A recent agreement between the World Health Organization (WHO) and the German pharmaceutical company Bayer promises hope of expanding access to essential medicines for the treatment of people exposed to or infected by the pork tapeworm Taenia solium.
Infection with the parasite T. solium is estimated to cause 30% of all epilepsy cases in countries where it is endemic, affecting mostly the poorest people and the most marginalized communities.
Donated praziquantel and niclosamide as part of expanded collaboration
In a five-year agreement signed last year, Bayer agreed to support WHO's global programme in combating taeniasis and neurocysticercosis through donated praziquantel and niclosamide and to provide funding to sustain control and prevention activities.
For more than 15 years, Bayer has donated medicines to WHO to support the control of human African trypanosomiasis and Chagas disease. This latest collaboration for the control and treatment of T. solium infection is opportune as WHO prepares to launch its new road map for neglected tropical diseases for 2021–2030.
How to request the medicines
Both praziquantel and niclosamide are now available through WHO.
To request a donation, a set of forms should be completed to facilitate application, review and reporting. These are also expected to improve coordination and integration among different programmes. The three forms are:
- Request for selected PC medicines (RSM) – to assist countries in quantifying the number of tablets of the relevant medicines required to reach the planned target population and districts during the year for which medicines are requested.
- Reporting form (RF) – to assist countries in reporting annual progress on integrated and coordinated distribution of medicines across diseases in the reporting year in a standardized format.
- PC epidemiological data reporting form (EPIRF) – to standardize national reporting of epidemiological data on taeniasis/cysticercosis. National authorities are encouraged to complete this form and submit it to WHO every year, together with the RF.
All donations are subject to review and/or availability of medicines. In addition, use of donated medicines must be adequately reported to WHO upon completion of treatment activities.
The reports generated in the RSM and in the RF (SUMMARY worksheets) must be printed and signed by the NTD coordinator or a Ministry of Health representative to formally endorse the country's request for these medicines and the reported annual progress of the national programme(s). The date of signature must also be included.
Once signatures have been obtained, the scanned copies of the two worksheets, together with the full Excel versions of the RSM, the RF and the EPIRF, can be jointly submitted to WHO. All three duly completed forms should be submitted to the WHO Country office and copies emailed to:
The forms should also be copied to the NTD focal point in the respective WHO Regional Office.
The turnaround time (from submission of forms to WHO country office to the delivery of the preventive chemotherapy medicines to the national warehouse of the respective countries) may take up to 6–8 months. This lead time is required for review and approval of the request that includes order placement, production of medicine and shipment.
Data reporting and collection at community and district levels
Recording and collecting reliable information on the use of medicines (i.e. coverage) at peripheral and district levels and compiling such information at the national level is essential for completion of the RF.
Breaking the cycle of transmission
Efforts to control neurocysticercosis are mainly aimed at breaking the cycle of active transmission of the parasite. An important component of this strategy is treating patients who harbour the T. solium tapeworm. This is done through large‐scale treatment (also known as preventive chemotherapy) of eligible populations. The most effective medicines at a single dose are praziquantel or niclosamide.
Over the past few years, many endemic countries affected by cysticercosis have requested WHO to facilitate access to quality‐assured medicines. The current agreement, under the umbrella of universal health coverage, allows Bayer to donate praziquantel ("Biltricide") and niclosamide ("Yomesan") tablets.
Taeniasis is an intestinal infection caused by three species of tapeworm: Taenia solium (pork tapeworm), Taenia saginata (beef tapeworm) and Taenia asiatica. Humans can become infected with T. saginata or T. asiatica when they consume infected beef meat or pig liver tissue, respectively, which has not been adequately cooked, but taeniasis due to T. saginata or T. asiatica has no major impact on human health.
Infection with the T. solium tapeworm occurs when a person eats raw or undercooked, infected pork. People infected with T. solium can develop two distinct conditions: taeniasis and cysticercosis.
While the adult tapeworm in the human intestine (taeniasis) does not have major health impact, humans can develop cysticercosis with tapeworm larvae (cysticerci) in the muscles, skin and eyes. When cysts develop in the brain – a condition known as neurocysticercosis – they can cause severe headache, blindness, convulsions and epileptic seizures. The latter can also be fatal.
Epilepsy is a public health problem in these endemic communities, where the association with neurocysticercosis can be up to 70% in some areas. In settings where the disease is present, epilepsy is difficult to diagnose and treat. It also causes major stigmatization, particularly among girls and women (where it is commonly associated to witchcraft).