Cancer care challenges in developing countries




Health systems in Sub-Saharan Africa are not prepared for the rapid rise in cancer rates projected in the region over the next decades. More must be understood about the current state of cancer care in this region to target improvement efforts. Yaounde General Hospital (YGH) currently is the only site in Cameroon (population: 18.8 million) where adults can receive chemotherapy from trained medical oncologists. The experiences of patients at this facility represent a useful paradigm for describing cancer care in this region.


In July and August 2010, our multidisciplinary team conducted closed-end interviews with 79 consecutive patients who had confirmed breast cancer, Kaposi sarcoma, or lymphoma.


Thirty-five percent of patients waited >6 months to speak to a health care provider after the first sign of their cancer. The delay between first consultation with a health care provider and receipt of a cancer diagnosis was >3 months for 47% of patients. The total delay from the first sign of cancer to receipt of the correct diagnosis was >6 months for 63% of patients. Twenty-three percent of patients traveled for >7 hours to reach YGH, and 40% of patients interviewed spent >$200 on a single round of chemotherapy.


Cancer patients experienced numerous geographic and health care system challenges, resulting in significant delays in receiving diagnosis and treatment, even for cancers highly amenable to early intervention. This unacceptable and unethical situation is likely explained by limited knowledge about cancer among patients and health care professionals, government neglect, poverty, and reliance on traditional healers. Cancer 2012;3627–3635. © 2011 American Cancer Society.


Cancer care and treatment in Sub-Saharan Africa, until recently, has been largely ignored by national governments and international funding agencies.1, 2 The relative success of programs to control infectious disease morbidity and mortality (thus, unmasking chronic diseases that affect older populations) and the wave of immunodeficiency enabled by human immunodeficiency virus (HIV) infection and chronic malnutrition have prompted both an increase in cancer burden and a growing awareness of the serious public health problem cancer represents. In 2008, an estimated 500,000 individuals in Sub-Saharan Africa died from cancer.3 New cases of cancer in the region are projected to increase 34% to 1.1 million annually by 2020.2 Worldwide, cancer already kills more individuals than HIV/acquired immunodeficiency syndrome (AIDS), malaria, and tuberculosis combined,4 and these trends are projected to increase as populations in the developing world age and adopt western lifestyles.5

Sub-Saharan Africa is unprepared to meet this growing disease burden. In Cameroon, a lower middle income country in West Africa, there are 2 medical oncologists serving a population of 18.8 million, both of whom are based in the capital of Yaounde.6 Efforts led by the Ministry of Health to subsidize generic chemotherapy and to screen for cancer have been seriously under-funded, so that many patients who are diagnosed with treatable cancers die unnecessarily. Even for patients who do seek treatment, outcomes are poor. For example, in 2007, the 5-year survival rate for the 12,280 women in the United States who were diagnosed with cervical cancer was 92%; whereas, in Sub-Saharan Africa, only 30% of the 99,360 new cervical cancer cases lived 5 years past diagnosis.2, 7, 8 The estimated 83,079 patients with newly diagnosed breast cancer in Africa in 2009 had equally low survival rates.2 Although 81% of women with breast cancer in the United States survive 5 years past diagnosis, only 32% of women in Sub-Saharan Africa are alive 5 years later.8

Although many of the most common cancers in Sub-Saharan Africa (for example, Kaposi sarcoma, cervical cancer, breast cancer, and certain types of non-Hodgkin lymphoma) are amenable to prevention, early detection, and treatment,9, 10 health care development assistance continues to heavily favor communicable diseases.1, 11 However, there are early indications that the focus of the international health community may be shifting to address noncommunicable diseases.11-13 The recent United Nations resolution to better control noncommunicable diseases,14 the Harvard Global Health Equity Initiative,15 and recent World Health Organization (WHO) proclamations16 are just the beginning of a realignment of attention and resources necessary to effectively deal with the global cancer crisis.

