Tropical Health Matters

A new study from Kenya addresses one of the major challenges to malaria elimination. The authors note changing vector behaviour towards early morning biting has been established. Children are observed to come to school early, as do mosquitoes that have “peak landing between 06:00 and 07:00.” They also found that mosquitoes continue their activity until 11:00. The An. funestus mosquitoes they collected “were either fed or gravid, potentially indicative of multiple bloodmeals within each gonotrophic cycle, and had a sporozoite rate of 2.05%.” this is of particular concern because school aged children are not always prioritized in various malaria control interventions.

In Cambodia researchers found that “20% of collected Anopheles were active during the day, with increased day biting during the dry season.” Ellie Sherrard-Smith and colleagues explain that bednets and indoor residual spray are intended to work best when people are indoors and sleeping. They caution that, “Mosquito bites taken outside of these times contribute to residual transmission which determines the maximum effectiveness of current malaria prevention.” Their review documented that on average 21% of mosquito bites in Africa take place outside bedtime.

A study in Tanzania by Nicodem J Govella et al. noted that the use of insecticide-treated nets for malaria control has been associated with shifts in mosquito vector feeding behaviour including earlier and outdoor biting on humans. They concluded that efforts highlighting the need for control methods that target early and outdoor biting mosquitoes are now required.

In short, various changing factors ranging from climate and mosquito genetics to even the existing interventions like bednets that we use to control the biting of malaria carrying mosquitoes, threaten our ability to eliminate malaria. New vector control measures are urgently needed as is expansion of other interventions like malaria vaccines.

Bill Brieger and Bright Orji conducted an examination of national surveys and program reviews to document achievement of antenatal care and IPTp targets in Nigerian preparation for a poster presentation at the 2023 American Society of Tropical Medicine and Hygiene annual meeting in Chicago.

In 2012, the World Health Organization updated the Intermittent Preventive Treatment of malaria during pregnancy (IPTp) coverage indicator to a minimum of three doses. In 2014, Nigeria set the national target of 100% of women attending ANC to receive IPTp.

This study reviewed national survey data for antenatal care (ANC) attendance and IPTp provision from the 2013 and 2018 Demographic Health Surveys (DHS) and the 2015 and 2021 Malaria Indicator Surveys (MIS). Extracted from the national malaria program reviews (MPR) of the National Malaria Strategic Plans (NMSP) of 2014 and 2019 were explanations of program implementation issues. ANC4 attendance and IPTp uptake (1st and 3rd doses) were compared using descriptive statistics.

The 2015 MIS did not document ANC 4th visit, so attendance in the remaining surveys was 51%, 57%, and 52% (X2=160.0, df2, p <0.0001). The slow increase of ANC attendance and drop in 2021 meant that opportunity to acquire three IPTp doses was not possible for most women. Over the four surveys, IPT1 increased from 23% to 47% to 64%, then dropped to 58%. IPTp3 rose from 6% to 19% then dropped to 16.6% before increasing to 31% (X2= 1755, df3, p<0.0001).

The MPR reports identified four factors inhibiting achievement of the ANC and IPTp targets including insecurity (terrorism, civil unrest), poor integration of malaria in pregnancy into reproductive and maternal health programs, inadequate procurement and stock-outs of SP, and logistical hurdles (lack of vehicles and fuel). By not meeting ANC4 and IPTp1 targets, limits were set for IPTp3 uptake.

As other researchers have suggested, NMSPs embody global targets and may not reflect local realities. Local governments, who deliver the bulk of ANC and IPTp services, must be part of the process of setting and planning how to achieve targets.

The United States has been assisting in the fight against malaria and tropical diseases throughout the tropics. The question now arises is it ready to tackle these diseases on the home front?

In recent months CBS News reported that “Malaria cases in Florida and Texas are first locally acquired infections in U.S. in 20 years,” according to CDC. Local transmission of these 8 cases is the key concern because there are always imported cases from travelers to malaria endemic areas throughout the year. This has led to better planning of mosquito control activities. All of the Florida cases were found in Sarasota County. Although Anopheles mosquitoes still existed in the environment, they had not been infected in recent years.

