When diagnosis of malaria is made by the Japan Overseas Cooperation Volunteers (JOCV) in sub-Sahara African countries, we have sometimes noted discrepancies between the results of the malaria rapid diagnostic test (RDT) and the results of the microscopic examination of blood smears (Slide test).
Therefore, we retrospectively investigated the possible reasons for the occurrence of these discrepancies, in order to re-establish the health care measures for JOCV.
We analyzed the cases of 33 patients who were diagnosed as having malaria by JOCVs or local doctors,and for whom malaria treatment was started. For 22 out of 33 patients, both RDT and a Slide test were performed. The results of the tests were identical in 10 cases (45%) and not identical in 12 cases (55%).
Twenty-two out of 33 patients were given the final diagnosis of malaria by local or Japan International Corporation Agency physicians. The concordance rate between the final diagnosis and the test result was 96% in the RDT group and 80% in the Slide test group. Among 9 patients whose test results were RDT-positive and Slide test-negative, 6 had already started Emergency Standby Medicine before the Slide test was performed at the hospitals.
The slide test is the gold standard for malaria diagnosis, and RDT is regarded as a supplementary test in developed countries. However, the accuracy of RDT results is confirmed by the WHO based on comprehensive studies and is recommended for use in developing countries where medical resources are insufficient. The promotion of the use of RDT is strongly recommended for the health care of JOCVs employed in such areas.
A 25-year-old Japanese female was admitted with fever, headache and nausea. She had recurrent fever every 48 hours and a CT scan revealed splenomegaly. An automated hematology analyzer displayed an error message of platelet aggregation. The laboratory technician checked a blood smear with a microscope and found Plasmodium parasites. Suspecting malaria infection, we reconfirmed her travel history and found that she had visited India and Nepal 8 months ago. The PCR test revealed that she was infected with Plasmodium vivax (P. vivax) malaria.
The average incubation period is 2-4 weeks for P. vivax malaria, but some cases of P. vivax malaria show a much longer incubation period up to a maximum of about 12 months. When a patient has malaria-like symptoms, it is of utmost importance to confirm his/her travel history within at least the previous 1 year.
A previously healthy 74-year-old male presented with anorexia, fever, wet cough, and altered consciousness. He was admitted to Itabashi Chuo Medical Center and diagnosed as having pneumococcal pneumonia complicated by sepsis and bacterial meningitis. His symptoms initially improved with antibiotic and anticoagulant therapy. However, the fever reappeared and a new symptom of lumbago surfaced after, he had completed the full course of treatment. Magnetic resonance imaging of the lumbar spine revealed a highintensity lesion between L4 and L5, indicating a diagnosis of pyogenic spondylitis. Blood cultures indicated that Streptococcus pneumoniae had in fact caused the spondylosis. After seven days, the patient requested a switch from intravenous to oral antibiotic treatment, and this improved the symptoms of fever and lumbago. Symptoms did not recur after a six-week course of oral antibiotics. Symptoms of spondylitis are important to consider in patients with pneumococcal pneumonia, and short-term intravenous antibiotic treatment with follow-up oral therapy for pneumococcal pyogenic spondylitis may enable early discharge．
A 49-year-old man was admitted to a local hospital on Tokunoshima Island in Kagoshima prefecture, Japan, after he experienced high fever and general fatigue for several days. A physical examination on admission revealed his temperature to be over 39.5℃, an eschar on the left thigh, and generalized skin erythema. Laboratory examination revealed thrombocytopenia, liver dysfunction, and raised levels of C-reactive protein. He was suspected to have Spotted Fever and recovered with the help of immediate treatment with minocycline alone. He was finally diagnosed as having Japanese Spotted Fever, which was confirmed based on antibodies positive for Rickettsia japonica detected with an immunofluorescence test using paired sera and DNA determination specific to R. japonica extracted from the eschar using PCR. Since Japanese Spotted Fever can be life-threatening if diagnosis and appropriate treatment are delayed, it should always be considered as a differential diagnosis for patients presenting with high fever and eruptions.
A 69-year-old woman received a diagnosis of multiple abscesses. Abscess drainage was performed, and methicillin-susceptible Staphylococcus aureus was isolated from blood and pus cultures. On post-operative day 4, she developed proteinuria and haematuria. She also complained of abdominal pain, and areas of purpura were seen over her extremities. CT scans showed ascites and ileum wall thickening. Leukocytoclastic vasculitis was observed on skin biopsy. Findings on renal biopsy were compatible Immunoglobulin A(IgA) nephropathy, therefore we diagnosed her illness as IgA vasculitis. She recovered following administration of antibiotics and steroids. The genes encoding for staphylococcal enterotoxin E and staphylococcal toxic shock syndrome toxin-1 were detected on the pathogen. Staphylococcal enterotoxins might have been involved in the pathogenesis of IgA vasculitis. Clinicians should bear IgA vasculitis in mind if patients with S. aureus infection develop abdominal pain, urine abnormality, and purpura.
A 65-year-old man who had diabetes and pneumocystis pneumonia was diagnosed as having AIDS, with a CD4 count of 4/μL. After completing his pneumocystis pneumonia treatment, antiretroviral therapy was immediately started. However, his respiratory symptoms deteriorated. A diagnosis was difficult because findings from blood tests, imaging studies, and sputum cultures were unremarkable. Therefore, bronchoscopy was performed, revealing the presence of Aspergillus fumigatus in the lung tissues. The patient was diagnosed as having invasive pulmonary aspergillosis, and antifungal therapy was started. He showed a good response to the treatment and was discharged. The diagnosis was confirmed to be aspergillosis occurring as immune reconstitution inflammatory syndrome (IRIS), because of the timing of the symptoms and the clinical course. A low CD4 count is a risk factor for aspergillosis；hence, aspergillosis is suspected to be related to AIDS. Only two cases of aspergillosis occurring as IRIS have been reported thus far. Aspergillosis rarely occurs in AIDS patients, but when it does, it should be considered to occur as IRIS.
A total of 188 patients with a bacteriologically-confirmed diagnosis of enteric fever, treated at Tokyo Metropolitan Komagome Hospital during 1975-2002, were retrospectively studied based on the described records on medical charts. Interpretation of the Widal titer results were defined as follows according to the instructions of the manufacturer, Denka Seiken, Co. Ltd, Tokyo：O agglutination；Salmonella Typhi ≧1：160,S. Paratyphi A ≧1：80, S. Paratyphi B ≧1：160, and Vi agglutination for S. Typhi ≧1：20. In symptomatic cases, positive results (sensitivity) were seen in 29 of 99 cases (29.3%) for typhoid fever, 8 of 47 cases (17.0%) for paratyphoid fever A, and 4 of 6 cases (66.7%) for paratyphoid fever B. In asymptomatic cases, positive results were 0 of 14 cases with S, Typhi (0%), 0 of 5 cases (0%) with S. Paratyphi A, and 2 of 17 cases (11.8%) with S. Paratyhi B. Positive results for Vi agglutination were obtained in 5 of 99 (5.1%) of symptomatic cases of typhoid fever, and one of 14 (7.1%) for asymptomatic cases yielding S. Typhi.
When we adopted 61 non-enteric fever cases (30 of malaria, 17 of dengue, 7 of hepatitis A, 4 of undetermined fever, and 3 miscellaneous diseases) as negative control, the specificity of the Widal O agglutination test was 100% for symptomatic cases of typhoid fever and paratyphoid fevers A and B.