To develop targeted and effective anti-cancer initiatives in Cameroon, patient behaviors and existing cancer-control and treatment resources must be better understood. There is a small but growing body of literature that describes cancer in Cameroon. Markedly higher rates of late-stage cancers at the time of first diagnosis have been well documented in low and middle income countries like Cameroon.17, 18 One study that included patients who presented with breast cancer to the Obstetrics Gynecology Department in Maroua, Cameroon over a 3-year period indicated that all presented with stage III or IV disease, whereas a larger study from Nigeria indicated that 75% of patients presented with stage III or higher breast cancer.19, 20 The Nigerian study indicated that 47% of patients waited longer than 6 months between initial notice of symptoms and hospital presentation, whereas a study of Cameroonian patients with breast cancer who presented for radiation therapy indicated that 69% waited longer than 6 months.21

Studies suggest several reasons for these patient delays and late presentations in Cameroon. Patients often believe their illness is caused by sorcery and witchcraft and thus resort to traditional healers rather than modern medicine.22-26 Widespread poverty makes western medicine an expensive alternative to traditional healers, and patients in developing countries like Cameroon often are isolated geographically from specialists capable of properly diagnosing and managing their illness.27-30 For example, a study of patients with breast cancer who presented for radiation therapy indicated that 55% had recourse to traditional medicine before their first medical evaluation.21 Even for Cameroonian patients who consult western physicians regularly, cancer is an under-appreciated ailment that often is missed on physical examination.20 To date, there have been few published studies on diagnosis and treatment delays in Sub-Saharan Africa and little data on the cost of treatment in low-income and middle-income countries like Cameroon, where the annual per-capita gross national product (GNP) is $1190.6, 31

The current retrospective, observational study is a higher resolution look at the experiences and behaviors of patients who had 1 of 3 commonly diagnosed cancers in Cameroon: breast cancer, Kaposi sarcoma, and lymphoma. This study makes an important distinction between patient and provider delays. The data shed light on what type of health care provider patients first consult (nurse vs general practitioner vs specialist) and the number of providers they must see before receiving a definitive diagnosis. In addition, special attention is paid to describing and quantifying geographic barriers to accessing health care facilities and obtaining a real-world estimate of the financial impact cancer has on patients.



After a 3-week pilot-testing phase, this study was conducted at Yaounde General Hospital (YGH) between July 13, 2010 and August 12, 2010. YGH is a 500-bed municipal hospital centrally located in Cameroon's capital city, Yaounde, where the only specialized medical oncology clinic in the country is located. After obtaining informed consent, 2 trained interviewers used a quantitative, closed-end data-collection instrument to conduct interviews with all consecutive, eligible patients in a quiet, private room located in the oncology clinic. Interviews were conducted in French or in the local tribal language that was most familiar to the patient.

Patient Inclusion Characteristics

Participants who were included in the study were consenting adults (aged >18 years) who were diagnosed with invasive carcinoma of the breast (ductal, lobular, inflammatory, medullary, colloid, and tubular), Kaposi sarcoma, or lymphoma (Hodgkin and non-Hodgkin) who presented to the medical oncology clinic and received chemotherapy between July 13 and August 12, 2010. The diagnosis of cancer was confirmed by tissue biopsy or cytology samples read by Cameroonian pathologists for 98% of breast cancer cases (n = 50), 53% of Kaposi sarcoma cases (n = 19), and 100% of lymphomas (n = 10) (Table 1). Clinical diagnoses were made by 1 of the 2 medical oncologists at YGH for those patients without tissue confirmation. Cancer stage data and cancer subtype were available only for a subset of patients. In total, 83 patients who met eligibility criteria for inclusion in the study were identified during the recruitment period and were given the opportunity to participate in the study. Of these, 4 eligible patients declined to be interviewed.

Table 1. Patient Sample Characteristics: Cameroon, 2010
Type of CancerNo. of Patients (% Total)No. of Patients With Tissue Confirmation by Cytology or Biopsy (% for cancer subtype)aMean Age [Min-Max]% Male/ % Female
  1. Abbreviations: Min, minimum; max, maximum.

  2. aPatients with breast cancer were 2.1 times more likely (95% confidence interval, 1.3-3.3) than KS patients to have tissue confirmation of their diagnosis. Patients with lymphoma were 2.1 times more likely (95% confidence interval 1.3-3.4) than KS patients to have tissue confirmation of their diagnosis.