Likewise Pensacola News Journal noted that, “Rising evidence is pointing to the possibility that leprosy has become endemic in the southeastern U.S. with Florida being named among the top reported states.” The paper explains that these Leprosy cases in central Florida account for nearly 20% of the national total, and that the state is considering instituting contact tracing.

Chagas disease may affect up to 300,000 people from Florida across to California, but an Emerging Pathogens Institute report shared in the Apopka Voice, explained that most cases remain undetected. While Chagas primarily affects people who have immigrated from Latin America, researchers are discovering locally acquired cases because the vector, the kissing bug, has been found in 29 states, and thus local transmission now occurs.

An article in PLoS NTDs explains that Zika, Dengue, and Chikungunya viruses are spread in the southern and Gulf Coast states by members of the Aedes mosquito family, aided by changes in weather and climate patterns. Just as in other countries where NTDs are endemic, the US experience of these diseases also sees that, “poverty equates to substandard housing that exposes residents to insect vectors, a lack of access to sanitation and water, and degraded environments.”

Local, State and National health agencies in the US are starting to awaken to the fact that diseases which we thought were eliminated back in the mid-19^th-century are making a comeback. At a minimum, funding and training are needed to equip our Health Departments with environmentally appropriate vector control measures, appropriate treatment regimens, and disease surveillance tools to tackle the same problems that are threatening the lives of people throughout low- and middle-income countries throughout the world.

The concept and goal of eliminating a disease appears simple on the surface, but complications ensue when the words “as a public health problem” are added.  We know that the distinction exists between eradication and elimination with the former being globally and the latter being nationally or regionally. The sum total action of eliminating a disease from all endemic countries therefore results in total global eradication.

The challenge comes when we try to qualify the concept of elimination. The US CDC defined elimination of disease as, “Reduction to zero of the incidence of a specified disease in a defined geographical area as a result of deliberate efforts; continued intervention measures are required.” Thus, there is no more transmission.  Following from this eradication is defined as, “Permanent reduction to zero of the worldwide incidence of infection caused by a specific agent as a result of deliberate efforts; intervention measures are no longer needed.” Penn Medicine summarized this as, “Elimination means stopping the transmission of a disease in a specific geographic area or country, but not worldwide. Elimination is a crucial step in the path toward eradication, requiring constant monitoring and interventions to keep serious diseases at bay.”

The foregoing definitions seem straightforward, but what does elimination as a public health problem or a disease of public health concern mean? The World Health Organization recently “congratulate(d) Benin and Mali for eliminating trachoma as a public health problem. Concerning another neglected tropical disease (NTD), lymphatic filariasis (LF), global control programs are aiming “to reduce the prevalence of infection below target thresholds and to alleviate the suffering of people affected by lymphoedema and hydrocele.” Wiegand and colleagues in The Lancet Global Health note that, “For schistosomiasis, the criterion for elimination as a public health problem (EPHP) is defined as less than 1% prevalence of heavy-intensity infections (ie, ?50 Schistosoma haematobium eggs per 10 mL of urine or ?400 Schistosoma mansoni eggs per g of stool).” They take issue with the fact that such definitions mean that morbidity still exists, though at very levels, so elimination of transmission has not really occurred for any of these NTDs.

Because the social, environmental, and behavioral conditions that favor transmission may still exists, one cannot guarantee that incidence such diseases may not increase again. All three diseases, LF, Schistosomiasis, and Trachoma have been tackled primarily through preventive chemotherapy, is simply put, using mass drug administration (MDA) over a period of years until active surveillance determines that “infection (is) below target thresholds.” Trachoma does have its SAFE strategy which includes water, sanitation and hygiene interventions, but drugs can reduce the disease without long term achievements in such activities have become sustainable.

