About Tropical Diseases
Tropical diseases are diseases that are indigenous to subtropical or tropical regions and are less prevalent in temperate climates which are subject to seasonal changes. Whereas the term covers all communicable and non-communicable illnesses, genetic disorders, and conditions caused by nutritional deficiencies or environmental factors, we mostly understand tropical diseases to be of infectious nature. This is especially true, since rising migration and globalization have led to a faster spread of such diseases.
Besides socio-economic factors, high infection rates are largely attributed to the availability of many animal reservoirs for vector-borne transmission (e.g., bats, mosquitoes, flies), and a hot and moist climate accelerating replication of pathogens.
The WHO and other health programs established research institutions to study neglected infectious diseases, as they disproportionally affect low-income and marginalized regions in Africa, Asia, Central America, and South America, to provide monitoring-, diagnosis-, treatment-, and prevention tools to combat these diseases.
Our variety of peptide formats provide many necessary tools to monitor immune response of high-risk patients, epitope discovery, immunodominant antigen identification for development of vaccines, treatment solutions and diagnostics. Our peptides range from research-use-only to clinical formats that meet authority regulations.
List of common Tropical Diseases
The most commonly studied tropical diseases, for which we provide peptide tools, include:
- Chagas Disease (Trypanosomiasis)
- Crimean Congo Hemorhagic Fever
- Dengue Fever
- Ebola Fever
- Lassa Fever
- Nipah Virus Disease
- West Nile Fever
- Yellow Fever
- Zika Fever
JPT's peptide formats
Cellular Immune Response
- Antigen specific stimulation of T-cells
- Immune monitoring of high-risk patients
- Qualification of immunodominant antigens
- Validating clinical T-cell assays
- T-cell assays in
- High-throughput T-cell epitope discovery
- Monitoring of cellular immune response
- Clinical trials
Humoral Immune Response
- Immune monitoring of humoral responses
- Profiling of specific samples or antibodies
- Evaluation of co-infection
- Detection of epitopes and epitope spreading
- Immune monitoring of humoral responses
- epitope discovery and epitope mapping
- SPOT synthesis is a technique for custom synthesis of hundreds of membrane peptides in parallel
- fast and economical
Crimean-Congo Hemorrhagic Fever
About the Disease
This tick-borne viral disease causes severe symptoms two weeks after transmission, including fever, nausea, diarrhea, and a severe skin condition. More severely, CCHF may be associated by liver failure resulting in a very high fatality rate. As the name implies, the virus has been primarily found and is now endemic in Africa, Russia, the Balkans, the Middle East and India. According to the WHO, fatality rates range between 10-40%, making CCHF a priority disease for research and development.
CCHF results from infection with CCHF virus, which is a member of the genus orthonairoviridae. This circular, negative sense stranded RNA virus recognizes seven genotypes that are dependent on location. However, CCHF virus is genetically quite diverse. The spread via ticks and migratory birds, as well as coinfections, contribute to the generation of such genetic variability in the same locations. Among other factors, this genetic spontaneity poses a challenge to vaccine development, and to date, none have been officially approved. Some supportive treatment options (ribavirin and immunoglobulin preparations) are available.
About the Disease
This mosquito-borne disease is caused by the Dengue Virus. Symptoms include fever, headache, vomiting and skin rash, and more severely hemorrhagic fever. Since the symptoms and regional occurrence overlaps, Dengue fever is often mistaken for Yellow Fever or Malaria.
Similar to the West Nile and Yellow Fever viruses, the single positive-stranded Dengue virus belongs to the genus of flavivirus, and occurs in the tropics and subtropics. 4 serotypes have so far been confirmed, with a potential 5th on the way.
Common immunogenic proteins that elicit an immune response are the envelope protein E, the membrane protein M, and NS2-5 proteins which include serine proteases, RNA helicases, RTPase/NTPase, methyltransferase, and other non-structural but co-factorial proteins. These NS proteins are considered potential targets for therapeutic intervention, but to date, no NS-inhibitors have been developed and released.
In addition, two Dengue vaccines have been approved: Qdenga (2022) and Dengvaxia (2016). The challenge is to develop a vaccine that covers all 4 (5) serotypes to be effective. Infection leads to the production of serotype-specific cross-reactive antibodies which do not neutralize other serotypes upon reinfection and may even enhance the rate of viral replication. Considering a 5th serotype might yet have to be confirmed, the development of an effective vaccine is crucial.
Ebola virus disease or ‘Ebola fever’ is an often lethal hemorrhagic fever. Occasionally, Ebolaviruses cause disease outbreaks, mostly in African countries. These viruses infect humans and other primates and are likely to spread from bats to humans through contact with blood, body fluids, and tissues of infected animals.
