Serological evidence of flaviviruses infection among acute febrile illness patients in Afghanistan.

INTRODUCTION: Current published reports on the causative agents of acute febrile illness (AFI) in Afghanistan are scarce, and the burden of disease due to flaviviruses is unknown. METHODOLOGY: A hospital-based surveillance study for AFI was established in 2008 through 2010 to determine the seroepidemiology of West Nile virus (WNV), tick-borne encephalitis virus (TBEV) and dengue viruses (DENV) using commercial ELISA kits. Due to major logistical challenges, only acute sera were collected. RESULTS: Serological analysis for IgG were as follows: WNV 30.4% (277/913); TBEV 23.4% (214/913); DENV 19.7% (180/913). Single positive IgG reactions for WNV, TBEV and DENV were noted in 11% (100/913), 7.2% (66/913), and 5% (47/913), respectively. Reactivity for all three screened flaviviruses was detected in 44.5% (406/913) of sera. IgM positivity was uncommon, with only 0.5% (5/913), 2.2% (20/913) and 2.6% (8/312) of samples positive for WNV, TBEV, and DENV, respectively. Serological findings were confirmed in random positive samples by neutralization assay. CONCLUSIONS: These serological results suggest circulation of WNV, TBEV, and DENV within Afghanistan, with evidence of current or prior infection noted in a significant proportion of patients seeking care for AFI. Obtaining additional information on the prevalence of these and other causes of AFI is paramount for improving the distribution of available limited syndromic treatment and improving the existing health protection policy in Afghanistan.

Non-bacterial etiologies of diarrheal diseases in Afghanistan.

BACKGROUND: Microbial diarrheal diseases are one of the leading causes of child morbidity and mortality in developing countries. This study aimed to identify the main causes of non-bacterial diarrhea in Afghanistan. METHODS: A total of 699 stools were collected from children aged under 5 years who presented with diarrhea at Indira Gandhi and Kandahar hospitals. Frozen aliquots were preserved for screening against rotavirus, astrovirus, adenovirus, norovirus, Cryptosporidium and Giardia, when bacterial cultures tested negative. Tests were performed at the hospitals after laboratory staff were trained and provided with enzyme-immunoassays and equipment. Results were confirmed at the U.S. Naval Medical Research Unit No. 3, Cairo, Egypt. RESULTS: Of the samples tested, 71.9% (503/699) were infected with one or more pathogens. However, the majority (85.8%; 432/503) showed single infections: rotavirus (72.2%; 329/432), Cryptosporidium (14.1%; 61/432), Giardia (5.1%; 22/432), astrovirus (2.3%; 10/432), adenovirus (1.6%; 7/432) and norovirus (0.7%; 3/432). The remaining 14% (71/503) showed mixed infections of the tested pathogens. CONCLUSIONS: Non-bacterial pathogens were identified that could enable health officials to adopt more effective treatment and control measures for diarrhea in Afghanistan.

PCR analysis of egyptian respiratory adenovirus isolates, including identification of species, serotypes, and coinfections.

Eighty-eight adenovirus (Ad) isolates and associated clinical data were collected from walk-in patients with influenza-like illness in Egypt during routine influenza surveillance from 1999 through 2002. Respiratory Ad distributions are geographically variable, and serotype prevalence has not been previously characterized in this region. Serotype identity is clinically relevant because it predicts vaccine efficacy and correlates strongly with both clinical presentation and epidemiological pattern. Species and serotype identities were determined using several well-validated multiplex PCR protocols culled from the literature and supplemented with a few novel primer sets designed to identify rare types. The isolates included common species B1 serotypes (Ad3 and Ad7), common species C serotypes (Ad1, Ad2, and Ad5), the less common species B2 serotype Ad11, and three isolates of the rare species B1 serotype Ad16. Two isolates that appear to be variant Ad16 were also identified. Fifteen coinfections of multiple adenoviral types, primarily AdB/AdC and Ad3/Ad7 dual infections, were detected. The majority of these were verified using redundant PCR tests targeted at multiple genes. PCR is able to resolve coinfections, in contrast to traditional serum neutralization tests. PCR is also comparatively rapid and requires very little equipment. Application of the method allowed an inclusive determination of the serotypes found in the Egyptian respiratory sample set and demonstrated that coinfections are common and may play a previously unrecognized role in adenovirus pathogenesis, evolution, and epidemiology. In particular, coinfections may influence adenoviral evolution, as interserotypic recombination has been identified as a source of emerging strains.