Prada et al. in the Journal of Infectious Diseases warn that there can be resurgence of a disease that was documented to be eliminated as a public health problem. They explain that the transmission assessment survey held after several MDA rounds for LF may not be enough to guarantee that low levels of transmission and eventual elimination are achieved. They conclude that, “The risk of resurgence after achieving current targets is low and is hard to predict using just current prevalence. Although resurgence is often quick (<5 years), it can still occur outside of the currently recommended post-intervention surveillance period of 4–6 years,” and recommend monitoring beyond this period.

Toor and co-researchers suggest for NTD programs that, “as case numbers drop and elimination comes into prospect, transmission reduction through other interventions, such as vector control and sanitation, becomes crucial in reducing the probability and speed of resurgence, particularly when MDA or screening programs are halted. Surveillance activities for detecting elimination and resurgence become increasingly important to ensure that successes are maintained.”

Ultimately, unless the context of NTD transmission is addressed, elimination will be an elusive goal. Therefore, as WHO advocated on the recent World NTD Day, “Everybody, including leaders and communities, to confront the inequalities that drive NTDs and to make bold, sustainable investments to free the world’s most vulnerable communities affected by NTDs from a vicious cycle of disease and poverty.”

David Kanamugire has published a blog on the need to add the malaria vaccine to Tanzania’s arsenal of malaria elimination strategies. The original posting is found in the class blog for the Social & Cultural Basis for Community and Primary Health Programs class at the Johns Hopkins Bloomberg School of Public Health. Below is his perspectives on the issue.

Malaria is still a major public health problem. In 2021, malaria killed an estimated 619,000 people – 95 percent of them in Africa. Children under the age of 5 accounted for 80 percent of Africa malaria deaths. Tanzania is among 4 countries that account for just over half of all global malaria deaths.

The country has significantly reduced malaria cases, from a prevalence of 18% in 2008 to 8.1% in 2022. This reduction is attributed to intervention such as Insecticide Treated bed Nets, Indoor Residual Spray, effective drugs and Malaria Rapid Diagnostic tests.

But recently the global progress on malaria has stalled and this could be due to emerging drug resistance, insecticide resistance and the spreading of invasive species Anopheles stephensi. For the past 3 years, the global malaria death remains above 600,000. Therefore there is need for new approaches to help in efforts to prevent and control malaria.

Photo: Gavi, the Vaccine Alliance

Vaccines are safe and cost-effective way combat communicable diseases and improve health outcomes. One of malaria vaccine that have been approved by the WHO is R21. It was developed by Oxford and is produced at a large scale by the Serum Institute of India.

The R21 vaccine is cheap and can be easily produced thus making it ideal for Africa countries. The R21 is also effective against malaria as three initial doses followed by a booster give up to 80 percent protection against malaria.

Essential Medicines, Commodities and Supplies Needed for Community Level Primary Health Care Interventions is our 2-credit online course offered from 5-9 June 2023 as part of the Global Health Systems Summer Institute. Please check the syllabus and share with colleagues.

Course Description” Essential commodities are among the 8 basic primary health care services and the 6 health systems building blocks as defined by the World Health Organization

Primary health care programs in low and middle-income countries require essential health commodities be made available at the community level. Logistic systems need to be developed to ensure that commodities are adequately estimated and delivered. In addition, systems for safely maintaining and monitoring stocks are needed at the community level.

The Summer Institute offers a variety of short-term courses in a variety of global health areas between 5-30 June 2023. The Global Health Systems Summer Institute provides early- and mid-career public health professionals with cutting-edge skills in a variety of global health topics. The Institute is also a great opportunity for part-time MPH and other Hopkins students and fellows to learn a valuable set of skills in an in-demand and rapidly growing field of public health. Below are issues covered in the Essential Medicines course.

