Adapted from "Malaria" module, Pre-Service Health Training for Volunteer Binder, Peace Corps Office of Medical Services

BACKGROUND

Students should understand the following information regarding malaria:

1. Know what causes malaria and how it is transmitted.
2. Know how to prevent malaria.
3. Know how to recognize or suspect malaria infection and what to do.

Description of malaria

• Malaria is an infectious disease caused by protozoa of the genus Plasmodium. The four species of Plasmodium that cause human malaria are P. falciparum, P. vivas, P. ovale, and P. malariae.
• All four species are transmitted by the bite of an infected anopheles mosquito.
• Both P. vivax and P. ovale can have prolonged dormant (liver) phase of up to three years after leaving infected area.
• The most dangerous species is P. falciparum, which causes life threatening disease.

Distribution

• Malarial transmission occurs in large areas of Central and South America, Hispaniola, Sub-Saharan Africa, the Indian subcontinent, Southeast Asia, the Middle East and Oceania.
• P. vivax and P. ovale are present in all malarial areas except Haiti.
• (Administrators should refer to the U.S. Centers for Disease Control and Prevention (CDC) Yellow Book and consult local health professionals (doctors) for detailed information on the distribution of malaria and chloroquine-resistant plasmodium falciparum (CRPF).)

Transmission

Malaria transmission is influenced by climate. High humidity increases mosquito life span, and seasonal outbreaks of malaria often occur around rainy seasons.

Immunity

Whereas populations continually exposed to and infected with malaria in endemic areas develop a degree of immunity, students do not develop immunity during their brief stay in malarial areas.

PREVENTION

Prevention of mosquito bites (Primary prevention)

• Anopheles mosquitoes feed primarily at dusk and at night.
• Cover up with long –sleeved shirts, long pants and socks.
• Screens on windows and doors.
• Sleep under mosquito nets. Permethrin-impregnated nets provide additional protection.
• Insect repellents. 30-35% DEET is quite effective and lasts for about 4 hours.
• Pyrethroid-containing flying insect spray in living and sleeping area. Permethrin may be sprayed on clothing.
• Remove sources of standing water in the immediate vicinity of the house.

Chemoprophylaxis (secondary prevention)

• The goal of chemoprophylaxis is to suppress malaria (keep asymptomatic) during the student’s stay abroad. Chemoprophylaxis does not prevent infection.
• Students must be advised to take the most effective anti-malarial available.
• (Program administrators should check for most appropriate chemoprophylaxis for their country.)
• Starting chemoprophylaxis: Usually, malaria prophylaxis is started prior to going abroad.. For students living in malaria-free areas and traveling to a malaria area, chemprophylaxis should be started 1-2 weeks before traveling if possible. If immediate, intense malaria exposure to CRPF is anticipated, a loading dose of mefloquine may be given.
• Conflicting advice: Students will inevitably receive conflicting advice from other medical providers and expatriates regarding the "best" malaria prophylaxis. It is useful to acknowledge that while these differences of opinion are inevitable, host country nationals with at least partial immunity are at less risk than students and local public health policies are driven by considerations such as cost and availability of chemoporphylaxis.
• This information is adapted from Peace Corps recommendations which were endorsed by CDC and consistent with World Health Organization (WHO) recommendations and are considered helpful in developing guidelines for study abroad.

Missed doses

• Drugs given weekly doses: Students should be advised that if they forget a dose, they should take the missed dose as soon as they remember it, and continue on their regular schedule.
• Drug given daily doses: Students are more likely to forget drugs which are given daily, and this may lead to breakthrough cases of malaria. Students who regularly miss a daily dose should be advised to switch to weekly medication.

Leaving a malaria area

• Students should continue malaria prophylaxis for four (4) weeks after leaving malaria area.

CLINICAL ILLNESS

Classical presentation

• Malaria classically presents with chills or rigors, high fever, anemia and spenomegaly.

Variable presentation, especially when prophylaxis is taken

• The signs and symptoms depend on the malaria species, the patient’s degree of immunity, and whether the patient took chemoprophylaxis.
• The prodromal phase of malaria is often similar to a non-specific viral illness. Symptoms may include:
  • Malaise, myalgia, backache
  • Mild or severe headache, dizziness, fatigue
  • Anorexia, nausea, vomiting, diarrhea
  • Slight fever
  • Dry cough and shortness of breath

A presumptive diagnosis of malaria should be considered in a student who has been in a malarial area with:

1. Episodes of high fever associated with chills and sweats
2. Headache, myalgia, vomiting or cramps

Complications of falciparum malaria include:

• Cerebral malaria (mental disturbances, neurologic signs, convulsions)
• Hemolytic anemia
• Dysenteric or cholera-like diarrhea
• Acute kidney failure ("Blackwater Fever")

Non-falciparum malaria generally does not result in the serious consequences described for P. falciarum.

DIAGNOSIS AND TREATMENT

Administrators should identify medical facilities were diagnosis and treatment can take place.

Leaving the Malarial Area

• Students should continue malaria prophylaxis for four (4) weeks after leaving a malarial-endemic area.
• Students should consult with a physician regarding any irregular conditions or for follow-up care.

Adapted from "Malaria" module, Pre-Service Health Training for Volunteer Binder, Peace Corps Office of Medical Services