Pathogenesis and Management of a Late Manifestation of Vivax Malaria after Deployment to Afghanistan: Conclusions for NATO Armed Forces Medical Services

Military Medicine, Jun 2005 by Boecken, Gerhard H, Bronnert, Jan

Because of the worldwide engagement of the German armed forces, tropical diseases may come to the attention of their medical services. In particular, acquired malarial infections, which sometimes become symptomatic only months or even years after soldiers return from military operations, need to be addressed. Other forces, such as the British, U.S., Australian, and Italian armed forces, reported cases of vivax malaria up to ~20 months after soldiers returned from military operations. The importance of a sound history and rapid diagnosis, leading to appropriate treatment, is emphasized in this case report of a 27-year-old German soldier who reported for sick call in his unit complaining of a flu-like illness, which later proved to be vivax malaria. The special parasitological features of Plasmodium vivax infection are discussed.

Introduction

Worldwide 300 to 500 million people suffer from malaria, and there are between 1 and 2.5 million deaths each year. German soldiers and military forces of other NATO member nations have been and will continue to be deployed in malaria-endemic areas. Medical officers must always consider malaria in their differential diagnosis of febrile illnesses, diarrhea, exhaustion, or an influenza-like syndrome that occurs in a service member who has returned from a mission in a malaria-endemic area. The unique characteristics of vivax malaria add to the diagnostic challenge.

Malarial infections are caused by four different species of the genus Piasmodium, transmitted by the bite of a night-active, infected, female, Anopheles mosquito. Among nonimmune Europeans and Americans, Piasmodium falciparum causes severe malaria, which can sometimes be rapidly fatal. Early diagnosis and treatment can reduce the morbidity and mortality rates for severe forms of malaria. Deaths caused by malaria are more common in Germany than in other western nations,' which is mainly attributable to late specific diagnosis and delayed onset of specific chemotherapy. Nonfatal malaria can be caused by Piasmodium vivax, Piasmodium ovale, or Piasmodium malariae parasites. The disease may not be fatal, but the infection can take a severe course and cause organ complications. The tertian parasites (P. ovale and P. vivax) cause similar illnesses, with bouts of fever that relapse periodically but irregularly over a period of up to 5 years. These relapses occur despite treatment with drugs that entirely eliminate the parasites from the blood. The relapses are attributable to reinvasion of the blood by merozoites produced when hypnozoites in the liver awake from dormancy and develop into preerythrocytic schizonts.

Early diagnosis and treatment of malaria are key to preventing complicated disease outcomes. Provided the examiner has had adequate experience, specific diagnosis can be achieved by simple means, e.g., microscopic examination of a peripheral smear stained with Giemsa stain or a dipstick test, which is simple and quick. Treatment should be commenced without delay, with chemotherapy appropriate to the given geographical region. This is a case report of a P. vivax infection in Germany involving a soldier who had returned home from his mission in Kabul 9 months earlier.

Case Report

Having shown signs of flu-like illness for 6 days, a 27-year-old soldier was admitted to a local hospital in June 2003 as an emergency case, with sudden onset of tachydyspnea, pronounced bilateral spasticity, and high-grade fever (rectal temperature of 40.7°C). Early clinical signs were nausea and vomiting, anorexia, cephalalgia, and neuralgia. The physical examination did not reveal any striking features. The patient was put on the sick list and sent home after flu was diagnosed. Subjective improvement could be observed at first, but the next day the patient started shivering and his temperature increased; after profuse sweating, the patient recovered on the third day. On the following day, the patient's rectal temperature increased again, up to 38.5°C. The unit surgeon diagnosed tenderness on pressure of the facial nerve exit points, slightly enlarged cervical lymph nodes, and symptoms of a bacterial infection (seropurulent expectoration). An antibiotic (azithromycin) was prescribed. After this treatment, the patient subjectively felt slightly better. On the fifth day, the patient presented himself again to the unit surgeon; his rectal temperature was 37.8°C and he felt fatigued. On the sixth day, the patient was admitted to the local hospital after having had another attack of fever up to 40.7°C, with continuous vomiting and rapidly increasing dyspnea. In a routine blood count performed that day, a technician noticed intraerythrocytic structures, which were described as "malaria" without species differentiation. This led to the patient's admission to our institution.

Nine months earlier, the patient had returned from his deployment in Afghanistan, where he served in the International security Assistance Force mission for 11 weeks, from June to September 2002, as a junior intelligence officer in the city of Kabul. He lived in the German military camp in the city, participated in only 3 night patrols in town, and never left the city borders. He plausibly assured us that he took his malaria chemoprophylaxis (chloroquine and proguanil) punctually and in the correct dosage. He was not provided with an impregnated uniform or bed net, and he did not use skin repellents at any time.