• Overview of Essential Medicines for Primary Health Care
• Essential Medicines for Primary Health Care
• Basic Primary Health Care Procurement and Logistics
• Financing for Essential Medicines
• Implementation of Essential Medicines Programs in Primary Health Care
• Preventative Chemotherapy for Neglected Tropical Diseases
• Ensuring Essential Pharmaceuticals Go “Beyond the End of the Road”
• Supply Chains
• The Role of Indigenous Medicine
• Supply Chain Management for CDI: The Malaria Example
• Logistics Management Information System in Community Based PHC
• Community Mass Drug Distribution
• The CDI Process: Expanding Beyond Ivermectin
• Supply Chain Management in Ethiopia
• Community Supply Chain Challenges in Nigeria

Solomon Afolabi, a graduating MPH student from the JHU Bloomberg School of Public Health examined the challenge of epidemics and outbreaks in Africa with special reference to Uganda as an example. The abstract of his report is found below.

According to the WHO, preparedness for emergency health conditions like infectious disease outbreaks should be an ongoing action supported by adequate funding, resources, partnerships, and political will that is executed at all levels to keep it sustained. Emergency preparedness is a framework that identifies practical in-country health emergency preparedness principles and elements by acknowledging lessons learned from previous response activities for priority planning, implementation, and reinforcing operational capacities.

Uganda is an ecological hotspot for various infectious diseases making the country liable to outbreaks. In the last two decades, multiple significant outbreaks have occurred, prominent of which are from yellow fever, Ebola virus disease, and COVID-19 global pandemic. Efforts to build a strategic framework for emergency outbreak preparedness and to strengthen the national operational capacity led to the establishment of the Ugandan National Institute of Public Health (UNIPH) in 2013.

This paper presents a blend of literature that takes account of the successes, challenges faced, and gaps identified in the preparedness and response capacities to the infectious disease outbreaks experienced in the last two decades. It also reviewed how the national efforts had fared in operational readiness for an emergency response to epidemics, building a resilient health system, practicing the One-Health human-animal-environment interface, and in government, community, and individual capacities to contribute effectively to strengthen the national emergency preparedness and response to these frequent disease outbreaks. The findings revealed that Uganda’s outbreak preparedness had made much progress over two decades, from the overwhelming Sudan strain Ebola virus outbreak in 2000-2001 to a similar episode from the same species in 2022 to 2023.

The response measures that feature the activation of a national response plan by the MoH were well coordinated locally to swiftly lead to the activation of NTF, NRRT, DTF, DRRT, and VHTs for immediate mobilization and deployment of operational resources to affected districts. The response was strengthened by well-organized local coordination by the MoH and development partners (WHO, CDC, UN agencies, etc.). The immediate setting up of treatment and isolation centers, provision of Ebola kits, training of more health workers, and coverage of 10 high-risk districts ensured a significant impact.

The provision of more than 5000 doses of vaccines with the support of WHO and partners was a global capacity milestone impact, and the country was declared Ebola-free in a record 69 days. Uganda’s current national emergency preparedness and response plan has received commendations locally and from global international partners, having progressively built capacity from lessons learned in just over a decade of responding to frequent infectious disease outbreaks and using the recommendations proffered accordingly.

This sustained momentum of preparedness supported the swift transition to contain COVID-19 and laid a good foundation for their strengthened readiness for an emergency response to outbreaks.

World Malaria Day 2023 is focusing on three key themes, Investment, Innovation, and Implementation, the 3 I’s. The recently approved malaria vaccines and those still under development embody these themes fully.  They all represent decades of investment in innovation, research, and now implementation.

After extensive several decades of clinical research and three years of field implementation in Ghana, Malawi, and Kenya by the World Health Organization and National Malaria and Immunization Programs, the RTS,S/AS01 malaria vaccine is being rolled out with assistance of GAVI, the Global Vaccine Alliance. During the malaria vaccine implementation program (MVIP) and also based on GAVI’s philosophy for vaccine programs generally, a key strategy was to provide RTS,S as routine immunization services alongside other essential services including a comprehensive package of malaria control and elimination interventions. RTS,S is not only being made available to the three MVIP countries, but as supplies come on board, other falciparum malaria endemic countries have started to apply for supplies and funding through GAVI.