Breast cancer50 (63)49 (98)46 [29-75]4/96
Kaposi sarcoma19 (24)9 (53)41 [22-74]68/32
Lymphoma10 (13)10 (100)54 [38-79]50/50
Total79 (100)68 (88)46 [22-79]25/75

Data Collection

Before the study start date, the physician team and nursing staff were briefed on the study. The data-collection team included a study coordinator (A.J.P.), 2 Cameroonian interviewers, and 2 intake nurses, and all were supervised by the chief of the Oncology Service at YGH. A.J.P. and 1 interviewer performed a 3-week pilot study to develop the 52-item data-collection instrument that was used. Before the start of the study, the 2 interviewers were provided a detailed data dictionary and were thoroughly briefed on the study and questionnaire. At the close of each day during the study period the team reviewed data for ambiguities and errors. Face-to-face interviews lasted approximately 30 minutes.

Data were entered within 24 hours of collection into a Microsoft Access database (Microsoft Corporation, Redmond, Wash) by A.J.P., and entries were verified by another member of the data-collection team. Data were evaluated using Microsoft Access (version 12: Microsoft Corporation) and OpenEpi (version 2.3.1; The statistical significance of comparison between subcategories of cancers indicated in Tables 2, 3, and 4 was calculated using chi-square tests. Differences were not statistically significant except when noted otherwise.

Table 2. Geographic Distribution of Patients Included in the Study: Cameroon, 2010
 No. of Patients (%With Cancer Type)
Type of CancerPatients Residing Outside Central ProvinceTraveled >4 Hours to HospitalaSpent >$10 on 1-Way Transportationb
  • a

    Patients who had breast cancer were 4.4 times more likely (95% confidence interval, 1.1-16.8 times more likely) and patients who had lymphoma were 5.7 times more likely (95% confidence interval, 1.4-23.2 times more likely) to travel >4 hours to reach the hospital compared with patients who had Kaposi sarcoma.

  • b

    Patients who had lymphoma were 3.8 times more likely (95% confidence interval, 1.2-12.1 times more likely) to spend >$10 on travel compared with patients who had Kaposi sarcoma.

Breast cancer24 (48)23 (46)21 (42)
Kaposi sarcoma5 (26)2 (10)3 (16)
Lymphoma5 (50)6 (60)6 (60)
Total34 (43)31 (39)30 (38)
Table 3. Referral by First Health Care Contact and Delays of Cancer Diagnosis: Cameroon, 2010
 No. of Patients (% With Cancer Type)
Type of CancerReferred to Cancer Specialist/GynecologistReferred to Other Health Care ProviderConsulted ≥4 Providers Before DiagnosisHad System Delay >3 MonthsaHad System Delay >6 MonthsHad >6 Months Between First Sign and Diagnosisb
  • a

    System delay was defined as the delay between first presentation because of symptoms from cancer and the diagnosis of cancer.

  • b

    This category does not include data from 3 respondents (2 patients with lymphoma and 1 patient with Kaposi sarcoma) for whom date of first sign was unavailable.

Breast cancer4 (8)13 (26)23 (46)21 (42)16 (32)30 (60)
Kaposi sarcoma1 (5)5 (6)6 (32)12 (63)10 (53)15 (79)
Lymphoma0 (0)6 (60)5 (50)4 (40)3 (30)5 (50)
Total5 (6)24 (30)34 (43)37 (47)29 (37)50 (63)
Table 4. Cost Incurred by Cancer Patients: Cameroon, 2010
 No. of Patients (%With Cancer Type)
Type of CancerSpent >$1000 Before Consulting a Cancer SpecialistSpent >$200 on Most Recent Round of ChemotherapyUnable to Schedule or Keep Chemotherapy Appointments in a Timely ManneraCited Money Problems as Primary Reason for Appointment Delaysb
  • a

    Timely manner defined as scheduling chemotherapy within 14 days of prescription, or receiving chemotherapy on day it was prescribed.

  • b

    Patients who had Kaposi sarcoma were 3.0 times more likely (95% confidence interval, 1.3-6.5 times more likely) than patients who had breast cancer to cite money problems as a primary reason for appointment delays.

Breast cancer20 (40)24 (48)17 (34)8 (16)
Kaposi sarcoma3 (16)4 (21)10 (53)9 (42)
Lymphoma4 (40)4 (40)3 (30)3 (30)
Total27 (34)32 (40)30 (38)19 (24)

Ethical Review

This project was reviewed and approved by the University of California-San Diego Human Research Protections Program and by the National Ethics Committee of Cameroon. Participant data were recorded and are presented without patient identifiers.