Ebolaviruses belong to the family of Filoviridae. Four of the six known ebolavirus species cause disease in humans: Sudan ebolavirus, Bundibugyo ebolavirus, Tai Forest ebolavirus, and Zaire ebolavirus, with the latter having the highest mortality rate (83% on average). The 2014-2016 Ebola outbreaks in West Africa were caused by a Zaire ebolavirus strain and were considered among the most severe to date in terms of mortality. All ebolaviruses are in risk group 4 (RG4) of human and animal pathogens according to the WHO.
Ebolaviruses are single-stranded RNA (ssRNA) viruses. Their genome codes for a number of proteins that are potentially relevant to the human immune response. These include, for example, a nucleoprotein (NP), a spike glycoprotein (GP), a polymerase cofactor, a transcription activator, and an RNA-dependent RNA polymerase.
If you are interested in viruses causing hemorrhagic fever, you may also be interested in the Crimean-Congo hemorrhagic fever virus (CCHFV), tools which will soon add to our catalog. It belongs to the genus of Orthonairoviruses and is tick-borne. It is also called the ‘Asian ebolavirus’, because the clinical picture in humans resembles ebolavirus disease and the underlying disease mechanisms appear very similar.
Lassa Hemorrhagic Fever
About the Disease
Endemic in rodent populations in West Africa, human infection with the Lassa (mammarena-) virus occurs through exposure to urine- and feces-contaminated food. On more rare occasions, human-to-human transmission is also possible. Although 80% of people infected do not present any symptoms, the remaining 20% experience severe fever and less commonly bleeding from the mouth and gastrointestinal tract, resulting in an overall 1% case-fatality.
Belonging to the genus of mammarenaviruses the Lassa viruses are enveloped, single-stranded, bisegmented, ambisense RNA viruses, coding for four proteins: the small zing finger protein (Z), RNA polymerase, the nucleoprotein (NP) and surface glycoprotein (GP). Clinical diagnosis is difficult due to the wide range and non-specificity of presenting symptoms. There are currently no vaccines or treatments available, and reducing the infection rates relies solely on prevention and host controls.
About the Disease
Malaria is a tropical infectious and mosquito-borne disease caused by five types of Plasmodium parasites with P. falciparum and P. vivax being the deadliest. It is typically transmitted through mosquito saliva and symptoms occur within the following two weeks, including fever, fatigue, nausea, jaundice, seizures, and coma. These symptoms manifest particularly severe in children under the age of 5, and immunocompromised and pregnant people.
The above mentioned types of plasmodia are most prevalent in the African continent and other countries such as the South-East Asia and some areas of South and Central America, respectively. According to the World Malaria Report approximately 247 million infections and 619.000 deaths were reported in 2021 with cases being disproportionally prevalent in sub-Saharan Africa, such as Nigeria, Niger, the Democratic Republic of Congo, and Tanzania.
Methods to reduce infections and mortality of malaria include bite prevention, early testing, chemoprophylaxis, and treatment. Considering parasite diversity, and the fact that these parasites display a high replication rate rendering resistance to treatment at a very fast pace, the task of developing prophylactic and immediate treatment plans is a complex process. In addition, infections, especially multiple infections, are unfortunately associated with a very slow process of acquired immunity, which in turn drives the demand for vaccine development.
Only recently the very first malaria vaccine RTS,S/AS01 became available and has so far immunized 1.5 million children in high-risk areas against P. falciparum (as of April 2023). This was soon followed by the even more effective vaccine R21/Matrix-M, which has been approved in Ghana for distribution and use in children under 5. Other vaccines using different technologies, and immunizing against different plasmodium types are currently in their trial-stages.
About the Disease
Nipah virus disease – as the name implies – is caused by the Nipah virus. Although rare, human infection usually presents with fevers, coughs, headaches, breathing difficulties, and eventually inflammation of the brain with accompanying seizures and a very high likelihood of death, with the disease having a 50-75% risk of fatality. The disease occurs mainly in South-East Asian countries during the winter months. It is usually reported among farmers, and consumers of raw date palm sap and other fruits, or hospital workers, as the transmission occurs mainly through fruit bat and pig feces, and sometimes through fluids from person-to-person.
The WHO classifies Nipah virus as a priority disease, with multiple clinical trials for (mRNA or monoclonal antibody) vaccines on the way, including vector-, mRNA-, and monoclonal antibody-based platforms.