It was well known from the beginning that although RTS,s might be first out the gate, other vaccines would be following closely on its heels. The benefits as well as the efficacy limitations of RTS,S were well known.  Therefore, talk was common for new products being available by 2026. Now in 2023, countries have started to move ahead on another vaccine candidate.

BBC reported that “Ghana is the first country to approve a(nother) new malaria vaccine that has been described as a ‘world-changer’ by the scientists who developed it.” R21 appears to be more effective than its predecessor, so Ghana’s drug regulators moved ahead quickly using final trial data on the vaccine’s safety and effectiveness, which is not even public, to approve it. Interestingly, this move is in parallel to the World Health Organization’s consideration of approving the vaccine.  Shortly thereafter, Nigerian medicine regulators also approved R21. Reuters noted that these “approvals are unusual as they have come before the publication of final-stage trial data for the vaccine.” The actual roll out will ultimately depend on official publication of the safety data and sourcing of funds.

As mentioned above, these malaria vaccines represented considerable investment of time and resources, embody the kind of innovation that is needed to tackle malaria as drug and insecticide resistance threaten progress toward elimination, and require detailed planning right down to the grassroots levels to ensure that a malaria vaccine delivery is part of a comprehensive package of malaria and child health services.

We need to return to the theme of investment. While international organizations, universities, ministries of health, and of course pharmaceutical companies have been investing in developing a safe, effective, and feasible product, these innovative products will not save lives until funds are invested for both purchase and service delivery are guaranteed. GAVI and Partners have put together over $200 million in support for RTS,S implementation for three years. The first window was open in September 2022 for the initial three MVIP countries, and a second window for others, depending on available supplies was open in December 2022.

Investment FOR implementation is a challenging subject because GAVI and collaborating agencies are not a bottomless well of money. What level of national investment by a country to protect its own children is feasible? Is there the national political will to contribute and invest in children in endemic countries, and not continue depending heavily on donors?

Malaria vaccines are a perfect example of what the 3 I’s can achieve. But beyond celebrating this addition to the malaria elimination toolkit, will we also be celebrating commitments by endemic countries of local funds to make zero malaria a reality?

By Jordan Kerr and originally posted in the Social and Behavioral Foundations of Primary Health Care Blog.

Malawi is making strides in increasing HPV vaccinations among adolescent girls across the nation. Since the official implementation of the HPV vaccine program in 2019, 20 out of the 29 districts in Malawi have begun administering the vaccine to adolescent girls between the age of 9 and 14. Despite this success, Malawi continues to be one of the leading countries worldwide in cervical cancer-related mortality. New cases of cervical cancer in Malawi are reported at a rate five times higher than the global average.

This highly preventable disease places a more significant burden on low-income countries like Malawi due to poor access to healthcare services and resources. International agencies are improving their outreach efforts to reach girls not enrolled in school and address vaccine hesitancy in districts with higher vaccine refusal rates. Due to this outreach vaccine registration is improving however healthcare facilities are experiencing stockouts. In some districts, healthcare facilities are reporting that the main reason individuals are not receiving vaccinations is that they are running out of vaccine stocks.

The World Health Organization (WHO) set a goal in 2018 to eliminate cervical cancer by increasing HPV vaccination uptake globally. This initiative has shown to be successful in addressing disparities in low- and middle-income countries however, in 2020 an HPV vaccination shortage began and is expected to continue through 2025.

The Center for Strategic and International Studies (CSIS) presents several strategies that can be used to address this shortage to keep on track with the goal to eliminate cervical cancer. Efforts must be taken to support facilities developing the HPV vaccine to ensure stockouts do not continue. We need policymakers to lobby for policies that increase funding for vaccination development and establish priority vaccination allocations to countries like Malawi that are experiencing high mortality rates from cervical cancer