Patient Decision Challenges

Forty percent of cancer patients in the sample waited for >3 months between the onset of their initial symptom(s) of cancer and their first health care contact, and 87% of those delays were >6 months. After referral to a cancer specialist, 41% of patients waited >1 week to consult a cancer specialist, and 16% waited >1 month. Reasons cited for delays >1 week were lack of financial support to pay for the visit (43%), lack of available appointment times (17%), and other miscellaneous reasons.

Overall, 84% of patients received their first chemotherapy treatment within 1 week of its prescription, although there were some outliers who had much longer delays (up to 4 years). Receipt of radiation therapy was relatively uncommon in the group, with only 4% of all patients receiving any radiation therapy. Sixty-two percent of patients with breast cancer, 5.3% of patients with Kaposi sarcoma, and 30% of patients with lymphoma reported having undergone surgery. Of the 34 patients who underwent surgery, 4 reported delays of their surgery for >2 weeks, most often because of financial difficulties (75%).

Challenges Navigating the Health Care System

Forty-three percent of patients reported residing outside the central province where YGH is located (Table 2), resulting in 1-way travel times from residence to hospital >4 hours for 39% of patients, with 38% of patients spending >5000 Cameroonian Francs (CFA) (approximately $10) on 1-way transportation. Twenty-three percent of patients who were interviewed traveled for >7 hours 1-way to reach YGH. Patients who had breast cancer were 4.4 times more likely (95% confidence interval [CI], 1.1-16.8 times more likely) and patients who had lymphoma were 5.7 times more likely (95% CI, 1.4-23.2 times more likely) to travel for >4 hours to reach YGH compared with patients who had Kaposi sarcoma. Likewise, patients who had lymphoma were 3.8 times more likely (95% CI, 1.2-12.1 times more likely) to spend >$10 on travel compared with patients who had Kaposi sarcoma.

The type of health care professional study participants first consulted for their cancer symptoms varied greatly. Fifty-four percent of patients first consulted general practitioners, 19% consulted specialist physicians, 17% consulted nurses, and 9% consulted religious or traditional healers. Subsequently, the first health care contact referred 6% of patients to a cancer specialist or a gynecologist (in the case of breast cancer) and 30% of patients to another type of health care provider (Table 3). Only 13% of patients were prescribed either a biopsy or cytology to confirm suspicions of malignant disease by the first health care contact. Forty-three percent of patients consulted with 4 or more health care professionals about their illness before receiving their final diagnosis.

The delay between the first time a patient consulted a health care professional and when he/she finally was diagnosed, also known as “system delay,” was >3 months for 47% of patients and >6 months for 37% of patients. The total delay between developing the first sign of cancer and a definitive diagnosis of cancer was >3 months for 71% of patients and >6 months for 63% of patients.

Economic Challenges

Sources of money to pay for treatment included personal income and savings for 53% of patients and gifts and loans from family for 75% of patients. One percent of patients used private insurance, and 1% received support from the government to pay for treatment.

Table 4 indicates that 34% of patients who were interviewed spent more than $1000 (approximately 84% of annual per capita GNP) on costs related to their illness before they were diagnosed. After diagnosis, the cost of the medications and hospital supplies for the least expensive round of chemotherapy that patients in our sample received was approximately 70,000 CFA (approximately $140), although the cost was >100,000 CFA (approximately $200) for 40% of patients we interviewed because of other factors, such as extended hospital stay or receipt of extra medications to treat side effects from chemotherapy. Thirty-eight percent of patients either delayed scheduling their first chemotherapy appointment for more than 2 weeks or missed a chemotherapy appointment, and 63% of these patients cited money as the primary reason for the delay. Patients who had Kaposi sarcoma were 3.0 times more likely (95% CI, 1.3-6.5 times more likely) than patients who had breast cancer to cite money problems as a primary reason for appointment delays.


