HEP 444 McConnon Strain Levitt Book Chapter 2

Arizona State University

Dr. Adams

9/25/2022

McConnon Strain

Setting of the story.

The McConnon story refers to an outbreak of a drug-resistant strain of malaria. The story is set in around 1982 and involves two epidemiologists namely Patrick McConnon, a United States citizen, and Roland, a Switzerland citizen. The story is set in Thailand where the US government officials were planning the repatriation of over 20,000 Cambodian, Vietnamese, and Laos refugees. The government wanted to fly these refugees from Thailand to the Philippines where it would be easier for the US government to process their entry into the United States. This malaria strain was common among males from the age of 13 to 35. The strain was prevalent in the Kamput refugee camp.

Case-control study conducted.

McCannon and Roland conducted a case-control study at the Kamput border camp to investigate which activities (i.e., fishing, farming, water collection, etc.) could have exposed the refugees to that kind of malaria. The goal of this kind of research is to identify the risk factors that are and are not linked to an illness by contrasting a group of patients (the case patients) with a group of healthy individuals (the controls). They intended to compare healthy camp inhabitants who were matched by gender and age with malaria cases seen at the Kamput clinic. The researchers conducted “thick smears” and “thin smears,” two common diagnostic procedures for malaria, to determine that the case patients had malaria and not another feverish illness. Both a control group of healthy refugees and Kamput refugees who had malaria symptoms (chills and fever) provided blood samples for Sutter and McConnon to analyze. McCannon and Roland plotted each case of this strain of malaria on a map to spot a pattern. However, from the case-control study, the researchers were able to conclude that there was a null association between malaria and the peoples’ daily activities e.g., cultivation or working near the swamp, forest, or garbage dump.

Retrospective study conducted

McCannon and Roland conducted a retrospective study at Kamput border camp to investigate which activities (i.e., fishing, farming, water collection, etc.) could have exposed the refugees to this kind of malaria. Using the health records of the Kamput clinic, McConnon and Sutter decided to utilize a second epidemiologic method, a retrospective investigation of malaria cases seen in Kamput during the previous six months. They started by coming to terms with the case criteria for malaria, which is a high fever characterized by headache, chills, sweats, muscle pains, diarrhea, or nausea. Dr. Eschevarria assisted them as they went line by line through the Kamput clinic’s logs looking for patients with malaria diagnoses or whose symptoms met the case description. They kept track of the patient’s age, marital status, sex, and employment for each case of malaria. Additionally, they kept track of each patient’s pharmacological therapy and whether it was successful. Again, after plotting each malaria case on a map, the researchers did not find any kind of association.

Solving the mystery

McCannon and Sutter were able to solve their inconclusive epidemiologic study after engaging with a Texan named Richard who had already figured it out after interviewing the refugees. On their journey to bases used by the Khmer Rouge, such as Pailin, a small group of smugglers—men and teenage boys crossed the border between Cambodia and Thailand at night, exposing themselves to night-biting mosquitos. That is why the strain was prevalent among young men.

Areas where malaria is endemic.

Malaria occurs in more than 100 countries worldwide. Malaria is endemic in most areas of South Asia and Africa as well as parts of the Caribbean, the Middle East, Central and South America, and Oceania. Malaria is very prevalent in Africa for a few reasons (Mali et al., 2018). Firstly, the main malaria mosquito, Anopheles gambiae, transmits malaria quite effectively in Africa south of the Sahara. Furthermore, the development of effective malaria control programs may be hampered by a lack of funding and political unrest.

References

Mali, S., Steele, S., Slutsker, L., Arguin, P. M., & Centers for Disease Control and Prevention (CDC). (2018). Malaria surveillance—United States, 2016. MMWR Surveill Summ, 57(5), 24-39.