About M. tuberculosis
Mycobacterium tuberculosis belongs to the family of Mycobacteriaceae and is the main cause for tuberculosis (TB). In most individuals M. tuberculosis does not cause acute clinical disease but remains a latent tuberculosis infection (LTBI). Nevertheless, TB is still a severe and potentially lethal infection of all times causing about 1.5 million deaths annually.
Unfortunately, TB vaccines provide incomplete protection, but appear to be able to prevent the most severe clinical courses. Improving TB vaccines is the focus of ongoing research studies worldwide. In addition a range of immunological TB diagnostics tests are available including both established clinical tests and experimental approaches.
Both the WHO and the United Nations defined global TB goals, to reduce infection rates and even to eradicate the epidemics by 2030, respectively.
One of these goals is the development of a new vaccine that overcomes the challenges of the current employed vaccine relying on M. bovis bacilli Calmette Guérin. More than a dozen TB vaccine candidates are under active clinical evaluation to prevent infection, disease, and recurrence. However, a reoccurring issue is the lack of reliable biomarkers to assess a vaccine’s efficacy. Furthermore, to monitor infections, affordable rapid-tests are being expanded. In 2021 the WHO issued a recommendation to improve access to testing and summarized innovations that are being investigated up to date.
We provide an extensive and continuously updated peptide catalog covering many antigens from Ag85 to ESAT-6 of secreted proteins allowing screening and monitoring humoral and cellular immune responses against these major TB antigens.
West Nile Fever
About the Disease
West Nile Fever originated and was first described in Uganda in 1937. Although the majority of human infections are asymptomatic, 20% do in fact develop a fever, nausea, rash, and in 1% of cases encephalitis, meningitis, and seizures. Compared to humans however, West Nile Virus can cause severe disease and death in horses. It is transmitted by birds via mosquitos, and is subject to seasonal changes in climate.
West Nile Virus is another mosquito-borne virus of the of flavivirus genus, and its positive-sense single-stranded RNA is enveloped by an icosahedral capsid, membrane, and envelope proteins.. These structural proteins elicit immune responses, and are common targets for vaccine development and therapeutic intervention. Although vaccines are available for horses (an inactivated WNV vaccine (K-WN), a modified-live vaccine (CP-WN) and a live-chimera vaccine (WN-FV), none are yet available for humans, nor are there any treatment options.
About the Disease
As expected, yellow fever is caused by the mosquito-borne yellow fever virus, which can be traced back to one of its main disease symptoms: yellow skin associated with liver damage. Other symptoms include, fever, nausea, muscle, head and abdominal pain, and more severely hemorrhagic fever.
Belonging to the flavivirus genus, this enveloped positive-sense single-stranded RNA virus is 40–50 nm wide and infects monocytes, macrophages, Schwann cells, and dendritic cells among others. According to the WHO, since 2023 13 countries and multiple regions in Central and South Africa report the disease as endemic.
Besides PCR blood testing and ELISA in late stage of Yellow Fever, early diagnosis renders itself difficult and symptoms often present themselves similar to other regionally common diseases. For preventative measures, a single-shot vaccination called YF-VAX with a live attenuated form of the virus derived from a 17D-204 strain is available and in increasing demand. However, there is no anti-viral treatment available to date. JPT’s Yellow Fever Peptides include a Single Antigen Peptides, a PepMix for cellular immune monitoring covering non-structural protein surfaces, a PepMix Pan Select addressing the virus’ sequence diversity, and PepStar Peptide microarrays for humoral immune monitoring purposes. Take your pick or consider our other customizable formats.
About Zika Virus and other Flaviviruses
Zika virus (ZIKV) belongs to the flaviviruses such as dengue virus, West Nile virus, yellow fever virus, Saint Louis encephalitis virus and tick-borne encephalitis virus. Flaviviruses carry a positive-sense, single-stranded RNA and most flaviviruses are transmitted by the bite from an infected arthropod (mosquito or tick). We offer specific Zika virus peptides, Zika peptide pools and Zika peptide microarrays (ZIKV peptides, ZIKV peptide pools, ZIKV peptide microarrays).
- Transmitted by the mosquitoes A. aegypti and A. albopictus
- Was first isolated in 1947 from the Zika Forest of Uganda
- From 2007 the virus spread across the Pacific Ocean to South America, leading to the Zika virus epidemic
- Zika virus causes Zika fever or Zika virus disease
- Usually shows no or only mild symptoms
- Zika can also spread from a pregnant women to the fetuses
- Causes microcephaly, severe brain malformations, and other birth defects in unborn children
JPT's Peptide Tools to Study Zika Virus