In Cameroon and most of Sub-Saharan Africa improvements must be made in cancer detection and treatment and in treatment cost. Many patients who were interviewed in the current study were not able, willing, or worried enough to seek timely care for their cancer. The number of study participants waiting >3 months between the first symptom of cancer and the first consultation with a health care provider (40%) was roughly double the levels reported in developed countries25, 33 and was consistent with findings in other developing countries, such as Peru and Iran.34, 35 Reasons for this delay likely included attitudes about disease, fear of surgery, misidentification of the disease by the patient or his/her care provider, preference for alternative treatments, and cost.18, 22-27 In Cameroon, patient decisions and readily available economic resources have an outsized influence on care because virtually no systematic cancer screening programs exist, and yearly checkups for the general population are virtually unheard of. In Asia and Africa, patient delays have been identified as an important factor associated with later cancer stage at presentation and increased mortality.30, 36

The role of traditional healers in Africa is a subject that deserves special attention. Although 9% of the patients we interviewed said that the first provider they consulted about their cancer was a traditional/religious healer, other studies in Africa for various illnesses, including cancer, put the rate closer to 20% and sometimes much higher.29, 37, 38 In 2002, the WHO reported that 80% of Africans use traditional healers,39 whereas a study of patients with breast cancer in Cameroon indicated that 55% went to traditional healers before presenting for medical consultations.21 Acceptance of traditional healing in Cameroon is so widespread that there is an Office of Traditional Medicine under the Ministry of Health, and the government has sanctioned traditional healer organizations that license practitioners.40, 41 Traditional healers are geographically widespread and accessible, and they often combine ancient ritual practices with Animist, Christian, and Islamic beliefs.

For example, 1 study participant with a particularly advanced case of endemic Kaposi sarcoma (Fig. 1) believed that his illness was the result of a “curse” inflicted upon him by a neighbor with whom he had a land dispute. The participant had spent approximately $250 (approximately 22% of annual per capita GNP) and approximately 1 month on repeated interactions with a traditional healer who made incisions with a razor blade in the area of the Kaposi sarcoma lesions and rubbed various compounds, such as tree barks and minerals, into the wounds. Another traditional healer that we spoke to described a healing ritual in which he writes prayers on a wooden tablet with ink and then collects the water used to wash the tablet. He gives the patient the ink-filled water to ingest and rub onto their bodies (Fig. 2). The ubiquity of healers and the relatively low cost of care they offer means that they are often the first stop for patients with cancer, and they probably make an important contribution to the diagnosis delays we measured as well as further adding to the costs of treatment.

Figure 1.

Endemic Kaposi sarcoma on the leg of a study participant is shown. The participant believes that the illness is the result of a curse and left the western health care model for several years. The participant recently consulted a traditional healer, where he spent approximately $250. When the lesion did not improve he decided to consult physicians.

Figure 2.

Traditional healers combine ancient ritual practices with Animist, Christian, and Islamic beliefs. In this ritual, the traditional healer writes prayers on a wooden tablet with ink and then washes the ink off. The inky water is then given to the patient to drink and for bathing.

In the current study, we also identified the significant physical and economic hardships that the scarcity of cancer specialists in Cameroon causes. The presence of only 1 location where adults can consult a medical oncologist in a country of approximately 19 million is especially notable considering that patients who receive chemotherapy must visit YGH at least every 3 weeks when undergoing a course of chemotherapy, and sometimes their treatments are delayed by several days because of poor health. Some patients who were included in the current study had traveled at least 3 days at great cost to reach YGH. The data also indicated that patients with breast cancer and lymphoma experienced longer travel times to the hospital, suggesting these patients have fewer options for local management of their disease, whereas Kaposi sarcoma more often is diagnosed and treated locally.

Even when cancer patients have accessed the health care system, accurate diagnoses are difficult to obtain. That nearly half of study participants consulted with ≥4 health care professionals before final diagnosis indicates that large numbers of health care professionals in Cameroon fail to recognize cancer in patients and do not make the appropriate referral to oncologists. System delay in Cameroon compares particularly unfavorably with the developed world, where studies have indicated diagnosis delays averaging 2.5 months,42 with only 22% to 25% of patients waiting >2 months to receive diagnosis43, 44 and only 10% of patients waiting >3 months (compared with 47% of patients in Cameroon).45

Finally, the relatively high cost of cancer treatment in Cameroon negatively affects care at all levels. A course of chemotherapy for the cancers examined in the current study costs roughly the same as the annual per-capita GNP in Cameroon. This is the equivalent of cancer patients in America paying approximately $47,000 for a course of generic chemotherapy.27 In addition to being the most cited culprit for delaying time-sensitive rounds of chemotherapy and consultations with cancer specialists, costs often cause patients to delay accessing health care in the first place. Poverty affects treatment in other ways as well. According to the medical oncologists in Cameroon, important cancer subtype information is often missing from patient's charts because of the costs of obtaining biopsies.

