Epidemiology of Opisthorchis viverrini in a rural district of southern Lao PDR.

In Lao PDR, detailed investigations on Opisthorchis viverrini are scarce. The objective was to document epidemiological features of O. viverrini infections in a highly endemic district. A random sample was selected (13 villages, 15 households/village, all household members aged >6 months). Clinical examinations, short interviews and stool examinations (Kato-Katz technique) were performed. Fish samples were dissected for the presence of metacercaria. In total, 814 persons were enrolled (median age 16 years, 51.5% women). The prevalence was 58.5%. Infection rates increased with age (from 20.0 to 85.5%; P<0.001). Intensity of infection and the habit of consuming insufficiently cooked fish also increased with age. Of the study participants, 75.2% reported cooking fish insufficiently. Of the 23 different species of cyprinoid fish consumed in the study villages, 20 species were infected. At the village level, the prevalence of raw fish consumption was strongly associated with the infection status of O. viverrini (r=0.76, P=0.003). At individual level, age, the consumption of insufficiently cooked fish, and the absence of sanitation were strongly associated. The disease associated with O. viverrini infection needs to be assessed in order to develop and conduct adequate interventions.

Risk factors for epilepsy in rural Lao PDR: a case-control study.

The objective of this study was to assess the major etiologic categories of epilepsy in a rural district of the Lao PDR. Thirty-one newly identified patients with confirmed active epilepsy were compared with 124 controls, matched for gender, age and village residence. Risk factors for epilepsy were investigated with particular focus on cysticercosis serology. A history of head trauma (OR=4.7, p=0.05), family history of epilepsy (OR=12.8, p=0.03), and the use of human feces to fertilize domestic vegetable gardens (OR=4.9, p=0.04) were significantly associated with epilepsy. The study did not confirm any direct relation between epilepsy and cysticercosis serology. The cysticercosis seroprevalence was nil in the epilepsy group. This is the first study in the Lao PDR on epilepsy risk factors representing important data for the subregion. Parasitic, environmental, and behavioral factors of this traditional population deserve further studies to explain the missing link between epilepsy and cysticercosis.

Intestinal parasitic infections in HIV-infected patients, Lao People's Democratic Republic.

BACKGROUND: HIV infection is an emerging problem in Laos. We conducted the first prospective study on intestinal parasites, including opportunistic protozoa, in newly diagnosed HIV infected patients, with or without diarrhea. The aims were to describe the spectrum of infections, to determine their prevalence and to assess their associations with diarrhea, CD4 cell count, place of residence and living conditions. METHODOLOGY: One to three stool samples over consecutive days were obtained from 137 patients. The Kato thick smear method, formalin-ethyl concentration and specific stains for coccidia and microsporidia diagnosis were performed on 260 stool samples. Baseline characteristics regarding relevant demographics, place of residence and living conditions, clinical features including diarrhea, were collected using a standardized questionnaire. PRINCIPAL FINDINGS: The 137 patients were young (median age: 36 years) and severely immunocompromised (83.9% at WHO stage 3 or 4, median CD4 cell count: 41/mm3). Diarrhea was present in 43.0% of patients. Parasite infection was found in 78.8% of patients, infection with at least two species in 49.6%. Prevalence rates of protozoan and helminth infections were similar (54.7% and 58.4% respectively). Blastocystis sp. was the most frequent protozoa (26.3%). Cryptosporidium sp., Cytoisospora belli and microsporidia, found at low prevalence rates (6.6%, 4.4%, 2.9%, respectively), were described for the first time in Laos. Cryptosporidium sp. was associated with persistent diarrhea. Strongyloides stercoralis was the most prevalent helminth following Opisthorchis viverrini (20.4% and 47.5% respectively). The most immunocompromised patients, as assessed by a CD4 count ≤ 50 cells/mm3, were more likely to be infected with intestinal parasites. CONCLUSIONS/SIGNIFICANCE: HIV infection was mainly diagnosed at an advanced stage of immunosuppression in Lao patients. Intestinal parasite infections were highly prevalent regardless of their diarrheal status. Opportunistic infections were reported. Improving the laboratory diagnosis of intestinal parasite infections and the knowledge on their local risk factors is warranted.

Three cases of intestinal capillariasis in Lao People's Democratic Republic.

Capillaria philippinensis is a rare zoonotic intestinal parasite that emerged in the 1960s. The outcome of intestinal capillariasis may be fatal if untreated in due time. We report three cases of intestinal capillariasis in Lao People's Democratic Republic (Lao PDR). The three patients were unrelated previously healthy young men (24, 26, and 27 years of age) with no underlying disease or immune depression. They had chronic diarrhea, abdominal pain, edema, and severe weight loss. Two of them acquired the infection in Thailand; the other patient had no travel history outside Lao PDR. All patients were seen several times in different hospitals before the diagnosis was made. All had concurrent parasite infections: Giardia lamblia, Entamoeba histolytica, Strongyloides stercoralis, Opisthorchis viverrini, and hookworm. The patients frequently consumed uncooked fish. After treatment with albendazole (400 mg/day for 21-30 days) all patients recovered. In Lao PDR, consumption of raw small freshwater fish is common. Therefore, the possibility of a capillariasis outbreak should be considered.

Improving tuberculosis case detection rate with a lay informant questionnaire: an experience from the Lao People's Democratic Republic.

PROBLEM: In many countries, the tuberculosis (TB) annual case detection rate is below the target of 70%. In the Lao People's Democratic Republic in 2005, it did not exceed 55% APPROACH: The DOTS strategy promotes passive case detection of TB. In order to increase the detection rate, we validated a questionnaire targeting lay informants at village level to notify patients with chronic cough and assessed the relevance for TB case-finding. A three-item questionnaire was sent through the district health departments to all villages in six districts in six provinces. The village headmen were asked to notify chronic cough patients. Answers were validated in a door-to-door survey (20 villages/district). In a sub-sample (four villages/district) all confirmed patients were screened for TB and paragonimiasis. LOCAL SETTING: Attapeu, Luang Namtha, Luang Prabang, Saravane, Savanakhet and Vientiane provinces in the Lao People's Democratic Republic. RELEVANT CHANGES: Lay informant questionnaires sent from district health offices to villages are cost-effective and foster interaction between the health services and remote and underserved communities. Although the correct detection of patients is highly dependent on direct respondents, a substantial number of new TB and paragonimiasis cases were consistently diagnosed in chronic cough patients. LESSONS LEARNED: Out of 456 questionnaires, 295 were returned (65%). Return rates were highly variable between districts (48-87%), questionnaires' sensitivity (56-98%), positive predictive value (34-88%) and correlation between number of notified and confirmed patients (r: 0.26-0.78). In sub-sampled villages (13,541 population) 19 (5.1%) TB and 26 (7.0%) paragonimiasis cases were detected in 374 chronic cough patients. This quick questionnaire approach proved motivating for district authorities and village key informants, although no incentives were provided. The highly operator-dependent approach yielded a consistent detection rate of TB and paragonimiasis cases. This approach brings health services and populations in need in close contact, which is particularly crucial in remote and underserved areas.