of cases dropping significantly over the last decade, with the number of children dying from malaria being halved. 

MALARIA VACCINE

Vaccines are a hot topic in the world we live in. Vaccines help us strengthen our immune system against specific disease which protects us from that illness. Vaccines are usually needle injections but can also be given by mouth or sprayed into the nose.

WHO claims that the malaria vaccine is capable of reducing malaria cases by 75% and put us on goal of the eradication of the illness. Malaria is responsible for 219 million cases each year with an estimated 660,000 deaths of the illness.

Tanzania has the third largest population that is at risk of the illness in Africa, with 90% of the population at risk of contracting malaria. Tanzania has 10 to 12 million cases of malaria annually, with most of them being children. The number of cases has been controlled a lot better of the decade leading to significant decrease, and number of children dying from malaria halved. However, due to climate change and the migration of people malaria cases are rising in areas that were considered low risk in the past. This is complicating the fight against malaria. 

Vaccine RTS,S acts on Plasmodium falciparum, the most deadly malaria parasite in the world and specifically in Africa. The vaccine is the first and only successful vaccine for malaria, which helped in reduction of children death in Africa. This vaccination is part of the Malaria Vaccine Implementation Progamme (MVIP), this program is established by WHO to deliver the vaccine in selected areas of Africa with the help of each country’s governments. The 3 African countries that are currently in pilot introduction are Ghana, Malawi and Kenya. The goal is to supply the whole region by 2023. Vaccine RTS,S is considered a safe vaccine, and no proven direct side effects are there. The pharmaceutical giant GSK will be conducting a number of Phase 4 studies in the 3 African countries chosen for pilot. 

In 1987 the discovery of a synthetic peptide polymer (SPf66) in Columbia enabled the development of the first vaccine candidate. Tanzania was the second country after Columbia to participate the clinical trials of SPf66. This indicates that historically Tanzania has an advantage as researchers will have a deeper pool of information in Tanzania compared to other African countries. Researcher George M Bwire states in his article that the inclusion of Tanzania in the Malaria Vaccine Implementation Program for the current RTS, S vaccine is crucial.

REFERENCES

  1. Agnandji, S. T., Agnandji, S. T., Asante, K. P., Lyimo, J., Vekemans, J., Soulanoudjingar, S. S., . . . Abdulla, S. (2010). Evaluation of the Safety and Immunogenicity of the RTS,S/AS01E Malaria Candidate Vaccine When Integrated in the Expanded Program of Immunization. The Journal of Infectious Diseases, 202(7), 1076-1087. Retrieved 2 11, 2021, from https://academic.oup.com/jid/article-abstract/202/7/1076/837083
  2. Bwire, George & Sanga, Anna. (2019). Malaria control in Tanzania: Current status and future prospects. 2664-8490..
  3. Dimala, C. A., Kika, B. T., Kadia, B. M., & Blencowe, H. (2018). Current challenges and proposed solutions to the effective implementation of the RTS, S/AS01 Malaria Vaccine Program in sub-Saharan Africa: A systematic review. PLOS ONE, 13(12). Retrieved 2 11, 2021, from https://ncbi.nlm.nih.gov/pubmed/30596732
  4. Galactionova, K., Tediosi, F., Camponovo, F., Smith, T., Gething, P. W., & Penny, M. A. (2017). Country specific predictions of the cost-effectiveness of malaria vaccine RTS,S/AS01 in endemic Africa. Vaccine, 35(1), 53-60. Retrieved 2 11, 2021, from https://sciencedirect.com/science/article/pii/s0264410x16311033
  5. Malaria vaccine implementation PROGRAMME (MVIP). (n.d.). Retrieved February 12, 2021, from https://www.who.int/news-room/q-a-detail/malaria-vaccine-implementation-programme
  6. Malaria in Tanzania. (n.d.). Retrieved February 12, 2021, from https://malariaspot.org/en/eduspot/malaria-in-tanzania/
  7. White, N. J. (2011). A vaccine for malaria. The New England Journal of Medicine, 365(20), 1926-1927. Retrieved 2 11, 2021, from https://nejm.org/doi/full/10.1056/nejme1111777