It is noteworthy that our data indicated that patients with Kaposi sarcoma were more likely than patients with breast cancer to cite money problems as a primary reason for appointment delays. One possible explanation for this is that patients with breast cancer in our sample tended to be older women and often were married, whereas the patients with Kaposi sarcoma tended to be younger men, presumably with less reliable family support.

High relative cost, along with the system and patient delays outlined above, mean that Cameroonian cancer patients lose precious time needed to treat and prevent the spread of their cancer. Such factors contribute to nonimprovement in clinical stage at presentation in Sub-Saharan patients with breast cancer over the past 20 years despite improvements in other socioeconomic variables, such as literacy.20

In collecting and analyzing data for the current study, several weaknesses were identified by the team. Sample sizes were relatively small, so that most differences between the experiences of breast cancer, Kaposi sarcoma, and lymphoma did not reach statistical significance. Because of the detailed nature of some questions in the survey, we cannot be sure that all patients answered questions accurately. In addition, bias may have been introduced by the way questions were asked and by the patient's desire to please the interviewer. For example, patients consulting with health care professionals may be reluctant to admit that they have visited a traditional healer. It is important to bear in mind that the patients who were interviewed for this study were not representative of most Cameroonians. This study only included patients who were willing to spend relatively large sums of money on western-style health care (versus traditional healing) and patients with the ability to reach the medical oncology clinic at YGH. In a country of approximately 19 million individuals, where poverty is the rule rather than the exception, we believe that most cancer patients never make it to the hospital.

This project demonstrates an already dire situation for cancer patients in Cameroon, a situation that will only grow worse if more is not done to improve care. The project identified 3 areas in which a research strategy and resources are needed: patient education, health care system improvement, and reducing drug costs. More qualitative studies are needed that highlight the factors that cause cancer patients to delay seeking care once they are symptomatic. On the basis of these data, public awareness campaigns focused on prevention and early detection, and pilot screening and treatment programs, can be designed and a model exemplified by the success of the Cancer Control Center of Harlem.46

These projects will require partnerships between international health organizations and regional and local African nongovernmental organizations (NGOs) focused on fighting cancer. For example, the African Organization for Research and Training in Cancer sponsors international conferences and has participated in cervical cancer research and palliative care training.47 SOCHIMIO (Solidarite Chimiotherapie) is a Cameroonian NGO based in Yaounde that has initiated and facilitated the execution of several cancer research projects in Cameroon.48 The organization has several promising initiatives, including a badly needed information hotline where Cameroonians can receive accurate information about cancer, and culturally informed strategies for public relations campaigns. SOCHIMIO already provides discounted chemotherapy to some qualifying patients. Partnerships with these organizations offer a fast track to achieving results in the fight against cancer in Africa and fertile ground for demonstration programs to document efficacy.

Furthermore, although western medicine often views traditional healers as a barrier to patients obtaining the care they need, the reality is that these practitioners are often the first stop for patients with cancer. Partnerships with these actors at the local level must be a priority for any program seeking to improve cancer care in Sub-Saharan Africa.

The results of this and other studies demonstrate that ignorance about cancer is not limited to patients. Health authorities in Cameroon and aid organizations must partner with cancer centers and specialists worldwide to prioritize training of medical oncologists and their strategic placement in the country. To strengthen the referral chain, every effort must be made to educate the general practitioners and nurses who often serve as the first points of contact for patients to recognize early signs of cancer. Research in this area should be aimed at demonstrating which training programs are effective.

Finally, partnerships must be forged between aid organizations and large life-science companies to more effectively study and treat cancer in Sub-Saharan Africa. The high prevalence of HIV, Epstein-Barr virus, hepatitis B virus, hepatitis C virus, human papillomavirus, Helicobacter pylori, and other infectious diseases give rises to a unique cancer profile in Africa, which offers researchers the opportunity to better understand the environmental and genetic factors that lead to cancer.49 The outflow of research and cancer discoveries must be coupled with efforts by commercial and philanthropic groups to lower the price of chemotherapeutics in much the same way first-line antiretroviral therapy in the fight against HIV/AIDS was made attainable in recent years.


We thank Ferdinand Ndom and Leonard J. Price, PhD.


This work was supported by the Arnold P. Gold Foundation, the University of California-San Diego Friends of the International Center, and by the American Society of Tropical Medicine and Hygiene.


The authors made no disclosures.